CERTIFIED REFERENCE MATERIAL
Prepared by and Distributed by
MINTEK
P/Bag X3015 Randburg 2125
Republic of South Africa
Email
Telephone
Fax
: [email protected]
: + 27 11 7094046
: + 27 11 7094006
SARM 146
CERTIFICATE OF ANALYSIS
1.
Chrome ore
STATUS OF CERTIFICATE
This is the first issue of the certificate.
2.
DATE OF ORIGINAL CERTIFICATION
2015-07-24
3.
AVAILABILITY OF THE MATERIAL
100 g units of the pulverised material are available.
4.
SOURCE AND SUPPLIER OF THE MATERIAL
The material was supplied by Samancor Eastern Chrome Mine, Steelpoort in South Africa
5.
PREPARER OF THE REFERENCE MATERIAL
The reference material was prepared by Mintek’s Analytical Services Division
6.
DESCRIPTION OF THE MATERIAL
Chrome ore, characterised by the mineralogical composition, tabulated below.
Relative abundance of minerals present in SARM 146
Mineral
Abundance
in mass %
Chromite
100
Enstatite was observed on the SEM
7.
INTENDED USE AND STATEMENT ON STABILITY
The reference material can be used as a control sample in the analysis of samples of a similar type,
verification of analytical methods for chrome ore and as a calibration standard for the calibration of
equipment used for analysing similar materials.
SARM 146
8.
LEGAL NOTICE
This certificate and reference material described has been prepared with due diligence. Mintek or the
Manager of the Analytical Service Division accepts no liability for any decisions or actions taken
following the use of the reference material.
8.
TRANSPORTATION AND STORAGE INSTRUCTIONS
Care must be taken to avoid undue vibration, since this could cause segregation within the bottles. The
bottles must be stored in a cool dry place out of direct sunlight.
9.
INSTRUCTIONS FOR THE CORRECT USE OF THE MATERIAL
The material should be well mixed and dried at 105C over night before sub-samples are taken.
10.
METHOD OF PREPARATION OF THE REFERENCE MATERIAL
The material was reduced in particle size until 95% was less than 75 microns. This was achieved by
using a ball mill. The sample was then blended and packaged into 100 g units.
Percent passing 20 µ and 75 µ screen
11.
20 µ screen
75 µ screen
Replicate 1
54%
95%
Replicate 2
56%
95%
STATE OF HOMOGENEITY
This reference material consists of 100 g units. 20 units were analysed from one to three times, each
prepared by alkaline fusion followed by ICP-OES analysis. The homogeneity and relative standard
deviation of the reference material calculated from the data based on the analysis of 0.2 grams sample
aliquots. The state of homogeneity cannot be guaranteed for sample mass less than 0.2 grams.
Analysis of variance at alpha 0.05 was used to confirm that there was no significant difference in means
between the units. The overall relative standard deviation (RSD) for each analyte, expressed as a
percent, is shown in the table below.
Al2O3
Cr2O3
Fe
MgO
MnO
TiO2
SiO2
3.45
1.48
1.56
3.16
2.18
3.81
2.07
Page 2 of 10
SARM 146
12.
TRACEABILITY
The traceability of this CRM is ensured by the use of proven collection techniques and resultant
components are quantified using methods which are calibrated against pure metals or stoichiometric
compounds. Collaborating laboratories operate according to ISO guide 17025 accreditation.
13.
PROPERTY VALUES
Property values
Certified
Cr2O3
Certified
FeO
Certified
Al2O3
Certified
MgO
Certified
MnO
Certified
SiO2
Certified
TiO2
Certified
CaO
Certified
V205
Unit
Average
Lab S
N
%
46.91
0.416
13
Unit
Average
Lab S
N
%
25.58
0.346
12
Unit
Average
Lab S
N
%
14.54
0.190
12
Unit
Average
Lab S
N
%
10.62
0.102
12
Unit
Average
Lab S
N
%
0.22
0.009
9
Unit
Average
Lab S
N
%
0.616
0.054
10
Unit
Average
Lab S
N
%
0.57
0.011
11
Unit
Average
Lab S
N
%
0.10
0.056
10
Unit
Average
Lab S
N
%
0.32
0.015
6
The Certified Value is an estimate of the "consensus" value based upon the best available data at the
time of the certification. Normal distribution is assumed and the arithmetic mean and inter laboratory
standard deviation is assigned.
