QEMSCAN analysis
Example Report
Cu-bearing Mill Products
By Dr. Katharina Pfaff
Department of Geology
Colorado School of Mines
1516 Illinois Street, Room 119
Golden, Colorado 80401 USA
kpfaff@mines.edu
January 21, 2013
Client: None
Project Title: Example Report
Survey Code: N/A
Date: 1/21/13
Table of Contents
Executive Summary ...............................................................................................................2
Project Background................................................................................................................3
Sample Preparation and Measurements .................................................................................3
Results....................................................................................................................................4
Grain Images ....................................................................................................................4
Mineralogy .......................................................................................................................7
Particle size distribution...................................................................................................9
Cumulative Particle Size Distribution .................................................................... 9
Grain size distribution of bornite, chalcopyrite, and covellite .......................................10
Bornite .................................................................................................................. 10
Chalcopyrite.......................................................................................................... 10
Covellite................................................................................................................ 11
Locking/liberation characteristics of bornite, chalcopyrite, and covellite .....................11
Mineral association ........................................................................................................13
1
Client: None
Project Title: Example Report
Survey Code: N/A
Date: 1/21/13
Executive Summary
In January of 2013, three samples of Cu-bearing mill products were analyzed at the
QEMSCAN Facility at Colorado School of Mines. One sample was a copper flotation
concentrate (Cu con), one sample was of partially roasted copper floatation concentrate
(Cu con – part roast), and one sample was of leach residue.
The copper flotation concentrate mainly consists of chalcopyrite and pyrite, with minor
concentrations of FeCu sulfate, Cu-mica/Cu-clay, quartz, K-feldspar, plagioclase,
muscovite, Ca sulfate, and chlorite group minerals (Tables 1 and 2, Fig. 4).
The sample of partially roasted copper concentrate (Cu con – part roast) consists mainly
of FeCu oxide, FeCu sulfate, Fe oxides/hydroxides, and quartz. This sample also contains
minor concentrations of copper sulfide minerals, cuprite, Ca sulfate, and silicate minerals
(Tables 1 and 2, Fig. 4).
The sample of leach residue consists mainly of FeCu oxide, Fe oxide/hydroxide, and
bornite. This sample also contains minor concentrations of associated copper sulfides,
cuprite, Ca sulfate, pyrite, and silicate minerals (Tables 1 and 2, Fig. 4).
Particle sizes for all three samples vary from 4 μm to >120 μm (Fig. 5). Cumulative
particle size distribution analysis shows the samples of partial roast and leach residue to
have comparable particle size distributions (Fig. 6).
Grain sizes for bornite (in volume %) range from <4 μm to 80 μm, with the majority of
grains occurring in the <4 μm to 30 μm size range (Fig. 7). Grain sizes of chalcopyrite
range from <4 μm to >120 μm, with most grains occurring in the 6 μm to 45 μm size range
(Fig. 8). Grain sizes for covellite range from <4 μm to 15 μm, and show a bimodal size
distribution (Fig. 9).
Bornite is almost entirely locked in all samples, while covellite is fully locked in all
samples (Fig. 10 and 12). Chalcopyrite is dominantly locked in the partial roast and leach
residue samples, but shows a range of liberation in the sample of copper flotation
concentrate (Fig. 11).
2
Client: None
Project Title: Example Report
Survey Code: N/A
Date: 1/21/13
Project Background
In January of 2013, three samples of Cu-bearing mill products were analyzed at the
QEMSCAN Facility at Colorado School of Mines. The samples were named copper
concentrate (Cu con), copper concentrate – partial roast (Cu con – part roast), and leach
residue. The aims of the analyses are to:
1. Quantify the modal mineralogy;
2. Calculate the particle size distribution;
3. Calculate the grain size distribution;
4. Quantify the locking and liberation characteristics;
5. Quantify mineral associations in the samples.
Sample Preparation and Measurements
1. Each sample was split into representative aliquots using a rotary micro-riffler.
2. Sized graphite was added to mitigate particle agglomeration, preferred orientation and
settling. Subsequently, all samples were mounted in a 30-mm block with epoxy-resin
and left to cure.
