碘量电位滴定法测定锌锰废旧电池中二氧化锰

在测定锌锰干电池锰粉中活性二氧化锰含量时,由于制备电池时正极锰粉中添加了乙炔黑、石墨等导电材料,使制得的样品溶液显色且混浊,影响用淀粉作为指示剂进行碘量法滴定终点的判断。本文提出结合电位滴定技术用碘量法测定废旧锌锰干电池锰粉中剩余活性二氧化锰含量的新方法,对方法中反应时间、温度、碘化钾用量等影响因素进行试验,确定了最优实验条件。结果表明:选择在室温下加入1～1.5g碘化钾、5mL1mol/L硫酸,静置30min,结果准确,精密度高。样品加标回收率为96.9%～99.2%,RSD为0.2%,0.8%。

Determination of manganese dioxide in waste Zn-Mn battery by iodimetry combined with potential titration

The graphite and acetylene black are added to a anode material in making Zn-Mn battery, therefore the sample solution prepared appears as feculency and the titration end point of the solution is difficult to judge when active manganese in the battery is determined by iodimetry with starch as a indicator. In this article, a new analytical method for determination of the content of active manganese dioxide left in waste Zn-Mn battery was proposed by iodimetry combined with potential titration. The influence of reaction time, temperature and the quantity of potassium iodide were investigated. The result shows the excellent condition was in room temperature, 1-1.5 g of potassium iodide, 5 mL of 1 mol/L sulfuric acid and keep static station for 30 min. The recovery of addition standard sample is 96.9 %-99.2 %, and the relative standard deviation is 0.2 % ,0.8 %.