Residual cyanide distribution in a neutralized gold leach heap
by James Gregory Poell
A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Land
Rehabilitation
Montana State University
© Copyright by James Gregory Poell (1994)
Abstract:
Kendall Mine Heap Leach Pad No. 1 is located in Fergus County northwest of Lewistown, Montana.
The heap, constructed in the early 1980s, was most recently leached with sodium cyanide for gold in
1988. After leaching, Pad No. 1 was neutralized in spring, 1989 with fresh water rinsing followed by
alkaline chlorination using calcium hypochlorite. Thirty months later, samples were taken from 15
boreholes across the heap at incremental depths in order to determine the speciation, concentration, and
vertical and areal distribution of cyanide and associated metals. Two pore water samplers were used to
monitor cyanide and metals levels near the heap base during the spring and summer of 1992.
Analysis of solid ore samples showed significant increases in weak acid dissociable cyanide levels
from the surface to middle of the heap. This may correspond to the interface of two lifts or benches of
ore in the heap. Deeper in the heap, weak acid dissociable cyanide levels significantly decrease.
Soluble . copper and nickel levels had a similar vertical distribution pattern. No significant differences
with depth were found for total cyanide, pH, cadmium, iron, or zinc.
Across the heap, significant differences were found between boreholes for total cyanide, weak acid
dissociable cyanide, pH, cadmium, and copper. However, only cadmium levels, declining significantly
from west boreholes to east boreholes, exhibited any areal pattern. These results indicate that areal
patterns are not likely to be found across leach heaps.
Pore water cyanide data indicate that total and weak acid dissociable cyanide degradation may have
occurred as pore water drained the heap through spring and summer 1992. Pore water data suggest that
soluble copper and nickel levels decreased over the same period. These changes may be due to the
relative stability of metallo-cyanide complexes and competing degradation processes in the heap.
Cadmium, iron, zinc and pH in pore water did not change significantly over time and distance. RESIDUAL CYANIDE DISTRIBUTION
IN A NEUTRALIZED GOLD LEACH HEAP
by
James Gregory Poell
A thesis submitted in partial fulfillment
of the requirements for the degree
of
Master of Science
in
Land Rehabilitation
MONTANA STATE UNIVERSITY
Bozeman, Montana
March 1994
^qz0I
ii
APPROVAL
of a thesis submitted by
James Gregory Poell
This thesis has been read by each member of the thesis committee and has
been found to be satisfactory regarding content, English usage, format, citations,
bibliographic style, and consistency, and is ready for submission to the College of
Graduate Studies.
7 A p r i l 1994
Date
Chairperson, Graduate Committee
Approved for the Major Department
Approved for the College of Graduate Studies
Date
Graduate Dean
iii
STATEMENT OF PERMISSION TO USE
In presenting this thesis in partial fulfillment of the requirements for a
master’s degree at Montana State University, I agree that the Library shall make
it available to borrowers under rules of the Library.
If I have indicated my intention to copyright this thesis by including a
copyright notice page, copying is allowable only for scholarly purposes, consistent
with "fair use" as prescribed in the U.S. Copyright Law. Requests for permission
for extended quotation from or reproduction of this thesis in whole or in parts
may be granted only by the copyright holder.
Signat
Date
I
IV
ACKNOWLEDGEMENTS
I would like to acknowledge the support and guidance of Dr. Frank
Munshower, Dr. Doug Dollhopf, and Dennis Neuman as members of my graduate
committee. Bob Vince and Kevin Ryan of Canyon Resources Corporation’s ■
Kendall Mine are thanked for their assistance and consultation in the conduct of
my research. Thanks to Dr. William Schafer of Schafer and Associates for student
employment that gave me invaluable technical experience. Special thanks are
extended to Stuart Jennings, Bryce Romig, Gary Vodehnal, and. Murray Strong for
their advice and friendship.
Finally, I would like to thank my wife Martha for her support and kindness
through my graduate education.
TABLE OF CONTENTS
Page
ACKNOWLEDGEMENTS .............................. .. . ................... .............................. iv
TABLE OF C O N TEN TS....... ..................................................................................... v
LIST OF T A B L E S............................................ ............... .........................: ............. vii
LIST OF F IG U R E S .............. : ......................... ...................... .. . . .......................... xi
ABSTRACT .......................................................................... ...................................xii
IN T R O D U C T IO N ..........................................................
I
LITERATURE REV IEW ..................
5
History Of The Cyanide Leach Process ....................... ; ................................ 5
Leach Heap Cyanidation..................................
7
Leach Heap N eutralization............................................ ........................... .. . 10
Cyanide In The Neutralized H e a p ........................................................: . . .
11
Free Cyanide M easurem ent..........................................................
17
WAD Cyanide M easurem ent..............................
18
Total Cyanide Measurement . ................................... .................... ; . . . . . .
20
Measurement Of Cyanide In S o lid s ...................,.............................................20
Residual Cyanide Studies .............................. '. ............................ ..................21
STUDY A R E A ............................................ ..............i ...........................................
24
M E T H O D S .............. .........................; .'.................... .............................. I . . . . . .
27
Sampling Methods .......................................................... .. ...............................
Analytical Methods. ..........................................
27
30
RESULTS AND D ISC U SSIO N ......... ....................
Cyanide and Metals Depth Distributions .............................. . . ..............
Cyanide and Metals Areal Distributions ................................. .......................
Pore W ater Behavior .......................................... ............................................
34
34
37
39
SUMMARY AND CONCLUSIONS . ...................................................................... 43
Vi
TABLE OF CQNTENTS--Contimied
• Page
LITERATURE CITED . ......................................................................................
45
A PPE N D IC ES.................................................... .......................................................52
Appendix A - Data Tables .......................................................... .................. .5 3
Appendix B - Data Validation Tables .............. ............................................. 63
Appendix C - Statistical Data .............. ............................................................69
vii
LIST OF TABLES
Table
1.
Page
Selected Montana water quality standards applicable to
cyanide heap leach effluents.......................................................
2
2.
Relative stabilities of forms of cyanide in water. . T. .................
13
3.
Typical cyanide reactions in the abandoned heap leach
environment......................... ........................... ......................................... 14
4.
Analytical terms for cyanide measured in the leach heap
environment.......................................
.1 7
5.
Cyanide levels after fresh water rinsing at Kendall Mine
Heap Leach Pad No. I, March, 1989. . .................................................... 26
6.
Location of suction lysifneters used in pore water sampling..............
7.
Effect of Iog10 data transformation on data skewness and kurtosis. . . . 32
8.
Geometric mean levels of cyanide, pH and water soluble metals
in spent ore through Kendall Mine Heap Leach Pad No. I. . . . . . . . . 35
9.
Geometric mean levels of cyanide, pH and water soluble metals
for boreholes acrossKendall Mine Heap Leach Pad No. 1....................... 38
29
10. Pore water cyanide and metals levels at Kendall Heap
Leach Pad No. I, March - September, 1 9 9 2 ...................... .. . . ............ 40
11. Linear regression slope values and associated statistics for
Kendall Heap Leach Pad No. I pore water.................................. ..
41
12. Total cyanide levels at Kendall Heap Leach Pad No. I,
November I, 1991........................................................................................54
13. WAD cyanide levels at Kendall Heap Leach Pad No. I,
November I, 1991. ........................................ .. . ............ ........................... 55
14. Free cyanide levels at Kendall Heap Leach Pad No. I,
November I, 1991. ............................................
56
viii
LIST OF TABLES-Continued
Table
Page
15. pH levels at Kendall Heap Leach Pad No. I, November I, 1991..........57
16. Cadmium levels at Kendall Heap Leach Pad No. I,
November I, 1991.................................................................... ............. ..
58
17. Copper levels at Kendall Heap Leach Pad No. I,
' November I, 1991. ...........................................................^ . . . . ............... 59
18. Iron levels at Kendall Heap Leach Pad No. I,
November I, 1991............................................................................................60
19. Nickel levels at Kendall Heap Leach Pad No. I,
November I, 1991..........................
61
20. Zinc levels at Kendall Heap Leach Pad No. I,November I, 1991. . . . 62
y
21. Blind field replicate cyanide analysis re s u lts .......... ................................64
22. Laboratory replicate cyanide analysis results............................................ 65
23. Laboratory spiked cyanide analysis results. .......................... .................. 66
24. Blind field replicate pH and metals analysis results................... ■............67
25. Laboratory replicate pH and metals analysisresults....................................67
126. Laboratory pH and metals recovery results.
.
.............
68
27. Analysis of variance for total cyanide (weighted, Iog10
transformed data). . ................................................. .. . . .......................... 70
28. Student-Newman-Keuls means separation tests for borehole
total cyanide means (weighted, Iog10 transformed data). ........................71
29. Analysis of variance for WAD cyanide (weighted, Iog10
transformed data).................................. . ....................................................72
30. Student-Newman-Keuls means separation tests for depth
WAD cyanide means (weighted, Iog10 transformed data). . ................... 72
<-
.
ix
LIST OF TABLES-Contimied
Table
Page
31. ,Student-Newman-Keuls means separation tests for borehole
WAD cyanide means (weighted, Iog10 transformed data)........................ 73
32. Analysis of variance for pH (weighted, Iog10 transformed data)............. 74
33. Student-Newman-Keuls means separation tests for borehole
pH means (weighted, Iog10 transformed data)........................................... 75
34. Analysis of variance for cadmium (weighted, Iog10
transformed data). .....................................
76
35. Student-Newman-Keuls means separation tests for borehole
cadmium means (weighted, Iog10 transformed data)................
77
36. Analysis of variance for copper (weighted, Iog10 transformed data). . . 78
37. Student-Newman-Keuls means separation tests for depth
copper means (weighted, Iog10 transformed data).....................................78
38. Student-Newman-Keuls means separation tests for borehole
copper means (weighted, Iog10 transformed data). ................... ..
79
39. Analysis of variance for iron (weighted, Iog10 transformed d a ta ).......... 80
40. Analysis of variance for nickel (weighted, Iog10 transformed data). . . . 80
41. Student-Newman-Keuls means separation tests for depth
nickel means (weighted, Iog10 transformed data). . ............ .................. . 81
42. Analysis of variance for zinc (weighted, Iog10 transformed data)............. 81
43. Linear regression of pore water total cyanide data from
borehole 4, Kendall Heap Leach Pad No. I .............................................82
44. Linear regression of pore water total cyanide data from
borehole 8, Kendall Heap Leach Pad No. I ............................................. 83
45. Linear regression of pore water WAD cyanide data from
borehole 4, Kendall Heap Leach Pad No. 1............................................. 84
tN
X
LIST OF TABLES--Continued
Table
Page
46. Linear regression of pore water WAD cyanide data from
borehole 8, Kendall Heap Leach Pad No. I ................. ...................... . . 85
47. Linear regression of pore water pH data from borehole 4,
Kendall Heap Leach Pad No. I ..................................................................86
48. Linear regression of pore water pH data from borehole 8,
Kendall Heap Leach Pad No. I ............................................... ..................87
49. Linear regression of pore water cadmium data from
borehole 4, Kendall Heap Leach Pad No. I ........................................... . 88
50. Linear regression of pore water cadmium data from
borehole 8, Kendall Heap Leach Pad No. I ...................... .......................89
51. Linear regression of pore water copper data from
borehole 4, Kendall Heap Leach Pad No. 1............................................. 90
52. Linear regression of pore water copper data from
borehole 8, Kendall Heap Leach Pad No. I ........................................... . 91
53. Linear regression of pore water iron data from
borehole 4, Kendall Heap Leach Pad No. I .......................... .................. 92
54. Linear regression of pore water iron data from
borehole 8, Kendall Heap Leach Pad No. I. . ........................................ 93
55. Linear regression of pore water nickel data from
borehole 4, Kendall Heap Leach Pad No. I ...............................
94
56. Linear regression of pore water nickel data from
borehole 8, Kendall Heap Leach Pad No. 1............................................. 95
57. Linear regression of pore water, zinc data from
borehole 4, Kendall Heap Leach Pad No. I. . ........................................ 96
58. Linear regression of pore water zinc data from borehole 8, Kendall Heap Leach Pad No. I ................................. .. . . . . 97
xi
LIST OF FIGURES
•
-
I
Figure
Page
j
1.
Relationship between HCN and CN' with pH ..........................
2.
Detailed schematic showing potential geochemical conditions and
cyanide reactions in and around an abandoned leach heap. .................15
3.
Location of Kendall Mine. . ...................................................................... 24
4.
Location of sampling boreholes I to 15 across the heap surface
and sampling boreholes I to 7 and 8 to 15 in cross-section
through Kendall Mine Heap Leach Pad No. I. ......................................28
5.
Conceptual view of heap construction showing characteristics
of material within the heap.
............................................................ 36
11
/
xii
Ab s t r a c t
<
Kendall Mine Heap Leach Pad No. I is located in Fergus County northwest
of Lewistown5 Montana. The heap, constructed in the early 1980s, was most
recently leached with sodium cyanide for gold in 1988. After leaching, Pad No. I
was neutralized in spring, 1989 with fresh water rinsing followed by alkaline
chlorination using calcium hypochlorite. Thirty months later, samples were taken
from 15 boreholes across the heap at incremental depths in order to determine
the speciation, concentration, and vertical and areal distribution of cyanide and
associated metals. Two pore water samplers were used to monitor cyanide and
metals levels near the heap base during the spring and summer of 1992.
Analysis of solid ore samples showed significant increases in weak acid
dissociable cyanide levels from the surface to middle of the heap. This may
correspond to the interface of two lifts or benches of ore in the heap. Deeper in
the heap, weak acid dissociable cyanide levels significantly decrease. Soluble
. copper and nickel levels had a similar vertical distribution pattern. No significant
differences with depth were found for total cyanide, pH, cadmium, iron, or zinc.
Across the heap, significant differences were found between boreholes for
total cyanide, weak acid dissociable cyanide, pH, cadmium, and copper. However,
only cadmium levels, declining significantly from west boreholes to east boreholes,
exhibited any areal pattern. These results indicate that areal patterns are not
likely to be found across leach heaps.
(
.
Pore water cyanide data indicate that total and weak acid dissociable
cyanide degradation may have occurred as pore water drained the heap through
spring and summer 1992. Pore water data suggest that soluble copper and nickel
levels decreased over the same period. These changes may be due to the relative
stability of metallo-cyanide complexes and competing degradation processes in the
heap. Cadmium, iron, zinc and pH in pore water did not change significantly over
time and distance.
I
INTRODUCTION
In the past 25 years there has been a wide expansion ,of the use of cyanide
heap leaching by the mining industry. This process allows profitable recovery of
gold and silver from low-grade ore. Heap leach pads are constructed on slight
drainage grades and lined with an impervious clay and/or geotextile. Mined ore is
stacked and leached in successive ten to thirty foot lifts or benches on the pad.
Sprinkler systems set on the surface of the lift to be leached deliver a high pH
sodium cyanide solution that, in its percolation through the ore, forms stable
complexes with gold, silver, cobalt, iron, copper, nickel, zinc, and cadmium. This
"pregnant" solution is then collected as it drains off the pad for precious metal
I
recovery and refinement.
After leaching, the heap still contains interstitial and adsorbed cyanide
species, including free cyanide and metal-complexed cyanides. The metalcomplexed cyanides are present as weak acid dissociable (WAD) complexes of
cadmium, copper, nickel, and zinc, and extremely stable iron and cobalt cyanide
complexes (Smith and Muddier 1991). These cyanides, in sufficient concentration,
have the potential to degrade surface and ground water resources.
The Montana W ater Quality Act directs the Montana Department of
Health and Environmental Sciences (MDHES) to maintain standards for pollut­
ants threatening its nondegradation policy. The standards are referenced by the
Montana Department of State Lands in mine operation and reclamation regula­
tion. Standards of interest to cyanide heap leach mining are listed in Table I.
2
Table I. Selected Montana water quality standards applicable to cyanide heap
leach effluents (MDHES 1993).
A cute
A quatic Life Standards
C hronic
A quatic Life Standards
H um an H ealth
Stan d ard s for
S urface W aters
(AS I 1)
(Ag I 1)
(Ag I"1)
WAD Cyanide
22.0
5.2
200.0
Cadmium
3.9'
LI*
5.0
Copper
18.0*
12.0'
1000.0
P ollu tan t
Iron
— *
1000.0*
300.0
Nickel
1400.0*
160.0*
100.0
Zinc
120.0*
110.0'
5000.0
Water hardness dependent criteria (100 mg I"1 used).
— No standard has been adopted.
Cyanide in the heap will degrade naturally, if the heap is not disturbed.
