| 摘要 |
<p>PURPOSE:To produce high-purity electrolytic copper contg. low sulfur content by performing electrolysis with periodical reversible current under the specified conditions in the case of performing electrolysis by using a diaphragm type electrolytic cell, copper nitrate or copper sulfate as an electrolyte and a cathode made of Ti. CONSTITUTION:Electrolytic copper is deposited on a cathode made of Ti by performing electrolysis in a diaphragm type electrolytic cell in which a crude copper contg. a small amount of Ag, S, Fe and Ni, etc., is used as an anode and the cathode made of Ti is used and copper nitrate or copper sulfate is used as an electrolytic bath. In this case, electrolysis is performed by a periodical reverse current electrolytic method of 2,000msec period and as the conditions at a time for depositing Cu on the cathode in this case, 0.2-10A/dm<2> current density and 10musec-2,000msec electrification time are regulated and as the conditions at a time for dissolving electrolytic copper deposited on the cathode by means of reverse current, 0.05-5A/dm<2> current density and 10musec-1,000msec electrification time are regulated. Further in the case of repeatedly using an anolyte, the anolyte is subjected to desilverizing treatment, filtered and used, and thereby the electrolytic bath is not involved in the electrolytic copper deposited on the cathode and extremely high-purity electrolytic copper contg. small sulfur content can be deposited and recovered on the cathode.</p> |
