Iron Ore
152-158 St Georges Terrace
Perth 6000
Western Australia
T + 61 (8) 9327 2000
Memo
From
Steven Lee
Department
Development and Technical Projects
To
Melinda Brand
CC
Rosalind Green
Reference
Yandi Geochemistry
Date
08 February 2012
Number of pages
16
Preliminary results of geochemical characterisation of
Yandicoogina samples
Purpose and Scope
This memo summarises the results of preliminary solid extra element analysis, short
term liquid extract/leach testing and phase 1 acid base accounting (ABA) completed on
samples obtained from the Yandi Junction South West (JSW) drilling programme
completed in June 2011 and grab samples selected by mine geology in 2009 and 2011
from Junction Central (JC) and Junction South East (JSE) (Appendix 1). This follows on
from grab samples collected from the active JC and JSE pits. This sampling was
undertaken to comply with the RTIO Mineral Waste Management Plan.
A total of 274 samples were sent off for solid geochemistry and 188 underwent short
term leach testing.
Material representing the following strand-tag groups were collected for analysis:
• Alluvials (ALL);
• Basal clay conglomerate (BCC);
• Eastern clay conglomerate (ECC);
• Goethite vitreous lower (GVL);
• Goethite vitreous upper (GVU);
• Limonitic goethite CID (LGC);
• Weathered CID (WCH); and
• Weeli Wolli Formation (WW).
More detailed descriptions of these strand-tag groups are given in Appendix 3.
Methodology
In 2009 and in 2011 Mine geology collected 40 grab samples from JC and JSE. These
samples were opportunistically selected from areas where mining was occurring
covering material that is representative of ALL, BCC, ECC, GVL, GVU, LGC, WCH and
WW. The 2009 samples were dispatched to Ultra Trace laboratory in Canning Vale for
the solid extra element and short term liquid extract tests. The solid extra element
analysis included Ag, B, Be, Cd, F, Hg, Mo, Se, Th and U. The 2011 samples were
dispatched to ALS Chemex in Malaga for solid geochemical analysis and liquid extracts
and phase 1 ABA testing.
Continues
Page 2 of 16
The Grab samples have been taken from Junction Central and Junction South East
specifically Phil’s Creek, Hairpin North, Waterstand North, Marsh North and South and
Union North and Central (Appendix 1).
During March through to April 2011, RC drilling was undertaken by Resource Geology
Evaluation on the Yandi Junction SW deposit. Samples were selected at random from
the strand-tag groups representing ALL, BCC, ECC, GVL, GVU, LGC, WCH and WW.
These samples were sent to the Ultra Trace laboratory in Canning Vale for analysis of
Fe, Si, Al, P, Ti, Ca, Mg, K, As, Ba, Cl, Co, Cr, Cu, Na, Ni, Pb, Sn, Sr, V, Zn, Zr, S and
Loss on ignition. Once the results were received strand-tag interpretation was
completed for the drillholes and intervals were selected to undergo extra element solid
analysis and short term liquid extract/leach test (for details of the test methods see
Appendix 2). Additional to this, 33 samples underwent phase 1 acid base accounting
(ABA) testwork (AMIRA, 2002) including acid neutralising capacity (ANC) and net acid
generation (NAG) tests at ALS Chemex.
Results
The median solid geochemistry assay for each element is compared against the mean
crustal abundances outlined in Bowen (1979). From this the global abundance index
can be calculated to determine to what level an element is either elevated or enriched
compared to these crustal abundances. Table 1 below summarises the results and the
full details are included in Appendix 4. Results indicate:
• All strand-tag units are either enriched or elevated in Fe, As and Sn;
• ECC contains elevated V;
• WW contains elevated Sb; and
• The grab samples contain elevated levels of Ba and Se.