The 95% Confidence Interval for the Certified Value is the range of values having a 95% chance of
containing the certified value, should the certification program be repeated an infinite number of times.
The precision of the user's proposed analytical method must be taken into account when using this
reference material.
The standard deviation shown is the inter-laboratory standard deviation. Ideally a repeat analysis by a
laboratory should fall in a range of 0 - 3 times the standard deviation from the accepted value.
Page 3 of 10
SARM 146
14.
VALUES OBTAINED BY INDIVIDUAL LABORATORIES
A total of eleven laboratories submitted analytical results for this material. Some Laboratories did not
submit results for some of the requested elements.
15.
MEASUREMENT TECHNIQUES USED FOR THE CERTIFICATION
The techniques used by the contributing laboratories were the following;
16.

Fusion Bead - XRF (FB-XRF)

Fusion – ICP-OES (F-ICP-OES)

Wet Chemistry titration (WC-Titration)
TREATMENT OF THE NUMERICAL VALUES
The data was assumed to belong to a normal distribution. This was assumed after examining the data
statistically using tests for Normality, specifically kurtosis which examines the shape of the curve. The
difference between the arithmetic mean and median were considered. A large difference could suggest
a skewed distribution.
Outlier tests (Grubbs) were used to identify points which were far from the mean. Relative standard
deviation was considered before assigning a value.
17.
PARTICIPATED LABORATORIES
ANALYTICAL LABORATORY PARTICIPANTS
SAMANCOR WCM
THARISA MINING
ASSMANG DWAARSRIVIER
ANGLO RESEARCH
METCHEM LABORATORY
COUNCIL FOR GEOSCIENCE
SAMANCOR - FERROMETALS
SAMANCOR - ECM
ALS - MINERALS (JHB)
MINTEK
INTERTEK
SAMANCOR - Tubatse Chrome
18.
NAME OF CERTIFYING OFFICERS
________________________
Page 4 of 10
SARM 146
Mr Joe Baloyi,
Manager: Analytical Service Division, Mintek
Mr B.R. Lokothwayo,
Senior Scientist: Analytical Service Division, Mintek
19.
Data and Distribution for individual elements
KEY
FB - XRF
X-ray Fluorescence analysis after fused beads fusion preparation
F – ICP-OES
Inductively Coupled Plasma Optical Emission Spectroscopy after alkaline fusion
preparation
WC-Titration
Wet chemical analysis (titration)
NB.
Labs without values for some of the elements, i.e. did not report that element or greater or less than value.
The (highlighted) value was rejected by Grubbs test as an outlier and
evaluation for the property value.
was not included in the statistical
Page 5 of 10
SARM 146
Certified
Element
Unit
Average
Lab S
N
Cr 2O3
%
46.91
0.416
13
lab
29
21A
21B
27
31
25
28
23
26
30
32
