Deep lead removal from anodic electrolyte of nickel electrolysis

In order to deal with nickel materials which contain high lead,experimental investigations were performed to remove deeply lead from anodic electrolyte.By analyzing the relationship of Pb²⁺ concentration in electrolyte and lead content in electrolytic nickel,the mechanism of lead removal by coprecipitation,and the effects of Cl^- and Fe³⁺ on the results of lead removal,some optimum technological parameters were determined for deep lead removal by coprecipitation: the coefficient of adding barium chloride is 150,the temperature of lead removal is 55 ℃,the time of lead removal by stirring and the time of adding barium chloride solution by spraying are 60 min and 21 min respectively,and the mass concentration of flocculant is kept constant at 2.5 g·L^-1. It is shown that lead can be removed by coprecipitation with barium chloride,the mass concentration of Pb²⁺ is not more than 0.000 3 g·L^-1 in lead removal electrolyte,and the mass fraction of nickel in slag is less than 4%,which meet the need of producing electrolytic nickel for electrolyte composition.The enlarged experiments prove that the technological parameters derived from the laboratory experimenters are reliable and the process has been applied to industrial production successfully.