X射线荧光光谱法测定碳化钨粉中钽、铌量

Determination of Tantalum and Niobium Contents in Tungsten Carbide Powder by X-ray Fluorescence Spectrometry

碳化钨粉是生产硬质合金的主要原材料,碳化钨粉中钽、铌含量是一个重要的成分指标,通常采用化学重量法、原子发射光谱法(AES)分析。本方法采用经典的压片制样法,将碳化钨氧化成三氧化钨混合磨匀,以消除颗粒效应,在无合适含钽、铌的碳化钨及三氧化钨标样情况下,采用在三氧化钨基体中加入钽、铌标准溶液的方式配制标样,采用变动的理论α影响系数法校正基体效应,建立了X射线荧光光谱仪(XRF)测定碳化钨粉中钽、铌含量的分析方法。校准曲线在钽质量分数0.005%~1.0%范围内相关系数为0.999,铌质量分数0.005%~1.0%范围内相关系数为0.999,方法加标回收率95.8%~104.0%,相对标准偏差(RSD,n=7)小于3.6%,分析结果同原子发射光谱法(AES)、化学重量法一致。

Tungsten carbide powder is the main raw material for the production of cemented carbide. Tantalum and niobium contents in tungsten carbide powder are usually analyzed by chemical gravimetric method and atomic emission spectrometry（AES）, as they are important components. In order to eliminate the particle effects, classic tablet sample preparation method was used in this method for oxidating from tungsten carbide into tungsten trioxide and grinding. The determination method with the X-ray fluorescence（XRF） spectrometer for the tantalum and niobium contents in tungsten carbide powder was established, in the absence of appropriate standard samples of tungsten carbide and tungsten trioxide, by using the theory of α influence coefficient method to correct the matrix effect, and making the prototype by the way of joining tantalum and niobium standard solution into tungsten trioxide matrix. In this method the correlation coefficient reaches 0.999 when the mass fraction of tantalum is within 0.005% ~1.0%, and the correlation coefficient reaches 0.999 when the mass fraction of niobium is within 0.005%~1.0%. The recovery rate of standard addition is in the range of 95.8%~104.0%. The relative standard deviation（RSD, n=7） is less than 3.6%. The analysis results are in accordance with that determined by the atomic emission spectrometry（AES） and chemical gravimetric methods.