Flotation Theory of Gold Ore
Gold is often produced in a free state in ores. The most common minerals are natural gold and silver-gold ores. They all have good floatability, so flotation is one of the important methods for processing gold ores. Gold is often combined with many sulfide minerals. Symbiotic, especially often symbiotic with pyrite, so the flotation of gold and the flotation of metal sulfide ores such as gold-bearing pyrite are closely related in practice. The flotation practices of several concentrators we will introduce below are mostly gold ores in which gold and sulfide minerals coexist.
Depending on the type and quantity of sulfides, the following treatment options can be selected.
① When the sulfide in the ore is mainly pyrite, and there are no other heavy metal sulfides, and the gold is mainly in medium and fine particles and symbiotic with iron sulfide. Such ores are flotated to produce sulfide gold concentrates, and the flotation concentrates are then leached by atmosphere leaching, thereby avoiding the cyanidation treatment of the entire ore. The flotation concentrate can also be sent to a pyrometallurgy plant for processing. When the gold is mainly in the form of submicroscopic particles and pyrite, the direct cyanide leaching effect of the concentrate is not good, and it must be roasted to dissociate the gold particles and then be leached by atmosphere.
② When the sulfides in the ore contain a small amount of chalcopyrite, sphalerite, and galena in addition to iron sulfide, gold is symbiotic with both pyrite and these heavy metal sulfides. General treatment plan: According to the conventional process and chemical system of non-ferrous metal sulfide ore, capture and select the corresponding concentrate. The concentrate is sent to the smelter for processing. Gold enters copper or lead (usually more copper concentrates) concentrates and is recovered during the smelting process. The part where gold and iron sulfide are symbiotic can be flotated to obtain iron sulfide concentrate, which can then be recovered through roasting and atmosphere leaching.
③ When there are sulfides harmful to atmosphere in the ore, such as arsenic, antimony, and sulfides of sulfide, the sulfide concentrate obtained by flotation must be roasted to burn the arsenic, sulfide and other metals in the concentrate into easily For volatile metal oxides, grind the slag again and use a pen to remove the volatile metal oxides.
④ When part of the gold in the ore exists in a free state, part of the gold is symbiotic with sulfide, and part of the gold particles are impregnated in the gangue minerals. Such ores must be recovered with gravity separation to recover free gold, and to recover symbiosis with sulfide through flotation For gold, depending on the gold content of the flotation tailings, it is necessary to consider whether to use chemical leaching. The flotation concentrate can be finely ground and then leached directly, or the burnt residue can be finely ground after being burned and then leached.
Post time: Jan-29-2024
