硫化物矿物标准物质的研制

The Preparation of Sulphide Mineral Reference Materials Research Group of Sulphlde Mineral Reference Materlals

研制的黄铁矿、黄铜矿、方铅矿和闪锌矿４个标准物质是国内首次成功研制的硫化物矿物成分分析标准物质。样品采用重选、磁选和电磁选等选矿技术提纯矿物，获得纯度大于９５％的单矿物样品。黄铁矿和闪锌矿用棒磨机少量多级粉碎至０．１４７ｍｍ，方铅矿和黄铜矿用小型玛瑙球磨机粉碎至０．０９７ｍｍ。经单因素方差分析检验，均匀性符合要求。采用小包装在干燥、充氩气气氛中保存样品，使样品稳定性有足够保证。连续４年定期监测了样品中全硫含量，证明稳定性良好。样品由国内经计量认证的５家实验室采用多种分离富集手段、不同原理方法协同分析。标准值的确定依据数据分布特征而定，对于服从正态分布的元素，用算术平均值作为定值，对不服从正态分布的元素用多参数模式定值。共确定了５６个标准值，１６个参考值，６个信息值。该批标准物质于１９９４年１２月通过了国家标准物质研究中心组织的专家复审，并于１９９５年４月被国家技术监督局批准为国家一级标准物质，标准号分别为ＧＢＷ０７２６７（ＧＳＭ－１）、ＧＢＷ０７２６８（ＧＳＭ－２）、ＧＢＷ０７２６９（ＧＳＭ－３）、ＧＢＷ０７２７０（ＧＳＭ－４）。

he preparation of four sulphide mineral reference materials---pyrite,chalcopyrite,galenaand sphalerite was accomplished which was the first successful attempt in China. The referencematerial candidates were subjected to gravitational, magnetic and electromagnetic separations toobtain enough quantities of minerals with a purity of>95%. Pyrite and sphalerite were grounded to 0.147 mm in a cylinder mill and chalcopyrite and galena to 0.097 mm in an agate ball mill.The F-test results showed that the degree of homogeneity is satisfactory for all samples. The prepared materials were packed in small bottles and stored in desiccator under argon atmosphere tomake sure that the homogeneity and stability of the sarnples to meet the technical requirements of the CRMs. Four years of continuous monitoring of the total sulphur contents showed that thematerials are stable under the above mentioned storage condition. The contents of the componentsof the materials were determined using various techniques by five accredited laberatories withdifferent separation and preconcentration procedures. Arithmetic mean is used as certified valuewhen the data of an element are normally distributed. But if the data are not normally distributedthe value derived from a multi-parameter data processing model is used as the certified value. 56certified values,16 reference values and 6 information values were given. The above four RMs have been examined by an expert group called by the Research Center for CRMs in 1994 and were accepted as CRMs(GBW O7267,GBW 07268,GBW 07269 and GBW 07270 respectively)by the State Bureau of Technical Supervision in April l995.