Study on determination of impurities in tungsten concentrates with ICP-MS

The determination of impurity elements of So, 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 Na2O2-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 Sc-45, In-115, Tl-205 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%similar to 101.5%, and the relative standard deviation was 1.2%similar to 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.