Natural degradation of cyanide can occur through volatilization, biodegradation,
photodecomposition, and oxidation (Rolfes 1989). Other degradation mechanisms
associated with cyanide chemistry include complexation with transition metals,
precipitation of complex cyanide compounds, formation of thiocyanate, and the
hydrolysis of free cyanide (Smith and Mudder 1991). How degradation will
proceed, though, is site specific, depending on the interaction between geochemi­
cal conditions in the heap and site conditions such as precipitation, ore mineralo­
gy, and ore permeability (Struhsacker and Smith 1990, van Zyl et al. 1988). To
speed this degradation process, most mines use fresh or chemically-treated water
rinses. Rinsing is continued until effluent draining from the pad falls and remains
below regulatory standard for a specified period of time. Currently, the Montana
.3
Department of State Lands considers a spent heap to be neutralized for reclama­
tion when effluent WAD cyanide concentrations remain below 0.220 mg T1 through
one full spring after rinsing. This WAD cyanide standard, commonly used by
western state mine regulators, is 20 /Leg I4 above the MDHES human health
standard (Table I).
Despite acceptable effluent levels from abandoned leach heaps, later
"spikes" or "slugs" of cyanide have been measured in effluent following large
precipitation events or rinsing (Haight 1991, Struhsacker and Smith 1990). It is
believed that residual cyanide in spent ore, pore spaces, and/or blind-off zones
diffuses out into the heap over time. Subsequent wetting fronts generated by
precipitation events may pick up this cyanide as they pass through the heap,
degrading effluent water quality. Spent ore sampling that does not examine the
full depth and breadth of a heap may not give a representative measure of
I
neutralization success.
The concentration of cyanide throughout a decommissioned leach heap has
not been thoroughly investigated. With funding supplied by the Montana Depart­
ment of Natural Resources and Conservation and the cooperation of the Montana
Department of State Lands Hardrock Bureau and Canyon Resources Corporation,
the Reclamation Research Unit of Montana State University sampled a decom­
missioned leach heap from October, 1991 through summer 1992. The objective of
this study was to measure the concentration of residual cyanide species and
associated metals throughout the heap, comparing the results for evidence of
4
vertical or areal distribution patterns. A second objective was to monitor cyanide
and metals levels in pore water at the base of the heap through spring and
summer 1992.
This study was limited to one relatively small leach heap with limited
construction and Operation documentation. No control data were available for ore
leached in the heap. Rather than being a definitive work explaining the behavior
of residual cyanide in neutralized leach heaps, this study will provide basic data to
decision makers regarding the concentrations and distributions of cyanide species
that may develop under similar conditions.
Z
.5
LITERATURE REVIEW
History Of The Gyanide Leach Process
The evolution of cyanidation technology in the pursuit of precious metals
dates back 200 years in the historical record. In 1793, potassium cyanide was
recognized as a gold solvent (Hiskey 1985). In 1844, Eisner investigated the
reactions of various metals in a potassium cyanide solution, discovering that gold
dissolution took place only in the presence of dissolved oxygen (Bosqui 1899).
This dissolution reaction, known as Eisner’s Equation, is written as:
4 Au + 8 KCN + O2 +211,0 = 4 AuK(CN)2 + 4 KOH
In 1896, Bodlaender found that the dissolution of gold was a two-step
reaction with intermediate production of hydrogen peroxide (Hiskey 1985). This
reaction proceeds as follows:
2 Au + 4 CN' + O2 + 2 H2O = 2 Au(CN)2' + 2 OH + H2O2 '
2 Au + 4 CN + H2O2 = 2 Au(CN)2 + 2 OH
The sum of this reaction sequence is equivalent to the dissolution reaction
developed by Eisner. It is written as:
4 Au + 8 CN' + O2 + 2 H2O = 4 Au(CN)2" + 4 OH
6
The extraction of gold from gold ore using cyanidation was developed into
a commercial process in Scotland by John MacArthur and Drs. Robert arid
William Forrest (von Michaelis 1985). They were issued patents for their process
in 1887 (Britain) and in 1889 (United States). The extraction is based on the
agitation of finely ground gold ore in aerated potassium cyanide solution. Metals
in the ore, including gold, complex with cyanide during the agitation. The gold
cyanide complex is precipitated with zinc shavings (Eisele 1988). This precipita­
tion proceeds as follows:
2 Au(CN)2- + Zn = 2 Au + Zn(CN)42"
The Merrill-Crowe process, as it is !mown in use today, improved gold
recovery by removing oxygen from gold-bearing cyanide solutions before the
addition of zinc (Hiskey 1985). After treatment with zinc, the solution is filtered
under pressure to reitiove the gold precipitate for smelting.
Carbon adsorption technology to recover dissolved gold from cyanide
solutions was developed by Chapman in 1939 (Hiskey 1985). This technology did
not require the filtration and deaeration of gold-bearing solutions as did the
Merrill-Crowe process (Heinen et al. 1978). Activated charcoal, introduced to a
cyanide-ore pulp (slurry), adsorbed the dissolved gold and floated away for
collection (Hiskey 1985). As burning the enriched charcoal was the only known
method to recover gold, carbon adsorption was not widely used (Eisele et al.
1984).
7
The Merrill-Crowe process was the predominant method of solution gold
recovery when Zadra and .his associates (1952) developed a method to desorb gold
from carbon. This process sent hot caustic cyanide solution through enriched
carbon, stripping the gold for electrowinning onto stainless steel wool. .Despite
lower costs, the low price of gold in the 1950s and 1960s precluded an expansion
in the use of carbon adsorption and solution gold mining in general.
Leach Heap Cyanidation
Heap leaching may be defined as the percolation leaching of piles of lowgrade ores or mine waste that have been stacked or piled on specially prepared
watertight drainage pads for the collection of precious metal-enriched "pregnant"
solution (Heinen et al. 1978). Heap leaching of minerals dates back to sixteenth
century Hungarian copper mines, with large-scale practice developed by the
eighteenth century in Spanish copper mines (Hiskey 1985). Uranium producers
have utilized heap lWching as an extraction technology for low-grade ores since
the late 1950s (Dorey et al. 1988). Heap leach cyanidation of porous, low-grade,
gold-bearing ores was first proposed in 1967 by U.S. Bureau of Mines metallur­
gists (Heinen et al. 1978). This treatment chemistry is the same as that of
Bodlaender’s two-step dissolution reaction. , Gold is recovered from the pregnant
solution draining from the heap leach using either Merrill-Crowe or carbon
adsorption processes.
In order ,to widen the applicability of cyanide heap leaching to include
8
impermeable high-clay ores, the U.S. Bureau of Mines developed an ore
agglomeration treatment. After crushing, ore is mixed with 2 to 7 kg/metric ton
(5 to 15 Ibs/short ton) of portland cement (to act as a binding and pH control
agent), wetted with 8 to 16% (by weight) water, and subjected to mechanical
tumbling to ensure adhesion of fines to coarser particles (Heinen et al. 1978,
Heinen et al. 1979, McClelland and Eisele 1982). By 1983, it was estimated that
agglomeration pretreatment allowed half of cyanide heap leach projects to operate
(McClelland et al. 1983).
The cyanide heap leach process is an efficient, low cost method of recover­
ing gold and silver from low-grade ore. Average ore grades recovered by heap
leaching are 0.9 grams of gold per metric ton of ore (0.03 oz/short ton), with an
extreme cutoff grade of 0.2 grams of gold per metric ton (0.006 oz/short ton) at
the Round Mountain Mine in central Nevada (Spickelmier 1993). Relative ore
grade dictates the choice of two heap leaching methodologies. Higher grade ores
are crushed, agglomerated and stacked in short lifts of I to 3 in (3 to 10 ft) high
on permanent asphalt or concrete leach pads. This method treats 900 to 9,000
metric tons (1,000 to 10,000 short tons) of ore for 7 to 30 days, after which the
spent ore is neutralized and removed for disposal (Higgs and Gofmley 1992a,
Rolfes 1989). Lower grade ores are typically not treated, being stacked as run-ofmine size (including boulders) in lifts of 3 to 9 m (10 to 30 ft) high on compacted
clay and/or synthetic-lined pads. On these heaps, leaching of 9,000 to 1.8 million
metric tons (10,000 to 2 million short tons) of ore will take months or years, after
9
which the spent ore heap is neutralized and abandoned (Hiskey 1985, Rolfes
1989).
Pads under all leach heaps are constructed with a 2 to 5% slope to facili­
tate drainage of pregnant solution (Chamberlin and Pojar 1984). Leach heap
pads are also designed to eliminate the loss of pregnant solution to the ground
and prevent contamination of local water resources (Heinen et al. 1978).
The objective of heap leach construction is to build a stable, porous heap
that allows an even downward percolation of cyanide solution (Herzog 1990)..
Heaps are commonly built in successive lifts using conveyor stacking, end dump­
ing, or truck and dozer techniques. The criteria in selecting a heap construction
technique are to minimize layering, compaction, and ore particle segregation.
(Dorey et al. 1988).
The completed heap is put under cyanide leaching by a surface network of
sprinklers or capillary tubes. Typical application rates, adjusted to result in a
,
partially-saturated flow of leachate through the heap, range from 0.002 to 0.003
1/s/m2 (0.003 to 0.005 g/min/ft2) (Dorey. et al. 1988). Though it is possible to leach
gold with several types of solutions', all current commercial operations use 0.2 to
0.7 kilograms of sodium cyanide (NaCN) per metric ton of water (0.5 to 1.5 lbs of
NaCN per short ton of water) (Chamberlin and Pojar 1984, Stanton et al. 1986).
This produces a leach solution concentration of 200 to 700 mg T1 NaCN, or 125 to
350 mg I 1 free cyanide (Stanton et al. 1986). Leach solutions are maintained at
pH 9.5 to 11 with lime (CaO) or caustic soda (NaOH) to ensure effective gold
10
dissolution (Chamberlin and Pojar 1984). Leaching consumes NaCN at a rate of
0.04 to 1.4 kg/metric ton (0.1 to 3.0 Ibs/short ton) of ore, depending on ore type,
application method, porosity, solution pH, and the concentration of cyanide­
consuming metals and sulfides in the ore (U.S. EPA 1986, Stanton et al. 1986).
Leach Heap Neutralization
The consumption of NaCN is a major expense in heap leach operations
that exploit low-grade ore (Barratt and McElroy 1990). To recover NaCN for use
on other leach heaps and maximize precious metal recovery, leached ore is
thoroughly rinsed with fresh water at the end of a leaching cycle (Heinen et al.
1978). This recovery action can be regarded as the initiation of heap neutraliza­
tion in reclaiming a heap leach project. The ultimate purpose of this washing or
rinsing is to alter the chemistry of the reclaimed heap so that future drainage from
the heap degrades neither surface or groundwater resources (Struhsacker and
Smith 1990). Effective neutralization of spent ore heaps involves detoxifying
residual cyanides and cyanide complexes found in interstitial solutions, adsorbed
on ore particle surfaces, and diffused into the ore (Denton et al. 1992).
1'
Active neutralization methodologies in use today include fresh water
rinsing, alkaline chlorination, hydrogen peroxide treatment, sulfur dioxide oxida­
tion, bio treatment and acidification. These methods, are well documented by Scott
(1984), Rolfes (1989), and Thompson and Gerteis (1990).
11
Cyanide In The Neutralized Heap
Cyanides comprise a large class of compounds that are characterized by the
presence of the cyanide ion (CN ) in their molecular structures (Higgs and
Gormley 1992b). The forms of cyanide of particular interest to the heap leach
process are free cyanide, simple cyanide and complex cyanide (U.S. EPA 1986).
Free cyanide is the sum of the cyanide ion (CN ) and hydrocyanic acid (HCN)
species released into an aqueous solution by the dissolution and dissociation of
cyanide compounds (Mudder 1991). These two species coexist in solution, their
relative proportions depending on pH and temperature. The relationship between
solution pH and the ratio of CN' to HCN is illustrated in Figure I. Below a pH of
7.0, all free cyanide is present as HCN in the toxic gaseous state.
Figure I.
Relationship between HCN and CN' with pH (Higgs and Gormley
1992b).
Percent HCN
Percent CN
12
Simple cyanides are the salts of hydrocyanic acid that completely and easily
dissociate in water (Maynard et al. 1986). These cyanides ionize in water, as
sodium does .in Reaction [I].
. r
' NaCN = Na+ + CN'
[1]
The cyanide ion (CN") then hydrolyzes to form HCN in Reaction [2].
CN + HOH = HCN + OH
[2]
Again, the amount of HCN produced depends on solution pH and temperature.
In the heap environment, the formation of gold and silver cyanide com­
plexes is the means of precious metal extraction from ores. Other transition
metals present in the ore may also complex with cyanide. Most commonly, these
metals are cadmium, copper, cobalt, iron, nickel and zinc (IEC 1979). The
stability tif these metal-cyanide complexes depends on the stability of the particu­
lar metal. Cadmium and zinc are relatively unstable, easily dissociating to release
the cyanide ion (CN"). The dissociation of complex cyanides is inversely related to
solution pH and complex ion concentration (Huiatt et al. 1983). The toxicity of
complex cyanides is related to their ability to release cyanide ions to solution,
producing toxic HCN (Eisler 1991). Metals freed by. the dissociation of complex
cyanides in a heap are not considered a threat to effluent water quality. Solubility
of metals is limited at the high pH levels (7.5 to 9.5) normally observed in leach
heaps rinsed of cyanide (Lindsay 1979). Further, once a complex cyanide
13
degrades, the metal would be expected to precipitate as a hydroxide or to adsorb
onto solids surfaces (Schafer et al. 1991). The relative stabilities of the forms of
cyanide common in leach heap solutions are shown in increasing order of stability
in Table 2 (Huiatt 1984).
Table 2.
Relative stabilities of forms of cyanide in water (Huiatt 1984).
Cyanide Form
Free cyanide
Typical Cyanide Compounds
CN', HCN
Simple cyanides:
Readily soluble
NaCN, KCN, Ca(CN)2, Hg (CN)2
Relatively insoluble
Zn(CN)2, CuCN, Ni(CN)2, AgCN
Weak complexes
Zn(CN)42', Cd(CN)32-, Cd(CN)42"
Moderately strong complexes
Cu(CN)2', Cu(CN)32', Ni(CN)42-, Ag(CN)22"
Strong complexes
Fe(CN)64-, Co(CN)64", Au(CN)22'
Regardless of the method of leach heap neutralization, natural degradation
of residual cyanide and metal-cyanide complexes will occur after abandonment.
Smith and Struhsacker (1988) have detailed a schematic showing potential
geochemical conditions and cyanide reactions in and around an abandoned leach
14
heap. Table 3 lists the chemical reactions and their equations shown in schematic
form in Figure 2.
Table 3.
Typical cyanide reactions in the abandoned heap leach environment
(Smith and Struhsacker 1988).
Hydrolysis
(1) CN + H2O - HCN + OH
Oxidation of HCN and CN
(2) 2HCN + O2-* 2HCNO
(3) 2CN + O2 + catalyst - 2CNO
Hydrolysis of CNO
(4) HCNO + H2O - NHw + COw
Hvdrolvsis/Saponification of HCN
(5) HCN + 2H20 -* NH4COOH (ammonium formate)
or
(6) HCN + 2HzO - NH3 + HCOOH (formic acid)
Aerobic biodegradation of HCN
(7) 2HCN + O2 + enzyme -» 2HCNO
(4) HCNO + H2O - NH3 + CO2
Thiocyanate formation
(8) S, + S2- + CN - S1., + CNS(9) S2O3 + CN- - SO32- + CNS
Simple cyanide compound dissociation
(10) NaCN - Na+ + CN
Metal-cvanide complexation
(11) Zn(CN)2 + 2CN" - Zn(CN)/
Anaerobic biodegradation of HCN and CN'
(12) CN + H2S(aq) -» HCNS + H+
(13) HCN + HS - HCNS + H+
Figure 2.
Detailed schematic showing potential geochemical conditions and cyanide reactions in and around an
abandoned leach heap (Smith and Struhsacker 1988).
Typical Cyanide
Reactions
Equation No.
(see Table 2)
No. 1-7, 10, 11
+ 8 if sulfide
present.
precipitation
OXIDIZED
UNSATURATED
SPENT ORE HEAP
No. 2-7, 10, 11
if oxidized.
SEEPAGE POTENTIAL
No. 9, 10, 12,
13 if reduced.
WEATHERED BEDROCK
WATER TABLE
REDUCED
UNWEATHERED BEDROCK
SATURATED
16
The degree and rate of natural cyanide degradation in the heap is a
function of the type of cyanide species present, their concentration, ore
mineralogy, available bacteria, heap permeability, and site conditions (tempera­
ture, precipitation, elevation) (Denton et al. 1992). Free cyanide in the heap
degrades quicker than simple and complex cyanides. Cyanide reactions consuming
free cyanide include hydrolysis and volatilization with decreasing pH, oxidation,
hydrolysis/saponification, biodegradation, and thiocyanate formation (Smith and
Struhsacker 1988). The mineralogy of ore in the heap determines the type and
amount of metals available for metal-cyanide complexation and sulfides for the
formation of thiocyanate. Biodegradation of free cyanide requires bacteria and an
energy source. A permeable heap ensures an oxygen supply for oxidation and
aerobic biodegradation reactions. It also ensures a water supply for hydrolysis,
hydrolysis/saponification, and solute transport processes (Smith and Struhsacker
1988). Increases in temperature will speed reaction rates. Higher elevation
locations will experience increased volatilization of HCN from the aqueous phase.
