SARM74 Page 1 of 17 CERTIFICATE OF ANALYSIS SARM 74 FERROCHROME METAL CERTIFIE REFERENCE MATERIAL Prepared by and istributed by TE P/Bag X3015 Randburg 2125 Republic of South Africa Email: info@mintek.co.za Telephone: + 27 11 7924313 fax: + 27 11 7094006 1. STATUS OF CERTIFICATE This is the first issue of the certificate. 2. ATE OF ORIGINAL CERTIFICATION 19 July 2006 3. AVAIILITY OF THE MATERIAL 100 g units of the powdered material are available. 4. SOURCE OF THE MATERIAL The material was supplied by Xstrata. 5. ESCRIPTION OF THE MATERIAL Ferrochrome metal. 6. INTENE USE As a control sample in the analysis of samples of a similar type. Verification of analytical methods for analysis Ferrochrome metal. As a reference material for the calibration of equipment used for analysing similar materials. 7. LEGAL NOTICE This certificate and reference material described in it has been prepared with due diligence. Mintek, or the Manager of the Analytical Science ivision accept no liability for any decisions or actions taken following the use of the reference material. 8. STABILITY, TRANSPORTATION AN STORAGE INSTRUCTIONS Care must be taken to avoid undue vibration, since this could cause segregation within the container.
SARM74 Page 2 of 17 9. INSTRUCTIONS FOR THE CORRECT USE OF THE MATERIAL The material should be well mixed and dried at 110 C over night before subsamples are taken. The minimum sample mass for analysis is 0.2 grams. 10. METHO OF PREPARATION OF THE REFERENCE MATERIAL Approximately 100 kg of material was reduced in particle size until 90% was less than 80 µm. This was achieved by using a ball mill. The sample was then split using a rotary splitter into 100 gram units. cumulative distribution Q3(x) / % 100 90 80 70 60 50 40 30 20 10 0 Sympatec WINOX esignator Mean value Upper limit Lower limit Comparison curve Nr. 1 Nr. 2 Graph 1 Graph 1: Particle size distribution 0.1 0.5 1 5 10 50 100 500 particle size / µm 11. STATE OF HOMOGENEITY 1.20 1.10 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0-0.10 This reference material consist of 1000 of 100g units. 17 units were analysed FOUR times by XRF powder technique each for Fe, Cr and Si. Analysis of variance at alpha 0.02 was used to test if there is a significant difference in means between the units. There was no difference for Cr, Si and Fe just failed. The overall relative standard deviation (RS) expressed a percent was 0.4 % for Cr and 0.7% for Fe. The RS was also compared to SARM 10 a previous standard and there was a good comparison 0.4 and 0.3 for Cr and 0.7 each Fe. Therefore the sample has appropriate homogeneity for its intended use. density distribution q3lg(x)
SARM74 Page 3 of 17 12.1 CERTIFIE AN TENTATIVE PROPERTY VALUES INCLUING CONFIENCE LIMITS AN INTER-ORATORY STANAR EVIATION. Table 1 Certified and Tentative values Cr % Average 49.7 49.50-49.83 0.270 13 TOT Fe % Average 37.5 37.1-37.8 0.520 11 Si % Average 4.34 4.28-4.40 0.098 12 C % Average 6.44 6.39-6.50 0.082 11 S % Tentative* Value 95% Lab S N Average 0.04 0.035-0.045 0.007 11 P % Tentative & Value 95% Lab S N Average 0.018 0.016-0.019 0.002 10 V % Average 0.36 0.35-0.37 0.012 10 TI % Tentative^ Value 95% Lab S N Average 0.47 0.46-0.49 0.019 9 Ni % Average 0.21 0.203-0.216 0.0103 12 Mn % Tentative #$ Value 95% Lab S N Average 0.193 0.183-0.202 0.0170 13 Co % Tentative +Q Value 95% Lab S N Average 0.06 0.051-0.069 0.0150 13 *Reason for tentative value, the Relative Inter - laboratory Standard deviation to high 18 % & Reason for tentative value, the Relative Inter - laboratory Standard deviation to high 20 % ^ Tentative distribution has kurtosis,(to spread out and flat). The inter laboratory standard deviation will be under estimated.
