X射线荧光光谱法同时测定矿石中铀和钍

建立了X射线荧光光谱法测定矿石样品中铀、钍含量的快速分析方法。采用高压粉末制样法,对不同含量的放射性样品的压片压力、粒径、含水率、用量等处理条件到进行单因素实验。在400 MPa压力下压制,克服了低压制样的弊端,制备的样片表面光滑、致密,大幅改善了制样重现性,有效地减少了部分基体效应,铀校准曲线的标准偏差从0.053%降到0.0071%,钍校准曲线的标准偏差从0.062%降到0.0057%。经国家一级标准物质验证,表明方法准确、可靠,能满足样品中铀、钍含量日常分析要求。

Simultaneous Determination of Uranium and Thorium in Ores by X-ray Fluorescence Spectrometry

A method for the determination of uranium and thorium in ores was established by X-ray fluorescence spectrometry. The samples were made by high pressure powder sampling preparation method. Experiment parameters, such as tablet pressure, particle size, moisture content and dosage of radioactive sample with different concentrations, were investigated through single factor tests. The samples were pressed under 400 MPa to overcome the disadvantages of low press sampling preparation method, which making the samples pressed smooth and compact. This sampling preparation method could improve obviously the reproducibility of samples, and effectively reduce the part of the matrix effect. The standard deviations of uranium and thorium in calibration curve were reduced to 0.0071% from 0.053% and to 0.0057% from 0.062%, respectively. The method was validated by the analysis of national reference materials. The results showed that the proposed method was accurate and reliable for determining uranium and thorium content in ores for daily analysis.