钽内标X射线荧光光谱法测定钨精矿中WO_3

提出了以钽为内标波长色散X射线荧光光谱法测定钨精矿中WO3的新方法。以Na2B4O7和Li2B4O7(质量比65:35)的混合物作为熔剂,Ta2O5为内标,同时加入LiNO3为氧化剂,在1200℃下进行熔融制样,最后将本方法应用于实际样品的分析,结果表明,以钽作为内标测定WO3,不仅可以在很大程度上降低实验操作和仪器测量带来的偏差,也可以消除基体效应的影响。方法用于测定白钨精矿和黑钨精矿中WO3,其准确度和精密度优于重量分析法。

Determination of WO_3 in tungsten concentrate using tantalum internal standard X-ray fluorescence spectrometry

A method has been developed for the X-ray fluorescence determination of WO_3 in tungsten concentrate. The samples are fused with mixture flux of sodium tetraborate and lithium tetraborate (65∶35) at 1200℃, and tantalum pentoxide was added as the internal standard. After cooling the cast bead, the W Lα and TaLα fluorescence emission intensity was determined by X-ray fluorescence spectrometry. The standard calibration beads were prepared with specpure tungsten trioxide. Tungsten contents of the samples are found by comparing the measured intensity ratio between sample beads and standard calibration beads. The experiment results show that with tantalum as the internal standard, not only the errors introduced by experimental operation and machine measurement can be depressed greatly, but also the matrix effect can be eliminated. The proposed method provides simple, rapid operation and high precision, and can be used for the determination of the tungsten content in both worfremite and scheelite accurately. The accuracy and precision of the method are found to be superior to those of the classical gravimetric method.