柠檬酸盐铅锡合金电镀溶液中铜、铁的连续测定  

CONTINUOUS DETERMINATION OF THE COPPER AND IRON CONTENTS IN CITRATE LEAD-TIN AIIOY PLATING SOLUTION

作　　者：申顺保 

机构地区：[1]桂林国营长海机器厂

出　　处：《电镀与环保》1990年第6期19-19,共1页Electroplating & Pollution Control

摘　　要：在柠檬酸盐铅锡合金电镀过程中,杂质的多少对镀层的质量有着很大的影响。当镀液中铁和铜的含量迟到一定量时,镀层就会粗糙、发黑,可焊性明显下降。因此需要对镀液中铜和铁的含量进行测定。本文提出用硫酸将铅沉淀,用过硫酸铵破坏柠檬酸盐,用久氟化铵掩蔽锡,在pH=2的情况下,以磺基水杨酸为指示剂,用EDTA滴定铁,再用氨水调节pH=8-9,再用EDTA滴定钢。本法是连续滴定,操作简单、易掌握,终点明显,结果完全符合电镀液分析的要求。In the process of citrate lead-tin alloy plating, the amount of impurities has grat influence on the quality of coating. When iron and copper contents reach a certain level, the deposit will become rough and darkish; and the solderablity will be obviously decreased, Therefore, it is necessary to determine the copper and iron contents in the plating bath. The method suggested in this paper is: Use sulfuric acid to precipitate lead; ammonium persulfate to decompose citrate and ammonium fluoride to mask tin, then at pH=2.use sulfosalicylic acid as indicator and titrate iron with EDTA, after that, adjust the pH value to 8-9 with ammonia water, and again use EDTA to titrate copper. This process is a continuous titration; simple to operate; easy to handle and the end point obvious. In addition, the results obtained cad fully meet the reqirements of bath analysis.

关 键 词：电镀 镀液 铜 铁 测定 合金 

分 类 号：TQ153.2[化学工程—电化学工业]