SARM74 Page 4 of 17 # Reason for tentative value, the Relative Inter - laboratory Standard deviation to high 9 % $ Tentative distribution has kurtosis,(to spread out and flat). The inter laboratory standard deviation will be under estimated. + Tentative distribution has kurtosis,(to spread out and flat). The inter laboratory standard deviation will be under estimated. Q Reason for tentative value, the Relative Inter - laboratory Standard deviation to high 25 % 12.2 Information values These values are for information only the range and number of results are reported with the median value. Table 2 Information values Al % Information Value Range N Median 0.1 0.04-0.16 4 Cu % Information Value Range N Median 0.006 0.004-0.007 3 O % Information Value N Median 0.36 1 N ppm Information Value Range N Median 65 61-68 1 Cr VI ppm Information Value N Median <0.04 1 NOTES: The Certified Value is an estimate of the "true" value based upon the best available data at the time of the certification. 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 2.3 times the standard deviation from the accepted value.
SARM74 Page 5 of 17 13. VALUES OBTAINE BY INIVIUAL ORATORIES Twelve laboratories submitted analytical results on this material. See 19 for all the results. 14. MEASUREMENT TECHNIQUES USE FOR THE CERTIFICATION Techniques used by the contributing laboratories were the following: Gravimetric analysis Optical emission spectroscopy with ICP source Combustion Analysis Titration Colorimetric X-ray Fluorescence Atomic Absorption 15. TREATMENT OF THE NUMERICAL VALUES The data was assumed to belong to a normal distribution after examining the data statistically using tests for Normality, specifically kurtosis which examines the shape of the curve. Three elements, (Ti Mn Co) had platykurtic tendency i.e. the probability density function is flat and has a shorter tail. The significance of this is that the inter - laboratory standard deviation would be underestimated therefore these results were marked as Tentative values. The difference between the arithmetic mean and median were considered and in no cases was this greater than 1.8 % for certified values. Large difference could suggest a skewed distribution. Outlier tests (Grubbs and Cochran's) were used to identify points which were far from the mean. These tests were never used twice on the same dataset and conservative approach was used before a result was rejected. Also results were plotted using the box and whisker method and this gives a very visual indication if a value belongs to the population see section 18. Relative standard deviation was considered before assigning a certified value. The elements S, P, Mn and Co had high values and were thus assigned a tentative value. The sum of the values for the certificate is 99.4 % excluding oxygen which is 0.4%. This could be free oxygen or associated with silicate elements. This brings the value very close to 100 %. Arithmetic mean was used as an estimator of the central value for certified and tentative values. Information values were quoted with median and range.
SARM74 Page 6 of 17 16. Participating Laboratories Columbus Stainless. Inspectorate M&L (PTY) Ltd. Xstrata (woderkop) Zimasco (Pvt) Ltd Mogale alloys Set Point Laboratories Hernic Ferrochrome(Pty) Ltd Mintek Analytical Laboratories Xstrata Alloys Assmang chrome SGS Richards Bay Samancor 17. NAME OF CERTIFYING OFFICERS Mr M. Mtakati, Manager Analytical Services ivision, TE. Mr S. A. Marsland, Head Reference Materials, Analytical Service ivision, Mintek
