METHOD FOR ZNCL2 PLATING CRUDE LIQUID FROM ZN PLATING WASTE LIQUID

摘要

PURPOSE: A method is provided to produce a ZnCl2 plating crude liquid of high purity and high concentration and an assistant agent of conduction contained a KCl used to an electric plating operation by using a waste liquid generated from a zinc plating process. CONSTITUTION: A metal sludge existed as an impurity among a waste liquid is generated by adding an oxygenated water in the Zn plating waste liquid, adding a KOH in the plating waste liquid to be a pH3-4 and agitating. The generated sludge is removed by separating through a filter. A Ni in the Zn plating waste liquid to absorb heavy metals is removed by adding a Zn powder in the remained liquid to be 1-2g/l and agitating. A deposit having a moisture content under 1% is produced by drying after obtaining a ZnCl2*4Zn(OH)2 the deposit by controlling the waste plating liquid removed impurities with adding the KOH to be a pH 9-12. The ZnCl2 aqueous solution of high purity and high concentration is produced by reacting the deposit with a hydrochloric acid over 8mols.