EDTA络合滴定法快速测定碳酸锆中锆铪合量

Rapid determination of zirconium-hafnium oxide content in zirconium carbonate with EDTA compleximetry

锆铪氧化物合量的测定通常采用苦杏仁酸[C6H5CH(OH)COOH]重量法。该法经典、准确,但操作烦琐,分析时间长,对日常生产、入库或销售不利。乙二胺四乙酸二钠(EDTA)络合滴定法(容量法)操作简便、快速、准确,适合日常检验。但用基准氧化锌、高纯二氧化锆或氯氧化锆来标定EDTA时,测定结果偏低。采用重量法和容量法相结合,先用重量法测定锆铪氧化物合量,以已知锆铪氧化物合量的碳酸锆作标定物,再标定EDTA标准溶液的滴定度,用此EDTA标准溶液测定相同原料生产的碳酸锆。该法简便、快速、准确,试剂安全性好。

The content of zirconium - hafnium oxide is usually determined by mandelic acid （ alpha - Hydroxybenzeneacetic acid ） gravimetric analysis, which is traditional and accurate. But the procedure of this analysis is complicated, time - consuming and not convenient for daily production, storage and distribution. EDTA compleximetry （ volumetric analysis ） is simple,fast,accurate and suitable for daily analysis. However, its determination results were on the low side when using standard zinc oxide, high - purity zirconium dioxide or zirconyl chloride to calibrate the EDTA. This paper introduced a new method which combine the gravimetric analysis and volumetric analysis together i. e. determine the zirconium - hafnium oxide content of zirconium carbonate by gravimetric analysis at first, use zirconium carbonate （ whose zirconium - hafnium ox- ide content has been known） as the calibration agent to re - calibrate titer value of standard EDTA solution, then use this EDTA to determine the zirconium - hafnium oxide content of zirconium carbonate produced with the same raw material. This analysis is simple,fast and accurate and the reagents applied are safe.