SARM74 Page 7 of 17 18. ata and istribution EY CHROME ISTRIBUTION OF RESULTS TIT ICP GRAV Titration Inductively coupled plasma Optical Spectrometry Gravimetric Cr % Average 49.7 49.50-49.83 0.270 13 lab METHO S N lab10 TIT 49.11 0.28 8 lab12 M GRAV 49.22 0.01 3 lab6 F TIT 49.58 1 lab1 A TIT 49.60 1 lab3 C1 ICP 49.62 0.17 6 lab8 H ICP 49.65 1 lab4 TIT 49.67 0.12 3 lab3 C2 TIT 49.76 0.12 6 lab9 J TIT 49.77 0.12 3 lab11 L TIT 49.78 0.10 3 lab7 G TIT 49.85 0.06 3 lab2 B TIT 49.91 0.06 3 lab5 E ICP 50.17 0.14 6 Laboratories with one result the average deviation was assigned. 49.0 M 49.7 F A C1 H C2 J L G B 50.4 E
SARM74 Page 8 of 17 EY IRON: ISTRIBUTION OF RESULTS TIT ICP AA XRF Titration Inductively coupled plasma Optical Spectrometry Atomic Absorbtion X Ray Fluorescence * Rejected Grubb s Test TOT Fe % Certified Value 95% Lab S N Average 37.5 37.1-37.8 0.520 11 lab METHO S lab12 M AA 36.33 0.01 3 lab10 J ICP 36.89 0.23 8 lab5.1 E2 TIT 37.3 0.050 4 lab7 G XRF 37.34 0.05 3 lab2 B ICP 37.40 0.10 3 lab6 F TIT 37.54 1 lab5.2 E1 ICP 37.55 0.10 6 lab3 C ICP 37.65 0.10 3 lab9 I TIT 37.80 0.10 3 lab4 TIT 37.83 0.06 3 lab11 TIT 38.4 0.253 3 lab1 A* ICP 39.80 1 Laboratories with one result the average deviation was assigned. 35. 37. M J G B F E C I 40. A
SARM74 Page 9 of 17 EY SILICON: ISTRIBUTION OF RESULTS TIT ICP Titration Inductively coupled plasma Optical Spectrometry * Failed Grubbs test for outliers Si % Certified Value 95% Lab S N Average 4.34 4.28-4.40 0.098 12 lab METHO S N lab6 F GRAV 4.20 1 lab12 M GRAV 4.23 0.03 3 lab3 C ICP 4.24 0.17 6 lab5.1 E2 GRAV 4.24 0.02 3 lab8 H ICP 4.31 1 lab11 ICP 4.33 0.01 3 lab2 B ICP 4.36 0.01 3 lab5.2 E1 ICP 4.38 0.02 6 lab7 G GRAV 4.40 0.07 3 lab4 GRAV 4.44 0.17 3 lab10 J GRAV 4.45 0.09 8 lab9 I ICP 4.50 0.00 3 lab1 A* ICP 5.07 1 Laboratories with one result the average deviation was assigned 3.735 85891 5.087 15497 F M C E2 H B E1 G J I 4.411 50694 A
SARM74 Page 10 of 17 EY CARBON: ISTRIBUTION OF RESULTS COM Combustion C % Certified Value 95% Lab S N Average 6.44 6.39-6.50 0.082 11 lab METHO S N lab5 E Com 6.33 0.02 2 lab8 H Com 6.36 1 lab9 I Com 6.40 0.00 3 lab12 Com 6.40 0.05 3 lab7 G Com 6.43 0.04 3 lab3 C Com 6.44 0.03 6 lab2 B Com 6.45 0.03 2 lab11 Com 6.46 0.04 3 lab10 J Com 6.49 0.07 8 lab4 Com 6.58 0.04 2 lab6 F Com 6.59 1 Laboratories with one result the average deviation was assigned 6.2 6.46 E H I 1 G C B 6.68 J F
SARM74 Page 11 of 17 EY SULPHER: ISTRIBUTION OF RESULTS COM Combustion S % Tentative* Value 95% Lab S N Average 0.04 0.035-0.045 0.007 11 lab METHO S N 10 COM 0.023 0.002 8 8 COM 0.033 1 3 COM 0.039 0.002 6 4 COM 0.040 1 9 COM 0.041 0.001 3 7 COM 0.041 0.001 3 11 COM 0.042 0.001 3 2 COM 0.045 0.000 2 6 COM 0.045 1 5 COM 0.046 0.001 2 12 COM 0.050 0.000 3 *Reason for tentative value, the Relative Inter - laboratory Standard deviation to high 18 % Laboratories with one result the average deviation was assigned 0.028 39678 L 0.042 16 H C J G B F E M 0.055 92321
SARM74 Page 12 of 17 EY PHOSPHOR: ISTRIBUTION OF RESULTS COL XRF Colorimetric UV VIS X Ray Fluorescence P % Tentative & Value 95% Lab S N Average 0.018 0.016-0.019 0.002 10 lab METHO S N lab6 F* XRF 0.0090 1 lab12 M ICP 0.0133 0.0006 3 lab1 A ICP 0.0150 1 lab11 ICP 0.0158 0.0004 3 lab2 B ICP 0.0167 0.0012 3 lab9 I ICP 0.0180 0.0000 3 lab8 H ICP 0.0190 lab3 C ICP 0.0197 0.0015 3 lab4 ICP 0.0197 0.0015 3 lab7 G COL 0.0197 0.0006 3 lab5 E COL 0.0202 0.0002 2 & Reason for tentative value, the Relative Inter - laboratory Standard deviation to high 20 % * Failed Grubbs. Laboratories with one result the average deviation was assigned 0.010 F 0.017 0.024 M A B I H C G E
