Patent ID: 6036025
Filing Date: 2000-03-14
Classification: B03D

Abstract:
A process of treating a milled slurry or a slurry of a flotation concentrate consisting essentially of a mixture of sulfidic mineral, with or without precious metals, and non-sulfidic gangue material, comprising conditioning the slurry with an inert gas selected from the group consisting of nitrogen, argon and neon and a reducing, deoxifying agent selected from the group consisting of sulfoxy agents, metabisulfites, sulfites and their potassium, calcium and ammonium salts, sodium bisulfite, sodium bisulfide, sodium sulfide, carboxymethylcellulose, dextran, guar gum and mixtures thereof, thereby achieving a controlled dissolved oxygen content of less than 1 ppm or an electrochemical potential of between about 0 and -700 mV, conductive to the flotation of the sulfidic material from the non-sulfidic gangue material by reducing the floatability of the gangue material, followed by flotation of the valuable sulfidic mineral from the non-sulfidic gangue material using an inert gas as the flotation gas thereby achieving an enhanced concentration grade of the valuable sulfidic material at a given recovery level, said conditioning step being conducted prior to or simultaneously with the flotation step.