CERTIFICATE OF ANALYSIS SARM 74 FERROCHROME METAL

Transcription

1 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 info@mintek.co.za Telephone: fax: STATUS OF CERTIFICATE This is the first issue of the certificate. 2. ATE OF ORIGINAL CERTIFICATION 19 July 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.

2 SARM74 Page 2 of 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) / % Sympatec WINOX esignator Mean value Upper limit Lower limit Comparison curve Nr. 1 Nr. 2 Graph 1 Graph 1: Particle size distribution particle size / µm 11. STATE OF HOMOGENEITY 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)

3 SARM74 Page 3 of CERTIFIE AN TENTATIVE PROPERTY VALUES INCLUING CONFIENCE LIMITS AN INTER-ORATORY STANAR EVIATION. Table 1 Certified and Tentative values Cr % Average TOT Fe % Average Si % Average C % Average S % Tentative* Value 95% Lab S N Average P % Tentative & Value 95% Lab S N Average V % Average TI % Tentative^ Value 95% Lab S N Average Ni % Average Mn % Tentative #$ Value 95% Lab S N Average Co % Tentative +Q Value 95% Lab S N Average *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.

4 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 Cu % Information Value Range N Median O % Information Value N Median N ppm Information Value Range N Median Cr VI ppm Information Value N Median < 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.

5 SARM74 Page 5 of 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.

6 SARM74 Page 6 of 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

7 SARM74 Page 7 of ata and istribution EY CHROME ISTRIBUTION OF RESULTS TIT ICP GRAV Titration Inductively coupled plasma Optical Spectrometry Gravimetric Cr % Average lab METHO S N lab10 TIT lab12 M GRAV lab6 F TIT lab1 A TIT lab3 C1 ICP lab8 H ICP lab4 TIT lab3 C2 TIT lab9 J TIT lab11 L TIT lab7 G TIT lab2 B TIT lab5 E ICP Laboratories with one result the average deviation was assigned M 49.7 F A C1 H C2 J L G B 50.4 E

8 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 lab METHO S lab12 M AA lab10 J ICP lab5.1 E2 TIT lab7 G XRF lab2 B ICP lab6 F TIT lab5.2 E1 ICP lab3 C ICP lab9 I TIT lab4 TIT lab11 TIT lab1 A* ICP Laboratories with one result the average deviation was assigned M J G B F E C I 40. A

9 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 lab METHO S N lab6 F GRAV lab12 M GRAV lab3 C ICP lab5.1 E2 GRAV lab8 H ICP lab11 ICP lab2 B ICP lab5.2 E1 ICP lab7 G GRAV lab4 GRAV lab10 J GRAV lab9 I ICP lab1 A* ICP Laboratories with one result the average deviation was assigned F M C E2 H B E1 G J I A

10 SARM74 Page 10 of 17 EY CARBON: ISTRIBUTION OF RESULTS COM Combustion C % Certified Value 95% Lab S N Average lab METHO S N lab5 E Com lab8 H Com lab9 I Com lab12 Com lab7 G Com lab3 C Com lab2 B Com lab11 Com lab10 J Com lab4 Com lab6 F Com Laboratories with one result the average deviation was assigned E H I 1 G C B 6.68 J F

11 SARM74 Page 11 of 17 EY SULPHER: ISTRIBUTION OF RESULTS COM Combustion S % Tentative* Value 95% Lab S N Average lab METHO S N 10 COM COM COM COM COM COM COM COM COM COM COM *Reason for tentative value, the Relative Inter - laboratory Standard deviation to high 18 % Laboratories with one result the average deviation was assigned L H C J G B F E M

12 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 lab METHO S N lab6 F* XRF lab12 M ICP lab1 A ICP lab11 ICP lab2 B ICP lab9 I ICP lab8 H ICP lab3 C ICP lab4 ICP lab7 G COL lab5 E COL & Reason for tentative value, the Relative Inter - laboratory Standard deviation to high 20 % * Failed Grubbs. Laboratories with one result the average deviation was assigned F M A B I H C G E

13 SARM74 Page 13 of 17 EY VANAIUM: ISTRIBUTION OF RESULTS ICP XRF Inductively coupled plasma Optical Spectrometry X Ray Fluorescence V % Average lab METHO S N lab11 ICP lab10 J ICP lab6 F ICP lab7 G XRF lab8 H ICP lab2 B ICP lab9 I ICP lab5 E ICP lab4 ICP lab1 A ICP lab3 C* ICP * Failed Grubbs Laboratories with one result the average deviation was assigned J F G H B I E A 0.49 C

14 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 lab METHO S N lab6 F* ICP lab5 E ICP lab9 I ICP lab7 G XRF lab2 B ICP lab10 J ICP lab8 H ICP lab11 ICP lab3 C ICP lab1 A ICP Laboratories with one result the average deviation was assigned F 0.41 E 0.47 I B J H C 0.53 G A

15 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 lab METHO S N Lab2 B ICP Lab4 ICP Lab9 I ICP Lab7 G XRF Lab10 J ICP Lab8 H ICP Lab3 C ICP Lab12 L AA Lab5 E ICP Lab6 F ICP Lab11 ICP Lab1 A ICP Laboratories with one result the average deviation was assigned B I G J H C L E F A

16 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 Average lab METHO S N lab5.2 E2 MS lab5.1 E1 ICP lab4 ICP lab10 J ICP lab8 H ICP lab9 I ICP lab2 B ICP lab6 F ICP lab12 L AA lab3 C ICP lab7 G XRF lab11 ICP lab1 A ICP * Reason for tentative value, the Relative Inter - laboratory Standard deviation to high 9 % ^ istribution is to flat, kurtosis.

17 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 lab METHO S N Lab8 H ICP Lab5.2 E2 MS Lab4 ICP Lab9 I ICP Lab2 B ICP Lab7 G XRF Lab6 F ICP Lab3 C ICP Lab11 ICP Lab1 A ICP Lab10 J ICP Lab5.1 E1 ICP Lab12 L AA Laboratories with one result the average deviation was assigned H E2 I B G F C A J E1 L