| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for producing silver powder which can obtain a silver ingot satisfying acceptable standards (≤1 ppm) regarding tellurium required by users. <P>SOLUTION: In the method for producing silver powder mainly composed of: a leaching step where copper electrolysis slime is treated using chlorine or hydrochloric acid and hydrogen peroxide so as to be separated into a leach liquor comprising noble metals such as gold, platinum and palladium and a leaching residual substance comprising silver; a gold refining step where the noble metals such as gold, platinum and palladium in the leach liquor are sorted and recovered; and a silver refining step where silver chloride in the leaching residual substance is recovered as silver powder, before the leaching residual substance is fed to the silver leaching step, repulpe cleaning is performed in a neutral to weak alkali state, preferably, at pH of 7 to 9. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
