The second example of flotation and cyanide gold extraction
2020-09-14 10:11Introduction：The secondexample of flotation and cyanide gold extraction Another gold processing plant in China deals with gold pyrite quartz vein ore, mainly pyrite, magnetite, limonite, molybdenum, natural gold, etc. The gangue minerals are mainly qua
The second example of flotation and cyanide gold extraction
Another gold processing plant in China deals with gold pyrite quartz vein ore, mainly pyrite, magnetite, limonite, molybdenum, natural gold, etc. The gangue minerals are mainly quartz, sodium carbonate, plagioclase, sericite, etc. The ore contains 6g/t of gold, and the gold grain is fine and closely symbiotic with pyrite. The plant uses a combined flotation and agitating cyanide extraction process (Fig. 5-29).
Flotation of Ore to obtain Au-bearing Sulphur concentrate ,the concentrate containing 117.5g/t of gold, 43.17g/t of silver, 0.18g/t of copper, 0.05% of molybdenum, 25.26% of sulfur, 1.54% of carbon and 96% of gold recovery were obtained by flotation. After the concentrate is concentrated, the flotation agent is removed by the filter holder, then the concentrate is continuously milled to 98- 0.044mm after two stages of continuous grinding, and then it is fed into four mechanical agitation leaching tanks with inflatable devices for cyanide leaching. Lime is used as protective alkali and added to stage I regrinding machine. The leaching pH value is 10, the concentration of sodium cyanide is 0.1%, the leaching time is 36 hours, the concentration of leaching pulp is 25%~30% and the leaching rate of gold can reach 94%~96%.
After filtration and washing, the molybdenum flotation system of filter cake (cyanide tail residue) was added with sodium silicate 8000g/t, kerosene 80g/t, NO.2oil 60g/t, and the molybdenum intermediate ores containing 13% molybdenum were produced by flotation. Ammonium molybdate and tailings are produced by chemical treatment after oxidation roasting of molybdenum intermediate ore. The gold content in the tailings is about 300g/t, mainly due to the loss of dissolved gold from the adsorbed carbon in the gold-bearing concentrate. Tailings return to cyanide leaching with gold and sulfur concentrate to recover gold. Molybdenum flotation tailings contain about 25-30 sulfur, sold to the sulphuric acid plant. The material consumption (kg/t) for the treatment of gold-containing sulfur concentrate is: sodium cyanide 8; lime 12; lead acetate 3; zinc wire 2~ 3.
Later on, the plant carried out technical renovation, changing the replacement of zinc wire into zinc powder to replace gold with zinc powder, deoxidizing the gas tower by clarifying and removing the gold from the solution containing gold, and then replacing the gold with zinc powder, thus increasing the gold content in the gold mud and reducing the consumption of zinc and flux. The total recovery rate of gold is increased.
