硫酸高铁铵滴定法测定制备金属钛的电解质熔盐中Ti2+和Ti3+

摘要

Based on the basic principle of TaaakoBaC ammonium ferric sulfate titration) , the content of Ti2+ , Ti3+ and low-valence titanium (Ti2+ + Ti3+ ) in metallic titanium electrolyte was determined through two steps under CO2 protection atmosphere. The sample was dissolved by HC1-HF, the Ti2+ was oxidized to Ti3+ with H+. Then, Ti2+ + Ti3+ was oxidized to Ti4+ with ammonium ferric sulfate. The excessive Fe3+ was titrated with titanium trichloride standard solution. The key influencing factors on determination results, such as addition amount of ammonium ferric sulfate, reaction acid, standard titration solution and oxygen interference, were tested to obtain the optimal reaction conditions. The low-valence titanium in two metallic titanium electrolytes was determined under the optimized conditions. The relative standard deviations (RSD, n=8) were less than 10 %. The recovery of pure Ti2O3 and TiO was higher than 97 %, which could meet the analytical requirements.%利用TaσakoBa(硫酸高铁铵滴定法)的基本原理,在CO2保护气氛下,分两步测定出金属钛电解质中的Ti2+、Ti3+,以及低价钛的合量(Ti2++ Ti3+).文中采用HCl-HF溶解试样,用H+氧化Ti2+为Ti3+,用硫酸高铁铵氧化Ti2+和Ti3+为Ti4+,用三氯化钛标准滴定溶液滴定过量的Fe3+.文中对影响测定结果的关键因素,如硫酸高铁铵加入量、反应酸、标准滴定溶液、氧气干扰等进行了试验,确定最佳反应条件.在优化的条件下,测定了两个金属钛电解质中的低价钛,结果的相对标准偏差(RSD,n=8)均小于10％.纯物质Ti2 O3和TiO的加标回收率在97％以上,满足分析要求.