Mine operators are required by regulators to neutralize spent leach heap
ore to protect human health and the environment. Neutralization criteria vary
from state to state, requiring analysis of heap effluent or leachate extracted from
heap ore (Heriba 1991). The establishment of effective neutralization criteria is
hampered by a confusion of terminology used to describe cyanide forms and the
variety of analytical methods used to measure them (Smith and Struhsacker 1988).
Huiatt (1984) classified cyanide and cyanide compounds into five forms
17
according to their stability (Table 2). Over the past decade, however, three
analytical terms (total, WAD, and free cyanide) have come into common use in
describing cyanide species in leach heaps. These terms and the cyanide com­
pounds they represent are listed in Table 4.
Table 4.
Analytical terms for cyanide measured in the leach heap environ­
ment (DeVries 1988).
Cyanide Species
Free cyanide
Typical Cyanide Compounds
CN", HCN, NaCN, KCN, Ca(CN)2,
Hg (CN)2
WAD cyanide
Free cyanide + Zn(CN)2, CuCN, Ni(CN)2,
AgCN, Zn(CN)A Cd(CN)A Cd(CN)A
Cu(CN)2", Cu(CN)A Ni(CN)A Ag(CN)22-
Total cyanide
WAD cyanide + Fe(CN)A Co(CN)A
Au(CN)22"
Free Cyanide Measurement
The objective of free cyanide analysis is to measure the amount of CN' and
HCN in a given sample (Maynard and Szczahor 1992). This measure will also
include the readily soluble simple cyanides (Maynard et al. 1986). American
18
Society for Testing and Materials (ASTM) Procedure D4282 (1993) analyzes HCN
which diffuses from a sample solution chamber (buffered at pH 6) to a NaOH
solution chamber in four hours. Colorimetric analysis of the diffused solution is
sensitive from 0.010 to 0.150 mg I"1 HCN. Diffusion methods for HCN in mine
wastes suffer interference from the production of HCN by metal-cyanide complex
dissociation (Maynard and Szczachor 1992). The American Public Health Associ­
ation (APHA) Cyanide-Selective Electrode Method 4500-CN-F (1992) measures
CN concentrations in a range of 0.05 to 10 mg I 1 in sample solutions. Cyanide
ion-selective electrode readings are compared to a cyanide standard calibration .
curve, and a CN' concentration is calculated. This method is particularly sensitive
to interference from the precipitation of sulfides, chlorides, and. mercury on the
cyanide ion-selective electrode (Smith and Struhsacker 1988).
WAD Cyanide Measurement
The measurement of WAD cyanide in effluent solutions is most commonly
performed using reflux distillation in APHA Standard Method 4500-CN-I (1992)
or ASTM D-2036 Test Method C (1993). Distillation of sample solution (buffered
at pH 4.5) for one hour liberates HCN from free cyanide and weak metal-cyanide
complexes. Collected in a NaOH absorption solution, WAD cyanide is best
estimated using direct colorimetric determination, accurate to 0.03 mg I 1 (ASTM
D-2036 Test Method C 1993). The. reflux distillation method recovers all the
cyanide from complexation with zinc and nickel, 70 percent from copper
19
complexes and 30 percent from cadmium complexes (Smith and Struhsacker .
1988). Cyanide is not recovered from its strongest complexes with iron, cobalt or
gold. The appeal of this method is that it is relatively free of thiocyanate or
sulfide interference, and other interferences can be removed before distillation
(Mudder 1991).
A less rigorous, less accurate method of measuring WAD cyanide concen­
trations in mine effluents is the picric acid method (Smith and Mudder 1991).
This method, accurate to 0.5 mg I"1, involves the development of color with picric
acid in the presence of nickel while heating over a water bath for 20 minutes,
followed by colorimetric measurement (Smith and Mudder 1991). Though less
accurate, it can be used more easily for on-site monitoring of effluents for WAD
cyanide concentration changes (Maynard and Szczahor 1992).
A new method for measuring WAD cyanide is found in Kelada’s procedure
for cyanide speciation (Kelada et al. 1992). It was adopted by ASTM as Automat­
ed Methods for Determination of Total Cyanide, Dissociable Cyanide, and
Thiocyanate (D4374) in September 1991 (ASTM 1993). This procedure uses
acidification and thin film distillation to free cyanide from weak metal complexes,
capturing HCN in a NaQH absorber for colorimetric measurement. It is free of
thiocyanate interference and results are regarded as more reliable than distillation
methods (Kelada et al. 1992).
20
Total Cyanide Measurement
Analytical methods to measure total cyanide in wastewater can use manual
or automated procedures. The most widely accepted procedure for determining
total cyanide in mine effluents is the manual reflux distillation in APHA Standard
Method 4500-CN-C (1992), ASTM D-2036 Test Method A (1993), or EPA 9010/
9012 (1986). This procedure is almost the same as that used in reflux distillation
for WAD cyanide measurement. However, the total cyanide reflux distillation
procedure uses a strong acid (1:1 sulfuric acid) to free cyanide from stronger iron
complexes. Interference may be caused by the presence of thiocyanate and sulfide
(Smith and Mudder 1991).
The ASTM D4374 (1.993) Automated Method for Determination of Total
Cyanide, Dissociable Cyanide, and Thiocyanate uses ultraviolet radiation to free
cyanide from the strongest iron, cobalt, gold and platinum complexes. As in the
measurement of WAD cyanide, Kelada (1992) reports this method to be free from
thiocyanate interference and regards it as more reliable than distillation methods
in the measurement of total cyanide concentrations.
Measurement Of Cyanide In Solids
Cyanides can also exist on and in spent leach heap ores. Their measure­
ment in the past has typically involved homogenization and direct distillation of a
solid sample or leachate using ASTM D-2036 (1993) or EPA 9010 (1986) methods
(Hendrix et al. 1985, Durkin 1990, and Davis et al. 1991). Most recently, an
21
ongoing Bureau of Mines cyanide degradation study (Comba et al. 1992) adopted
a sample preparation procedure whereby frozen ore is crushed to 10 to 20 mesh
size. Subsequent cyanide analysis uses HO to 120 grams of the frozen sample in
direct distillation using ASTM D-2036 (1993) procedures. A study to develop a
standard solid sample analytical procedure (Davis et al. 1991) concluded that 60day bottle-roll extraction using 1.25 N NaOH solution, followed by leachate
distillation, provided the most reliable WAD and total cyanide measurement. The
study recommended further refinement of bottle roll extraction methods.
Residual Cyanide Studies
As more and more heap leach projects undertaken in the past 25 years
near completion, effective neutralization of residual cyanide is of interest to both
the mineral industry and regulators. Little information is available on residual
cyanide levels following heap neutralization from the few projects decommissioned
to date. Engelhardt (1985) found that approximately 85% of the free cyanide
present in an untreated, inactive silver leach heap in California was degraded by
natural processes over an 18 month period. The pH of the agglomerated ore
declined from 10.5 to 9 through the course of this study. The Golden Maple-Gilt
Edge gold heap leach project near Lewistown, Montana, was closed by regulators
in late 1985 (Schafer et al. 1991). Leached ore had a high clay content but was
not agglomerated. The heap was rinsed with calcium hypochlorite after closure.
Subsequent inspection of the heap as it was excavated showed zones of high
/
22
residual cyanide that were not effectively rinsed.
The Borealis Mine in Hawthorne, Nevada was deactivated in 1987 after
two year’s cyanide leaching of agglomerated ore (Schafer et al. 1991). Twenty-tWo
months later, the heap was rinsed with fresh water to reduce effluent WAD cyan­
ide concentrations to less than 0.2 mg I'1. For five months following this neutral­
ization, effluent WAD cyanide levels remained less than 0.2 mg I 1 and the pH
remained below 8.5 in most samples. Ore sampled from three backhoe pits had
total cyanide levels below the 10 mg kg'1 limit set by the Nevada Division of
Environmental Protection.
In their study of the Gilt Edge Mine heap leach operation in Deadwood,
South Dakota, Smith and Mudder (1990) concluded that sampling of ore is a
superior method of assessing neutralization success compared to heap effluent
monitoring. In a study of neutralization at Kendall Mine’s Heap Leach Pad No. I
and Pad No. 2, Haight (1991) found total cyanide levels increasing from the
surface to 6 m (20 ft) depth. He concluded that spent ore must be sampled at
various depths and locations throughout a heap, as surface oi;e or effluent sam­
pling will not accurately characterize the cyanide concentrations within it.
Schafer et al. (1991) conducted an intensive investigation of the behavior of
cyanide and metals in a spent leach heap at the Landusky Mine near Malta,
Montana. Ore in the heap was very permeable and was not agglomerated. Heap
excavation and neutron probe data showed no evidence of blind-off zone develop­
ment. Natural degradation processes were predicted to reduce WAD cyanide
23
levels to less than 0.22 mg I"1 within 6 to 8 years. The addition of one pore
volume of fresh water rinse reduced cyanide, nitrate and metal levels by 50 to 90
percent. Soluble metal levels were, found to be closely related to the level of
cyanide in solution. WAD cyanide levels less than 0.22 mg I"1 in heap effluent had
copper levels 4%, zinc levels 1%, iron levels 47%, and cadmium levels less than
10% of the drinking water standard for each metal (Schafer et al. 1991).
The Snow Caps Mine gold leach heap near Independence, California was
neutralized in 1991 using the INCO SO2ZAir process. Subsequent auger drill
sampling found total cyanide levels below the regulatory level of 10 mg kg'1 in 9 of
10 samples (Young et al. 1992). In an ongoing study of natural degradation of
cyanide forms in an inactive spent leach heap at the Trinity Silver Mine in Nevada
(Comba et al. 1992), preliminary data indicate total and WAD cyanide levels are
higher at lower heap depths. Natural cyanide degradation rates are slow, but are
expected to increase as leach solution more completely drains from the heap.
24
STUDY AREA
The Kendall Mine is located in the North Moccasin Mountains, approxi­
mately 32 kilometers (20 miles) northwest of Lewistown, Montana (Figure 3).
Gold has been produced in this area since the late 1800s advent of cyanide
Figure 3.
Location of Kendall Mine (Canyon Resources Corporation 1991).
.^M issouri Ri ver
S. Moccasin
Mountains
Snowy
.
\ j
Ij
i 4I i I '
I
i*
\ Tr
v
0
30
I
L_
miles
25
vat leaching. Open pit heap leach mining of gold began in 1982: After several
ownership transfers, Canyon. Resources Corporation acquired Kendall Mine in
February 1988. The mine project is currently permitted for operation in Township
18N, Range I SE, Sections 29, 30, 31 and 32 and Township 17N, Range 18E,
Section 6. Heap Leach Pad No. I, the focus of this investigation, is located in
Township 18N, Range 18E, Section 31.
Construction of Heap Leach Pad No. I was not thoroughly documented.
The heap covers I hectare (2.4 acres) and contains 82,000 metric tons (90,000
short tons) of agglomerated, run of mine ore on a compacted clay liner (Haight
1991). The heap was constructed in two lifts using either end dump or truck and
dozer techniques. The sandy gravel ore at the top of Pad No. I is comprised of
62% gravel, 24% sand, and 14% clay (HKM Associates 1982). In August of 1988,
the new owners ripped the surface of the heap to increase permeability and
r
.
■
'
,
subjected it to cyanide leaching during the next month. The heap was leached for
68 hours with approximately 760,000 liters (200,000 gallons) of sodium cyanide
solution. No economically-recoverable gold was found and the. heap was left to
drain before spring decommissioning.
Active neutralization of Heap Leach Pad No. I began in March, 1989 w ith.
one week of fresh water rinsing. Prior to chemical neutralization, ore at the
surface was sampled for cyanide. Results are shown in Table 5. Effluent dis­
charge from the heap at this time measured 49.0 mg L total cyanide and had a
pH of 8.6.
i
26
Table 5.
Cyanide levels after fresh water rinsing at Kendall Mine Heap Leach
Pad No. I, March, 1989 (Haight 1991).
Location
Total Cyanide
(mg I 1)
WAD Cyanide
(mg I 1)
Free Cyanide
(mg I 1)
Pad No. I - East
<0.5
<0.5
<0.5
Pad No. I 1- West
2.1
1.2
<0.5
’
Neutralization of the heap with calcium hypochlorite followed the rinsing
and continued through May, 1989. At this point, effluent draining the heap
measured 0.1 mg I:1 total cyanide with a pH of 8.8. By the end of September,
1989, effluent draining the heap measured 0.02 mg. I"1 total cyanide with a pH of
8. 1.
.
/
27
METHODS
Sampling Methods
Ore samples were collected from Kendall Mine Heap Leach Pad No. I
from October 29 to November 2, 1991, thirty months after active chemical
neutralization ceased. Fifteen boreholes were located along two random transects
across the heap in a randomized complete block field plot design (Figure 4).
Boreholes were regarded as blocks and sampled depth increments as treatments.
Block/depth interaction was assumed to be negligible.
Samples were taken from nine to eleven depth increments: 0 to 0.2, 0.2 to
0.5, 0.6 to 1,2, 1.5 to 2.1, 3.0 to 3.7, 4.6 to 5.2, 6.1 to 6.7, 7.6 to 8.2, 9.1 to 9.8, 10.7
to 11.3, and 12,2 to 12.8 m (0 to 0.5, 0.5 to 1.5, 2 to 4, 5 to 7, 10 to 12, 15 to 17,
20 to 22, 25 to 27, 30 to 32, 35 to 37, and 40 to 42 ft), with incremental sampling
halted at the clay liner. A truck-mounted drill rig using a hollow stem auger was
used to bore into the heap, pausing at the top of each sampling depth to pound a
split spoon sampler through the depth increment. Retrieved split spoon samples
were halved along the length of the spoon and examined for lithological character­
ization. One half of the sample was bagged for cyanide analyses. The other half
was bagged for metals analyses, Both samples were sealed in air-tight plastic bags,
logged and stored in coolers. Sample splits for cyanide analyses were shipped to
Energy Laboratories in Billings, Montana for measurement of total, WAD, and
free cyanide.
28
Figure 4.
Location of sampling boreholes I to 15 across the heap surface (top
diagram) and sampling boreholes I to 7 and 8 to 15 in cross-section
(bottom diagrams) through Kendall Mine Heap Leach Pad No. I.
25.9m
WEST
EAST
48.8m
Boreholes
1
2
3
4
5
6
7
10.2m
10.7m
11.1m
11.7m
12.2m
clay liner
Boreholes
15
14
13
12
11
10
9
8
10.1m
10.7m
11.0m
11.9m
clay liner
12.2m
29
Split spoons were decontaminated between samples with a wire brush and
cloth wipe. Auger sections were decontaminated between boreholes by pressur­
ized steam cleaning. Any contact with the clay liner was backfilled with bentonite
pellets. Boreholes were backfilled with drill cuttings after sampling was complete.
Three boreholes were fitted with pore water samplers (suction lysimeters)
prior to backfilling (Table 6). These three suction lysimeters were installed to
monitor pore water quality near the heap base on a bimonthly basis through
spring and summer 1992. The suction lysimeter installed in Borehole 13 was
accidentally destroyed by a mine grader before the sampling program commenced.
Table 6.
Location of suction lysimeters used in pore water sampling.
Borehole
Number
Lysimeter Installation
Depth (meters)
4
9
8
10
13
8
Pore water samples for cyanide analyses were collected 6 to 8 hours after
negatively pressurizing the suction lysimeters. These samples were collected
directly into opaque sample bottles. They were preserved for cyanide analyses by
the addition of sodium hydroxide to pH 12 and cold storage. After this sampling,
the suction lysimeters were again negatively pressurized for collection of additional
pore water samples 12 hours later. The second set of samples was used for
metals analyses. Upon collection, these samples were measured for pH. Samples
30
s
. were then preserved for metals analyses by the addition of nitric acid to pH 2 and
. cold storage.
Analytical Methods
Because standard methods for a solids cyanide analysis applicable to mine
ore were, as they remain, in a state of flux (Comba et al. 1992, Smith and Mudder
1991), ASTM (1993) D-2036 Test. Method C reflux distillation procedures for
cyanide in liquids were modified to measure spent ore total and WAD cyanide
levels. The modification consisted of adding one-half gram of < 2 mm air-dried
ore sample to the reflux distillation solution prior to analysis. Free cyanide in the
ore solutions was measured using a cyanide ion-specific electrode (APHA Method
45 OO-CN-F 1992).
Saturated paste extracts of oven-dried ore samples were prepared for pH
and soluble metals measurement using American Society of Agronomy Method
10-2.3.1 (Rhoades 1982). An Orion Model 901 meter/91-55 electrode was used to
measure pH. Soluble cadmium, copper, iron, nickel, and zinc levels were mea­
sured in the saturated paste extracts by atomic absorption spectroscopy.
Pore water samples were analyzed for total and WAD cyanide using ASTM
D-2306 Test Method C (1993). Free cyanide was measured using APHA Method
4500-CN-F (1992). Atomic absorption spectroscopy was used to measure soluble
cadmium, copper, iron, nickel and zinc concentrations in pore water samples.
