Cyanide recovery
AssigneeCrane Co.
InventorGeorge J. Crits
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Abstract
Spent aqueous liquor containing cyanide, as from ore treatment, is passed through a bed of suitable anion-exchange resin to segregate the cyanide, which is subsequently recovered in regeneration of the resin by weak alkaline solution. Both the eluted cyanide and the alkaline regenerant are recycled, if desired, for further ore treatment. A most important benefit of such procedure is nearly complete elimination of cyanide as a component of the treatment effluent. Free cyanide may be separated from complexed cyanides when present by using weak alkaline regenerant to elute the free cyanide from the resin and stronger alkaline regenerant to elute the complexed cyanides.
Claims17
In treatment of particulate ore with aqueous liquor comprising cyanide to segregate minerals therefrom, wherein spent aqueous liquor is discharged subsequently, the improvement comprising the steps of passing the spent liquor through a bed of Type II strong-base anion-exchange resin and thereby removing and retaining cyanide present in the liquor, subsequently passing weak alkaline regenerant solution through the bed and thereby eluting cyanide therefrom and regenerating the resin, and recycling the regenerant solution with eluted cyanide for further ore treatment.
Process of treating spent aqueous liquor comprising cyanide, as from ore treatment, comprising passing the spent liquor through a bed of Type II anion-exchange resin and discharging the effluent therefrom to waste so long as the cyanide leakage is within tolerance, next backwashing the resin bed, then regenerating the resin by flowing an aqueous solution comprising weak alkali through the bed.
Process of separating free and complexed cyanide anions from aqueous liquor containing both, comprising passing such aqueous liquor through a bed of Type II anion-exchange resin and thereby segregating the cyanides from the effluent from the bed, passing weak base or salt solution at intervals through the bed and thereby eluting the free cyanide, then passing strong base or salt solution through the bed and thereby eluting the complexed cyanide.
Dependencies are inferred from the claim text.