Table 1 Summary of GAI values for enriched and elevated elements for Yandi
samples
Elevated
Elevated (GAI ≥ 3)
Strand-tag
(GAI = 1 or
Group
Fe
As
2)
ALL
BCC
ECC
GVL
GVU
LGC
WCH
WW
GRAB
3
3
3
3
3
3
3
3
3
4
4
3
3
3
3
Fe,Sn
Fe, Sn
Fe,Sn,V
Sn
Sn
Sn
Sn
Sn,Sb
Ba,Sn,Se
Although these elements are either enriched or elevated that does not necessarily mean
the element may mobilise upon contact with water. The results of the short term leach
tests are given in Table 2.
These results have been compared against both background ground water (taken from
mean value + 10% from Yandi water bores) and ANZECC water trigger values for
Aquatic ecosystems (due to the presence of stygofauna and other aquatic animals).
These have been highlighted in the table (where the lower detection limit is greater than
the trigger value this also has been highlighted). The elements that exceed these values
include: Ag, As, Cr, Cu, F, Hg, Ni and Pb. In the majority of cases the exceedance is
due to the fact that the trigger value is less than the lower detection limit. Full details of
the comparison are given in Appendix 4.
Continues
Page 3 of 16
Table 2 Summary of short term leach test data (median values used)
Lower
Detection
Limit
pH_LIQUID
0.1
SO4_ICP_mg_L
0.2
EC_LIQUID µS/cm 50
ALK_LIQUID
20
HCO3_mg_L
20
AG_ICP_mg_L
0.001
AL_ICP_mg_L
0.01
AS_ICP_mg_L
0.005
BA_ICP_mg_L
0.01
B_ICP_mg_L
0.01
CA_ICP_mg_L
0.05
CD_ICP_mg_L
0.0002
CL_COL_mg_L
2
CO_ICP_mg_L
0.01
CR_ICP_mg_L
0.002
CU_ICP_mg_L
0.002
F_SIE_mg_L
1
FE_ICP_mg_L
0.01
HG_FIMS_mg_L
0.001
K_ICP_mg_L
0.1
MG_ICP_mg_L
0.01
MN_ICP_mg_L
0.01
MO_ICP_mg_L
0.005
NA_ICP_mg_L
0.1
NI_ICP_mg_L
0.01
PB_ICP_mg_L
0.01
SE_ICP_mg_L
0.005
SB_ICP_mg_L
0.001
U_ICP_mg_L
0.001
ZN_ICP_mg_L
0.005
Element/oxide_
Analysis_Units
ALL
BCC
ECC
GVL
GVU
LGC
WCH
WW
6.8
8.4
132
40
40
0.001
0.22
0.005
0.03
0.1
9.3
0.0002
10
0.01
0.002
0.005
1
0.18
0.001
5.5
3.8
0.02
0.001
6.8
0.01
0.01
0.005
0.001
0.001
0.01
6.7
6.5
74.5
20
20
0.001
0.105
0.005
0.01
0.13
1.3
0.0002
13
0.01
0.002
0.002
1
0.255
0.001
1.45
1.455
0.01
0.005
12.45
0.01
0.01
0.005
0.001
0.001
0.005
7.2
12.2
265
80
80
0.001
0.05
0.005
0.03
0.31
11.8
0.0002
16
0.01
0.002
0.002
1
0.07
0.001
3.4
9.1
0.01
0.005
25.2
0.01
0.01
0.005
0.001
0.001
0.005
6.9
11.2
107
20
20
0.001
0.01
0.005
0.01
0.09
3.35
0.0002
10
0.01
0.002
0.002
1
0.07
0.001
1.7
3.48
0.01
0.005
12.5
0.01
0.01
0.005
0.001
0.001
0.005
6.8
11.8
109
20
20
0.001
0.01
0.005
0.01
0.09
3.45
0.0002
10
0.01
0.002
0.002
1
0.03
0.001
2.1
2.83
0.01
0.005
8.5
0.01
0.01
0.005
0.001
0.001
0.005
6.8
19.2
235
20
20
0.001
0.2
0.005
0.01
0.12
7.4
0.0002
40
0.01
0.002
0.004
1
0.14
0.001
2.1
7.33
0.01
0.005
28.7
0.01
0.01
0.005
0.001
0.001
0.005
6.5
15
131
20
20
0.001
0.04
0.005
0.02
0.12
4.7
0.0002
10
0.01
0.002
0.002
1
0.08
0.001
2.4
2.52
0.01
0.005
14.2
0.01
0.01
0.005
0.001
0.001
0.005
6.8
4.8
84.5
20
20
0.001
0.03
0.005
0.01
0.11
2.525
0.0002
16
0.01
0.002
0.002
1
0.07
0.001
1.4
2.56
0.01
0.005
11.95
0.01
0.01
0.005
0.001
0.001
0.005
Continues
Page 4 of 16
A total of 85 Grab and drillhole samples were also sent to ALS Chemex for phase 1
