辛可宁重量法测定钨铁中钨含量方法的改进

IMPROVEMENT ON THE CINCHONINE GRAVIMETRIC METHOD FOR THE DETERMINATION OF TUNGSTEN CONTENT IN FERROTUNGSTEN

研究了辛可宁重量法测定钨铁中钨含量的分析方法。试料以硝酸、氢氟酸溶解,以硫酸冒大量白烟驱氟。加水和盐酸溶解可溶性盐类,不溶性残渣以碳酸钠熔融。在盐酸溶液中,以辛可宁和α-安息香肟使钨酸沉淀完全。过滤、灼烧,得到不纯的三氧化钨,称重。用碳酸钠熔融不纯的三氧化钨,热水溶解后生成钨酸钠溶于水中,其他不溶杂质过滤、灼烧、称重,由两次质量差计算钨的质量分数。若试样中含有钼,则进行钼的光度法测定,校正钨量。该方法应用到实际生产中,具有很好的回收率和精密度,分析结果稳定。

It studies the analytical method for the determination of tungsten content in ferrotungsten by cinchonine gravimetric method.The sample is dissolved in nitric acid and hydrofluoric acid,and a large amount of white smoke is emitted by sulfuric acid to drive fluorine.The soluble salts are dissolved with water and hydrochloric acid,and the insoluble residue is with sodium carbonate fusion.In hydrochloric acid solution,tungstic acid is completely precipitated with cinchonine andα-benzoin oxime.After filtration and ignition,impure tungsten trioxide is obtained and weighed.The impure tungsten trioxide is melted with sodium carbonate and dissolved in hot water to form sodium tungstate.Other insoluble impurities are filtered,ignited and weighed.The mass fraction of tungsten is calculated by two mass differences.If there is molybdenum in the sample,molybdenum shall be determined by spectrophotometry and tungsten content shall be corrected.The method has been applied to practical production with good recovery and precision,and stable analysis results.