METHOD FOR PROCESSING OF MINERAL ORE CONTAINING GOLD AND SILVER AT SITE OF THEIR DEPOSITION Russian patent published in 2000 - IPC

FIELD: mining industry. SUBSTANCE: method relates to oxichloride technology of lixiviation of noble metals from ores containing arsenic and mercury at site of their deposition and it can be used at heap and underground lixiviation and also in hydrometallurgy for separation gold and silver from ores and concentrates. According to method, solutions of reagents are delivered into blocks of ore body through system of injection wells, and productive solutions are withdrawn through system of withdrawing wells. Lixiviation of gold and silver is performed by stages. At first stage, delivered into block of ore body is acidiferous chlorinated solution of trivalent iron so as to prevent lixiviation of arsenic from ore and also to prevent spreading of solutions from ore block being treated. At second stage, lixiviation is carried out by delivery of chlorine solution so as value pH of productive solution is maintained at level below 3. Removed from productive solution which is produced at first stage prior to its processing is surplus chlorine down to its minimal values, thus allowing for keeping gold in solution. Absorption of separated chlorine is performed by mother liquors of sorption freed from mercury. At last stage, withdrawn are solutions containing chlorine and iron to be delivered to next ore block prepared for processing. Then, silver is lixiviated in ore block being processed by means of sulfur-containing reagents. After that, productive solutions are processed by means of sorption and cementation. Ground water involved in lixiviation process is reclaimed. At each stage of lixiviation, process is monitored through inspection wells. Application of aforesaid method improves efficiency of underground lixiviation due to increased recovery of noble metals in conditions of ecological safety of process. EFFECT: higher efficiency. 5 cl, 6 tbl