| 摘要 |
<p>PURPOSE:To recover high-purity gold of >=99.998% without an electrolytic refining method by subjecting an aq. soln. contg. thickened gold to solvent extraction, dissolving the reduced crude gold formed by reducing said soln. at a high temp. and blowing the dissolved crude gold to a gaseous mixture composed of gaseous chlorine and inert gas. CONSTITUTION:The precipitate of copper electrolysis or the precipitate of decopperization obtd. by decopperizing and arsenizing said precipitate is made into a slurry by using an aq. metallic chloride soln. of NaCl, MgCl2, etc. and is then subjected to gaseous chlorine leaching. Preferably an aq. NH3 soln. is added to the resultant decoction in which gold is leached at >=99.5% to precipitate and remove Pt, etc. in the form of insoluble salt. The decoction from which Pd and Pd are removed is subjected to solvent extraction of gold by using a solvent having good selectivity with gold (e.g.; dibutyl carbitol). The reduced crude gold obtd. by reducing the soln. of gold extraction by a reducing agent such as oxalic acid or the like is dissolved at 1,100-1,200 deg.C and a gaseous mixture composed of gaseous chlorine and inert gas is blown thereto to evaporate and remove impurities. The above-described gold having high purity is thus recovered.</p> |
