PROCESS FOR THE TREATMENT OF VOLCANIC IGNEOUS ROCKS TO RECOVER GOLD, SILVER AND PLATINUM.

摘要

The present invention discloses a process for the recovery of gold, silver and platinum metal from iron-containing volcanic scoria, said recovery process being achieved by mixing scorias with a suitable flux, and metallic copper, and fusing said mixture at a temperature high enough to produce a metal melted mass containing iron and copper, and a melted scoria. The melted scoria is separated from the melted metal mass by suitable means. The scoria is eliminated and the metal mixture is cooled down to a solid state. Both the copper and iron are then dissolved in acid, leaving a non-dissolved portion that can be separated later from the resulting lixivation liquor, by filtration. Alternatively, the metal carrying iron and copper can be moulded in an anode and electrolyzed in a sulphuric acid solution, wherein the copper is deposited in the cathode and iron is introduced into a solution as ferric sulphate. The nonsoluble residue in the anode can be recovered from the sulphuric acid solution by filtration. The solids so filtrated either from the acid dissolution or from electrolysis, contain a significant quantity of metals from gold, silver and platinum group, which were present in the original ore. These solids can then be processed by a well known technology to recover metal content from gold, silver and platinum group in essentially pure form. The solution containing most of the silver can be treated by conventional means to recover said metal. By using electrolysis the copper is recovered as a cathode deposit. By using a dissolution with acid, the copper might be recovered by other conventional methods. With any method, copper might be recycled towards process.