Copper, Molybdenum & Gold
Copper & Molybdenum
The most common types of ore, are copper oxide and copper sulfide. The first steps of copper processing are the same for both ores: mining and transporting. most ores are then sent through crusher (s), which is typically located very close to or sometimes in the pit. In processing of copper sulfide, the crushed ore is further grinded in several stage of wet milling for copper ore liberation. To separate liberated copper ore from gang, The slurry is placed in a tank and copper ore is separated by process called froth floatation in which, the copper ore is separated by using chemical reagents mainly collector and frother in pH-controlled condition, the copper is concentrated in froth phase and skimmed off from the surface of tank. The gangue sinks to the bottom of the tank to be removed or disposed of as tailings. The next stage after froth flotation is the concentrate dewatering in thickener which followed by filtration. the final product of the thickening stage is a combination of 30% copper and other metals; this copper concentrate is then sent to the smelter. At the smelter, high temperatures are used to further purify the ore in a series of smelting steps which followed by electrolysis to produce 99.99% copper.
Copper and molybdenum are frequently found together as sulfides in ore bodies throughout the world. While there is primary molybdenum mine production, a significant amount of moly is recovered as copper mine by-product. in copper ore processing by flotation, the copper and molybdenum are concentrated in froth together, separation and upgrading the molybdenite from the bulk copper-molybdenite concentrate is generally accomplished by selective molybdenite flotation following copper and iron supplied depression.
Copper oxide ores are generally processed using hydrometallurgy. This process uses aqueous (water-based) solutions to extract and purify copper from copper oxide ores at ordinary temperatures, usually in three steps: heap leaching, solvent extraction, and electrowinning.
Gold
Gold is one of the least reactive chemical elements and often occurs in free elemental (native state), as nuggets or grains, in rocks, veins. Depend on gold ore type, different processing method can be used, mainly including the gravity separation, flotation, amalgamation d, cyanide leaching, resin in the pulp, carbon paste adsorption and heap leaching. If gold particle be dispersed in other mineral whole ore leached (cyanidation). Different processing scenario can be summarized as below:
Flotation and Leaching of the Float Conc
Flotation and Leaching of the sulfide-free Float Tails
Gravity Gold Concentration followed by Flotation and Leaching of the Float Conc
Heap Leach amenability (cyanidation) after coarse crush
Whole ore cyanidation
The gold cyanidation process is the most important method ever developed for extracting gold from its ores. The basis of the cyanidation process is that weak solutions of sodium cyanide (NaCN) have a preferential dissolving action on small particles of metallic gold and silver over other materials usually found in gold ores. After dissolving, gold- cyanide complex adsorbed on activated carbon. The next step is striping of adsorbed gold from activated carbon with an efficient eluant. The elute solution passes through an electrowinning cell where the gold metal is deposited.