用电解法评估纯铜和普通黄铜样品的质量

在用电解法采集纯铜和 普通黄铜样品时，根据样品的牌号确定样品的近似电化摩尔质量ｋ，选择合适的电解条件使电流效率为１００％，用Ｆａｒａｄａｙ定律ｍ＝ｋＩｔ计算采集样品的质量。

Quality Evaluation for Pure Copper and Brass Samples by Electrolysis

Based on the electrolytic dissolution principle and the characteristics of an anionexchange membrane which hinders cation passage, a novel procedure for dissolving pure copper and brass is described. The dissolver is a dual-cavity electrolytic cell with a membrane placed between the cavities. The dissoved amount of sample is calculated according to the Faraday law m=kIt. The proportion factor, i. e. electrochemical mole mass (k) of the law is defined according to the specifications of the sample. As compared with accurate value of k of the sample, the relative error of the defined k is <0. 042%. Suitable electrolysis conditions,e. g. electrolyte composition and current intensity, are selected to make the current efficiency be equal to 100%. For a 300 mA electrolytic current and 1 h of electrolysis, the calculated values of mass dissolved from pure copper, H96-07 and H62-2 brass are 0. 3558, 0. 3561and 0. 3597 g, respectively, in accordance with those of weight method. Copper and zinc in the anode liquor were titrated with EDTA after electrolysis. The results are in agreement with certified values of the above samples.