Ore treatment process

A process for extracting an ore containing a metal selected from the group consisting of:

• iron, copper, zinc, arsenic, antimony, molybdenum, silver and cadmium, said metals being present in either their sulfidic or oxidic forms, comprising preheating said ore to a temperature sufficient to dehydrate same;
• mixing said ore at said temperature with a anhydrous, air-free melt containing a compound selected from the group consisting of saturated hydrogen and alkali metal polysulfides and an amount of sulfur sufficient to sulfidize those metals present in their oxidic form and to completely oxidize those metals present in their sulfide forms;
• separating by filtering while hot the melt-soluble sulfides of Mo, As, Sb, Cu, and Fe from the melt-insoluble sulfides with water to separate said saturated polysulfide and the water-soluble sulfides of Mo, As and Sb from the water-insoluble sulfides of Cu and Fe;
• mixing said water-soluble sulfides in aqueous solution with a more electropositive metal thereby precipitating said metals in their elemental form together with the sulfide of said more electropositive metal and said saturated polysulfide, drying said water-insoluble copper and iron sulfides;
• reacting copper and iron sulfides with a melt containing a saturated hydrogen or alkali metal polysulfide at a temperature above the melting point of said polysulfide under a vacuum of between one-half Torr and 760 mm;
• separating the resulting free metals from said melt and magnetically separating said iron from said copper;
• treating said melt-insoluble Zn, Pb, Ag, and Cd sulfides with a saturated hydrogen or alkali metal polysulfide under a vacuum of between 1/2 Torr and 760 mm;
• separating lead containing Cd, Ag, and Zn dissolved therein;
• placing a cover layer of an unsaturated hydrogen or alkali metal polysulfide over said lead, heating the resulting mixture above the melting point of zinc to distill said zinc and collecting said zinc.