光度法EDTA滴定法联合测定铌铁合金中Nb、Al

Combined Determination of Niobium and Aluminium in Ferro-Niobium Alloy by Spectrophotometry and EDTA Titration Method

建立了一种快速测定铌铁合金中Nb和Al的分析方法。以硝酸、氢氟酸、硫酸溶解试样,加热蒸发至硫酸冒烟以除去Si和F,用二甲酚橙光度法测定铌铁合金中Nb量。用氢氧化钠沉淀分离试液中Fe、Nb、Ti等干扰元素后,以氟盐置换EDTA滴定法测定Al量。该方法用于实际铌铁合金标样中Nb和Al的分析,测定值与标准值相符,Nb和Al相对标准偏差分别≤0.14%和≤5.30%。

One rapid analysis method for determination of niobium and aluminium in ferro-niobium alloy was built up. The sample was dissolved with nitric acid, hydrofluoric acid and sulfuric acid, and the silicon and fluorine were removed by accelerating the evaporation until sulfuric acid smoking. The content of niobium in the alloy was determined by xylenol orange spectrophotometry. Then after the sodium hydroxide was added to precipitate and separate the interference elements such as iron, niobium and titanium in solution. The content of aluminium was determined by fluoride salt replacement EDTA titration method. The measured value obtained by this method used in the analysis on niobium and aluminium in actual fen＇o-niobium alloy standard sample was in conformity with the standard value. The relative standard deviation of niobium and aluminium were respectively less than 0.14% and less than 5.30%.