To monitor the precision of analyses, blind field replicates and laboratory
31
replicates were entered into the sample set at a 5 percent (I in 20) rate. Blind
field replicate relative percent difference (RPD) averaged 18.4% total cyanide,
16.0% WAD cyanide, 3.1% pH, 19.1% cadmium, 23.4% copper, 22.8%, iron,
9.3% nickel, and 30.9% zinc. Laboratory replicate RPD averaged 23.2% total
cyanide, 10.8% WAD cyanide, 1.6% pH, 11.8% cadmium, 21.9% copper,
6.2% iron, 20.1% nickel, and 19.5% zinc.
Laboratory natural matrix spikes and laboratory digestion/extraction spikes
were utilized at a 5 percent rate to monitor the accuracy of cyanide analyses.
Natural matrix spike recoveries for total and WAD cyanide averaged 83.0% and
58.9%, respectively. Laboratory digestion/extraction spike recoveries for total and
WAD cyanide averaged 98.4% and 96.1%, respectively. Accuracy of pH and
metals analyses were monitored using laboratory standards at a 10 percent
(I in 10) rate. Recoveries averaged 100.3% pH, 98.1% cadmium, 97.6% copper,
98.8% iron, 101.1% nickel, and 99.3% zinc.
To clarify interpretation, the most complete data (from the upper nine of
the eleven depth increments sampled for all boreholes) were combined into five
depth categories. Measurements below analytical detection limit were adjusted for
inclusion in the development of the five depth categories. This adjustment
multiplied respective analytical detection limits by a factor of 0.7 to obtain a
numerical value (Severson 1979). The five depth categories were 0 to 0.5, 0.6 to
2.1, 3.0 to 5.2, 6.1 to 8.2, and 9.1 to 9.8 m (0 to 1.5, 2 to 7, 10 to 17, 20 to 27, and
30 to 32 ft).
32
Skewness and kurtosis of untransformed data from the five depth catego­
ries (Table 7) indicate nonnormality in six of eight parameters at the 90% confi­
dence level. With a sample size of 75, skewness should lie within the range of
-0.34 to +0.34 to indicate a normal data distribution at the 90% confidence level
(Sachs 1982). Likewise, kurtosis should lie within the range of 2.40 to 3.50 (Sachs
1982). These data were normalized by a Iog10 transformation. Skewness and
kurtosis of the transformed data indicate nonnormality in three of eight parame­
ters (Table 7). Transformed cadmium (skewness), nickel (skewness and kurtosis),
and zinc (skewness and kurtosis) data were not improved enough to put them
within the ranges reported by Sachs (1982). Despite indications of nonnormality,
transformed cadmium, nickel, and zinc data were included in subsequent statistical
analysis and interpretation.
Table 7. Effect of Iog10 data transformation on data skewness and kurtosis.
Parameter
Untransformed
Data Skewness
Log10 Transformed
Data Skewness
Untransformed
Data Kurtosis
Log10 Transformed
Data Kurtosis
Total CN
1.69
-0.06
8.47
2.84
WAD CN
4.40
-0.04
31.42
3.25
pH
0.10
0.07
3.21
3.47
Cadmium
0.80
0.67
3.30
2.88
Copper
-0.24
0.16
10.66
3.40
Iron
1.62
0.13
7.12
3.26
Nickel
2.33
0.92
15.36
5.44
Zinc
0.73
-0.57
4.69
3.63
33
Overall two way analysis of variance and its source components (depth and
borehole) for normal total cyanide, WAD cyanide, pH, and metals data were
evaluated at the 95. percent confidence interval using the PROC GLM procedure
in SAS (SAS Institute 1987). Where the p-value for the observed F-statistic was
less than or equal to 0.05, the hypothesis of equality of means was rejected. Data
sets with unequal means were then subjected to the Student-Newman-Keuls means
separation procedure at the 0;05 level of significance.
'
Pore .water, data collected from suction lysimeters in boreholes 4 and 8
were subjected to linear regression at the 95 percent confidence interval. This
regression was performed in order to identify trends in cyanide and metals levels
in pore water near the clay heap pad through the spring and summer of 1992.
34
RESULTS AND DISCUSSION
All solids analytical data are found in Appendix A. D ata validation tables
are found in Appendix B. Statistical output from ANOVA, means separations,
and linear regressions are provided in Appendix C. Data presented in this text
are summaries of this information. .
Many spent ore sample analyses showed cyanide at or below detection
limits (Appendix A, Tables 12, 13, and 14). Samples which had total cyanide
measurements below analytical detection limit were not further analyzed for WAD
or free cyanide. Similarly, samples which, had WAD cyanide measurements below
either WAD or free cyanide analytical detection limits were not further analyzed
for free cyanide. With two exceptions, free cyanide was either below analytical
detection limits or not analyzed at all.
Cyanide and Metals Depth Distributions
Depth category comparisons of cyanide, pH, and metals means are present­
ed in "Table 8. No significant differences exist for total cyanide, pH, cadmium,
iron or zinc. Depth category three had significantly higher WAD cyanide concen­
trations than depth categories I, 2, and 5. WAD cyanide levels increase Mth
depth to a peak in depth categories three and four, followed by a significantly
lower concentration in depth increment 5.
Soluble copper concehtrations were significantly higher in the upper three
depth categories of the heap, subsequently declining through depth categories
35
T a b le 8.
G e o m e tr ic m e a n lev els1 o f c y an id e, p H a n d w a te r so lu b le m e ta ls in
s p e n t o re th ro u g h K e n d a ll M in e H e a p L e a c h P a d N o . I.
_______
Copper
Iron
Nickel
Zinc
O tg r 1)
O tg r 1)
O t g r 1)
O tg r 1)
O t g r 1)
8A2
113A2
264A2
93AB2
112A2
IOA
144A
302A
113A
127A
7.7A
9A
113A
360A
61B
140A
0.6AB
7.7A
IlA
76B
255A
64B
166A
0.2D
7.7A
8A
54C
140A
28C
139A
D cplh
Cnlegory
D epth
(m )
ToialCN
WADCN
(A ee"')
(M g -1)
I
0-0.5
L lA 2
0.4C2
7.9A2
2
0.6-2.1
1.3A
0.5BC
7.7A
3
3.0-5.2
2.2A
0.7A
4
6.1-8.2
1.5A
5
9.1-9.8
0.8A
pH
1 Mean values are based on N = 10, 11, 12, 13, 14 or 15 observations.
2 Multiple means comparisons were performed using Student-Newman-Keuls Test on Iog10
transformed data. Means followed by the same letter in columns are not significantly different
(p s 0.05).
4 and 5. Soluble nickel concentrations in depth category 2 were significantly
higher than concentrations in depth categories 3, 4, and 5.
The peak of WAD cyanide concentrations in depth category three and four
(3.0 to 8.2 m) may be attributable to textural changes and/or compaction at a lift
interface. These depth categories, approximately halfway through the heap, would
be inclusive of the interface between the two lifts comprising Heap Leach Pad
No. I. Schafer et al. (1991) detailed the concept behind particle segregation in
heap lift construction that can lead to textural changes at lift interfaces. Coarser
ore end-dumped on the second lift rolls to the base where it accumulates over
finer ore particles at the top of the first lift (Figure 5). The gradation of each lift,
therefore, would change from coarse at the bottom to finer at the top. The
texture of the upper several feet of each lift may also be made finer by mechani­
cal weathering and particle disaggregation during leaching. Porosity and
36
Figure 5.
Conceptual view of heap construction showing characteristics of
material within the heap (Schafer et al. 1991).
DETAIL
Fine ore
Coarse or
Coarser
%
v *
'0 • 0
interface
Ripper
track
permeability could be further limited in this zone by compaction caused by lift
construction traffic (Chamberlin 1981). Changes in flow paths at this interface or
the development of blind-offs under the compacted ore may protect residual
cyanide from neutralizing rinses and natural degradation processes.
Evidence of the existence of the coarse/fine interface might be found in an
examination of the lithological descriptions from split spoon samples from each
depth category. Sampling in the interface zone would find rock fragments
immediately above fine material. Sampling spoon lithological descriptions from
Heap Leach Pad No. I do not contain any notation of this distinction. They do
indicate rock fragments in 97% of depth categories sampled. However, the
37
descriptions do not differentiate undisturbed whole rock fragments from rock
fragments cored from larger rocks and stones by the force of the pounded split
spoon.
. Cyanide and Metals Areal Distributions
The comparisons of mean cyanide, pH, and soluble metals concentrations
for each borehole across Heap Leach Pad No. I are summarized in Table 9.
.
Significant differences exist between boreholes for all parameters except soluble
iron, nickel, and zinc. However, with one exception, no discernible areal pattern
(e.g. mean concentrations increasing north to south across the heap) is apparent
among parameters with significant differences between boreholes. Only mean
borehole cadmium levels exhibited an areal pattern, declining significantly moving
west to east across the heap.
The distribution pattern of significant differences, where they exist, for each
of the parameters is predominantly random. This would indicate that areal pat- .
terns have not developed in the neutralized leach heap environment. An explana­
tion or hypothesis for these random patterns and the areal pattern of cadmium
levels is not possible without control data from the heap prior to leaching and
neutralization.
T a b le 9.
Borehole
G e o m e tric m e a n lev els1 o f c y an id e, p H a n d w a te r so lu b le m e ta ls fo r b o re h o le s a cro ss K e n d a ll M in e H e a p
L e a c h P a d N o . I.
Total CN
(Mg g l)
WAD CN
(Mg g"‘)
pH
Cadmium
(Mg I*1)
Copper
(Mg I 1)
Iron
(Mg I'1)
Nickel
(Mg I 1)
Zinc
(Mg I'1)
I
1.05CDEF2
0.39BCD2
8.16ABC2
19A2
95CDE2
160A2
65A2
142A2
2
1.17DEF
0.47ABCD
8.22AB
12ABCD
101CD
368A
54A
87A
3
2.32ABC
0.78A
8.29A
5F
179B
280A
136A
IlOA
4
3.46A
0.69AB
7.89BCD
280A
206A
172A
130A
5
1.10CDEF
0.38BCD
7.69DE
6EF
130BC
170A
58A
225A
6
1.25CDE
0.43ABCD
7.02F
5F
81CDE
284A
39A
200A
7
0.48F
0.24D
7.61DE
6EF
57DE
113A
31A
182A
8
0.53EF
0.35BCD
7.56DE
7DEF
49E
219A
35A
15IA
9
1.09CDEF
0.35BCD
7.92BCD
70CDE
312A
79A
76A
10
0.48F
0.40BCD
7.67DE
8CDEF
61DE
373A
43A
86A
11
2.93AB
0.36BCD
7.46E
7DEF
7ICDE
186A
38A
172A
12
1.5 IBCD
0.31CD
7.81CDE
IOBCDE
95CDE
24IA
48A
104A
13
0.81EFD
0.29CD
7.72DE
16AB
84CDE
146A
73A
135A
14
0.75EFD
0.26D
7.87BCD
13ABC
81CDE
248A
79A
108A
15
1.62BCD
0.59ABC
8.19AB
15AB
88CDE
387A
173A
86A
8CDEF
6EF
1 Mean values are based on N = 3, 4 or 5 observations.
Multiple means comparisons were performed using Student-Newman-Keuls Test on Iog10 transformed data.
Means followed by the same letter in columns are not significantly different (p < 0.05).
39
Pore Water Behavior
Pore water samples were collected every two weeks, March through
September, 1992. Data from this sampling effort are summarized in Table 10.
Pore water WAD cyanide concentrations exceeded Montana’s effluent water
quality standard level of 0.22 mg I"1 once over the course of sampling. This
measurement, from borehole 4 on August 9, 1992, showed a WAD.cyanide
concentration of 0.31 mg I'1. The only measure of free cyanide (0.2 mg I'1) was,
notably, also registered here. The sample collected from borehole 8 on this date
was of insufficient volume for WAD or free cyanide analysis. The previous
borehole 4 pore water WAD cyanide concentration measured 0 J 9 mg I1 on July
24, 1992. Between July 24 and August 9, borehole 4 pore water pH decreased
from 7.8 to 6.4, the lowest pH recorded in the sampling program.
Linear regression analysis was used to describe concentrations of parame­
ters in the pore water as functions of time. Results of these analyses and regres­
sion coefficients are presented in Appendix C, Tables 43 to 58. Table 11 displays
the slope of each regression and associated F and p values. If the slope is
different (p < 0.05) than zero, then changes in concentration of that parameter
over the sampling period are demonstrated.
Pore water samples collected from the upgradient position of the heap
(borehole 4) showed increased concentrations of total and WAD cyanide, but
decreased levels of nickeh No changes were found for these parameters in
pore water collected from the downgradient position of the heap (borehole 8).
T a b le 10.
P o r e w a te r cy an id e a n d m e ta ls levels a t K e n d all H e a p L e a c h P a d N o. I, M a rc h - S e p te m b e r, 1992.
Total
Cyanide
(mg I"1)
WAD
Cyanide
(mg I"1)
Free
Cyanide
(mg I 1)
PH
Cadmium
Copper
4
0.48
—
0.69
0.76
0.96
0.94
0.99
0.97
1.08
1.14
0.64
1.99
0.07
—
0.12
0.15
0.15
0.17
0.14
0.15
0.19
0.31
0.15
0.19
BD
—
BD
BD
BD
BD
BD
BD
BD
0.2
ISV
ISV
6.8
6.7
6.5
7.4
7.6
7.7
7.1
6.8
7.8
6.4
7.8
7.6
ISV
33
26
26
20
26
33
26
33
26
26
ISV
ISV
48
19
38
87
0
0
29
0
0
0
ISV
8
0.69
0.88
0.41
0.33
0.36
0.40
0.44
0.55
0.55
0.52
0.35
0.41
0.05
0.06
0.06
0.04
0.05
0.05
0.05
0.06
0.07
ISV
0.03
ISV
BD
BD
BD
BD
BD
BD
BD
BD
BD
ISV
ISV
ISV
6.7
6.7
6.6
7.3
7.4
7.4
7.2
7.2
7.4
6.4
8.0
7.5
ISV
66
26
20
26
26
26
33
33
33
26
ISV
ISV
67
29
19
9
38
29
19
19
0
9
ISV
Sampling
Date
Borehole
3/19/92
4/10/92
4/25/92
5/07/92
5/20/92
6/06/92
6/21/92
7/09/92
7/24/92
8/09/92
8/23/92
9/06/92
3/19/92
4/10/92
4/25/92
5/07/92
5/20/92
6/06/92
6/21/92
7/09/92
7/24/92
8/09/92
8/23/92
9/06/92
BD
ISV
Below analytical detection limit.
Insufficient sample volume for analysis.
Sample destroyed in transit.
Iron
(Mg I"1)
Nickel
Zinc
ISV
649
375
1134
ISV
537
862
500
458
575
500
ISV
ISV
152
108
86
86
65
108
65
65
65
43
ISV
ISV
442
97
299
75
32
245
372
140
ISV
ISV
ISV
ISV
757
416
416
208
458
291
125
208
125
612
ISV
ISV
130
43
86
65
108
43
86
65
86
65
ISV
ISV
ISV
420
194
215
311
406
500
ISV
240
256
ISV
41
Table 11.
Linear regression slope values and associated statistics for Kendall
Heap Leach Pad No. I pore water.
Borehole
P aram eter
Slope
F V alue
p V alue
4
Total CN
0.0050
7.290
0.024
WAD CN
0.0007
7.208
0.025
PH
0.0038
1.800
0.209
Cadmium
-0.0002
4.327 E-05
0.995
Copper
-0.3810
4.315
0.071
Iron
-1.5030
0.688
0.434
Nickel
-0.5647
15.521
0.004
Zinc
-0.6733
0.161
0.702
Total CN
-0.0012
2.011
0.187
WAD CN
-4.067 E-05
0.248
0.632
PH
0.0042
3.352
0.097
Cadmium
-0.0850
0.791
0.400
Copper
-0.2830
6.867
0.031
Iron
-1.8980
1.601
0.241
Nickel
-0.1544
0.557
0.477
Zinc
-0.1214
0.013
0.913
8
Concentrations of copper decreased over the sampling period in pore waters at
the downgradient position. Pore water pH from both gradient positions in the
heap did not change.
Interpretation of these data is difficult because they are restricted to one
sampling season, and no attempts were made to describe the variation within a
particular sampling data or at other positions within the heap. Variation could be
measured if multiple pore water samplers were installed in various locations and
42
depths within the heap. The limited data do,, however, indicate that upgradient
cyanide concentrations increased over the sampling period while downgradient
cyanide levels did not change. Cyanide may have become attenuated as pore
water drained downgradient over the course of the spring and summer. It is
interesting to note that the slopes of the regressions for all metals were negative
(Table 11). Factors influencing these decreasing trends may be related to complex
stabilities and competing degradation processes described in the literature review.
Additional data from subsequent sampling periods and from additional pore water
samplers could be used to verify these trends.