3. The blocks were ground and polished to obtain a flat surface for X-ray analysis.
4. The blocks were carbon coated to establish an electrically conductive surface.
5. The samples were analyzed at a 2.5 µm resolution in Particle Analysis (PMA) mode.
3
Client: None
Project Title: Example Report
Survey Code: N/A
Date: 1/21/13
Results
Grain Images
Fig. 1: False color QEMSCAN image of sample Cu con.
4
Client: None
Project Title: Example Report
Survey Code: N/A
Date: 1/21/13
Fig. 2: False color QEMSCAN image of sample Cu con – part roast.
5
Client: None
Project Title: Example Report
Survey Code: N/A
Date: 1/21/13
Fig. 3: False color QEMSCAN image of leach residue sample.
6
Client: None
Project Title: Example Report
Survey Code: N/A
Date: 1/21/13
Mineralogy
The sample of copper concentrate (Cu con) consists mainly of chalcopyrite (72.8%) and
pyrite (15.3%). The remainder of the sample consists of minor concentrations of FeCu
sulfate, Cu-mica/Cu-clay, quartz, K-feldspar, plagioclase, muscovite, Ca sulfate, and
chlorite group minerals.
The sample of partially roasted copper concentrate (Cu con – part roast) consists mainly
of FeCu oxide (54%), FeCu sulfate (12%), Fe oxides/hydroxides (6.9%), and quartz (5.1
%). This sample also contains minor concentrations of copper sulfide minerals, cuprite, Ca
sulfate, and silicate minerals.
The sample of leach residue consists mainly of FeCu oxide (56.3%), Fe oxide/hydroxide
(9.7%), FeCu sulfate (9.1%), and bornite (8.7%). This sample also contains minor
concentrations of associated copper sulfides, cuprite, Ca sulfate, pyrite, and silicate
minerals.
Table 1: Mineral Groups
Mineral
Chalcopyrite
Bornite
Chalcocite/Digenite
Covellite
FeCu Oxide
Cu Oxide (Cuprite)
FeCu Sulfate
Cu Sulfate
Cu-mica/clay
Fe Oxide/Hydroxide
Pyrite
Quartz
K-Feldspar
Plagioclase
Muscovite
Ca Sulfate
Chlorite
Others
Chemical Composition
CuFeS2
Cu5FeS4
Cu2S/Cu9S5
CuS
Undifferentiated FeCu Oxide
Cu2O
Undifferentiated FeCu Sulfate
Undifferentiated Cu Sulfate
Cu-mica/Cu-clay
Undifferentiated Fe Oxide/Hydroxide
FeS2
SiO2
KAlSi3O8
(Na,Ca)(Si,Al)4O8
KAl2(Si3Al)O10
Gypsum/Anhydrite
Clinochlore/Chamosite
individual unidentified pixels
7
Client: None
Project Title: Example Report
Survey Code: N/A
Date: 1/21/13
Table 2: Modal mineral abundance (Volume %)
Leach residue
Cu con - part roast
Chalcopyrite
2.6
4.1
Bornite
8.7
4.2
Chalcocite/Digenite
1.9
1.7
Covellite
0.2
0.1
FeCu Oxide
56.3
54.0
Cu Oxide (Cuprite)
0.8
1.4
FeCu Sulfate
9.1
12.0
Cu Sulfate
0.1
0.9
Cu-mica/clay
3.2
4.3
Fe Oxide/Hydroxide
9.7
6.9
Pyrite
0.2
0.2
Quartz
3.5
5.1
K-Feldspar
1.4
1.7
Plagioclase
0.9
1.4
Muscovite
0.6
0.5
Ca Sulfate
0.1
0.4
Chlorite
Others
0.9
1.0
Cu con
72.8
2.6
1.5
15.3
2.7
1.9
1.5
0.4
0.1
0.1
0.9
Cu con:
Minerals
Chalcopyrite
Bornite
Chalcocite/Digenite
Covellite
FeCu Oxide
Cu Oxide (Cuprite)
FeCu Sulfate
Cu Sulfate
Cu-mica/clay
Fe Oxide/Hydroxide
Pyrite
Quartz
K-Feldspar
Plagioclase
Muscovite
Ca Sulfate
Chlorite
Others
Cu con - part roast:
Leach residue:
0
10
20
30
40
50
60
Volume (%)
70
80
90
100
Fig. 4: Graphic illustration of the modal mineral abundance in Volume % in Cu con, Cu
con - part roast, and leach residue samples.
