自动电位滴定法测定铜精矿中高含量氯

Determination of High Content Chlorine in Copper Concentrates by Automatic Potentiometric Titration

使用无水碳酸钠-氧化锌混合熔剂焙烧半熔铜精矿样品，分离大量的基体元素，用沸水浸取半熔物，在乙醇-水溶液中用硝酸银标准溶液电位滴定测定试液中的氯量；利用氯与银发生化学反应生成氯化银沉淀的原理以及电位突跃判断滴定终点。方法操作简单快速，重现性好，适应性强，可准确测定铜精矿中高含量氯（0．10％-5．00％）。

Mixed dehydrated Na2CO3-ZnO flux was used for the calcination of semi-smelting copper concentrate sample in order to remove massive matrix elements. After semi-smelting was leached with boiling water, the content of chlorine in the leaching solution was measured by the silver nitrate potentiometric titration in a ethanol-water solution system. The titration end-point was determined by the breakpoint of electric potential during the process, which caused by AgC1 precipitation reaction between C1- and Ag＋. The method is simple, rapid and with good reproducibility. It can be widely used for the accurate determination of high content chlorine （from 0. 10% to 5.00%） in copper concentrates.