ABA testing. The results are summarised in Table 3. Total sulfur was analysed using
the LECO method and gave results ranging from below the detection limit of 0.01%
through to the maximum of 0.1%. The calculated maximum potential acidity (MPA) for
these samples range from less than 0.306 kg H2SO4/t through to 3.06 kg H2SO4/t.
The lowest acid neutralisation capacity measured for these samples was <0.5 kg
H2SO4/t through to a maximum of 145. In most cases the neutralising capacity of the
samples was quite low. The results of the single addition NAG test ranged from pH 5.4
to 10.9, with an average of around pH 6.8. All these results indicate that the samples
that have undergone phase 1 ABA testing are non-acid forming (NAF) and in most
cases there is excess neutralising capacity to neutralise all of the acid that may be
generated by the sample.
Table 3 Summary statistics of phase 1 ABA testing
Unit
Measure
Mean
Minimum
Maximum
Median
Total S (LECO)
MPA
ANC
NAG
%
0.02
<0.01
0.1
0.01
kg H2SO4/t
0.612
<0.306
3.06
0.306
kg H2SO4/t
7.77
<0.5
145
1.3
pH
6.89
5.4
10.9
6.7
of
Conclusions and Recommendations
The results indicate that soluble metals/metalloids are generally below the trigger values
outlined in the ANZECC water guidelines and Yandi background water values. Where
there are exceedances, the trigger values (normally associated with ANZECC water
guidelines for 95% protection of freshwater species) were lower than the detection limits
used in the analysis. All samples were above drinking water trigger values and stock
water guideline trigger values.
Continues
Page 5 of 16
References
AMIRA International. (2002). ARD Test Handbook. Project P387A Prediction and
Kinetic Control of Acid Mine Drainage, Ian Wark Research Institute and Environmental
Geochemistry International Pty Ltd.
Bowen, H.J.M. (1979), Environmental Chemistry of the Elements, Academic Press,
London.
Lundy-Stern, T. and Green, R. (2007), Yandicoogina ARD and Geochemical Risk
Assessment (RTIO-PDE-0033672).
Continues
Page 6 of 16
Appendix 1
Sample Location Map
Continues
Page 7 of 16
Hairpin East
3 Grab Samples
Phil’s Creek
9 Grab Samples
Junction South West
151 drillhole samples
Waterstand North
8 Grab Samples
Junction South
Junction South East
Junction
Marsh North
6 Grab Samples
Marsh South
3 Grab Samples
Union North
9 Grab Samples
Union Central
3 Grab Samples
Figure 1 Location of samples collected across the various Yandicoogina Deposits
Continues
Page 8 of 16
Appendix 2
Testing methods
•
Multi-elemental solid analysis
Grind sample to ~200 mesh (~50 μm) or finer and digest with aqua regain,
HNO3/perchloric/HF (or make LiBO2 (lithium meteorite) bead by mixing sample with
LiBO2 in Pt crucible, heat to 1000oC, dissolve in HNO3/HF); analyse by Inductively
Coupled Plasma Atomic Emission Spectrophotometry (ICP-AES), Inductively Coupled
Plasma Mass Spectrometry (ICP-MS) (for trace metals), Atomic Absorption
Spectroscopy (AAS), Neutron Activation Analysis (NAA), or X-Ray Fluorescence (XRF)
(for semiquantitative analysis) for elements of interest (Maest et. al. 2005).
