熔融制样-X射线荧光光谱法测定硅钙钡合金中硅钙钡磷铝

为消除硅钙钡合金试样熔融制片时侵蚀铂-黄坩埚的难题,实验中硅钙钡样品以四硼酸锂-碳酸锂(m∶m=2∶1)为预氧化熔剂,在石墨垫底的瓷坩埚中高温熔融成熔球,再将熔球转到铂-黄坩埚中,再用四硼酸锂为熔剂熔融制成玻璃片,这样铂-黄坩埚在熔融制样过程中的腐蚀问题得到了有效解决,实现了熔融制样-X射线荧光光谱法(XRF)对硅钙钡合金中硅、钙、钡、磷、铝的测定。实验确定了最佳制样条件:0.2000g试样、2.0000g四硼酸锂、1.0000g碳酸锂在石墨垫底的瓷坩埚中,500℃灰化完全,900℃熔融15min,取出冷却;移入盛有3.0000g四硼酸锂的铂-黄坩埚中,加0.50mL 300g/L碘化钾脱模剂,在1150℃熔融15min,取出摇匀,再熔融15min,取出摇匀冷却,制得均匀玻璃片。实验方法选用具有适当梯度的硅钙钡合金标样和内控样绘制校准曲线,各待测元素校准曲线的相关系数r≥0.9997。精密度结果表明,各元素测定结果的相对标准偏差(RSD,n=10)在0.11%~5.9%;正确度结果表明,硅钙钡合金标样采用本法分析,其测定值与标准值相吻合。硅钙钡试样采用本法分析,其测定值与行业标准的分析值一致性较好,并进行了成对数据t检验,结果表明本法与行业标准分析方法无显著性差异,能满足日常生产检测要求。

Determination of silicon,calcium, barium,phosphorus, aluminum in silicon-calcium-barium alloy by X-ray fluorescence spectrometry with fusion sample preparation

In order to eliminate the corrosion problem of platinum-gold crucible during fusion sample preparation of silicon-calcium-barium alloy, the silicon-calcium-barium alloy sample was melted to molten ball at high temperature in porcelain crucible with graphite at the bottom using lithium tetraborate-lithium carbonate (m∶m=2∶1) as the pre-oxidation flux. Then the molten ball was transferred into platinum-gold crucible to prepare glass sheets using lithium tetraborate as the flux. In this way, the corrosion problem of the platinum-gold crucible in the process of fusion and sample preparation was effectively solved. The determination of silicon, calcium, barium, phosphorus and aluminum in silicon-calcium-barium alloy by X-ray fluorescence spectrometry (XRF) with fusion sample preparation was realized. The optimal sample preparation conditions were obtained in experiments: 0.2000g of silicon-calcium-barium alloy sample, 2.0000g of lithium tetraborate and 1.0000g of lithium carbonate were mixed in a porcelain crucible with graphite underlay; after complete ashing at 500℃ and fusion at 900℃ for 15min, the mixture was taken out for cooling and then transferred into platinum-gold crucible; 3.0000g of lithium tetraborate and 0.50mL of 300g/L potassium iodide as release agent were added; after fusion at 1150℃ for 15min, the mixture was taken out for shaking followed by fusion for another 15min; finally the mixture was taken out for shaking, cooling and preparation of uniform glass sheets. The certified reference materials and internal control sample of silicon-calcium-barium alloy with proper concentration gradient were employed to prepare the calibration curves. The correlation coefficients of calibration curves were all greater than or equal to 0.9997. The precision test results indicated that the relative standard deviations (RSD, n=10) of the measured results were between 0.11% and 5.9%. The accuracy test results showed that measured values of silicon-calcium-barium alloy standard sample were consistent with the standard values. The silicon-calcium-barium alloy samples were analyzed according to the experimental method, and the found results were in good agreement with those obtained by the industry standard. Moreover, the t-test of paired data was carried out. It indicated that there was no significant difference between proposed method and the industry standard analysis method. The proposed method could meet the requirements of daily production inspection.