Bacterially assisted heap leaching of low grade copper sulphides is a developing technology that has been applied successfully to the extraction of copper from sulphide minerals such as chalcocite at ore grades down to 0.15% . The ore is typically crushed to about 613 mm prior to stacking into heaps.
Oxide ores are generally processed using hydrometallurgy. This process uses aqueous solutions to extract and purify copper from copper oxide ores at ordinary temperatures, usually in three steps: heap leaching, solvent extraction, and electrowinning. Heap Leachingis the process of using percolating chemical solutions to leach out metals. Heap leaching is very commonly used for low grade ore, which would otherwise not be economical to send through a milling process. Following mining, transporting, and crushing to a consistent gravel or golf ball size, the crushed ore is piled into a heap on top of an impenetrable layer, on a slight slope. The leaching reagent is sprayed through sprinklers on top of the heap pile and allowed to trickle down through the heap, where it dissolves the copper from the ore. The resulting pregnant leach solution of sulfuric acid and copper sulfate is collected in a small pool. The copper compound can now be seen at conc...
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Sulfide ores are generally processed using pyrometallurgy, the extraction and purification of metals by processes involving the application of heat. This process uses a series of physical steps and high temperatures to extract and purify copper from copper sulfide ores, in four basic steps: 1) froth flotation, 2) thickening, 3) smelting, and 4) electrolysis. Following mining, transporting, and crushing to a consistent gravel or golf ball size, the crushed ore is further processed at a mill using secondary crushers, and reduced to pebbles, and finally to fine sand. After the copper ore is crushed, liquid is added to make it a slurry. The slurry is a mix of valuable copper ore minerals and worthless rock, called gangue . The slurry is placed in a tank and a process called froth floatation is used to separate the copper minerals from the gangue. Chemical reagents called collectors are added to the slurry and bind to the copper particles, making them hydrophobic,...
In addition to processing copper ores, new and old copper scrap or copper alloys can be melted, re purified, and recycled into new components. It is estimated that such recycling supplies 50% of copper used in the copper industry . In 2010, 770,000 metric tons of copper were recycled, at an estimated value of nearly six billion dollars .
THE TESTING AND CONCENTRATION OF A LOW GRADE COPPER NICKEL ORE The purpose of this thesis is to investigate the possi bility of concentrating a low grade copper nickel ore, to determine the most effective method of concentration, and to attempt to draw some conclusions to determine whether or not the concentrates produced would be of sufficient high
charge material of copper concentrate mixed with a siliceous flux is heated in air to about 650°C , eliminating 20 to 50 percent of the sulfur as sulfur dioxide
low grade ores , particularly those of copper and nickel, in terms of their life cycle based energy consumption and greenhouse gas emissions.