| 摘要 |
<p>PROBLEM TO BE SOLVED: To establish an industrially practicable useful system in place of the electrolytic collection of arsenic or the like by which harmful arsine is produced as a purifying method of a copper electrolytic circulating solution. SOLUTION: The withdrawn copper electrolyte is divided into two portions, thereby copper, arsenic, antimony, bismuth and the like in one divided electrolyte are precipitated and separated as sulfides by adding sodium hydrosulfide, then hydrogen sulfide gas is produced by adding excess sodium hydrosulfide to be allowed to react with remaining sulfuric acid and is passed through another divided electrolyte to precipitate and separate copper, arsenic, antimony, bismuth and the like in the electrolyte and the separated filtrate is circulated again. Heavy metal impurities in one divided electrolyte after the sulfides are precipitated and separated are neutralized to be precipitated and separated by adding an alkali agent. Almost of copper in the withdrawn copper electrolyte is recovered at first by electrolytic collection or concentration by heating.</p> |