43
SUMMARY AND CONCLUSIONS
In Montana, the use of heap leach cyanidation for gold recovery has
become widespread. These heaps, after gold extraction, must be neutralized to
state effluent standards to assure nondegradation of ground or surface water
quality. However, cyanide may still exist within a heap, protected from the full
effect of neutralization or natural degradation processes. Subsequent drainage
from these heaps, particularly in association with large precipitation events,
represent a possible threat to downstream water quality.
Cyanide and metal concentrations in ore and pore water from a decommis­
sioned leach heap (Kendall Mine Heap Leach Pad No. I) were measured and
compared. Thirty months after active neutralization with calcium hypochlorite,
WAD cyanide levels increased significantly from the heap surface to the middle of
the heap, and significantly declined toward the heap bottom. Copper and nickel
exhibited a similar vertical distribution. These concentration changes may be
attributable to altered flowpaths or .blind-off development at a lift interface within
the heap. Significant areal distribution patterns could not be derived for cyanide,
pH, or metals, with the exception of cadmium, which significantly decreased west
to east across the heap. On balance, the data indicate that areal patterns did not
develop in the neutralized heap environment.
Pore water data indicate that total and WAD cyanide concentrations near
the bottom of the heap may have degraded as pore water drained downgradient
over the course of spring and summer sampling. Pore water soluble metals data
44
indicate that copper and nickel levels declined over the sampling period. These
changes might be due to relative metallo-cyanide. complex stabilities and compet­
ing degradation processes. A more extensive and intensive pore water sampling
design inclusive of all depth categories sampled is recommended for future heap
investigations of cyanide or metals distributions.
Conclusions regarding the distribution of cyanide within this heap cannot be
made without recognition of the difficulty in measuring cyanide concentrations in
heterogeneous spent ore. Development and standardization of collection proto­
cols and analysis procedures for cyanide in spent leach heap ore, pore Water, and
effluent would be helpful to both industry and regulators in the evaluation of
neutralization efficacy.
45
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r
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management biotreatment processes for cyanide, nitrates and heavy metals,
pp. 271-278 In: Mining and Mineral Processing Wastes. Proc. of the
Western Regional Symp. on Mining and Mineral Processing Wastes.
F. Doyle (ed.). Soc. for Mining, Metallurgy and Exploration of AIME.
Littleton, CO.
U.S. Environmental Protection Agency. 1986. Test methods for evaluating solid
waste. U.S. EPA Office of Solid Waste and Emergency Response. SW. 846, Vol. I, Sect. C., Washington, D.C.
van Zyl, D., I. Hutchinson, and J. Kiel (eds.). 1988. Introduction to Evaluation,
Design and Operation of Precious Metal Heap Leaching Projects. Society
of Mining Engineers, Inc. Littleton, CO. 372 p.
51
von Michaelis, H. 1985. Role of cyanide in gold and silver recoveiy.* pp. 51-64
In: Cyanide and the Environment. D. van Zyl (ed.). Colorado State Univ.
Fort Collins, CO.
Young, A., M. Smith, G. Sintay and G. Bakker. 1992. The Snow Caps Mine - A
case history, pp. 369-372 In: Randol Gold Forum Proceedings, Vancouver,
B.C., Canada.
Zadra, J., A. Engel and H. Heinen. 1952. Process for recovering, gold and silver
from activated carbon by leaching and electrolysis. U.S. Dept, of Interior,
Bur. of Mines. Rept. of Investigations 4843. Washington, D.C. 32 p.
52
APPENDICES
.53
APPENDIX A
Data Tables
T a b le 12.
T o ta l c y an id e levels (/tg g'1) a t K e n d a ll H e a p L e a c h P a d N o . I, N o v e m b e r I, 1991.
Depth
Interval
(meters)
I
2
3
4
5
6
7
0 -0 .2
0.7
1.1
2.2
2.8
BD
LI
1.2
0.2 - 0.5
1.2
0.8
2.6
4.5
1.6
0.8
0.6 - 1.2
1.7
BD
LI
2.3
2.1
1.5 - 2.1
1.7
2.8
2.3
1.7
3.0 - 3.7
8.8
BD
13.8
4.6 - 5.2
4.8
BD
6.1 - 6.7
13.2
7.6 - 8.2
9.1 - 9.8
9
10
11
12
13
14
15
1.2
BD
BD
1.5
BD
1.5
0.8
0.5
BD
0.7
1.6
BD
0.8
1.4
1.0
1.8
1.3
2.7
BD
BD
BD
0.8
1.8
1.3
2.2
2.0
1.7
1.8
2.0
BD
BD
BD
1.3
1.9
2.9
1.9
1.7
2.0
3.0
2.2
2.2
1.2
0.9
BD
1.6
1.4
3.3
BD
BD
3.0
10.4
2.5
2.4
2.6
BD
BD
1.5
4.3
6.1
4.1
3.1
3.8
7.6
5.2
BD
2.4
BD
2.5
BD
BD
BD
BD
3.3
2.4
BD
5.9
4.6
LI
4.2
2.7
0.9
BD
BD
0.5
BD
BD
BD
10.3
LI
4.5
2.0
2.2
0.3'
0.5
1.7
4.8
0.9
1.2
BD
BD
2.2
BD
10.3
1.6
0.2'
0.1'
3.7
BD
BD
0.8
0.6
0.6
0.2'
—
—
Liner
0.2'
Liner
0.2'
Below
Liner
0.8
10.7 - 11.3
—
—
—
12.2 - 12.8
—
—
—
BD
1
Borehole
8
—
——
•—
—
—
—
——
Below analytical detection limit (<0.5 /ng g"1).
No sample from the depth indicated.
Analytical detection limit lowered to 0.1 /Ag g"1 due to minimal limestone interference with sample analysis.
——
T a b le 13.
W A D c y a n id e levels (/Ag g"1) a t K e n d a ll H e a p L e a c h P a d N o . I, N o v e m b e r I, 1991.
Depth
Interval
(meters)
I
2
3
4
5
6
7
0 -0 .2
BD
0.5
1.3
LI
NA
BD
0.21
0.2 - 0.5
0.6
BD
1.2
1.6
BD
BD
0.6 - 1.2
BD
NA
BD
0.6
BD
1.5 - 2.1
0.8
0.9
0.7
0.6
3.0 - 3.7
1.9
NA
10.0
4.6 - 5.2
2.0
NA
6.1 - 6.7
2.2
7.6 - 8.2
Borehole
8
9
10
11
12
13
14
15
BD
NA
NA
BD
NA
BD
BD
BD
NA
BD
BD
NA
BD
0.2'
BD
BD
0.6
BD
NA
NA
NA
BD
BD
BD
BD
BD
0.6
BD
BD
NA
NA
NA
BD
BD
0.5
0.6
0.6
0.7
0.8
0.9
BD
BD
BD
NA
0.6
BD
1.0
BD
NA
0.7
2.1
BD
0.6
0.6
NA
NA
BD
BD
0.5
0.6
1.0
0.9
1.2
1.5
NA
BD
NA
1.3
NA
NA
NA
NA
BD
BD
NA
0.9
0.9
BD
0.9
BD
BD
NA
NA
BD
NA
NA
NA
BD
BD
1.2
0.4'
0.3'
9.1 - 9.8
0.T
BD
BD
BD
BD
NA
NA
NA
BD
NA
BD
BD
0.1'
BD
*■
10.7-11.3
—
—
—
—
BD
NA
NA
BD
BD
BD
0.1'
—
——
——
12.2-12.8
—
—
—
—
--
--
Liner
0.1'
Liner
0.1'
Below
Liner
0.5
BD
NA
1
—
-
——
—
——
Below analytical detection limit (<0.5 /Ag g'1).
Not analyzed.
No sample from the depth indicated.
Analytical detection limit lowered to 0.1 /Ag g"1 due to minimal limestone interference with sample analysis.
T a b le 14.
Depth
Interval
(meters)
F r e e c y an id e levels (jx g g"1) a t K e n d a ll H e a p L e a c h P a d N o . I, N o v e m b e r I, 1991.
1
2
3
4
5
6
7
Borehole
8
9
10
11
12
13
14
15
0 -0 .2
NA
NA
BD
BD
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
0.2 - 0.5
NA
NA
BD
BD
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
0.6 - 1.2
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
1.5 - 2.1
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
3.0 - 3.7
BD
NA
3.0
NA
NA
NA
NA
NA
NA
NA
NA
BD
NA
NA
BD
4.6 - 5.2
BD
BD
2.0
NA
NA
NA
NA
NA
NA
NA
NA
NA
BD
NA
BD
6.1 - 6.7
BD
BD
NA
NA
NA
BD
NA
NA
NA
NA
NA
NA
NA
NA
NA
7.6 - 8.2
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
BD
NA
NA
9.1 - 9.8
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
—
—
10.7-11.3
—
—
—
—
NA
NA
NA
NA
NA
NA
NA
—
—
—
—
—
12.2-12.8
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
BD
NA
Below analytical detection limit (<1.0 /u-g g"1).
Not analyzed.
No sample from the depth indicated.
T a b le 15.
p H levels a t K e n d a ll H e a p L e a c h P a d N o. I, N o v e m b e r I, 1991.
Depth
Interval
(meters)
I
2
3
4
5
6
7
0 -0 .2
8.0
8.6
8.1
8.0
6.7
7.2
8.0
0.2 - 0.5
8.6
8.7
8.9
8.3
8.1
7.6
0.6 - 1.2
7.9
ISV
8.0
7.9
7.6
1.5 - 2.1
7.6
8.6
8.5
8.0
3.0 - 3.7
8.7
7.9
8.0
4.6 - 5.2
7.0
7.9
6.1 - 6.7
8.2
7.6 - 8.2
Borehole
8
9
10
11
12
13
14
15
7.3
8.2
7.6
7.8
7.9
7.9
7.8
8.1
7.8
7.3
7.9
7.6
7.0
7.5
7.7
8.2
8.2
6.9
7.5
6.6
7.8
7.3
7.2
7.6
7.6
8.1
8.3
7.7
5.9
7.5
6.8
8.3
7.2
7.6
7.2
8.3
7.8
8.7
7.4
7.3
6.7
7.4
8.0
7.2
7.4
ISV
8.4
7.7
7.8
8.3
7.8
7.9
7.5
7.4
7.4
7.8
7.7
7.6
7.6
7.8
7.5
7.8
8.1
7.7
7.5
ISV
7.6
7.8
7.4
7.4
ISV
7.4
7.9
7.8
7.5
7.8
7.6
7.5
7.4
8.2
8.0
7.6
ISV
6.9
7.7
ISV
7.9
7.1
8.1
7.9
7.9
8.1
9.1 - 9.8
8.2
7.8
8.1
7.5
7.9
6.5
7.5
8.2
7.9
8.0
7.7
8.1
7.6
7.6
10.7-11.3
—
—
—
—
7.9
7.7
7.3
8.0
7.7
7.6
7.8
—
—
—
12.2-12.8
—
—
—
—
—
—
Liner
7.5
Liner
7.8
Below
Liner
7.9
—
——
——
—
—
ISV
Insufficient sample volume.
No sample from the depth indicated.
—
T a b le 16.
C a d m iu m levels ( jig I"1) a t K e n d a ll H e a p L e a c h P a d N o . I, N o v e m b e r I, 1991.
Depth
Interval
(meters)
1
2
3
4
5
6
7
Borehole
8
9
10
11
12
13
14
15
0 -0 .2
15
BD1
BD1
BD1
BD1
BD1
11
BD2
BD2
BD2
BD2
14
17
8
13
0.2 - 0.5
10
10
BD1
BD1
BD1
BD1
8
BD2
BD2
BD2
12
9
14
14
22
0.6 - 1.2
12
ISV
ISV
BD1
28
BD1
BD1
25
BD2
22
14
14
14
BD2
11
1.5 - 2.1
32
10
BD1
8
BD1
BD1
BD1
22
BD2
11
14
14
12
8
11
3.0 - 3.7
20
BD1
28
BD1
13
BD1
BD1
BD2
11
BD2
ISV
12
7
BD2
8
4.6 - 5.2
17
12
BD1
14
BD1
BD1
BD1
BD2
BD2
18
12
14
14
8
11
6.1 - 6.7
28
35
25
ISV
BD1
25
BD1
BD2
ISV
14
7
12
14
8
14
7.6 - 8.2
12
BD1
10
7
17
ISV
28
BD2
ISV
BD2
3
3
BD2
BD2
8
9.1 - 9.8
32
21
BD1
21
BD1
BD1
BD1
BD2
BD2
BD2
3
7
25
25
——
10.7-11.3
—
—
—
—
7
17
17
BD2
BD2
22
44
—
—
—
12.2-12.8
—
—
—
—
—
—
Liner
11
Liner
BD2
Below
Liner
BD2
—
—
-
—
BD1 Below analytical detection limit (<5 /ig I"1).
BD2 Below analytical detection limit (<8 /Ag I"1).
ISV Insufficient sample volume.
No sample from the depth indicated.
—
—
T a b le 17.
C o p p e r levels (/tg I"1) a t K e n d a ll H e a p L e a c h P a d N o . I, N o v e m b e r I, 1991
Depth
Interval
(meters)
1
2
3
4
5
6
7
Borehole
8
9
10
11
12
13
14
15
0 - 0.2
94
138
568
645
131
88
43
62
119
81
62
175
64
62
62
0.2 - 0.5
116
61
383
1665
179
61
43
68
93
56
70
111
88
118
86
0.6 - 1.2
173
ISV
155
122
127
87
HO
228
62
HO
76
70
169
137
106
1.5 - 2.1
109
355
161
172
174
100
77
HO
62
157
100
226
361
193
275
3.0 - 3.7
173
77
161
238
355
77
77
56
126
138
ISV
706
86
75
81
4.6 - 5.2
111
230
750
54
122
72
66
31
31
63
58
41
86
75
62
6.1 - 6.7
145
90
100
ISV
83
109
55
25
ISV
181
29
35
118
112
HO
7.6 - 8.2
105
66
45
72
72
ISV
72
31
ISV
43
142
150
50
BD1
BD1
9.1 - 9.8
56
72
55
81
88
89
61
25
43
31
71
35
56
50
10.7-11.3
—
—
—
—
54
45
45
37
63
78
142
—
—
—
12.2-12.8
—
—
—
—
—
—
Liner
94
Liner
56
Below
Liner
BD2
—
—
—
—
BD1 Below analytical detection limit (<20 /ng I"1).
BD2 Below analytical detection limit (<31 /ig I'1).
ISV Insufficient sample volume.
No sample from the depth indicated.
—
——
—
T a b le 18.
Iro n levels (jug I"1) a t K e n d a ll H e a p L e a c h P a d N o. I, N o v e m b e r I, 1991.
Depth
Interval
(meters)
I
2
3
0 -0 .2
114
274
0.2 - 0.5
142
0.6 - 1.2
4
5
6
7
309
330
335
171
182
183
471
345
283
246
121
ISV
705
316
493
1.5 - 2.1
298
429
302
119
3.0 - 3.7
2212
316
974
4.6 - 5.2
633
938
6.1 - 6.7
3237
7.6 - 8.2
9.1 - 9.8
9
10
11
12
13
14
15
272
272
545
236
395
246
134
259
163
145
281
481
208
111
119
857
475
263
187
402
454
559
111
104
246
726
144
216
410
203
571
218
280
119
365
627
211
221
225
140
104
633
245
329
136
ISV
111
619
736
537
274
558
133
380
31
BD3
145
475
82
134
1512
1543
1018
2358
233
ISV
BD1
220
BD2
BD3
ISV
170
74
141
619
1236
893
107
522
298
584
38
ISV
103
54
ISV
136
195
158
1189
57
BD3
50
415
105
64
105
417
46
363
381
327
256
417
BD3
BD3
—
—
207
194
51
436
73
85
97
Liner
31
Liner
BD3
Below
Liner
72
10.7-11.3
—
—
—
—
12.2-12.8
—
—
—
—
BD1
BD2
BD3
ISV
Borehole
8
- -
—
Below analytical detection limit (<28 f i g I"1).
Below analytical detection limit (<30 f i g I"1).
Below analytical detection limit (<40 /ug I"1).
Insufficient sample volume.
No sample from the depth indicated.
—
—
—
—
—
■■
—
—
—
—
T a b le 19.
N ick el levels (/Ltg I'1) a t K e n d a ll H e a p L e a c h P a d N o. I, N o v e m b e r I, 1991.
