钨精矿中杂质元素ICP-MS测定方法的研究

Study on Determination of Impurities in Tungsten Concentrates with ICP-MS

摘要:

采用电感耦合等离子质谱技术，研究了钨精矿中Sn，P，Ca，Nb，Ta，Mo，Cu，Pb，Zn，As，Mn，Bi，Fe，Sb 14种杂质元素含量的质谱分析方法。钨精矿样经NaOH-Na2O2碱熔后，加入硝酸，钨以钨酸的形式从溶液中沉淀而分离，消除了钨基体的干扰。在试样溶液中加入内标元素Sc，In，Tl，采用内标法进行校正，有效克服了基体效应、接口效应及仪器波动所产生的影响：通过优化仪器工作参数，选择适当的待测元素的同位素，有效地克服了因质谱干扰所带来的影响。方法的加标回收率为90．5％～101．5％，相对标准偏差为1．2％～7．8％，分析结果与按国家标准方法分析的结果相吻合，且具有快速、简便、准确等特点，可用于钨精矿及钨产品中杂质元素含量分析。

Abstract:

The determination of impurity elements of Sn, P, Ca, Nb, Ta, Mo, Cu, Pb, Zn, As, Mn, Bi and Fe in tungsten concentrates have been studied using ICP-MS. After the samples were completely liquated by Na202-NaOH, tungsten was precipitated in the form of H2WO4 and separated from the solution on the addition of water and nitric acid. Adding internal standard elements of ^45Sc, ^115In, ^205T1 to the sample solution, the effect of matrix, interface and fluctuation of instrument has been overcome effectively by use of matrix match and internal standard calibration method. By choosing the optional operation parameters and appropriate isotopes of element to be detected, the influence of mass spectrometry interference has been conquered effectively. The effect of acidity on the separation of tungsten and detected elements has been tested. The recovery for spiking sample was 90.5%-101.5%, and the relative standard deviation was 1.2%-7.8%. This method is a simple, rapid and accurate method, and it could be used in the testing of tungsten concentrates and tungsten products.