金属铜还原-重铬酸钾滴定法测定总铁的研究

STUDY OF COPPER REDUCTION ——POTASSIUM DICHROMATE TITRATION MEASURING TOTAL IRON

本文研究了用金属Ｃｕ还原Ｆｅ３＋的方法，提出将铜粒填入还原柱中，使含Ｆｅ３＋的待测试样在硫酸介质中，通过铜还原柱，调节一定的流速，Ｆｅ３＋能定量还原为Ｆｅ２＋，用重铬酸钾标准溶液滴定，可测出总铁含量．当铜柱高３０ｃｍ，流速在１．４～３ｍＬ／ｍｉｎ之间，测定铁标液，相对标准偏差Ｓｒ＝０．１９％（ｎ＝１１），与锌还原法结果比较无显著性差异．该方法目前未见报道，操作简便，无需加热，不用除去过量的还原剂，干扰少，用于测定含铁废液中的总铁含量。

This paper gives the method of copper reducing Fe 3+ . Put copper grains into the reducing column, make the sample containing Fe 3+ flow through the column in the presence of sulfuric acid. With adjustment of flow rate, Fe 3+ can be reduced to Fe 2+ quantitatively. With titration of potassium dichromate standard solution, the content of total iron can be measured. When the column is 30 cm high and the flow rate is 1.4～3 mL·min -1 ,iron standard solution is measured, and the standard deviation is S r =0.19% (n=11). Compared with the zinc reduction method, the difference is so little. This method is simple and has not yet been reported up to now. It can be used to measure the content of total iron in iron liquid waste. The results are satisfactory.