铌钽精矿标准物质研制

铌钽精矿标准物质在监控选冶样品分析的过程起到重要作用,在选厂及冶金系统有很大的需求,国内外的文献检索均未发现铌钽精矿标准物质的报道;而铌钽矿物的性质决定了铌钽精矿的粉碎粒度及均匀性对铌钽精矿标准物质的研制提出了更高的要求。本文阐述了4个铌钽精矿标准物质的研制过程,铌钽精矿采集于宜春及尼日利亚铌钽选厂,样品经气流粉碎和高铝球磨两次细碎及机械混匀后,随机抽取包装好的样品进行均匀性和稳定性检验及定值。采用电感耦合等离子体发射光谱法与质谱法(ICP-OES/MS)进行均匀性和稳定性检验,结果表明样品的均匀性和稳定性良好。采用多个实验室协同测试的定值方式,利用不同原理的分析方法对此样品的铌钽等12个元素进行定值,给出了各定值元素的认定值和不确定度。4个铌钽精矿标准物质Ta(Nb)_2O_5的含量为9. 89%、20. 55%、40. 79%、53. 69%,形成一个从粗精矿到精矿较为完整的含量体系,可以满足选冶试验各阶段流程样品分析对标准物质的需求。

Preparation and Certification of Niobium-Tantalum Concentrate Reference Materials

BACKGROUND: Niobium-tantalum concentrate reference materials play an important role in monitoring mineral smelting and sample analysis. There is a great demand of niobium-tantalum concentrate reference materials in the dressing plant and metallurgical system, but no domestic and foreign literature has reported these materials. The nature of niobium-tantalum mineral determines the crushed grain size and homogeneity of the niobium-tantalum concentrate and puts forward higher requirements for the development of a niobium-tantalum concentrate standard substance.
OBJECTIVES: To develop the four standard materials of niobium-tantalum concentrate with different contents.
METHODS: The preparation process of niobium-tantalum concentrate reference materials is introduced. Niobium-tantalum concentrate samples collected from the Yichun and Nigeria selection plant were finely milled and mechanically mixed by air milling and high-alumina ball milling. The packaged samples were randomly selected for homogeneity and stability testing and determined values. The homogeneity and stability of the samples were tested by Inductively Coupled Plasma-Optical Emission Spectrometry/Mass Spectrometry (ICP-OES/MS).
RESULTS: Twelve elements of different samples are detected by the different analytical methods, with a calibration method for collaborative testing in multiple laboratories, the certified value and uncertainty of each element are given. The samples have good uniformity and stability.
CONCLUSIONS: The contents of Ta(Nb)₂O₅ in the four antimony concentrates are 9.89%, 20.55%, 40.79% and 53.69%, respectively, forming a complete system from crude concentrates to concentrates, which meets the sample requirements for reference materials in the stages of metallurgical tests.