22
24
METHOD
FB-XRF
F-ICP-OES
WC-TITRATION
WC-TITRATION
FB-XRF
WC-TITRATION
F-ICP-OES
F-ICP-OES
FB-XRF
F-ICP-OES
F-ICP-OES
F-ICP-OES
FB-XRF
LAB AVE
46.24
46.56
46.57
46.63
46.67
46.70
46.75
46.87
47.13
47.33
47.35
47.40
47.64
S
0.104
0.130
0.169
0.223
0.117
0.057
0.040
0.239
0.912
0.699
0.118
0.103
0.223
N
5
5
Certified Element
Unit
RSD
0.22
0.28
0.36
0.48
0.25
0.12
0.08
0.51
1.94
1.48
0.25
0.22
0.47
5
6
10
5
5
5
5
28
5
5
10
Average
Lab S
N
FeO
%
25.58
0.346
12
lab
32
29
27
26
30
28
21
31
23
25
24
22
METHOD
F-ICP-OES
FB-XRF
F-ICP-OES
FB-XRF
F-ICP-OES
F-ICP-OES
F-ICP-OES
FB-XRF
F-ICP-OES
WC-TITRATION
FB-XRF
F-ICP-OES
LAB AVE
25.16
25.20
25.25
25.31
25.35
25.45
25.66
25.69
25.77
25.81
26.09
26.19
S
0.065
0.036
0.304
0.393
0.409
0.032
0.024
0.135
0.165
0.029
0.151
0.094
N
5
5
5
5
28
5
5
10
5
5
10
5
RSD
0.26
0.14
1.20
1.55
1.61
0.12
0.09
0.53
0.64
0.11
0.58
0.36
min
max
46.15
46.41
46.34
46.30
46.52
46.62
46.70
46.50
46.08
45.60
47.24
47.27
47.32
46.42
46.68
46.75
46.99
46.87
46.78
46.80
47.13
48.01
48.60
47.55
47.53
47.92
min
max
25.10
25.16
24.99
24.66
24.70
25.42
25.63
25.47
25.53
25.77
25.84
26.11
25.26
25.25
25.72
25.73
26.00
25.50
25.69
25.90
25.92
25.85
26.36
26.35
Page 6 of 10
SARM 146
Certified
Element
Unit
Average
Lab S
N
Al2O3
%
14.54
0.190
12
lab
32
25
22
26
27
29
23
28
30
31
21
24
METHOD
F-ICP-OES
F-ICP-OES
F-ICP-OES
FB-XRF
F-ICP-OES
FB-XRF
F-ICP-OES
F-ICP-OES
F-ICP-OES
FB-XRF
F-ICP-OES
FB-XRF
LAB AVE
14.31
14.32
14.34
14.41
14.46
14.50
14.54
14.63
14.65
14.69
14.70
14.94
S
0.068
0.041
0.070
0.443
0.092
0.016
0.069
0.043
0.505
0.037
0.041
0.108
N
5
5
Certified
Element
Unit
Average
Lab S
N
MgO
%
10.62
0.102
12
lab
25
26
23
27
29
32
28
30
31
21
22
24
METHOD
F-ICP-OES
FB-XRF
F-ICP-OES
F-ICP-OES
FB-XRF
F-ICP-OES
F-ICP-OES
F-ICP-OES
FB-XRF
F-ICP-OES
F-ICP-OES
FB-XRF
LAB AVE
10.46
10.49
10.55
10.57
10.58
10.61
10.62
10.63
10.67
10.68
10.76
10.81
S
0.069
0.227
0.040
0.110
0.080
0.037
0.035
0.336
0.046
0.030
0.124
0.117
N
5
5
5
5
5
5
5
28
10
5
5
5
5
5
5
5
28
10
5
10
5
10
RSD
0.47
0.28
0.49
3.07
0.63
0.11
0.48
0.29
3.45
0.25
0.28
0.72
RSD
0.66
2.16
0.38
1.04
0.76
0.35
0.33
3.16
0.44
0.28
1.15
1.08
min
max
14.22
14.28
14.23
13.80
14.40
14.47
14.45
14.57
14.00
14.64
14.65
14.76
14.41
14.37
14.42
14.93
14.62
14.51
14.62
14.68
15.50
14.77
14.75
15.16
min
max
10.39
10.22
10.49
10.48
10.44
10.56
10.58
10.00
10.62
10.65
10.59
10.61
10.55
10.82
10.59
10.76
10.63
10.66
10.67
11.40
10.76
10.71
10.94
10.92
Page 7 of 10
SARM 146
Certified
Element
Unit
Average
Lab S
N
MnO
%
0.22
0.009
9
lab
21
27
28
31
25
32
30
29
24
26
22
23
METHOD
F-ICP-OES
F-ICP-OES
F-ICP-OES
FB-XRF
F-ICP-OES
F-ICP-OES
FB-XRF
