How is copper extracted from copper pyrites ?

Explanation

Extraction of copper from copper pyrites :
Copper pyrite is the main source of copper metal. Various setps involved in the extraction of copper discussed below.
Step-I :
Concentration of ore by froth floatation process :
The ore is first crushed in ball mills . The finely divided ore is suspended in water. A little pine oil is added and the mixture is vigorously agitated by a current of air . The froth formed carries the ore particles almost completely. The gangue sinks to the bottom of the tank The froth is separated and about 95% concentrated ore is obtained .
Step II :
Roasting : To remove the volatile impurities like AS (or)Sb, the ore is roasted in a free supply of air . A mixture of sulphides of copper and iron are obtained and these are partially oxidised to respective oxides.
`Cu_(2)S.Fe_(2)S_(3)+O_(2)rarrCu_(2)S+2FeS+SO_(2)`
`2Cu_(2)S+3O_(2)rarr2Cu_(2)+2SO_(2)` ,
`2FeS+3O_(2)rarr2FeO+2SO_(2)`
step -iii
The roasted ore is mixed with a little coke and sand (Silica)and smelted in a blast furnace and fused A Blast of air , necessary for the combustion of coke , is blow through the tuyeres present at the base of the furnace. The oxidation of the sulphides of copper and iron will be completed further .A salg of iron silicate is formed according to the reactions given below :
`{:(2FeS+3O_(2)rarr2FeO+2SO_(2)),(FeO+SiO_(2)rarrFe SiO_(3)),(" Ferrous Silicate(Slag)"),(Cu_(2)O+FeSrarrCu_(2)S+FeO):}`
Step -iv : After smelting the copper ore in blast furnace, the product of the blast furnace consists mosty of `Cu_(2)S` and a littel of ferrous sulphide. This product is known as "matte."It is collected from the bottom of the furnace. After then the following processes are carried out for getting pure copper.
Bessemerization : The matte is charged into a Bessemer converter. A bessemer converter is a pear - shape furnace. It is made of steel plates. The furnace is given a basic lining with lime or magnesium oxide (obtained from dolomite or magnesite). The converter is held in position by trunnions and can be tilted in any position . A hot blast of air and sand is blown through the tuyeres present near the bottom. Molten metal , the product in the furnace , collects at the bottom of the converter.
Reactions that took place in blast furnace go to completion . Almost all of iron is elimiated as a slag. Cuprous oxide combines with cuprous sulphide and forms Cu metal.
`2Cu_(2)O+Cu_(2)Srarr6Cu+SO_(2)`
The molten metal is cooled in sand moulds . `SO_(2)` escapes. The impure copper metal is known as "Blister Copper" and is about 98% pure.
Step -V :
Refining : The Blister copper is purified by electrolysis. The impure copper metal is made into plates. They are suspended into lead -lined tanks containing Copper (II)Sulphate solution. Thin plates of pure copper serve as cathode. The cathode plates are coated with graphite. On electrolysis, Pure copper is deposited at the cathode. The copper obtained is almost 100% pure Cu.