SARM74 Page 13 of 17 EY VANAIUM: ISTRIBUTION OF RESULTS ICP XRF Inductively coupled plasma Optical Spectrometry X Ray Fluorescence V % Average 0.36 0.35-0.37 0.012 10 lab METHO S N lab11 ICP 0.35 0.006 3 lab10 J ICP 0.35 0.006 8 lab6 F ICP 0.35 1 lab7 G XRF 0.35 0.010 3 lab8 H ICP 0.35 1 lab2 B ICP 0.35 0.004 3 lab9 I ICP 0.36 0.006 3 lab5 E ICP 0.37 0.000 6 lab4 ICP 0.38 0.015 3 lab1 A ICP 0.38 1 lab3 C* ICP 0.48 0.014 6 * Failed Grubbs Laboratories with one result the average deviation was assigned 0.25 0.37 J F G H B I E A 0.49 C
SARM74 Page 14 of 17 EY TITANIUM: ISTRIBUTION OF RESULTS ICP XRF Inductively coupled plasma Optical Spectrometry X Ray Fluorescence. ^ Tentative distribution is to flat, kurtosis. * Failed Grubbs. TI % Tentative^ Value 95% Lab S N Average 0.47 0.46-0.49 0.019 9 lab METHO S N lab6 F* ICP 0.35 1 lab5 E ICP 0.44 0.000 6 lab9 I ICP 0.47 0.006 3 lab7 G XRF 0.47 0.033 3 lab2 B ICP 0.47 0.002 3 lab10 J ICP 0.48 0.008 8 lab8 H ICP 0.48 1 lab11 ICP 0.48 0.006 3 lab3 C ICP 0.48 0.014 6 lab1 A ICP 0.51 1 Laboratories with one result the average deviation was assigned F 0.41 E 0.47 I B J H C 0.53 G A
SARM74 Page 15 of 17 EY NICEL: ISTRIBUTION OF RESULTS ICP AA XRF Inductively coupled plasma Optical Spectrometry Atomic absorption X Ray Fluorescence Ni % Average 0.21 0.203-0.216 0.0103 12 lab METHO S N Lab2 B ICP 0.19 0.002 3 Lab4 ICP 0.20 0.010 3 Lab9 I ICP 0.20 0.006 3 Lab7 G XRF 0.21 0.006 3 Lab10 J ICP 0.21 0.010 6 Lab8 H ICP 0.21 1 Lab3 C ICP 0.21 0.008 6 Lab12 L AA 0.21 0.010 3 Lab5 E ICP 0.21 0.004 6 Lab6 F ICP 0.21 1 Lab11 ICP 0.22 0.000 3 Lab1 A ICP 0.23 1 Laboratories with one result the average deviation was assigned 0.183 B 0.211 18 I G J H C L E F 0.239 A
SARM74 Page 16 of 17 MANGANESE: ISTRIBUTION OF RESULTS AA ICP MS XRF Atomic Absorbtion Inductively coupled plasma Optical Spectrometry Inductively coupled plasma Mass Spectroscopy X Ray Fluorescence Mn % Tentative*^ Value 95% Lab S N 0.183 - Average 0.193 0.202 0.0170 13 lab METHO S N lab5.2 E2 MS 0.17 0.006 3 lab5.1 E1 ICP 0.17 0.000 6 lab4 ICP 0.18 0.006 3 lab10 J ICP 0.19 0.008 8 lab8 H ICP 0.19 1 lab9 I ICP 0.19 0.006 3 lab2 B ICP 0.20 0.002 3 lab6 F ICP 0.20 1 lab12 L AA 0.20 0.006 3 lab3 C ICP 0.20 0.005 6 lab7 G XRF 0.20 0.010 3 lab11 ICP 0.20 0.006 3 lab1 A ICP 0.23 1 * Reason for tentative value, the Relative Inter - laboratory Standard deviation to high 9 % ^ istribution is to flat, kurtosis.
SARM74 Page 17 of 17 COBALT: ISTRIBUTION OF RESULTS ICP AA MS XRF Inductively coupled plasma Optical Spectrometry Atomic Absorption Inductively coupled plasma Mass Spectroscopy X Ray Fluorescence ^ istribution is to flat, kurtosis. Co % Tentative^ Value 95% Lab S N Average 0.06 0.051-0.069 0.0150 13 lab METHO S N Lab8 H ICP 0.05 1 Lab5.2 E2 MS 0.050 0.0015 3 Lab4 ICP 0.050 0.0000 3 Lab9 I ICP 0.05 0.001 3 Lab2 B ICP 0.054 0.0012 3 Lab7 G XRF 0.05 0.002 3 Lab6 F ICP 0.055 1 Lab3 C ICP 0.055 0.0050 6 Lab11 ICP 0.06 0.001 3 Lab1 A ICP 0.059 1 Lab10 J ICP 0.06 0.001 8 Lab5.1 E1 ICP 0.092 0.0015 6 Lab12 L AA 0.10 0.001 3 Laboratories with one result the average deviation was assigned 0.014 0.061 H E2 I B G F C A J 0.107 E1 L