<P> The copper ore is crushed and ground to a size such that an acceptably high degree of liberation has occurred between the copper sulfide ore minerals and the gangue minerals . The ore is then wet, suspended in a slurry, and mixed with xanthates or other reagents, which render the sulfide particles hydrophobic . Typical reagents include potassium ethylxanthate and sodium ethylxanthate, but dithiophosphates and dithiocarbamates are also used . </P> <P> The treated ore is introduced to a water - filled aeration tank containing surfactant such as methylisobutyl carbinol (MIBC). Air is constantly forced through the slurry and the air bubbles attach to the hydrophobic copper sulfide particles, which are conducted to the surface, where they form a froth and are skimmed off . These skimmings are generally subjected to a cleaner - scavenger cell to remove excess silicates and to remove other sulfide minerals that can deleteriously impact the concentrate quality (typically, galena), and the final concentrate sent for smelting . The rock which has not floated off in the flotation cell is either discarded as tailings or further processed to extract other metals such as lead (from galena) and zinc (from sphalerite), should they exist . To improve the process efficiency, lime is used to raise the pH of the water bath, causing the collector to ionize more and to preferentially bond to chalcopyrite (CuFeS) and avoid the pyrite (FeS). Iron exists in both primary zone minerals . Copper ores containing chalcopyrite can be concentrated to produce a concentrate with between 20% and 30% copper - in - concentrate (usually 27--29% copper); the remainder of the concentrate is iron and sulfur in the chalcopyrite, and unwanted impurities such as silicate gangue minerals or other sulfide minerals, typically minor amounts of pyrite, sphalerite or galena . Chalcocite concentrates typically grade between 37% and 40% copper - in - concentrate, as chalcocite has no iron within the mineral . </P> <Table> <Tr> <Td> </Td> <Td> This section does not cite any sources . Please help improve this section by adding citations to reliable sources . Unsourced material may be challenged and removed . (October 2008) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This section does not cite any sources . Please help improve this section by adding citations to reliable sources . Unsourced material may be challenged and removed . (October 2008) (Learn how and when to remove this template message) </Td> </Tr>

How does the feo impurity present in sulphide ore of copper is removed