hi, i need help with my chemistry homework and i cant find this anywere, its in for tomorrow so please get your answers in a.s.a.pHow is copper obtained from low grade ores?also what is the definition of Reduction with carbon? thanks
generally speaking, copper and many other base metals are processed in a very similar fashion. The raw ore is crushed into small bits and processed to concentrate the metal minerals. This is called density separation; metal ore minerals tend to be of much higher density than the gangue (the non-value minerals). There are also chemical ways of producing a concentrate of ore minerals The concentrate is then sent to a smelter where it is melted. Since most metal ores see the metal in minerals under an oxidized form (as a cation), the metal must be reduced. Commonly this is done in the presence of carbon, the carbon reduces the metal cation to the neutral elemental form (the carbon is oxidized in its turn to CO2). Reduction by carbon means that the metal gets electrons from the carbon, changing the metal's charge state from positive to neutral. During smelting, a very rich metal product is formed that can be separated physically (usually as a liquid) from the gangue residues, which are now called slag (waste rock from smelting). Many metals, copper among them, also undergo an additional step of purification involving electricity. The raw ore, which is fairly pure but not super pure, is placed in an acid or salt bath and electricity is put intot he system to create what is basically a reverse battery. The copper dissolves off the side with impure copper and collects as a very pure copper on the other side of the bath.