Depth
Interval
(meters)
I
2
3
4
5
6
7
0 -0 .2
BD5
118
913
1787
BD4
BD4
BD1
0.2 - 0.5
175
42
203
1044
139
BD4
0.6 - 1.2
74
ISV
BD2
194
162
1.5 - 2.1
108
262
169
127
3.0 - 3.7
83
BD2
1897
4.6 - 5.2
BD5
BD5
6.1 - 6.7
81
7.6 - 8.2
9.1 - 9.8
9
10
11
12
13
14
15
34
465
BD3
BD3
74
BD6
141
326
BD1
BD3
81
58
BD6
BD6
140
187
212
151
BD4
75
69
75
101
55
166
206
217
81
BD4
BD4
62
93
100
129
175
263
195
217
161
152
BD4
BD4
BD3
62
69
ISV
368
75
BD1
43
1248
BD4
33
BD4
BD4
BD3
46
75
BD6
BD6
137
BD1
43
121
54
ISV
BD2
782
49
34
ISV
37
BD6
BD6
62
326
162
46
BD5
BD4
BD4
BD4
ISV
67
34
ISV
58
25
50
BD1
BD1
BD1
BD5
BD4
BD2
BD4
BD2
BD4
49
46
BD3
BD3
50
BD6
BD1
BD1
——
BD4
BD4
BD4
BD3
BD3
100
162
Liner
40
Liner
58
Below
Liner
58
10.7-11.3
—
—
—
—
12.2-12.8
—
—
--
—
BD1
BD2
BD3
ISV
Borehole
8
—
--
Below analytical detection limit (<32 /ng I 1).
Below analytical detection limit (<33 /Hg I"1).
Below analytical detection limit (<34 /tg I"1).
Insufficient sample volume.
——
——
—
—
—
■■
BD4 Below analytical detection limit (<35 /Hg I"1).
BD5 Below analytical detection limit (<36 /Hg I"1).
BD6 Below analytical detection limit (<40 /Hg I"1).
No sample from the depth indicated.
——
T a b le 20.
Z in c levels (/Ag I"1) a t K e n d a ll H e a p L e a c h P a d N o. I, N o v e m b e r I, 1991.
Depth
Interval
(meters)
I
2
3
4
5
6
7
0 -0 .2
173
63
70
148
162
222
0.2 - 0.5
75
61
46
145
156
0.6 - 1.2
121
ISV
304
90
1.5 - 2.1
120
100
70
3.0 - 3.7
56
88
4.6 - 5.2
39
6.1 - 6.7
Borehole
8
9
10
11
12
13
14
15
103
156
55
89
73
81
60
88
46
no
96
375
81
73
104
243
118
190
116
153
137
248
248
77
186
155
169
123
76
84
131
339
180
183
159
34
0
148
164
1099
98
40
165
178
262
243
67
65
188
160
ISV
89
405
48
61
71
163
79
281
241
287
284
83
155
456
164
304
46
30
74
51
307
ISV
417
176
181
112
ISV
1000
131
183
230
25
218
7.6 - 8.2
426
160
127
169
451
ISV
378
126
ISV
89
371
97
69
92
135
9.1 - 9.8
256
125
171
111
272
322
347
55
79
79
274
34
159
108
10.7-11.3
—
—
—
—
123
245
202
91
133
0
284
—
—
—
12.2-12.8
—
—
—
—
Liner
232
Liner
149
Below
Liner
81
—
——
——
——
TO
ISV
—
Insufficient sample volume.
No sample from the depth indicated.
--
—
——
63
APPENDIX B
Data Validation Tables
64
T a b le 21.
B lin d field re p lic a te cy an id e an aly sis re su lts.
Relative Percent DifTerence (%)
BD1
BD2
NA
Sample
Number
Total
Cyanide
WAD
Cyanide
Free
Cyanide
115/116
BD1
BD2
NA
143/144
66.7
BD1
NA
153/155
BD2
BD2
NA
178/179
18.2
BD1
NA
197/198
BD2
BD2
NA
224/225
37.8
BD1
NA
240/241
0.0
BD2
NA
259/260
16.2
0.0
NA
272/273
6.9
52.6
NA
299/300
BD1
BD2
NA
325/326
BD2
BD2
NA
340/342
9.5
0.0
NA
356/358
22.8
6.5
NA
382/383
0.0
13.3
NA
407/408
BD2
BD2
NA
425/427
5.5
23.3
BD1
Both sample analyses were below analytical detection limit.
One sample analyses was below analytical detection limit, precluding RPD
calculation.
Not analyzed.
65
T a b le 22.
L a b o ra to ry re p lic a te c y an id e an aly sis resu lts.
Relative Percent Difference (%)
Sample
Number
BD
NA
Total
Cyanide
WAD
Cyanide
Free
Cyanide
102
25.0
BD
NA
122
66.7
0.0
NA
143
8.7
BD
NA
163
17.7
BD
NA
185
0.0
BD
NA
206
18.8
18.2
NA
228
14.6
0.0
NA
248
25.6
40.0
NA
271
4.9
0.0
NA
292
120.0
BD
NA
312
10.5
BD
NA
333
11.8
BD
NA
354
3.5
20.0
BD
376
0.0
0.0
BD
395
42.9
8.3
NA
417
0.0
BD
NA
Below analytical detection limit.
Not analyzed.
66
T a b le 23.
Sample
Number
NA
L a b o ra to ry s p ik e d cy an id e an aly sis re su lts.
Total
Cyanide
% Recovery
WAD
Cyanide
Free
Cyanide
104
86'
NA
NA
124
101"
NA
NA
144
91"
63', 105"
NA
166
69', 93"
NA
NA
187
98"
106"
NA
208
75'
62', 95"
105
231
100"
52', 92"
NA
251
98'
NA
NA
272
92'
61', 93"
NA
293
73', 102"
NA
NA
315
73', 97"
39', 92"
NA
335
81'
51', 95"
NA
356
75'
76'
82"
377
101"
67, 85"
95"
398
108'
98"
NA
418
103"
100"
NA
The soil was spiked with cyanide before distillation.
The soil distillate was spiked with cyanide before colorimetric analysis.
Not analyzed.
67
Table 24.
Blind field replicate pH and metals analysis results.
Relative Percent Difference
(% )
Sample
Number
pH
Cadmium
Copper
Iron
Nickel
Zinc
111/112
9.4
BD
83.0
BD
BD
21.4
183/184
1.3
19.4
12.8
11.9
15.0
12.1
204/205
1.3
15.4
0.0
40.0
5.6
72.6
226/227
0.0
15.4
4.8
6.1
6.3
40.9
238/239
0.0
27.3
49.7
BD
BD
20.3
257/258
0.0
BD
BD
17.1
BD
8.3
286/287
2.7
BD
22.2
67.1
BD
17.0
330/331
1.5
BD
36.3
36.7
BD
68.0
338/339
6.7
BD
6.5
13.0
10.4
47.4
357/359
3.7
BD
5.2
12.0
BD
38.7
412/413
6.5
BD
0.0
16.8
BD
23.8
432/433
3.9
18.2
37.3
6.8
BD
0.7
Table 25.
Laboratory replicate pH and metals analysis results.
Relative Percent Difference
(% )
Sample
Number
PH
Cadmium
Copper
Iron
Nickel
Zinc
175
2.3
BD
9.2
7.3
BD
12.8
200
1.5
0.0
9.3
0.0
46.7
14.9
244
2.5
25.0
9.8
11.7
12.5
23.5
283
1.4
15.8
26.3
5.3
BD
6.6
309
0.3
BD
6.6
14.4
BD
20.3
375
3.4
BD
7.3
4.4
1.1
25.0
436
0.1
6.5
85.1
0.0
BD
33.2
BD
Below analytical detection limit.
68
T a b le 26.
Sample
Lot
101-175 ICV
LCS
CCVl
CCV2
CCV3
177-227 ICV
LCS
CCVl
CCV2
L a b o ra to ry p H a n d m e ta ls re c o v e ry re su lts.
----
100.7
100.6
100.6
100.1
————
100.6
100.6
286-339 ICV
LCS
CCVl
CCV2
99.7
— —
100.3
100.6
•••■
99.7
100.7
341-405 ICV
LCS
CCVl
CCV2
100.1
406-436 ICV
LCS
CCVl
CCV2
100.0
100.0
100.4
SL1
100.0
SL1
SL2
ICV
LCS
CCVl
CCV2
ICV
LCS
CCVl
CCV2
106.0
100.0
96.0
93.0
93.0
93.0
100.0
100.0
100.0
106.0
100.0
100.7
96.2
90.8
95.3
98.4
100.4
106.5
106.5
103.9
101.0
101.7
101.0
108.5
102.2
97.5
102.0
96.5
97.5
100.0
98.8
97.1
98.1
100.0
100.0
100.9
99.3
101.0
99.5
103.3
104.7
100.3
100.0
103.0
103.0
97.0
98.5
94.0
94.0
100.0
93.0
98.9
98.9
100.8
104.1
101.6
103.6
95.6
97.9
102.4
99.5
101.0
98.0
100.0
97.5
94.0
97.0
94.0
94.0
98.0
97.4
96.3
96.3
98.5
100.0
98.5
97.0
100.0
99.0
99.0
101.6
101.0
99.3
100.3
101.0
100.0
100.0
97.5
96.0
97.6
96.0
95.4
92.3
100.0
98.1
97.8
96.3
102.9
101.7
103.6
109.3
99.0
98.4
101.6
100.7
97.5
92.0
96.5
97.5
100.0
99.1
100.0
99.1
100.7
100.3
98.4
97.7
99.3
99.0
107.4
100.0
100.0
98.6
100.5
97.5
109.0
104.0
104.0
100.0
95.2
95.2
95.2
90.6
94.0
96.4
102.3
100.0
101.1
97.7
104.5
96.5
97.0
98.0
93.0
91.0
106.5
103.0
96.5
93.0
102.3
100.0
96.7
93.7
101.2
97.4
96.1
97.4
100.0
100.0
100.0
95.6
98.5
93.0
93.0
97.0
100.0
100.0
SL2
N ickel
Cadm ium
237-285 ICV
LCS
CCVl
CCV2
ICV
LCS
CCVl
CCV2
% Recovery
C opper
Iron
pH
————
99.7
100.4
————
————
100.9
101.0
100.0
————
100.7
100.3
Zinc
Samples 104, 106, 132, 146, 156, 158, 163, 166, 172, 192, 195, 197, 216, 231, 232, 234, 244, 267, and 277.
Samples 297, 302, 320, 328, 335, 348, 352, 366, 372, 373, 385, 388, 392, 409, 414, 422, and 430.
Initial calibration verification.
Laboratory control standard.
Continuing calibration verification following ICV and ten sample analyses.
Continuing calibration verification following CCVl and ten sample analyses.
69
APPENDIX C
Statistical Data
70
T a b le 27.
A nalysis o f v a ria n c e fo r to ta l c y an id e (w e ig h te d , Iog10 tra n s fo rm e d d a ta ).
D e p e n d e n t V a ria b le : T O T A L C Y A N ID E
Source
DF
Sum of
Squares
Mean
Square
Model
Error
Corrected Total
18
55
73
1.998775
2.011509
4.010284
0.111043
0.036573
R-Square
0.498412
Source
DEPTH
BOREHOLE
C.V.
401.2983
DF
4
14
Root MSE
0.1912
Type III SS
0.3648411
1.6150962
F Value
Pr > F
3.04
0.0008
CYANIDE Mean
0.0477
Mean Square
F Value
Pr > F
0.0912103
0.1153640
2.49
3.15
0.0534
0.0012
71
T a b le 28.
S tu d e n t-N e w m a n -K e u ls m e a n s s e p a ra tio n te sts fo r b o re h o le to ta l cy an id e
m e a n s (w e ig h te d , Iog10 tra n s fo rm e d d a ta ).
1
Borehole
N
Transformed Mean
SNK Grouping
4
5
0.5393
A1
11
5
0.4662
AB
3
5
0.3653
ABC
15
4
0.2103
BCD
12
5
0.1795
BCD
6
5
0.0966
CDE
5
5
0.0426
CDEF
9
5
0.0356
CDEF
I
5
0.0213
CDEF
2
5
-0.0670
DEF
13
5
-0.0930
DEF
14
5
-0.1242
DEF
8
5
-0.2753
EF
7
5
-0.3149
F
10
5
-0.3181
F
Means with the same letter are not significantly different.
Alpha = 0.05
df = 55
MSE = 0.036573
Number of Means
I
2
I
3
I
4
!
5
I
6
- - - - - - - - - - - - - - - - - - - 1- - - - - - - - - - - - 1- - - - - - - - - - - - 1- - - - - - - - - - - H- - - - - - - - - h - - - - - - —
Critical Range
j 0.2444 | 0.2938 j 0.3231 j 0.3440 j 0.3601
Number of Means
!
7
!
8
I
9
! 10
I
11
- - - - - - - - - - - - - - - - - - - j- - - - - - - - - - - + - - - - - - - - - - - 1- - - - - - - — — + - - - - - - - - - - f—- - - - - - - Critical Range
j 0.3731877 j 0.3842 j 0.3937 j 0.4021 | 0.4095
Number of Means I
12
I
13
!
14
I
15
--------------------------- 1---------------- 4— ——--------H----------- ----- + -------------- 4
Critical Range
I 0.4161
j 0.4222 j 0.4278 I 0.4329
72
T a b le 29.
A nalysis o f v a ria n c e fo r W A D c y an id e (w e ig h te d , Iog10 tra n s fo rm e d d a ta ).
D e p e n d e n t V a ria b le : W A D C Y A N ID E
Source
DF
Sum of
Squares
Mean
Square
Model
Error
Corrected Total
18
42
60
0.9867030
0.7378051
1.7245081
0.0548168
0.0175668
R-Square
0.572165
C.V.
-33.23712
Source
DF
DEPTH
BOREHOLE
Table 30.
Pr > F
0.0012
3.12
Root MSE
0.1325
Type III SS
4
14
F Value
CYANIDE Mean
-0.3988
Mean Square
F Value
Pr > F
0.1338824
0.0359721
7.62
2.05
0.0001
0.0371
0.5355296
0.5036090
Student-Newman-Keuls means separation tests for depth WAD
cyanide means (weighted, Iog10 transformed data).
1
Depth
N
Transformed Mean
SNK Grouping
3
14
-0.1439
A1
4
11
-0.2101
AB
2
12
-0.3181
BC
I
14
-0.3795
C
5
10
-0.6346
D
Means with the same letter are not significantly different.
Alpha = 0.05
df = 42
MSE = 0.017567
Number of Means
!
2
I
3
I
Critical Range
j
0.1093
j
0.1315
j
- - - - - - - - - - - - - - - - - - + - - — - - - - - i-—
4
!
5
0.1448
]
0.1543
-------- — + --------
73
T a b le 31.
S tu d e n t-N e w m a n -K e u ls m e a n s s e p a ra tio n te sts fo r b o re h o le W A D
c y an id e m e a n s (w e ig h te d , Iog10 tra n s fo rm e d d a ta ) .
1
B orehole
N
T ransform ed M ean
S N K G rouping
3
5
-0.1069
A1
4
5
-0.1619
AB
15
4
-0.2286
ABC
2
4
-0.3253
ABCD
6
4
-0.3689
ABCD
10
2
-0.4007
BCD
I
5
-0.4132
BCD
5
4
-0.4246
BCD
11
5
-0.4486
BCD
8
2
-0.4559
BCD
9
3
-0.4559
BCD
12
5
-0.5127
CD
13
5
-0.5336
CD
14
5
-0.5927
D
7
3
-0.6261
D
Means with the same letter are not significantly different.
Alpha = 0.05
I
l
I
2
I
---------------------------------- + --------------- --— + —
Critical Range
j 0.1970 j
Number of Means
df = 42
MSE = 0.017567
l
3
l
!
l
4
!
------------ +---------- + —
0.2371
j
0.2611
j
5
I
--- + —
0.2781
|
6
-----
0.2914
Number of Means
S
7
I
8
I
9
I 10
I
11
----------------------------j------------- — I----------------- H------------------1---------------- 1------------Critical Range
|
0.3021
| 0.3112 |
0.3190
j 0.3259 j 0.3320
Number of Means
!
12
I
13
!
14
I
15
--------—- ——-------- 1-------------------1------------------1-------- — — I------- --------- 1
Critical Range
j 0.3375 I 0.3425 I 0.3471 j 0.3513
74
T a b le 32.
A nalysis o f v a ria n c e fo r p H (w e ig h te d , Iog10 tra n s fo rm e d d a ta ).
D e p e n d e n t V a ria b le : P H
Source
DF
Sum of
Squares
Mean
Square
Model
Error
Corrected Total
18
54
72
0.0087106
0.0062246
0.0149351
0.0004839
0.0001153
R-Square
0.583226
Source
DEPTH
BOREHOLE
C.V.
1.204340
DF
4
14
Root MSE
0.0107
Type III SS
0.0006444
0.0080161
F Value
Pr > F
4.20
0.0001
PH Mean
0.8915
Mean Square
F Value
Pr > F
0.0001611
0.0005726
1.40
4.97
0.2472
0.0001
75
T a b le 33.
S tu d e n t-N e w m a n -K e u ls m e a n s s e p a ra tio n te sts fo r b o re h o le p H
m e a n s (w e ig h te d , Iog10 tra n s fo rm e d d a ta ).
1
Borehole
N
Transformed Mean
SNK Grouping
3
5
0.9185
A1
2
5
0.9149
AB
15
4
0.9132
AB
I
5
0.9118
ABC
9
4
0.8987
BCD
4
5
0.8969
BCD
14
5
0.8958
BCD
12
5
0.8926
CDE
13
5
0.8875
DE
5
5
0.8860
DE
10
5
0.8848
DE
7
5
0.8811
DE
8
5
0.8783
DE
11
5
0.8728
E
6
5
0.8463
F
Means with the same letter are not significantly different.