Elements include:
Ag, B, Be, Cd, F, Hg, Mo, Se, Th, U
•
Multi-elemental liquid extract
Water extracts are conducted on a 1:2, solid to deionised water ratio (w/w). The
crushed portion of the sample (-4 mm) is used in the test and not pulverised samples.
The sample/water mixture is mixed thoroughly, placed into an automatic tumbler, and
left overnight (for approximately 16 hours), before the liquor is siphoned off and the pH
and EC measured. The liquor is then filtered (45 µm), acidified using concentrated
HNO3 before being analysed in a multi-element analysis.
Elements of interest include:
pH, EC, SO4, Al, As, Fe, Mn, Cu, Zn, Ca, K, Mg, Cl, Na, HCO3-, Co, Cr, Pb, Ni, F, Hg,
Ba, B, Sb, Se, U, Mo, Cd, Ag
Continues
Page 9 of 16
Appendix 3
Yandicoogina Stratigraphy
Taken from Lundy-Stern and Green (2007)
Continues
Page 10 of 16
Appendix 4
Geochemical Enrichment
Continues
Page 11 of 16
Table 4 Summary of the Global Abundance Index of samples selected as part of this study
Element/oxide_
Analysis_Units
Crustal
abundance
mg/kg
FE_XRF_pct
SIO2_XRF_pct
AL2O3_XRF_pct
P_XRF_pct
TIO2_XRF_pct
CAO_XRF_pct
MGO_XRF_pct
K2O_XRF_pct
ARS_XRF_ppm
BA_XRF_ppm
CL_XRF_ppm
CO_XRF_ppm
CR_XRF_ppm
CU_XRF_ppm
NA_XRF_ppm
NI_XRF_ppm
PB_XRF_ppm
SN_XRF_ppm
SR_XRF_ppm
V_XRF_ppm
ZN_XRF_ppm
ZR_XRF_ppm
S_XRF_pct
AG_ICP_ppm
B_ICP_ppm
BE_ICP_ppm
CD_ICP_ppm
F_SIE_ppm
HG_ICP_ppm
MO_ICP_ppm
SB_ICP_ppm
SE_ICP_ppm
TH_ICP_ppm
U_ICP_ppm
41000
GRAB
Mean
Median
3
ALL
Minimum
3
Maximum
3
Mean
Median
2
2
BCC
Minimum
1
Maximum
Mean
3
Median
3
3
Minimum
2
Maximum
3
592557
309886
1000
1
9343
1
57367
37540
50593
2
500
3
1
3
5
6
3
3
2
4
4
3
2
5
130
370
1
2
100
50
1
23000
80
14
2
1
1
1
1
1
2
2
2
1
4
2
2
2
1
3
3140
2
160
1
2
1
1
1
75
190
260
1
85
22
1
8061
0.4
2
10.2
1.7
0.42
102
2
2
20
1
1
Continues
Page 12 of 16
Table 4 continued
Element/oxide_
Analysis_Units
Crustal
abundance
mg/kg
FE_XRF_pct
SIO2_XRF_pct
AL2O3_XRF_pct
P_XRF_pct
TIO2_XRF_pct
CAO_XRF_pct
MGO_XRF_pct
K2O_XRF_pct
ARS_XRF_ppm
BA_XRF_ppm
CL_XRF_ppm
CO_XRF_ppm
CR_XRF_ppm
CU_XRF_ppm
NA_XRF_ppm
NI_XRF_ppm
PB_XRF_ppm
SN_XRF_ppm
SR_XRF_ppm
V_XRF_ppm
