锑矿石化学物相分析方法精密度的确定与评估

长期以来化学物相分析方法的精密度一直没有得到科学的量化控制,实验室间的精密度更是缺少控制限要求。实验在建立我国具有代表性锑矿石化学物相分析方法的过程中,按照标准GB/T6379.2—2004《测量方法与结果的准确度(正确度与精密度)第2部分:确定标准测量方法重复性与再现性的基本方法》,通过配制6个水平的协作试验样品,选择Al_2O_3、TFe(以Fe_2O_3形式表示)、CaO、MgO、Sb、S等主量组分或元素进行均匀性检验,检验结果 F值均小于临界值4.39,表明试验样品是均匀的。组织8家实验室进行协作试验,获得锑总量和3个锑矿物相中的锑随质量分数(m)变化的重复性限(r)和再限性限(R),结果表明,在确定的矿石中总锑和各矿物相中锑的重复性限和再现性限中,总锑的重复性限和再现性限最小,均小于锑矿石各相态分析的重复性限和再现性限,化学物相分析方法重复性限和再现性限参数验证了化学物相分析误差主要来源于串相误差的基本特性。锑矿石化学物相的精密度为锑矿石化学物相分析标准方法的建立和质量控制提供了依据。

Precision determination and evaluation of antimony ore chemical phase analysis method

For a long time,the precision in chemical phase analysis has not been scientifically quantified, and there were no control limit requirements for precision in inter-laboratory tests. The chemical phase analysis method with representative antimony ores was established. According to GB/T 6379.2-2004 of Accuracy(trueness and precision)of measurement methods and results—Part 2:Basic method for the determination of repeatability and reproducibility of a standard measurement method, the homogeneity examination were conducted by preparing the cooperation test samples of six levels and selecting major components or elements including Al₂O₃, TFe (in Fe₂O₃), CaO, MgO, Sb and S. The values of F of determination results were all less than the critical value (4.39), indicating the good homogeneity of test samples. The cooperation tests were performed in 8 laboratories. The variation of repeatability limit (r) and reproducibility limit (R) of the total antimony and its component in three mineral phase with the mass fraction change of antimony (m) were obtained. The results showed that the repeatability limit and reproducibility limit of total antimony were minimal among those of selected mineral phases. In other words, the repeatability limit and reproducibility limit of total antimony were less than that of antimony in mineral phases. The parameters of repeatability limit and reproducibility limit in chemical phase analysis method proved the basic characteristic that chemical phase analysis error was mainly from by other mineral phases. The precision of antimony ore chemical phase provided basis for the establishment and quality control of antimony ore chemical phase analysis method.