CERTIFICATE OF ANALYSIS

Transcription

1 CERTIFIED REFERENCE MATERIAL Prepared by and Distributed by MINTEK P/Bag X3015 Randburg 2125 Republic of South Africa asdenquries@mintek.co.za Telephone : Fax : CERTIFICATE OF ANALYSIS SARM 146 Chrome ore 1. STATUS OF CERTIFICATE This is the first issue of the certificate. 2. DATE OF ORIGINAL CERTIFICATION 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.

2 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 20 µ screen 75 µ screen Replicate 1 54% 95% Replicate 2 56% 95% 11. 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. Al 2 O 3 Cr 2 O 3 Fe MgO MnO TiO 2 SiO Page 2 of 10

3 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 accreditation. 13. PROPERTY VALUES Property values Cr 2 O 3 % FeO % Al 2 O 3 % MgO % MnO % SiO 2 % TiO 2 % CaO % V % The 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 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

4 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; Fusion Bead - XRF (FB-XRF) Fusion ICP-OES (F-ICP-OES) Wet Chemistry titration (WC-Titration) 16. 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

5 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 F ICP-OES WC-Titration X-ray Fluorescence analysis after fused beads fusion preparation Inductively Coupled Plasma Optical Emission Spectroscopy after alkaline fusion preparation 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 was not included in the statistical evaluation for the property value. Page 5 of 10

6 Cr 2 O 3 % FB-XRF A F-ICP-OES B 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 FeO % 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 Page 6 of 10

7 Al 2 O 3 % 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 MgO % 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 Page 7 of 10

8 MnO % 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 23 F-ICP-OES SiO 2 % Z-score 30 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 Page 8 of 10

9 TiO 2 % FB-XRF F-ICP-OES F-ICP-OES F-ICP-OES F-ICP-OES FB-XRF F-ICP-OES F-ICP-OES FB-XRF FB-XRF F-ICP-OES F-ICP-OES CaO % 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 30 F-ICP-OES Page 9 of 10

10 V % F-ICP-OES F-ICP-OES F-ICP-OES FB-XRF F-ICP-OES F-ICP-OES F-ICP-OES 26 FB-XRF 27 F-ICP-OES 29 FB-XRF 30 F-ICP-OES 31 FB-XRF 20. References 1. The Preparation and Certification of a Chrome Reference Material - SARM 146, Mintek Report no Page 10 of 10