强碱分离-硫酸铁铵滴定法直接测定钛合金中钛  

Direct determination of titanium in titanium alloy by ammonium ferric sulfate titrimetry with strong alkali separation

作　　者：张霞 王艳敏 于雪 陈雪莹 张真焕 孟庆榕 ZHANG Xia;WANG Yanmin;YU Xue;CHEN Xueying;ZHANG Zhenhuan;MENG Qingrong(NCS Testing Technology Co.,Ltd.,Beijing 100094,China)

机构地区：[1]钢研纳克检测技术股份有限公司,北京100094

出　　处：《冶金分析》2023年第10期90-95,共6页Metallurgical Analysis

摘　　要：钛合金中除钛外的其他元素含量的测定有很多方法,但是钛含量的直接测定却鲜有报道。通过对各种类型的钛合金元素含量进行分析发现,在用硫酸铁铵溶液直接滴定钛时,会有很多元素干扰测定。将钛合金溶解之后,补加6 mL 80 g/L三氯化铁溶液,之后加入氢氧化钠溶液分离可能存在的干扰元素如钒、钼、铬、锡等,过滤得到钛的氢氧化物沉淀,将钛的沉淀经酸溶解之后,加入70 mL盐酸溶盐,4 g铝箔还原钛,以20 mL 100 g/L硫氰酸铵做指示剂,迅速用硫酸铁铵溶液进行滴定,通过对结果进行换算,实现了钛合金中钛的直接测定。对钛合金样品进行精密度考察,结果的相对标准偏差(RSD,n=11)为0.09%~0.12%;钛合金标准样品中钛测定结果的相对误差为0.12%~0.22%。There are many methods for the determination of other elements in titanium alloys except of titanium.However,the direct determination of titanium content is rarely reported.Various types of titanium alloys were tested,and it was found that there were many elements interfering with the determination of titanium when it was directly titrated with ammonium ferric sulfate solution.6 mL of 80 g/L ferric chloride solution was added after the dissolution of titanium alloy.Then sodium hydroxide solution was added to separate the possible interfering elements such as vanadium,molybdenum,chromium and tin.The hydroxide precipitates of titanium were filtrated and then dissolved with acid.The salts were dissolved by adding 70 mL of hydrochloric acid.Then 4 g of aluminum foil was added to reduce titanium.The solution was immediately titrated with ammonium ferric sulfate solution using 20 mL of 100 g/L ammonium thiocyanate as the indicator.The results were converted to realize the direct determination of titanium in titanium alloy.The precision test was conducted on titanium alloy samples,and the relative standard deviations(RSD,n=11)were between 0.09%and 0.12%.The relative errors of titanium in titanium alloy CRMs were between 0.12%and 0.22%.

关 键 词：强碱分离 硫酸铁铵 滴定法 钛合金 钛 氢氧化钠 直接测定 

分 类 号：O655.2[理学—分析化学] TF651[理学—化学]