Alpha = 0.05
I
df = 54
i
MSE = 0.000115
i
i
i
Number of Means
!
2
!
3
I
4
I
5
!
6
-------------------------- -I— ----- —— + ------------- — I— —---------- + — ----------+ ------------Critical Range
j 0.0138 j 0.0166 j 0.0183 j 0.0195 j 0.0204
Number of Means
I
7
!
8
!
9
I 10
I
11
—--- ——--- ——4------------ 1------------H------------+-------—+-------—
Critical Range
g 0.0211 j 0.0218 g 0.0223 j 0.0228 g 0.0232
Number of Means
------
Critical Range
!
12
!
13
I 14
I 15
1-------------1----- ----- 4---------- —I--------- -H
j
0.0236
j
0.0239
j
0.0242
I
0.0245
76
T a b le 34.
A n aly sis o f v a ria n c e fo r c a d m iu m (w e ig h te d , Iog10 tra n s fo rm e d d a ta ).
D e p e n d e n t V a ria b le : C A D M IU M
Source
DF
Sum of
Squares
Mean
Square
Model
Error
Corrected Total
18
54
72
0.8635915
0.9072893
1.7708807
0.0479773
0.0168017
R-Square
0.487662
Source
DEPTH
BOREHOLE
C.V.
13.95810
DF
4
14
Root MSE
0.1296
Type III SS
0.0571687
0.8041337
F Value
Pr > F
2.86
0.0015
CADMIUM Mean
0.9286
Mean Square
F Value
Pr > F
0.0142922
0.0574381
0.85
3.42
0.4995
0.0006
77
T a b le 35.
S tu d e n t-N e w m a n -K e u ls m e a n s s e p a ra tio n te sts fo r b o re h o le c a d m iu m
m e a n s (w e ig h te d , Iog10 tra n s fo rm e d d a ta ).
1
Borehole
N
Transformed Mean
SNK Grouping
I
5
1.2704
A1
13
5
1.2071
AB
15
4
1.1708
AB
14
5
1.1068
ABC
2
5
1.0751
ABCD
12
5
0.9812
BCDE
4
5
0.8928
CDEF
10
5
0.8765
CDEF
8
5
0.8499
DEF
11
5
0.8403
DEF
7
5
0.7962
EF
9
4
0.7925
EF
5
5
0.7395
EF
3
5
0.7095
F
6
5
0.6826
F
Means with the same letter are not significantly different.
Alpha = 0.05
df = 54
MSE = 0.016802
I
Number of Means
!
2
!
3
■
4
I
5
I
6
0.2462
Critical Range
I
I
I
0.1671
I
I
I
0.2008
I
I
I
0.2209
I
I
I
0.2352
I
I
I
Number of Means
I
I
7
I
I
8
I
I
9
I
I
10
I
I
11
Critical Range
I
I
I
0.2552
I
I
I
0.2627
I
I
I
0.2692
I
I
I
0.2749
I
I
I
0.2800
Number of Means
I
I
12
I
I
13
I
I
14
I
I
15
0.2887
I
I
I
0.2926
I
I
I
0.2961
Critical Range
I
I
I
0.2846
I
I
I
78
T a b le 36.
A nalysis o f v a ria n c e fo r c o p p e r (w e ig h te d , Iog10 tra n s fo rm e d d a ta ).
D e p e n d e n t V a ria b le : C O P P E R
Source
DF
Sum of
Squares
Mean
Square
Model
Error
Corrected Total
18
54
72
1.4687654
0.9461275
2.4148928
0.0815981
0.0175209
C.V.
6.752258
R-Square
0.608211
Source
DF
Table 37.
Type III SS
4
14
DEPTH
BOREHOLE
Root MSE
0.1324
F Value
Pr > F
4.66
0.0001
COPPER Mean
1.9603
Mean Square
F Value
Pr > F
0.1514624
0.0628274
8.64
3.59
0.0001
0.0003
0.6058495
0.8795838
Student-Newman-Keuls means separation tests for depth copper means
(weighted, Iog10 transformed data).
1
Depth
N
Transformed Mean
SNK Grouping
2
15
2.1577
A1
I
15
2.0542
A
3
15
2.0534
A
4
14
1.8819
B
5
14
1.7356
C
Means with the same letter are not significantly different.
Alpha = 0.05
I
df = 54
i
i
2
i
----------------------- + — — -------1—
Critical Range
j 0.0983 j
Number of Means
MSE = 0.017521
i
i
3
!
0.1181
j
4
!
5
0.1299
j
0.1383
— — —+ — ------
79
T a b le 38.
S tu d e n t-N e w m a n -K e u ls m e a n s s e p a ra tio n te s ts fo r b o re h o le c o p p e r
m e a n s (w e ig h te d , Iog10 tra n s fo rm e d d a ta ).
1
Borehole
N
Transformed Mean
SNK Grouping
4
5
2.4472
A1
3
5
2.2518
B
5
5
2.1134
BC
2
5
2.0051
CD
12
5
1.9783
CDE
I
5
1.9780
CDE
15
4
1.9424
CDE
13
5
1.9237
CDE
6
5
1.9108
CDE
14
5
1.9059
CDE
11
5
1.8526
CDE
9
4
1.8443
CDE
10
5
1.7884
DE
7
5
1.7540
DE
8
5
1.6936
E
Means with the same letter are not significantly different.
Alpha = 0.05
•
Number of Means
I
df = 54
i
2
!
MSE = 0.017521
I
3
I
I
4
I
5
!
6
------------------- 1----- ——H-------- —+---- -----—+------ —+------—
Critical Range
j 0.1706 j 0.2051 j 0.2256 j 0.2402 j 0.2514
Number of Means
!
7
I
8
I
9
!
10
I
11
--------- -------- 1-------- —4---------- -+—------—4-------- —4-------- Critical Range
j 0.2606 I 0.2683 j 0.2749 | 0.2808 | 0.2859
Number of Means
I
12
I
13
I
14
I 15
--------------- --- I---- ----—H--- --------H—--------- 1--- ----—H
Critical Range
j 0.2906 j 0.2949 j 0.2987 j 0.3023
80
T a b le 39.
A n aly sis o f v a ria n c e fo r iro n (w e ig h te d , Iog10 tra n s fo rm e d d a ta ).
D e p e n d e n t V a ria b le : IR O N
Source
DF
Sum of
Squares
Mean
Square
Model
Error
Corrected Total
18
54
72
1.0212741
2.1967981
3.2180722
0.0567374
0.0406814
R-Square
0.317356
Source
C.V.
8.548673
DF
DEPTH
BOREHOLE
Table 40.
Root MSE
0.2017
Type III SS
4
14
0.4564189
0.5284874
F Value
Pr > F
1.39
0.1724
IRON Mean
2.3594
Mean Square
F Value
Pr > F
0.1141047
0.0377491
2.80
0.93
0.0345
0.5358
Analysis of variance for nickel (weighted, Iog10 transformed data).
Dependent Variable: NICKEL
Source
DF
Sum of
Squares
Model
Error
Corrected Total
18
54
72
2.4619855
2.4450649
4.9070504
C.V.
11.83867
R-Square
0.501724
Source
DEPTH
BOREHOLE
DF
4
14
Mean
Square
0.1367770
0.0452790
Root MSE
0.2128
Type III SS
1.2189305
1.1185310
F Value
Pr > F
3.02
0.0009
NICKEL Mean
1.7974
Mean Square
F Value
Pr > F
0.3047326
0.0798951
6.73
1.76
0.0002
0.0693
81
T a b le 41.
S tu d e n t-N e w m a n -K e u ls m e a n s s e p a ra tio n te sts fo r d e p th n ic k el m e a n s
(w e ig h te d , Iog10 tra n s fo rm e d d a ta ) .
1
Depth
N
Transformed Mean
SNK Grouping
2
15
2.0513
A1
I
15
1.9679
AB
4
14
1.8057
B
3
15
1.7830
B
5
14
1.4471
C
Means with the same letter are not significantly different.
Alpha = 0.05
df = 54
I
I
MSE = 0.045279
I
I
S
2
S
3
!
4
S
5
—--- ----------- -4---- ------- 1------ -----4----------—f —----Critical Range
j 0.1580 j 0.1899 j 0.2089 j 0.2224
Number of Means
Table 42.
Analysis of variance for zinc (weighted, Iog10 transformed data).
Dependent Variable: ZINC
Source
DF
Sum of
Squares
Model
Error
Corrected Total
18
54
72
0.5369455
0.9080027
1.4449482
R-Square
0.371602
Source
DEPTH
BOREHOLE
C.V.
6.160244
DF
4
14
Mean
Square
0.0298303
0.0168149
Root MSE
0.1297
Type III SS
0.0604987
0.4642185
F Value
Pr > F
1.77
0.0540
ZINC Mean
2.1050
Mean Square
F Value
Pr > F
0.0151247
0.0331585
0.90
1.97
0.4708
0.0383
82
I
T a b le 43.
L in e a r re g re ss io n o f p o r e w a te r to ta l cy an id e d a ta fro m b o re h o le 4,
K e n d a ll H e a p L e a c h P a d N o . I.
Observation
Number
Sampling
Date
Time
(Days)
I
2
3
4
5
6
7
8
9
10
11
3/19/92
4/25/92
5/07/92
5/20/92
6/06/92
6/21/92
7/09/92
7/24/92
8/09/92
8/23/92
9/06/92
0
37
49
62
77
92
HO
125
141
155
169
Total Cyanide
Level (mg I'1)
0.48
0.69
0.76
0.96
0.94
0.99
0.97
1.08
1.14
0.64
1.99
Number of points = 11
P aram eter
Expected
V alue
Standard
Error
Lower
95% C l
Upper
95% C l
Slope
0.00497
0.00184
0.00081
0.00913
Y intercept
0.50790
0.19400
0.06915
0.94660
X intercept
-102.22
Correlation coefficient (r) = 0.6690. r squared = 0.4475.
Standard deviation of residuals from line (Sy.x) = 0.3089.
Test: Is the slope significantly different from zero?
F = 7.290
The p value is 0.0244, considered significant.
This result was obtained from the following ANOVA table:
S ou rce o f variation
D egrees
o f freedom
Sum o f
squares
M ean
square
Linear regression (Model)
I
0.6955
0.6955
Deviations from linearity (Residual)
9
0.8587
0.0954
Total
10
1.5542
Runs test: Do the number of runs indicate a linear model?
There are 5 points above the line, 6 below, and 4 runs.
The p value is 0.1104, considered not significant.
There is not a significant departure from linearity.
83
T a b le 44.
L in e a r re g re s s io n o f p o r e w a te r to ta l c y an id e d a ta fro m b o re h o le 8,
K e n d a ll H e a p L e a c h P a d N o . I .
Observation
Number
Sampling
Date
Time
(Days)
1
3/19/92
4/10/92
4/25/92
5/07/92
5/20/92
6/06/92
6/21/92
7/09/92
7/24/92
8/09/92
8/23/92
9/06/92
0
22
37
49
62
77
92
no
125
141
155
169
2
3
4
5
6
7
8
9
10
11
12
Total Cyanide
Level (mg I"1)
0.69
0.88
0.41
0.33
0.36
0.40
0.44
0.55
0.55
0.52
0.35
0.41
Number of points = 12
Parameter
Expected
V alue
Standard
E rror
Lower
95% C l
Upper
95% C l
Slope
-0.00121
0.00085
-0.00311
0.00069
Y intercept
0.59550
0.08620
0.40350
0.78760
X intercept
492.53
Correlation coefficient (r) = -0.4092. r squared = 0.1675.
Standard deviation of residuals from line (Sy.x) = 0.1542.
Test: Is the slope significantly different from zero?
F = 2.011
The p value is 0.1865, considered not significant.
This result was obtained from the following ANOVA table:
S ou rce o f variation
D egrees
o f freedom
Sum o f
squares
M ean
square
Linear regression (Model)
I
0.0478
0.0478
Deviations from linearity (Residual)
10
0.2379
0.0238
Total
11
0.2857
Runs test: Do the number of runs indicate a linear model?
There are 6 points above the line, 6 below, and 5 runs.
The p value is 0.1753, considered not significant.
There is not a significant departure from linearity.
84
T a b le 45.
L in e a r re g re s s io n o f p o r e w a te r W A D cy an id e d a ta fro m b o re h o le 4,
K e n d a ll H e a p L e a c h P a d N o . I.
Observation
Number
Sampling
Date
Time
(Days)
I
2
3
4
5
6
7
8
9
10
11
3/19/92
4/25/92
5/07/92
5/20/92
6/06/92
6/21/92
7/09/92
7/24/92
8/09/92
8/23/92
9/06/92
0
37
49
62
77
92
no
125
141
155
169
WAD Cyanide
Level (mg I"1)
0.07
0.12
0.15
0.15
0.17
0.14
0.15
0.19
0.31
0.15
0.19
Number of points = 11
Parameter
Expected
Value
Standard
Error
Lower
95% Cl
Upper
95% Cl
Slope
0.00074
0.00028
0.00012
0.00137
Y intercept
0.09418
0.02910
0.02835
0.16000
X intercept
-127.04
Correlation coefficient (r) = 0.6669. r squared = 0.4447.
Standard deviation of residuals from line (Sy.x) = 0.0464.
Test: Is the slope significantly different from zero?
F = 7.208
The p value is 0.0250, considered significant.
This result was obtained from the following ANOVA table:
Source of variation
Degrees
of freedom
Sum of
squares
Mean
square
Linear regression (Model)
I
0.0155
0.0155
Deviations from linearity (Residual)
9
0.0193
0.0021
Total
10
0.0348
Runs test: Do the number of runs indicate a linear model?
There are 5 points above the line, 6 below, and 5 runs.
The p value is 0.2619, considered not significant.
There is not a significant departure from linearity.
85
T a b le 46.
L in e a r re g re ss io n o f p o r e w a te r W A D c y an id e d a ta fro m b o re h o le 8,
K e n d a ll H e a p L e a c h P a d N o . I.
Observation
Number
Sampling
Date
Time
(Days)
I
2
3
4
5
6
7
8
9
10
3/19/92
4/10/92
4/25/92
5/07/92
5/20/92
6/06/92
6/21/92
7/09/92
7/24/92
8/23/92
0
22
37
49
62
77
92
HO
125
155
WAD Cyanide
Level (mg I"1)
0.05
0.06
0.06
0.04
0.05
0.05
0.05
0.06
0.07
0.03
Number of points = 10
Parameter
Expected
Value
Standard
Error
Lower
95% Cl
Upper
95% Cl
Slope
-4.067 E-05
8.165 E-05
-0.00023
0.00015
Y intercept
0.05496
0.00704
0.03874
0.07119
X intercept
1351.50
Correlation coefficient (r) = -0.1734. r squared = 0.0301.
Standard deviation of residuals from line (Sy.x) = 0.0119.
Test: Is the slope significantly different from zero?
F = 0.2481
The p value is 0.6318, considered not significant.
This result was obtained from the following ANOVA table:
Source of variation
Degrees
of freedom
Sum of
squares
Mean
square
Linear regression (Model)
I
3.489 E-05
3.489 E-05
Deviations from linearity (Residual)
8
0.0011
0.0001
Total
9
0.0012
Runs test: Do the number of runs indicate a linear model?
There are 4 points above the line, 6 below, and 5 runs.
The p value is 0.4048, considered not significant.
There is not a significant departure from linearity.
86
T a b le 47.
L in e a r re g re s s io n o f p o r e w a te r p H d a ta fro m b o re h o le 4, K e n d a ll
H e a p L e a c h P a d N o . I.
Observation
Number
Sampling
Date
Time
(Days)
pH
I
2
3
4
5
6
7
8
9
10
11
12
3/19/92
4/10/92
4/25/92
5/07/92
5/20/92
6/06/92
6/21/92
7/09/92
7/24/92
8/09/92
8/23/92
9/06/92
0
22
37
49
62
77
92
HO
125
141
155
169
6.8
6.7
6.5
7.4
7.6
7.7
7.1
6.8
7.8
6.4
7.8
7.6
Number of points = 12
Parameter
Expected
V alue
Standard
Error
Lower
95% C l
Upper
95% C l
Slope
0.00376
0.00280
-0.00249
0.01001
Y intercept
6.85800
0.28360
6.22600
7.48900
X intercept
-1822.70
Correlation coefficient (r) = 0.3906. r squared = 0.1525.
Standard deviation of residuals from line (Sy.x) = 0.5073.
Test: Is the slope significantly different from zero?
F = 1.800
The p value is 0.2094, considered not significant.
This result was obtained from the following ANOVA table:
S ou rce o f variation
D egrees
o f freedom
Sum o f
squares
M ean
square
Linear regression (Model)
I
0.4632
0.4632
Deviations from linearity (Residual)
10
2.5730
0.2573
Total
11
3.0362
Runs test: Do the number of runs indicate a linear model?
