摘要
目前,EDTA滴定法测定碱液中锌含量已经应用于碱法炼锌工业,碱液中锡含量多采用碘量法测定;而EDTA滴定法联合测定碱液中锌和锡的研究应用较少。试验提出了以EDTA滴定法联合测定碱液中锌和锡,同时利用酸碱滴定法测定碱液中游离碱。EDTA滴定法是以EDTA为螯合剂,络合碱液中锌和锡,以六次甲基四胺作为缓冲液调节溶液pH值至5~6,以氟化铵作为锡的释放剂,将锡解蔽、释放,以硝酸铅反滴即可求出锡含量,同时根据硝酸铅的差值即可求出碱液中锌含量。酸碱滴定采用双指示剂法,用锡含量和消耗盐酸量即可求出游离碱(以氢氧化钠表示)。按照实验方法测定碱液中锌、锡和氢氧化钠,测定结果的相对标准偏差(RSD,n=5)不大于2%;加标回收率为94%~99%。
At present,the determination of zinc content in alkaline solution by EDTA titration method has been used in alkaline zinc smelting industry,while the content of tin in alkaline solution is usually determined by iodometry.However,there are few reports on the simultaneous determination of zinc and tin in alkaline solution by EDTA titration method.The simultaneous determination of zinc and tin in alkaline solution by EDTA titration was proposed.Meanwhile,the content of free alkali in alkaline solution was determined by acid base titration.In EDTA titration process,EDTA was used as chelating agent for the complexation of zinc and tin in alkaline solution.The pH of solution was adjusted to 5-6 using hexamethylenetetramine as the buffer solution.Ammonium fluoride was selected as the releasing agent for the demasking and releasing of tin.Then the content of tin was obtained by back titration with lead nitrate.The content of zinc in alkaline solution could be calculated according to the difference value of lead nitrate.The double indicator method was employed in acid base titration.The content of free alkali（expressed in sodium hydroxide）could be calculated using the content of tin and the amount of consumed hydrochloric acid.The contents of zinc,tin and sodium hydroxide in alkaline solution were determined according to the experimental method.The relative standard deviations（RSD,n=5）of measured results were less than 2%.The recoveries were between 94% and 99%.
作者
孙彬彬
童俊
鹿慧
蒋家超
SUN Bin bin;TONG Jun;LU Hui;JIANG Jia chao(School of Environmcnt Scicncc and Spatial lnformatics, China Univcrsity of Mining ＆Tcchnology, Xuzhou 221116, China)
出处
《冶金分析》
CAS
CSCD
北大核心
2018年第5期54-59,共6页
Metallurgical Analysis
基金
徐州市社会发展-基础应用研究项目(KC16SG260)
关键词
EDTA滴定法
酸碱滴定法
碱液
锌锡联合测定
游离碱
EDTA titration
acid base titration
alkaline solution
simultaneous determination of zinc andtin
free alkali
