ICP-MS法测定钨精矿中杂质元素

Determination of impurity elements in tungsten concentrates by ICP-MS

用ICP MS法同时测定钨精矿中Sn,P,Ca,Nb,Ta,Mo,Cu,Pb,Zn,As,Mn,Bi,Fe,Sb14种杂质元素含量。钨精矿试样经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。在样品溶液中加入内标元素45Sc,115In,205Tl,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。该方法加标回收率为90 5%～101 5%,相对标准偏差为1 2%～7 8%,分析结果与国家标准方法结果相吻合,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分析。

The contents of impurity elements of Sn,P,Ca,Nb,Ta,Mo,Cu,Pb,Zn,As,Mn,Bi,Sb and Fe in tungsten concentrates were determined directly by ICP-MS. After the samples were completely liquated by Na2O2-NaOH, tungsten was precipitated in the form of H2WO4 and separated from the solution of nitric acid. Adding internal standard elements of 45Sc, 115In, 205Tl to the sample solution, the effects of matrix and interface, and the fluctuation of instrument have been overcome effectively by use of matrix match and internal standard calibration method. By choosing the optional operation parameters and appropriate isotopes of determining element, the influence of mass spectrum interference has been conquered effectively. The effect of acidity on the separation of tungsten and the elements determined has been tested. The recovery for standard addition was 90.5% - 101.5%, and the relative standard deviation was 1.2% - 7.8%.This method is simple, rapid and accurate, and it can be used in the determination of tungsten concentrates and tungsten products.