铌铁中Al、P的快速测定方法研究

试样以过氧化钠熔融后用水浸取,定溶后干过滤,使铝于铁、铌等干扰元素分离,加过量EDTA再调PH值于4.5左右,使铝完全络合,以PAN为指示剂,用硫酸铜标准溶液回滴过量的EDTA,加入氟化钠使Al-EDTA解蔽,释放出与铝等量的EDTA,再用硫酸铜标准溶液滴定,由此计算Al的含量。分取滤液以钼酸铵-酒石酸钾钠混合溶液掩蔽硅并使磷生成“磷钼黄”,以氟化钠-二氯化锡掩蔽铁并将“磷钼黄”还原成“磷钼蓝”,测量吸光度。

Research on Method for Fast Determination of Al, P in Ferroniobium

Melted with sodium oxide, samples were leached with water and after the fixation of solution, dry filtrated, to separate aluminium from the interfering elements such as iron and niobium. Excessive EDTA was added to adjust PH values at around 4, 5 ,and make aluminium fully complexed. Then with PAN as an indicator,the standard solution of copper sulphate was used to titrate again the excessive EDTA, and sodium fluoride was added to damask Al-EDTA and release EDTA equivalent to aluminium and once again the standard solution of copper sulphate was used to titrate, by which the content of Al was counted, The filtrate was separated and the mixed solution of ammonium molybdium and sodium-potassium tartrate used to mask silicon and make phosphor form phosphomolybdate yellow. Sodium fluoride and stannous chloride was used to mask iron and reduce phosphomolybdate yellow into phosphomolybdate blue, by which absorbency is determined.