Process for the recovery of gold and/or silver and possibly bismuth contained in sulfuretted ores and/or sulfoarsenides
AssigneeMines et Produits Chimiques de Salsigne
InventorMarcel Lesoille
Life of this patent
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Abstract
The present invention relates to a process for the recovery of gold and/or silver and possibly bismuth contained in sulfuretted ores and/or sulfoarsenides, wherein said ores, after having been subjected to a reducing roasting, then to an oxidizing roasting then a possible crushing, are treated by a first lixiviation with sulfuric acid followed by a lixiviation with thiourea under precise conditions of operation.
Claims5
In a process for recovering gold and/or silver and possibly bismuth contained in a sulfuretted ore and/or sulfoarsenide, said ore, from which is gangue has been removed according to known processes, is treated according to the following successive operations:
- a reducing roasting;
- an oxidising roasting;
- a possible crushing;
- a first lixiviation by a sulfuric acid solution containing about 20 to 120 g of acid per liter, at a temperature of about 20.degree. to 85.degree. C. and for a duration of 0.5 to 3 hrs.;
- after separation of the solid, a lixiviation of said solid effected with the aid of a sulfuric acid thiourea solution containing from 10 to 50 g/l of thiourea, at a pH of 0.7 to 1.5, at a temperature of 20.degree. to 70.degree. C., for a duration of 15 mins. to 15 hrs., this lixiviation being conducted so that the potential of oxidoreduction of the medium is maintained at a value of between about 100 and about 180 mV;
- and, after filtration of the solution, a cementation of said solution to recover the gold, silver and bismuth that it contains.
Dependencies are inferred from the claim text.