EDTA返滴定法测定锌钴渣中锌的含量  

Determination of Zinc Content in Zinc Cobalt Slag by EDTA Back Titration Method

作　　者：叶再兴 Ye Zaixing(Laboratory of the Fourth Geological Brigade of Guangdong Geological Bureau,Zhanjiang 524000,China)

机构地区：[1]广东省地质局第四地质大队实验室,广东湛江524000

出　　处：《广东化工》2024年第13期127-129,共3页Guangdong Chemical Industry

摘　　要：使用盐酸、硝酸、高氯酸、硫酸等分解试样,使用混合铵盐和氨水沉淀分离大部分干扰元素,调节滤液pH值为5.8,加入碘化钾、硫代硫酸钠和氟化铵掩蔽滤液中干扰元素。使用二甲酚橙指示剂,加入过量的EDTA标准溶液,静置10min使其与滤液中锌钴离子完全络合,再用锌标准溶液滴定过量的EDTA溶液,测得试样中锌钴合量。通过亚硝基红盐光度法测得试样中钴的含量,锌钴合量减去钴量,便得到试样的锌含量。按照本方法测定锌钴渣中锌的含量,其结果的相对标准偏差(RSD)小于1%,加标回收率为98.8%~100.6%,符合一般检测需求。Use hydrochloric acid,nitric acid,perchloric acid,sulfuric acid,etc.To decompose the sample,use mixed ammonium salt and ammonia water to precipitate and separate most disturbing elements,adjust the pH value of the filtrate to 5.8,and add potassium iodide,sodium thiosulfate,and ammonium fluoride to mask the interfering elements in the filtrate.Using a xylenol orange indicator,add an excess of EDTA standard solution,let it stand for 10 minutes to completely complex with zinc and cobalt ions in the filtrate,and then titrate the excess EDTA solution with zinc standard solution to measure the zinc and cobalt content in the sample.The cobalt content in the sample is measured by the nitrite red salt spectrophotometry,and the zinc cobalt content is obtained by subtracting the cobalt content from the zinc cobalt content.According to this method,the content of zinc in zinc cobalt slag was determined,and the relative standard deviation(RSD)of the results was less than 1%,with a recovery rate of 98.8%~100.6%,meeting general testing requirements.

关 键 词：锌钴渣 PH 氟化铵 硫代硫酸钠 EDTA 

分 类 号：TQ[化学工程]