Hydrometallurgical extraction Copper extraction

sulfide ores

secondary sulfides – formed supergene secondary enrichment – resistant (refractory) sulfuric leaching. these ores mixture of copper carbonate, sulfate, phosphate, , oxide minerals , secondary sulfide minerals, dominantly chalcocite other minerals such digenite can important in deposits.

supergene ores rich in sulfides may concentrated using froth flotation. typical concentrate of chalcocite can grade between 37% , 40% copper in sulfide, making them relatively cheap smelt compared chalcopyrite concentrates.

some supergene sulfide deposits can leached using bacterial oxidation heap leach process oxidize sulfides sulfuric acid, allows simultaneous leaching sulfuric acid produce copper sulfate solution. oxide ores, solvent extraction , electrowinning technologies used recover copper pregnant leach solution.

supergene sulfide ores rich in native copper minerals refractory treatment sulfuric acid leaching on practicable time scales, , dense metal particles not react froth flotation media. typically, if native copper minor part of supergene profile not recovered , report tailings. when rich enough, native copper ore bodies may treated recover contained copper via gravity separation circuit density of metal used liberate lighter silicate minerals. often, nature of gangue important, clay-rich native copper ores prove difficult liberate.

oxide ores

oxidised copper ore bodies may treated via several processes, hydrometallurgical processes used treat oxide ores dominated copper carbonate minerals such azurite , malachite, , other soluble minerals such silicates chrysocolla, or sulfates such atacamite , on.

such oxide ores leached sulfuric acid, in heap leaching or dump leaching process liberate copper minerals solution of sulfuric acid laden copper sulfate in solution. copper sulfate solution (the pregnant leach solution) stripped of copper via solvent extraction , electrowinning (sx-ew) plant, barred (denuded) sulfuric acid recycled on heaps. alternatively, copper can precipitated out of pregnant solution contacting scrap iron; process called cementation. cement copper less pure sx-ew copper. commonly sulfuric acid used leachant copper oxide, although possible use water, particularly ores rich in ultra-soluble sulfate minerals.

in general, froth flotation not used concentrate copper oxide ores, oxide minerals not responsive froth flotation chemicals or process (i.e.; not bind kerosene-based chemicals). copper oxide ores have been treated via froth flotation via sulfidation of oxide minerals chemicals react oxide mineral particles produce thin rime of sulfide (usually chalcocite), can activated froth flotation plant.