8
Client: None
Project Title: Example Report
Survey Code: N/A
Date: 1/21/13
Particle size distribution
20
18
16
Volume %
14
12
Cu Con
Cu Con - Part roast
Leach Residue
10
8
6
4
2
68
810
10
-1
5
15
-2
0
20
-2
5
25
-3
0
30
-3
5
35
-4
0
40
-4
5
45
-5
0
50
-6
0
60
-7
0
70
-8
0
80
-9
90 0
-1
10 00
012
0
>1
20
<4
46
0
Particle size in micron
Fig. 5: Particle size distribution in volume %.
Cumulative Particle Size Distribution
Cumulative Particle Size Distribution
100
90
80
Volume %
70
60
Cu Con
Cu con - part roast
Leach residue
50
40
30
20
10
810
10
-1
5
15
-2
0
20
-2
5
25
-3
0
30
-3
5
35
-4
0
40
-4
5
45
-5
0
50
-6
0
60
-7
0
70
-8
0
80
-9
0
90
-1
0
10 0
012
0
>1
20
68
<4
46
0
Particle size in micron
Fig. 6: Cumulative particle size distribution curve.
9
Client: None
Project Title: Example Report
Survey Code: N/A
Date: 1/21/13
Grain size distribution of bornite, chalcopyrite, and covellite
Bornite
Bornite
100
90
80
Volume %
70
60
Cu con
50
Cu con - part roast
Leach residue
40
30
20
10
>120
100-120
90-100
80-90
70-80
60-70
50-60
45-50
40-45
35-40
30-35
25-30
20-25
15-20
10-15
8-10
6-8
4-6
<4
0
Grain size in micron
Fig. 7: Grain size distribution of bornite.
Chalcopyrite
Chalcopyrite
50
45
40
Volume %
35
30
Cu con
25
Cu con - part roast
Leach residue
20
15
10
5
>120
100-120
90-100
80-90
70-80
60-70
50-60
45-50
40-45
35-40
30-35
25-30
20-25
15-20
10-15
8-10
6-8
4-6
<4
0
Grain size in micron
Fig. 8: Grain size distribution of chalcopyrite.
10
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Project Title: Example Report
Survey Code: N/A
Date: 1/21/13
Covellite
Covellite
100
90
80
Volume %
70
60
Cu con
50
Cu con - part roast
Leach residue
40
30
20
10
>120
100-120
90-100
80-90
70-80
60-70
50-60
45-50
40-45
35-40
30-35
25-30
20-25
15-20
10-15
8-10
6-8
4-6
<4
0
Grain size in micron
Fig. 9: Grain size distribution of covellite.
Locking/liberation characteristics of bornite, chalcopyrite, and covellite
A mineral is completely liberated if >90% of the particle consists only of the respective
mineral. A mineral is ‘locked’ if the area of the respective mineral is <30% in the entire
particle, everything in between is called ‘middling’. These numbers do not reflect how
easy it is to liberate a mineral by e.g., grinding the material.
Analysis of liberation degree shows bornite to be fully locked in the Cu concentrate. In
the partial roast and leach residue samples, most of the bornite is locked, with 3.5% and
14.5% occurring as middling’s, respectively. Chalcopyrite shows a range of liberation in
the Cu concentrate sample, but is dominantly locked in the partial roast and leach residue
samples. Covellite is fully locked in all three samples.