ZN_XRF_ppm
ZR_XRF_ppm
S_XRF_pct
AG_ICP_ppm
B_ICP_ppm
BE_ICP_ppm
CD_ICP_ppm
F_SIE_ppm
HG_ICP_ppm
MO_ICP_ppm
SB_ICP_ppm
SE_ICP_ppm
TH_ICP_ppm
U_ICP_ppm
41000
ECC
Mean
Median
2
2
GVL
Minimum
1
Maximum
3
Mean
Median
GVU
3
3
Minimum
3
Maximum
3
4
4
2
4
Mean
3
Median
3
Minimum
3
Maximum
3
4
4
2
4
592557
309886
1000
1
9343
57367
37540
50593
2
3
3
2
500
130
4
1
2
1
370
100
1
50
23000
80
14
2
2
2
1
1
2
4
2
2
2
3
2
2
2
4
3140
160
1
75
190
260
1
85
22
1
8061
0.4
10.2
1.7
0.42
102
20
1
1
Continues
Page 13 of 16
Table 4 continued
Element/oxide_
Analysis_Units
Crustal
abundance
mg/kg
FE_XRF_pct
SIO2_XRF_pct
AL2O3_XRF_pct
P_XRF_pct
TIO2_XRF_pct
CAO_XRF_pct
MGO_XRF_pct
K2O_XRF_pct
ARS_XRF_ppm
BA_XRF_ppm
CL_XRF_ppm
CO_XRF_ppm
CR_XRF_ppm
CU_XRF_ppm
NA_XRF_ppm
NI_XRF_ppm
PB_XRF_ppm
SN_XRF_ppm
SR_XRF_ppm
V_XRF_ppm
ZN_XRF_ppm
ZR_XRF_ppm
S_XRF_pct
AG_ICP_ppm
B_ICP_ppm
BE_ICP_ppm
CD_ICP_ppm
F_SIE_ppm
HG_ICP_ppm
MO_ICP_ppm
SB_ICP_ppm
SE_ICP_ppm
TH_ICP_ppm
U_ICP_ppm
41000
LGC
Mean
Median
3
3
WCH
Minimum
1
Maximum
3
Mean
Median
3
3
WW
Minimum
3
Maximum
Mean
3
Median
3
3
Minimum
1
Maximum
3
592557
309886
1
1
1000
9343
57367
37540
50593
2
3
3
2
4
3
3
2
4
3
3
2
4
500
1
130
370
100
1
50
23000
1
80
14
2
2
2
2
3
2
2
2
3
2
2
2
1
3
3140
1
1
160
75
190
260
1
85
22
1
8061
0.4
10.2
1.7
0.42
102
20
1
1
1
2
Continues
Appendix 5
ANZECC water guideline trigger values and Yandi background groundwater chemistry
Page 14 of 16
Continues
Page 15 of 16
Table 5 various trigger and background ground water (GW) values used
Freshwater Aquatic
Mean Yandi Alluvials GW + 10%
Mean Yandi CID GW +10%
Mean Yandi WW GW +10%
6 – 7.5
6.6
6.5
6.8
SO4
55
55
47
EC
968
921
948
Hardness
311
361
310
Alkalinity
224
263
pH
Ag
0.00005
Al
0.055
0.1
0.077
As
0.013
0.0025
0.0021
0.131
0.119
0.283
0.324
51
55
0.0007
0.0008
137
114
Ba
B
0.37
Ca
Cd
0.0002
Cl
48
109
Co
Cr
0.001
0.012
0.0064
Cu
0.0014
0.012
0.0045
F
0.338
0.509
Fe
0.371
0.45
0.0001
0.0001
K
8
8
11
Mg
46
55
46
0.793
1.807
Mo
0.026
0.021
Na
84
71
Hg
Mn
0.00006
1.9
Ni
0.011
Pb
0.0034
Se
0.011
0.0028
0.0036
0.004
0.066
0.036
Sb
U
Zn
0.008
79
Continues
Page 16 of 16