自动电位滴定法测定铜精矿中的氯

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

用无水碳酸钠-氧化锌混合熔剂高温焙烧半熔铜精矿试样,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(等当点)判断滴定终点。采用试验方法与离子色谱法对6个铜精矿进行结果比对,测定值基本吻合。方法操作简单,重现性好,可准确测定铜精矿中的氯(0.010%~10.00%)。

By using a mixture of anhydrous sodium carbonate and zinc oxide to calcine a sample of semi molten copper concentrate at high tem-perature,separating a large amount of matrix elements,soaking the semi molten substance with boiling water,the amount of chlorine was poten-tiometric titrated in the test solution with silver nitrate standard solution in an ethanol aqueous solution.The principle of chemical reaction be-tween chlorine and silver to generate silver chloride precipitation as well as the potential jump(equivalent point)to determine the titration end point was used.The test method and ion chromatography were used to compare the results of six copper concentrates,and the measured values were basically consistent.The method is simple in operation and has good reproducibility,and can accurately determine the high content of chlorine(0.010%-10.00%)in copper concentrates.