碘量法连续测定选矿废水中的铜铁

针对选矿废水中的铜离子和铁离子,在滴定铜离子含量的基础上,向滴定液中继续加入三氯化铝溶液作为解蔽剂将铁离子解蔽,此时溶液呈深棕色,以硫代硫酸钠标准溶液继续滴定铁,溶液深棕色消失转为奶白色即为滴定终点,避免了单独滴定铜铁含量的麻烦,且在滴定铁离子含量时无需除铜。经实验验证,对选矿废水中铁含量进行滴定与重铬酸钾滴定铁含量的结果一致,相对误差小于2.03%,加标回收率在95.8%~101.9%,相对标准偏差(RSD,n=10)在0.48%~1.5%。方法精密度高,重现性好,简便快捷,可以满足选矿废水中铜、铁含量的测定要求。

Continuous Determination of Copper and Iron in Flotation Wastewater by Iodometric Method

In this paper, experiments were on flotation wastewater containing copper and iron ions,Based on the determination of copper content, aluminum chloride solution was added to unmask the ferric icon.At this point, the solution was dark-brown and the titration end point was ended when the solution color turned from dark-brown solution to milk white. This method avoided the troubles of individual titration of copper and iron ions. In addition, removal of copper ions was not required when iron ions were titrated. The determination results were consistent with those obtained by the potassium dichromate titrimetricmethod. The relative error was less than 2.03%, and the recovery was in the range of 95.80%~101.9%, with the relative standard deviations (n=10) of 0.48%~1.5%.The method is of high precision, and good reproducibility, and it is simple and efficient to meet the requirements for the determination of copper and iron contents in flotation wastewater.