本研究采用熔片制样-波长色散X射线荧光光谱法测定铁矿石中二氧化硅含量,并对其不确定度进行了评定。建立了不确定度评估的数学模型,对不确定度来源进行了分析,分别计算出不确定度分量并合成不确定度,最终确定了分析结果的置信区间。评估结果表明,校准样品及工作曲线的不确定度对测量不确定度的影响最大。 In this study, the melting sample preparation - wavelength dispersive X-ray fluorescence spectrometry determination of silica content in iron ore, and its uncertainty was assessed. The mathematic model of uncertainty assessment was established, the sources of uncertainty were analyzed, the components of uncertainty were calculated and the uncertainty was synthesized respectively, and the confidence intervals of the analysis results were finally determined. The evaluation results show that the uncertainty of the calibration sample and working curve has the greatest impact on the measurement uncertainty.