熔融制样-X射线荧光光谱法测定铝电解槽用干式防渗料中主次成分

介绍了X射线荧光光谱法测定铝电解槽用干式防渗料中主次量成分(三氧化二铝、二氧化硅、三氧化二铁、二氧化钛、氧化钾、氧化钠、氧化钙、氧化镁)的方法。根据干式防渗料中主次成分的含量范围, 采用相似标样和高纯化学试剂配制校准样品建立校准曲线。试验表明, 以四硼酸锂与偏硼酸锂混合熔剂〔m(Li₂B₄O₇)∶m(LiBO₂)=12∶22〕熔融制样, 控制熔剂和试样比为10∶1, 在1 100 ℃温度下熔样, 以1滴溴化锂饱和溶液作脱模剂, 制备的样片测量效果较好。采用理论α系数或基本参数法校正元素间的吸收-增强效应。对拟定方法的精密度进行考察, 主量组分11次测定的相对标准偏差小于0.50%, 次量组分11次测定的相对标准偏差均小于5.0%。对干式防渗料实际样品和粘土标准样品进行准确度验证, 测量值与化学值或标准样品的认定值基本一致。

Determination of major and minor components in dry barrier of aluminum electrolytic cell by X-ray fluorescence spectrometry with sample fusion preparation

The X-ray fluorescence determination of major and minor components in dry barrier of aluminum electrolytic cell was introduced, including Al₂O₃, SiO₂, Fe₂O₃, TiO₂, K₂O, Na₂O, CaO, MgO. According to the content range of major and minor components in dry barrier, similar standard samples and highly-pure chemical reagent were adopted to prepare calibration sample and establish calibration curve. It was showed that the determination results of the sample disks obtained were more satisfactory when the sample was fused at 1 100 ℃ with the mixture of lithium tetraborate and lithium metaborate m(Li₂B₄O₇)∶m(LiBO₂)=12∶22] and controlling the ratio of flux toward sample as 10∶1 and adding one drop release agent of lithium bromide saturated solution. The absorption-enhancement effect between elements was calibrated with theoretical α coefficient and fundamental parameter methods. The precision of the proposed method was tested. The relative standard deviations of eleven tests were less than 0.50 % for major component and less than 5.0 % for other component. The accuracy of practical dry barrier standard sample and clay standard sample was verified, whose results were basically consistent with the chemical values or the certified values of standard samples.