| 摘要 |
Pressure leaching metal bearing mineral material such as silver and copper bearing mineral material, e.g. sulfide and/or oxide, with an aqueous liquid containing sulfuric acid and very low concentration nitric acid under oxygen pressure, to dissolve out the corresponding desired metal values from such mineral material with nitric acid regeneration; ACID PRETREATMENT OF SUCH METAL BEARING MINERAL MATERIAL BY PRELIMINARY LEACHING WITH AN AQUEOUS LIQUID CONTAINING SULFURIC ACID AND VERY LOW CONCENTRATION NITRIC ACID UNDER NORMAL AMBIENT PRESSURE, TO DISSOLVE SUBSTANTIALLY ATTENDANT ACID SOLUBLE METAL CARBONATE VALUES, E.G. MANGANESE CARBONATE, FROM SAID MINERAL MATERIAL WITHOUT DISSOLVING THE DESIRED METAL VALUES; AND AFTER TREATMENT OF THE PRESSURE LEACHED AQUEOUS LIQUID WHERE IT CONTAINS SILVER VALUES AS DESIRED METAL VALUES DISSOLVED FROM SUCH MINERAL MATERIAL, BY CONTACT WITH METALLIC COPPER IN A CLOSED SYSTEM UNDER AUTOGENOUS STEAM PRESSURE TO REDUCE THE REMAINING NITRIC ACID VALUES TO GASEOUS FORM FOR REMOVAL FROM THE SYSTEM AND TO EFFECT SIMULTANEOUSLY BY DISPLACEMENT BOTH SILVER METAL DEPOSITION OR CEMENTATION FROM SAID AQUEOUS LIQUID AND COPPER METAL DISSOLUTION INTO SAID AQUEOUS LIQUID.
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