DESCRIPTION The source material for HV-2, two lots of ore grade material and a molybdenum concentrate, was donated by Highland Valley Copper in Logan Lake, British Columbia in 1997. The ore grade materials were dried at 66°C for 24 hours and the concentrate was dried at 105°C for 4.5 hours. After crushing and sieving each component separately to a mesh size of less than 75 µm, the yields were 49% and 47% for the two ores, and 7% for the concentrate. After blending, the resulting fine powder was put in glass bottles containing 200-g. This is the only size available. The mineralogy of the material includes quartz, plagioclase, orthoclase, kaolinite/sericite, amphibole, calcite, muscovite, bornite, chalcopyrite, hematite, apatite, rutile, molybdenite and barite. INTENDED USE HV-2 is suitable for use in applications involving the analysis of copper and molybdenum at minor levels. Examples of intended use are for quality control in the analysis of samples of a similar type, method development, arbitration and the calibration of equipment. INSTRUCTIONS FOR USE HV-2 should be used “as is”, without pre-treatment. The contents of the bottle should be thoroughly mixed before taking samples. The material can be stored at room temperature and pressure with no special precautions. HAZARDOUS SITUATION Normal safety precautions such as the use of safety glasses, breathing protection for fine particulate matter, gloves and a laboratory coat are suggested. LEVEL OF HOMOGENEITY Twenty-two bottles of HV-2 were chosen according to a random stratified sampling scheme. Samples of 250 mg were analyzed from two splits taken from each selected bottle. Hydrochloric, nitric, perchloric and hydrofluoric acids were used to digest the samples and the determination of copper and molybdenum was performed using atomic absorption spectroscopy. A one–way analysis of variance technique (ANOVA) was used to assess the homogeneity of these elements (1). The ratio of the between-bottles to within-bottle mean squares is compared to the F statistic at the 95% level of probability. No evidence of inhomogeneity was observed for copper and molybdenum. Further details are available in the certification report. Use of a sample mass smaller than 250 mg will invalidate the statistical parameters contained herein. CERTIFIED VALUES Fourteen industrial, commercial, and government laboratories participated in an interlaboratory measurement program. Copper, molybdenum and other elements were analyzed by methods of each laboratory's choice including various acid digestions, fusion, x-ray fluorescence, flame atomic absorption spectroscopy, inductively coupled plasma – optical emission spectroscopy, inductively coupled plasma – mass spectroscopy. A one-way analysis of variance technique was used to estimate the consensus value and other statistical parameters (1). The two criteria for certification involve the within- and between-laboratories standard deviations and the number of sets with acceptable agreement. Copper and molybdenum were given certified values, which, along with the associated statistical parameters, are indicated in Table 1. Full details of all phases of the work, including statistical analysis, the methods and the names of the participants are contained in CCRMP Report 04-1E. UNCERTIFIED VALUES Informational values are listed in Table 2 and are based on the mean of a minimum of two methods and/or two laboratories. TRACEABILITY The certified values quoted herein are based on the consensus value derived from the statistical analysis of the data from the interlaboratory measurement program. |
