Patent ID: 6508993
Filing Date: 2003-01-21
Classification: C22B,Y02P

Abstract:
Method for dissolving ores bearing base metals which develop hydrogen in contact with hydrohalic acid, and noble metals in metallic form, alloyed form or both, which comprisesa) forming a first solution of a non-acid oxidizing agent containing halide ions, with a minimum halide concentration in the solution of 1 mol/l and adding said ore to said first solution at a solution temperature of from 70Â° C. to 90Â° C., b) adding an aqueous second solution of acid to said first solution to form halide ions and dissolve the metal components of said ore, said second solution being added at a rate sufficient to prevent outgassing of hydrogen, and then c) adding a hydrohalic acid to adjust the H+ concentration of the solution formed by the addition of the second solution to the first solution to an H+ concentration of at least 1 mol/l.