| 摘要 |
<p>PROBLEM TO BE SOLVED: To efficiently separate elements of a platinum group and to easily recover high purity gold in a short time by chlorinating and dissolving treatment slag contg. gold and the elements of the platinum group at a specified acid concn. in the presence of oxalic acid, chlorinating and dissolving the dissolved slag, leaching the gold, reducing and depositing the gold. SOLUTION: Treatment slag of crude silver obtd. from decopper slime is chlorinated and dissolved by using hydrochloric acid contg. sodium chloride at 0.1-1N acid concn. and about 75-90 deg.C while inhibiting the leaching of gold by adding a small amt. of oxalic acid. Platinum and palladium contained along with gold in the slag are leached by the dissolution, separated and recovered from the leaching soln. On the other hand, the dissolved slag contg. residual gold is further chlorinated and dissolved by using hydrochloric acid contg. hydrogen peroxide or hydrochloric acid along with gaseous chlorine at about 60-80 deg.C and the gold is leached. After this gold leaching soln. is adjusted to about pH 1 by adding alkali such as sodium hydroxide, oxalic acid is added as a reducing agent to reduce and deposite the gold of about 99.99% purity.</p> |
