Process for treating arseniuretted or sulfarsenidic cobalt, nickel or cobalt and nickel ores

Claim 1

IN A TWO-STAGE, WET-TREATMENT, ACIDIC-OXIDATION PROCESS FOR EXTRACTION OF A METAL VALUE SELECTED FROM THE GROUP CONSISTING OF COBALT, NICKEL, AND MIXTURES THEREON FROM RAW ORE CONTAINING IRON AND THE METAL VALUE IN ASSOCIATION WITH ARSENIC, THE RECOVERY OF ARSENIC AS AS2O3 BY THE COMBINATION OF STEPS OF: IN THE FIRST STAGE, CONTACTING PULVERIZED ORE WITH AQUEOUS SULFURIC AND NITRIC ACID SOLUTIONS, THUS FORMING A PULP CONSISTING OF SOLIDS AND AN AQUEOUS LIQUOR CONTAINING A WATER SOLUBLE SULFATE OF THE METAL VALUE, SAID NITRIC ACID BEING EMPOLYED IN ABOUT THE STOICHIOMETRIC AMOUNT TO OXIDIZE ALL OF THE ARSENIC IN SAID ORE TO AS2O3, SAID SULFURIC ACID BEING EMPLOYED IN AN AMOUNT TO CONVERT THE METAL VALUE IN SAID ORE TO THE WATER SOLUBLE SULFATE AND TO PROVIDE A FREE SULFURIC ACID CONCENTRATION IN THE AQUEOUS LIQUOR, FILITERING THE PULP AT ABOUT AMBIENT TEMPERATURE TO SEPARATE THE AQUEOUS LIQUOR FROM THE SOLIDS, LEACHING SAID SOLIDS WITH WATER OF ABOUT BOILING TEMPERATURE AND FILTERING AT ABOUT BOILING TEMPERATURE TO SEPARATE A RESIDUE FROM AN AQUEOUS LEACH SOLUTION CONTAINING AS2O3, IN THE SECOND STAGE, CONTACTING SAID RESIDUE WITH AQUEOUS NITRIC ACID, THUS FORMING A SOLID-LIQUID MASS CONSISTING OF A LIQUID PORTION AND A SOLID PORTION, FILTERING THE SOLID-LIQUID MASS AT ABOUT AMBIENT TEMPERATURE TO SEPARATE THE LIQUID PORTION FROM THE SOLID PORTION, LEACHING THE SOLID PORTION WITH WATER OF ABOUT BOILING TEMPERATURE AND FILTERING AT ABOUT BOILING TEMPERATURE TO SEPARATE A LEACH LIQUOR CONTAINING AS2O3 FROM AN ORE RESIDUE SUBSTANTIALLY FREE FROM THE METAL VALUE AND ARSENIC, AND COOLING TO CRYSTALLIZE AS2O3 AND SEPARATING THE CRYSTALLIZED AS2O3 FROM THE LEACH SOLUTION AND THE LEACH LIQUOR.