MANUFACTURE OF HIGH-PURITY COPPER

摘要

PURPOSE:To obtain high-purity electrolytic copper usable for superconducting material, etc., by carrying out electrolysis by the use of pure copper prepared by the ordinary electrolytic refining of copper as an anode by means of an electrolyte accidified with sulfuric acid and further carrying out electrolysis by the use of the resulting electrodeposited copper as an anode. CONSTITUTION:First the primary electrolysis is carried out by using electrolytic copper or metallic copper having a purity equivalent to that of electrolytic copper as an anode and also using a Ti plate, high-purity copper plate, etc., as a base material as starting sheet by means of an electrolyte accidified with sulfuric acid in 2-5A/dm<2> current density. Then, the secondary electrolysis is carried out in 1-2A/dm<2> current density by using the resulting electrodeposited copper as an anode to produce high- purity electrolytic copper. Further, in the primary and the secondary electrolytic stages, it is desirable to disposed the above anode in an anode chamber divided by a diaphragm and also to regulate copper concentration and free sulfuric acid concentration in the electrolyte to about 20-45g/l and about 40-80g/l and further to regulate electrolytic bath temp. to about 10-40 deg.C. Moreover, it is desirable that, in the above stages, the electrolyte is supplied at a rate of about 0.1-2l/min per dm<2> cathodic area.