FB-XRF
FB-XRF
FB-XRF
F-ICP-OES
F-ICP-OES
LAB AVE
0.211
0.214
0.214
0.217
0.220
0.22
0.224
0.234
0.238
0.369
S
0.001
0.004
0.005
0.007
0.000
0.000
0.005
0.005
0.008
0.005
N
5
5
5
10
5
5
28
5
10
5
Certified
Element
Unit
Average
Lab S
N
SiO2
%
0.616
0.054
10
lab
30
28
21
29
32
27
23
31
25
26
22
24
METHOD
F-ICP-OES
F-ICP-OES
F-ICP-OES
FB-XRF
F-ICP-OES
F-ICP-OES
F-ICP-OES
FB-XRF
F-ICP-OES
FB-XRF
F-ICP-OES
FB-XRF
LAB AVE
0.53
0.55
0.59
0.59
0.61
0.63
0.64
0.64
0.66
0.72
1.13
S
0.011
0.010
0.019
0.022
0.018
0.026
0.014
0.015
0.072
0.049
0.036
N
28
5
5
5
5
5
5
10
5
5
5
RSD
2.12
1.82
3.26
3.79
2.96
4.21
2.21
2.38
10.86
6.82
3.21
RSD
0.60
1.64
2.56
3.11
0.00
0.00
2.18
2.34
3.37
1.23
min
max
0.21
0.21
0.21
0.21
0.22
0.22
0.22
0.23
0.23
0.36
0.21
0.22
0.22
0.23
0.22
0.22
0.23
0.24
0.25
0.38
min
max
Z-score
0.51
0.54
0.57
0.55
0.59
0.60
0.62
0.62
0.58
0.66
1.09
0.56
0.56
0.62
0.60
0.63
0.66
0.65
0.67
0.77
0.78
1.19
-1.54
-1.23
-0.50
-0.49
-0.04
0.24
0.37
0.46
0.85
1.87
Page 8 of 10
SARM 146
Certified
Element
Unit
Average
Lab S
N
TiO2
%
0.57
0.011
11
S
0.011
0.011
0.006
0.000
0.021
0.026
0.008
0.004
0.007
0.007
0.015
N
5
5
5
lab
26
27
25
22
30
31
21
28
29
24
32
23
METHOD LAB AVE
FB-XRF
0.55
F-ICP-OES
0.55
F-ICP-OES
0.55
F-ICP-OES
0.56
F-ICP-OES
0.56
FB-XRF
0.57
F-ICP-OES
0.57
F-ICP-OES
0.57
FB-XRF
0.57
FB-XRF
0.58
F-ICP-OES
0.58
F-ICP-OES
Certified Element
RSD
2.01
1.95
1.00
0.00
3.81
4.56
1.44
0.79
1.24
1.19
2.60
5
28
10
5
5
5
10
5
Unit
Average
Lab S
N
CaO
%
0.10
0.056
10
lab
23
24
22
31
29
27
21
32
25
28
26
30
METHOD
F-ICP-OES
FB-XRF
F-ICP-OES
FB-XRF
FB-XRF
F-ICP-OES
F-ICP-OES
F-ICP-OES
F-ICP-OES
F-ICP-OES
FB-XRF
F-ICP-OES
LAB AVE
0.03
0.04
0.06
0.08
0.08
0.10
0.10
0.13
0.19
0.19
S
0.023
0.009
0.035
0.010
0.000
0.036
0.007
0.013
0.035
0.039
N
5
10
5
10
5
5
5
5
5
5
RSD
71.10
25.22
55.44
13.24
0.00
37.20
6.75
10.01
18.58
20.72
min
max
0.54
0.54
0.55
0.56
0.54
0.54
0.56
0.56
0.56
0.57
0.57
0.56
0.57
0.56
0.56
0.64
0.63
0.58
0.57
0.58
0.60
0.60
min
max
0.01
0.03
0.03
0.06
0.08
0.04
0.10
0.12
0.15
0.16
0.07
0.05
0.10
0.09
0.08
0.14
0.11
0.15
0.23
0.25
Page 9 of 10
SARM 146
Certified
Element
20.
Unit
Average
Lab S
N
V205
%
0.32
0.015
6
lab
22
25
32
24
28
21
23
26
27
29
30
31
METHOD
F-ICP-OES
F-ICP-OES
F-ICP-OES
FB-XRF
F-ICP-OES
F-ICP-OES
F-ICP-OES
FB-XRF
F-ICP-OES
FB-XRF
F-ICP-OES
FB-XRF
LAB AVE
0.29
0.30
0.32
0.32
0.33
0.33
S
0.004
0.002
0.049
0.012
0.004
0.001
N
5
5
5
10
5
5
RSD
1.53
0.72
15.47
3.84
1.36
0.43
min
max
0.29
0.30
0.23
0.30
0.32
0.33
0.30
0.31
0.34
0.34
0.33
0.33
References
1. The Preparation and Certification of a Chrome Reference Material - SARM 146, Mintek Report no. 4214
Page 10 of 10