便携式能量色散X射线荧光光谱仪测定红土镍矿中7种元素

Determination of seven elements in laterite nickel ore by portable energy dispersive X-ray fluorescence spectrometry

选取具有代表性的红土镍矿样品为校准样品,建立了便携式能量色散X射线荧光光谱仪直接测定粉末红土镍矿样品中Fe、Ni、Cr、Mn、Ti、Zn、Ca含量的分析方法。实验采用滴定法对校准样品中主量元素铁,电感耦合等离子体原子发射光谱法(ICP-AES)对其它元素进行定值,解决了红土镍矿标准样品短缺的问题。对校准样品的前处理方法及测定条件等进行了探讨,并通过研磨使校准样品与测试样品达到相同颗粒度以降低颗粒效应的干扰,同时利用仪器自带的NDTr软件,以基本参数法(FP法)自动校正元素间相互干扰效应。精密度试验结果表明,各组分相对标准偏差(n=7)在0.16%～8.3%之间。方法用于红土镍矿实际样品分析,测定结果与湿法分析结果吻合,能够满足现场大批量样品主次元素同时快速分析的需要。

A direct determination method of Fe, Ni, Cr, Mn, Ti, Zn and Ca in powdered laterite nick- el ore by portable energy dispersion X-ray fluorescence spectrometer was established using representa- tive laterite nickel ore samples as calibration sample. The main element iron in calibration sample was certified by titration, while other elements were certified by inductively coupled plasma atomic emis- sion spectrometry （ICP-AES）. This solved the shortage problem of laterite nickel ore certified refer- ence materials. The pretreatment methods of calibration sample and determination conditions were discussed. The particle size of calibration sample and testing sample was ground to the same level to reduce the interference of grain effect. Meanwhile, the mutual interference effect among elements was automatically corrected by fundamental parameter method （FP） with the NDTr software in instru- ment. The results of precision test indicated that, the relative standard deviations （RSD, n= 7） of testing elements were 0.16 %-8.3 %. The proposed method was applied to the determination of actu- al laterite nickel ore samples, and the results were consistent with those obtained by wet method. This method could meet the requirements for simultaneous and rapid determination of main and minor elements in a large sum of samples on the site.