| 摘要 |
PURPOSE:To easily and surely revover the valuable substances and also, to enable to prevent the environmental pollution of drainage, by combining cyanide decomposition by hypochlorite, precipitation formation of valuble metal by pH regulation and adsorption removing of heavy metals in waste water by active carbon. CONSTITUTION:Hypochlorite is added to cyanide compounds containing gold, silver etc., as concentrated solution until its oxidation reduction electric potential is shown more than +350mV. Active carbon and mineral acid, are added to the above water solution and pH is controlled at less than 5.0 and the precipitate is separated. Obtained water solution here is passed through the active carbon layer pretreated by using mineral acid preliminary. Valuable matters are recovered from the above precipitate and active carbon adsorbed matter by publicly known method. Exhaust water by the above method is discharged without producing environmental pollution. |
