5－Br－PADAP作指示剂络合滴定法连续测定矿石中的锌和铜

5-Br-PADAP as Complexometric Titration Indi-cator for Continuous DetermInation of Zinc and Cop-per in Ores

本文在ｐＨ５．５的乙酸－乙酸钠介质中，对以５－Ｂｒ－ＰＡＤＡＰ作指示剂络合滴定法连续测定锌和铜进行了研究，对滴定的ｐＨ值及指示剂用量进行了选择，试验了锌、铜不同配比的滴定结果，研究了共存离子的干扰。实验表明，用５－Ｂｒ－ＰＡＤＡＰ作指示剂、ＥＤＴＡ作滴定剂连续测定锌和铜，滴定终点颜色变化敏锐，准确度高，锌和铜均在０～２０ｍｇ范围内与ＥＤＴＡ用量成正比，锌、铜比例在１：１０～１０：１范围内相互无影响，方法用于标样及金矿中锌、铜的连续测定，结果满意。

n this paper,an accurate and selective methodwith 5-Br-PADAP as the complexometric indicatorfor continuous determination of Zn and Cu is de-scribed in the medium of acetic acid-sodium acetate ofpH 5.5.Theend points for both Zn and Cu are sharp.The amounts of Zn and Cu are dircetly proportional toEDTA solution consumed in the range of 0～20mg,and do not interfere each other in the range of 10:1～1:10.Many common metals do not interfere ex-cept Ni. The method has been used in the continuousdetermination of Zn and Cu in ores with satisfactoryresults.