There are 6 points above the line, 6 below, and 6 runs.
The p value is 0.3918, considered not significant.
There is not a significant departure from linearity.
87
T a b le 48.
L in e a r re g re s s io n o f p o r e w a te r p H d a ta fro m b o re h o le 8, K e n d a ll
H e a p L e a c h P a d N o . I.
Observation
Number
Sampling
Date
Time
(Days)
pH
I
2
3
4
5
6
7
8
9
10
11
12
3/19/92
4/10/92
4/25/92
5/07/92
5/20/92
6/06/92
6/21/92
7/09/92
7/24/92
8/09/92
8/23/92
9/06/92
0
22
37
49
62
77
92
HO
125
141
155
169
6.7
6.7
6.6
7.3
7.4
7.4
7.2
7.2
7.4
6.4
8.0
7.5
Number of points = 12
Parameter
Expected
V alue
Standard
E rror
Lower
95% C l
Upper
95% C l
Slope
0.00423
0.00231
-0.00092
0.00937
Y intercept
6.78400
0.23350
6.26400
7.30400
X intercept
-1604.60
Correlation coefficient (r) = 0.5010. r squared = 0.2510.
Standard deviation of residuals from line (Sy.x) = 0.4177.
Test: Is the slope significantly different from zero?
F = 3.352
The p value is 0.0970, considered not quite significant.
This result was obtained from the following ANOVA table:
S ource o f variation
D egrees
o f freedom
Sum o f
sq u ares
M ean
square
Linear regression (Model)
I
0.5849
0.5849
Deviations from linearity (Residual)
10
1.7450
0.1745
Total
11
2.3299
Runs test: Do the number of runs indicate a linear model?
There are 7 points above the line, 5 below, and 6 runs.
The p value is 0.4242, considered not significant.
There is not a significant departure from linearity.
88
T a b le 49.
L in e a r re g re s s io n o f p o r e w a te r c a d m iu m d a ta fro m b o re h o le 4,
K e n d a ll H e a p L e a c h P a d N o . I.
Observation
Number
Sampling
Date
Time
(Days)
I
2
3
4
5
6
7
8
9
10
4/10/92
4/25/92
5/07/92
5/20/92
6/06/92
6/21/92
7/09/92
7/24/92
8/09/92
8/23/92
22
37
49
62
77
92
no
125
141
155
Cadmium
Level ( j i g I"1)
33
26
26
20
26
33
26
33
26
26
Number of points = 10
Parameter
Expected
V alue
Standard
Error
Lower
95% C l
Upper
95% C l
Slope
-0.00022
0.03299
-0.07630
0.07586
Y intercept
27.51900
3.20100
20.13800
34.9000
X intercept
126807.00
Correlation coefficient (r) = -0.0023. r squared = 5.408 E-06.
Standard deviation of residuals from line (Sy.x) = 4.4790.
Test: Is the slope significantly different from zero?
F = 4.327 E-05
The p value is 0.9949, considered not significant.
This result was obtained from the following ANOVA table:
S ou rce o f variation
D egrees
o f freedom
Sum o f
sq u ares
M ean
square
Linear regression (Model)
I
0.0009
0.0009
Deviations from linearity (Residual)
8
160.5000
20.062
Total
9
160.5009
Runs test: Do the number of runs indicate a linear model?
There are 3 points above the line, 7 below, and 6 runs.
The p value is 0.8333, considered not significant.
There is not a significant departure from linearity.
89
T a b le 50.
L in e a r re g re s s io n o f p o r e w a te r c a d m iu m d a ta fro m b o re h o le 8,
K e n d a ll H e a p L e a c h P a d N o . I.
Observation
Number
Sampling
Date
Time
(Days)
I
2
3
4
5
6
7
8
9
10
4/10/92
4/25/92
5/07/92
5/20/92
6/06/92
6/21/92
7/09/92
7/24/92
8/09/92
8/23/92
22
37
49
62
77
92
no
125
141
155
Cadmium
Level Og I"1)
66
26
20
26
26
26
33
33
33
26
Number of points = 10
Parameter
Expected
Value
Standard
Error
Lower
95% Cl
Upper
95% Cl
Slope
-0.08502
0.09559
-0.30540
0.13540
Y intercept
38.89600
9.27300
17.51200
60.28100
X intercept
457.52
Correlation coefficient (r) = -0.3000. r squared = 0.0900.
Standard deviation of residuals from line (Sy.x) = 12.9770.
Test: Is the slope significantly different from zero?
F = 0.7910
The p value is 0.3997, considered not significant.
This result was obtained from the following ANOVA table:
Source of variation
Degrees
of freedom
Sum of
squares
Mean
square
Linear regression (Model)
I
133.2200
133.2200
Deviations from linearity (Residual)
8
1347.3000
168.4100
Total
9
1480.5200
Runs test: Do the number of runs indicate a linear model?
There are 5 points above the line, 5 below, and 3 runs.
The p value is 0.0397, considered significant.
There are significantly fewer runs than expected, suggesting that the data follow a curve rather than
a line.
90
T a b le 51.
L in e a r re g re s s io n o f p o re w a te r c o p p e r d a ta fro m b o re h o le 4,
K e n d a ll H e a p L e a c h P a d N o . I.
Observation
Number
Sampling
Date
Time
(Days)
I
2
3
4
5
6
7
8
9
10
4/10/92
4/25/92
5/07/92
5/20/92
6/06/92
6/21/92
7/09/92
7/24/92
8/09/92
8/23/92
22
37
49
62
77
92
no
125
141
155
Copper
Level ( f i g I'1)
48
19
38
87
0
0
29
0
0
0
Number of points = 10
P aram eter
Expected
V alue
Standard
Error
Lower
95% C l
Upper
95% C l
Slope
-0.38100
0.18340
-0.80390
0.04195
Y intercept
55.24400
17.79300
14.21400
96.27400
X intercept
145.01
Correlation coefficient (r) = -0.5919. r squared = 0.3504.
Standard deviation of residuals from line (Sy.x) = 24.8990.
Test: Is the slope significantly different from zero?
F = 4.315
The p value is 0.0714, considered not quite significant.
This result was obtained from the following ANOVA table:
S ource o f variation
D egrees
o f freedom
Sum o f
sq u ares
M ean
square
Linear regression (Model)
I
2675.20
2675.20
Deviations from linearity (Residual)
8
4959.70
619.97
Total
9
7634.90
Runs test: Do the number of runs indicate a linear model?
There are 5 points above the line, 5 below, and 7 runs.
The p value is 0.8333, considered not significant.
There is not a significant departure from linearity.
91
T a b le 52.
L in e a r re g re s s io n o f p o r e w a te r c o p p e r d a ta fro m b o re h o le 8,
K e n d a ll H e a p L e a c h P a d N o . I.
Observation
Number
Sampling
Date
Time
(Days)
I
2
3
4
5
6
7
8
9
10
4/10/92
4/25/92
5/07/92
5/20/92
6/06/92
6/21/92
7/09/92
7/24/92
8/09/92
8/23/92
22
37
49
62
77
92
HO
125
141
155
Copper
Level (/ig I"1)
67
29
19
9
38
29
19
19
0
9
Number of points = 10
Parameter
Expected
V alue
Standard
E rror
Lower
95% C l
Upper
95% C l
Slope
-0.28300
0.10800
-0.53200
-0.03397
Y intercept
48.4200
10.47700
24.26100
72.57900
X intercept
171.10
Correlation coefficient (r) = -0.6796. r squared = 0.4619.
Standard deviation of residuals from line (Sy.x) = 14.6610.
Test: Is the slope significantly different from zero?
F = 6.867
The p value is 0.0306, considered significant.
This result was obtained from the following ANOVA table:
Source of variation
Degrees
of freedom
Sum of
squares
Mean
square
Linear regression (Model)
I
1476.10
1476.10
Deviations from linearity (Residual)
8
1719.50
214.94
Total
9
3195.60
Runs test: Do the number of runs indicate a linear model?
There are 6 points above the line, 4 below, and 5 runs.
The p value is 0.4048, considered not significant.
There is not a significant departure from linearity.
92
T a b le 53.
L in e a r re g re s s io n o f p o re w a te r iro n d a ta fro m b o re h o le 4, K e n d a ll
H e a p L e a c h P a d N o. I.
Observation
Number
Sampling
Date
Time
(Days)
Iron
Level (/Ag I 1)
I
2
3
4
5
6
7
8
9
4/10/92
4/25/92
5/07/92
6/06/92
6/21/92
7/09/92
7/24/92
8/09/92
8/23/92
22
37
49
77
92
HO
125
141
155
649
375
1134
537
862
500
458
575
500
Number of points = 9
Parameter
Expected
V alue
Standard
Error
Lower
95% C l
Upper
95% C l
Slope
-1.5030
1.8120
-5.7880
2.7810
Y intercept
756.0500
181.4400
326.9400
1185.2000
X intercept
503.01
Correlation coefficient (r) = -0.2992. r squared = 0.0895.
Standard deviation of residuals from line (Sy.x) = 241.28.
Test: Is the slope significantly different from zero?
F = 0.6884
The p value is 0.4341, considered not significant.
This result was obtained from the following ANOVA table:
S ou rce o f variation
D egrees
o f freedom
Sum o f
sq u ares
M ean
square
Linear regression (Model)
I
40073.0
40073.0
Deviations from linearity (Residual)
7
407500.0
58214.0
Total
8
447573.0
Runs test: Do the number of runs indicate a linear model?
There are 3 points above the line, 6 below, and 7 runs.
The p value is 1.0000, considered not significant.
There is not a significant departure from linearity.
93
T a b le 54.
L in e a r re g re ss io n o f p o r e w a te r iro n d a ta fro m b o re h o le 8, K e n d a ll
H e a p L e a c h P a d N o . I.
Observation
Number
Sampling
Date
Time
(Days)
Iron
Level Og I"1)
I
2
3
4
5
6
7
8
9
10
4/10/92
4/25/92
5/07/92
5/20/92
6/06/92
6/21/92
7/09/92
7/24/92
8/09/92
8/23/92
22
37
49
62
77
92
HO
125
141
155
757
416
416
208
458
291
125
208
125
612
Parameter
Expected
Value
Standard
Error
Lower
95% Cl
Upper
95% Cl
Slope
-1.8980
1.5000
-5.3580
1.5610
Y intercept
526.7700
145.5600
191.1000
862.4400
X intercept
277.47
Number of points = 10
Correlation coefficient (r) = -0.4084. r squared = 0.1668.
Standard deviation of residuals from line (Sy.x) = 203.70.
Test: Is the slope significantly different from zero?
F = 1.601
The p value is 0.2414, considered not significant.
This result was obtained from the following ANOVA table:
Source of variation
Degrees
of freedom
Sum of
squares
Mean
square
Linear regression (Model)
I
66434.0
66434.0
Deviations from linearity (Residual)
8
331948.0
41494.0
Total
9
398382.0
Runs test: Do the number of runs indicate a linear model?
There are 3 points above the line, 7 below, and 5 runs.
The p value is 0.5833, considered not significant.
There is not a significant departure from linearity.
94
T a b le 55.
L in e a r re g re s s io n o f p o r e w a te r n ic k el d a ta fro m b o re h o le 4,
K e n d a ll H e a p L e a c h P a d N o . I.
Observation
Number
Sampling
Date
Time
(Days)
Nickel
Level (jug I"1)
I
2
3
4
5
6
7
8
9
10
4/10/92
4/25/92
5/07/92
5/20/92
6/06/92
6/21/92
7/09/92
7/24/92
8/09/92
8/23/92
22
37
49
62
77
92
no
125
141
155
152
108
86
86
65
108
65
65
65
43
Number of points = 10
P aram eter
Expected
V alue
Standard
Error
Lower
95% C l
Upper
95% C l
Slope
-0.5647
0.1433
-0.8953
-0.2342
Y intercept
133.4300
13.9070
101.3600
165.5000
X intercept
236.28
Correlation coefficient (r) = -0.8123. r squared = 0.6599.
Standard deviation of residuals from line (Sy.x) = 19.46.
Test: Is the slope significantly different from zero?
F = 15.521
The p value is 0.0043, considered very significant.
This result was obtained from the following ANOVA table:
S ou rce o f variation
D egrees
o f freedom
Sum o f
squares
M ean
square
Linear regression (Model)
I
5878.20
5878.20
Deviations from linearity (Residual)
8
3029.90
378.74
Total
9
8908.10
Runs test: Do the number of runs indicate a linear model?
There are 4 points above the line, 6 below, and 6 runs.
The p value is 0.6905, considered not significant.
There is not a significant departure from linearity.
95
T a b le 56.
L in e a r re g re s s io n o f p o r e w a te r n ic k el d a ta fro m b o re h o le 8,
K e n d a ll H e a p L e a c h P a d N o . I.
Observation
Number
Sampling
Date
Time
(Days)
Nickel
Level Og I"1)
I
2
3
4
5
6
7
8
9
10
4/10/92
4/25/92
5/07/92
5/20/92
6/06/92
6/21/92
7/09/92
7/24/92
8/09/92
8/23/92
22
37
49
62
77
92
no
125
141
155
130
43
86
65
108
43
86
65
86
65
Number of points = 10
Parameter
Expected
V alue
Standard
Error
Lower
95% C l
Upper
95% C l
Slope
-0.1544
0.2069
-0.6315
0.3277
Y intercept
91.1330
20.0730
44.8440
137.4200
X intercept
590.22
Correlation coefficient (r) = -0.2551. r squared = 0.0651.
Standard deviation of residuals from line (Sy.x) = 28.09.
Test: Is the slope significantly different from zero?
F = 0.5569
The p value is 0.4769, considered not significant.
This result was obtained from the following ANOVA table:
S ou rce o f variation
D egrees
o f freedom
Sum o f
sq u ares
M ean
square
Linear regression (Model)
I
439.44
439.44
Deviations from linearity (Residual)
8
6312.70
789.08
Total
9
6752.14
Runs test: Do the number of runs indicate a linear model?
There are 5 points above the line, 5 below, and 10 runs.
The p value is 1.0000, considered not significant.
There is not a significant departure from linearity.
96
T a b le 57.
L in e a r re g re s s io n o f p o r e w a te r zin c d a ta fro m b o re h o le 4, K e n d a ll
H e a p L e a c h P a d N o. I.
Observation
Number
Sampling
Date
Time
(Days)
Zinc
Level (/xg I 1)
I
2
3
4
5
6
7
8
4/10/92
4/25/92
5/07/92
5/20/92
6/06/92
6/21/92
7/09/92
7/24/92
22
37
49
62
77
92
HO
125
442
97
299
75
32
245
372
140
Number of points = 8
Parameter
Expected
V alue
Slope
-0.6733
Y intercept
261.0600
X intercept
387.75
Lower
95% C l
Upper
95% C l
1.6780
-4.7800
3.4340
132.9700
-64.3200
586.4300
Standard
Error
Correlation coefficient (r) = -0.1616. r squared = 0.0261.
Standard deviation of residuals from line (Sy.x) = 159.50.
Test: Is the slope significantly different from zero?
F = 0.1609
The p value is 0.7022, considered not significant.
This result was obtained from the following ANOVA table:
S ou rce o f variation
D egrees
o f freedom
Sum o f
sq u ares
M ean
square
Linear regression (Model)
I
4093.70
4093.70
Deviations from linearity (Residual)
6
152638.00
25440.0
Total
7
156731.70
Runs test: Do the number of runs indicate a linear model?
There are 4 points above the line, 4 below, and 6 runs.
The p value is 0.8857, considered not significant.
There is not a significant departure from linearity.
97
T a b le 58.
L in e a r re g re s s io n o f p o r e w a te r zinc d a ta fro m b o re h o le 8, K e n d a ll
H e a p L e a c h P a d N o . I.
Observation
Number
Sampling
Date
Time
(Days)
Zinc
Level (fig I"1)
I
2
3
4
5
6
7
8
4/25/92
5/07/92
5/20/92
6/06/92
6/21/92
7/09/92
8/09/92
8/23/92
37
49
62
77
92
no
141
155
420
194
215
311
406
500
240
256
Number of points = 8
Standard
Error
Lower
95% C l
Upper
95% C l
P aram eter
Expected
V alue
Slope
-0.1214
1.0700
-2.7400
2.4970
Y intercept
328.7200
105.6600
70.1660
587.2800
X intercept
2708.00
Correlation coefficient (r) = -0.0463. r squared = 0.0021.
Standard deviation of residuals from line (Sy.x) = 120.45.
Test: Is the slope significantly different from zero?
F = 0.0129
The p value is 0.9134, considered not significant.
This result was obtained from the following ANOVA table:
S ource o f variation
D egrees
o f freedom
Sum o f
squares
M ean
square
Linear regression (Model)
I
186.73
186.73
Deviations from linearity (Residual)
6
87047.00
14508.00
Total
7
87233.73
Runs test: Do the number of runs indicate a linear model?
There are 3 points above the line, 5 below, and 4 runs.
The p value is 0.4286, considered not significant.
There is not a significant departure from linearity.
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