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前言钨钍合金主要用于电子工业,是一种重要的电真空材料。关于钨钍合金中钍的测定,据文献介绍可用钍试剂比色法、过氢化氢隐蔽钨等方法测定金属钨中的钍,但较为繁复并难以掌握。根据钍与氢氟酸反应,能定量生成难溶性的氟化钍沉淀(ThF_4·8H_2O)的原理。用氢氟酸直接溶解试样能将钍和大量钨分离,然后将氟化钍沉淀,溶解于加热至冒烟的硫酸中、转化成可溶性硫酸盐后进行络合滴定。近期来,关于络合滴定钍的文献报导甚多。在pH3的酸性介质中,EDTA 与钍络合生成十分稳定的1:1螯合物。在许多直接滴定、间接滴定和电位滴
Introduction Tungsten thorium alloy is mainly used in the electronics industry, is an important electrical vacuum materials. Thorium thorium alloy thorium determination, according to the literature available thorium reagent colorimetric, hydrogenated hydrogen hidden tungsten and other methods of determination of tungsten in tungsten, but more complicated and difficult to grasp. According to the reaction of thorium and hydrofluoric acid, the principle of quantitatively producing insoluble thorium fluoride precipitate (ThF_4 · 8H_2O) can be generated. Direct dissolution of hydrofluoric acid samples can thorium and a large number of tungsten separation, and then thorium fluoride precipitation, dissolved in sulfuric acid heated to smoke, into a soluble sulfate after complexometric titration. Recently, there are many reports about the complexation titration of thorium. In acidic media at pH 3, EDTA complexed with thorium to form a very stable 1: 1 chelate. In many direct titration, indirect titration and potential drops