LAUSR

Gold is mostly found in nature in metallic form and is associated with sulphide minerals and other precious metals, most often silver. Pyrite, chalcopyrite, sphalerite, and stibnite are the sulphidic minerals investigated in the present gold-silver cyanidation study by adopting the metal-sulphide multi-layer packed-bed reactor approach. Gold leaching kinetics was enhanced remarkably for the pyrite and chalcopyrite sulphide minerals, with 94.5% and 85% recovery respectively. The influence of a bilayer sulphidic mineral system on the dissolution of gold was also investigated with a maximum gold dissolution of 87% for the pyrite-chalcopyrite bilayer system. The effect of silver on the dissolution of gold was investigated with the gold associated with sulphidic minerals in an arrangement of mixed as well as segregated mineral layers. Three sets of mineral systems were established: pyrite-chalcopyrite-silica, pyrite-sphalerite-silica, and pyrite-stibnite-silica systems. The addition of silver enhanced the gold dissolution for the pyrite-sphalerite-silica system, slightly lessened the gold dissolution with the pyrite-stibnite-silica system, and retarded gold dissolution severely in the case of the pyrite-chalcopyrite-silica system, irrespective of the dispersion of gold and silver in the same as well as in the segregated mineral layers. This article is protected by copyright. All rights reserved