Occurrence and Mobility of Gold in Old Milltailings

Abstract

The particle size distribution and the material constitution of samples taken from old milltailings of sulfide and oxidized ore are studied. It is shown that more than 50% of gold occurs in fine size grade of – 0.044 mm. The method of gas adsorption reveals large specific area in the samples, which is important for re-entrainment and migration of gold and associate components. It is found that gold correlates with iron-bearing species, which is useful for the magnetic separation of gold. The differential scanning calorimetry shows that the samples of the milltailings lack significant quantity of carbon black capable to adsorb gold. It is found that it is possible to generate insoluble residuum of iron cyanoferrates in the tailings, and microne size particles of mobile gold will self-settle on them.