Method of precious metal recovery

Abstract

The proposed methods of precious metal recovery and may be applied to the recovery of precious metals from various types of mineral raw source materials containing organic compounds of precious metals and chlorides of alkali and earth metals, e.g. collective concentrate produced from clay-salt residue of potassium production, or marker clays, etc. This method includes chlorinating roasting of the collective concentrate produced during enrichment of the material with residual chlorides, or natural concentrate with up to 15% chlorides content. Thereafter, the cinder is leached by an aqua-regia solution, the precious metals are recovered from the pulp via of sorption, chlorinating roasting is held at 600-700° C., the precious metals are leached from the cinder using diluted solution of aqua-regia, and then via sorption. The process is cost-efficient due to the use of chlorinating agent, reduction of the process steps number, decreasing of the roasting temperature, and the leaching by diluted acid.

1 . A method for precious metal recovery from mineral raw materials containing chlorides of alkali and earth metals, and organic compounds of precious metals; said method comprising the steps of:
 providing a chlorinating roasting of said mineral raw materials carried at 600-700° C. with production of a cinder;   leaching the cinder by using a diluted solution of aqua-regia (HNO 3 +HCl) resulting in production of pulp; and   providing sorption of said precious metals carried out from said pulp.   
     
     
         2 . The method according to  claim 1 , wherein said mineral raw materials having 7-13% content of the total chlorides of alkali and earth metals. 
     
     
         3 . A method for precious metal recovery from natural concentrate including chlorides of alkali and earth metals, and organic compounds of precious metals, having a residual moisture not exceeding 5% and containing 15% or less of sodium salts, said method comprising the steps of:
 grinding said natural concentrate;   providing a chlorinating roasting of said mineral raw materials carried at 600-700° C. with production of a cinder;   leaching the cinder by using a diluted solution of aqua-regia (HNO 3 +HCl) resulting in production of pulp; and   providing sorption of said precious metals carried out from said pulp.