| 摘要 |
<p>A method of purifying copper electrolytic solution being circulated in a copper electrorefining system wherein a portion of the solution is withdrawn and is recycled to the system after purification treatment in which hydrosulfide is added to the solution withdrawn to generate only the necessary quantity of hydrogen sulfide gas on the spot and the hydrogen sulfide gas generated is utilized for purification treatment. One process comprises dividing the solution withdrawn into two portions, adding sodium hydro-sulfide to the first portion to precipitate and separate metals as sulfides from the first portion, further adding excess sodium hydrosulfide to the first portion for reaction with residual sulfuric acid in the solution to generate hydrogen sulfide gas, contacting the second divided portion with the hydrogen sulfide gas thus produced to precipitate and separate metals in the form of sulfides, and recycling the filtrate to an electrorefining system. There is also provided a process comprising contacting the solution with hydrogen sulfide gas to separate and remove Cu, As, Sb and Bi in the form of sulfides from the solution, dividing the solution into two portions, wherein the first portion is recycled to the electrorefining system, whereas excess sodium hydrosulfide is added to the second portion to separate and recover Ni as nickel sulfide from the solution, while resulting hydrogen sulfide gas is used for contact with solution to be treated.</p> |