11
Client: None
Project Title: Example Report
Survey Code: N/A
Date: 1/21/13
Bornite
100
90
80
Volume %
70
60
Cu Con
50
Cu con - part roast
Leach residue
40
30
20
10
0
Liberated
Middling
Locked
Fig. 10: Locking and liberation of bornite.
Chalcopyrite
100
90
80
Volume %
70
60
Cu Con
50
Cu con - part roast
Leach residue
40
30
20
10
0
Liberated
Middling
Locked
Fig. 11: Locking and liberation of chalcopyrite.
12
Client: None
Project Title: Example Report
Survey Code: N/A
Date: 1/21/13
Covellite
100
90
80
Volume %
70
60
Cu Con
50
Cu con - part roast
Leach residue
40
30
20
10
0
Liberated
Middling
Locked
Fig. 12: Locking and liberation of covellite.
Mineral association
Cu Con
100
90
80
Volume %
70
60
Chalcopyrite
Bornite
Covellite
50
40
30
20
10
C
ha
lc
op
C
yr
ha
ite
lc
oc Bo
ite rn
/D ite
ig
en
C ite
ov
Fe
e
C llite
u
Fe O
C xid
u
Su e
C lfat
u
e
Fe Cu Sul
f
a
O -m
te
xi
de ica/
c
/H
l
yd ay
ro
xi
de
Py
rit
e
Q
K- uar
Fe tz
l
Pl dsp
ag
a
io r
cl
M as
us e
c
C ovit
a
Su e
lfa
C te
hl
or
it
O e
th
er
s
0
minerals
Fig. 13: Mineral associations in volume % in sample Cu con sample.
13
C
ha
lc
op
C
yr
ha
it
lc
oc Bo e
ite rn
/D ite
ig
en
C ite
ov
Fe
C
el
u
O Cu lite
xi
O
de
x
(C ide
Fe up
r
C
u ite)
Su
C lfa
u
te
Fe C S u
u
O -m lfat
e
xi
de ica
/H /cla
yd
y
ro
xi
de
Py
rit
Q e
u
Ka
Fe rtz
l
d
Pl
s
ag pa
io r
c
M las
us e
c
C ovi
a
t
Su e
lfa
C te
hl
or
it
O e
th
er
s
Volume %
ha
lc
op
C
yr
ha
it
lc
oc Bo e
ite rn
/D i te
ig
en
C ite
ov
Fe
C
el
u
O Cu lite
xi
O
de
x
(C ide
Fe up
r
C
u ite)
Su
C lfa
u
te
Fe C S u
ulfa
O
xi mic te
de
a
/H /cla
yd
y
ro
xi
de
Py
rit
Q e
u
Ka
F e rt z
l
d
Pl
s
ag pa
io r
c
M las
us e
c
C o vi
a
t
Su e
lfa
C te
hl
or
it
O e
th
er
s
C
Volume %
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Project Title: Example Report
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Date: 1/21/13
Cu con - partial roast
100
90
80
70
60
50
40
Chalcopyrite
Bornite
Covellite
30
20
10
0
minerals
Fig. 14: Mineral associations in volume % in sample Cu con – part roast.
Leach Residue
100
90
80
70
60
50
40
Chalcopyrite
Bornite
Covellite
30
20
10
0
minerals
Fig. 15: Mineral associations in volume % in leach residue sample.
14
Client: None
Project Title: Example Report
Survey Code: N/A
Date: 1/21/13
The mineralogical data reported in this study directly reflect the best possible analysis of the materials
provided. All efforts were made to ensure the highest level of quality control for the materials provided.
Certain factors beyond the control of this laboratory may include: sample selection and representivity of
materials, sample preparation by other laboratories, small sample size, small grain size close to the
resolution of the system, and statistical representation of trace phases. The QEMSCAN Facility is not
responsible for any further interpretation or application of the data other than that contained herein, and
application to larger sample populations may not be valid without further analysis. Information regarding
laboratory operations, quality control and quality assurance is available on request.
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