Question
Question: In the extraction of copper, the copper matte is a mixture of: (a)- Copper (II) sulfide and iron (...
In the extraction of copper, the copper matte is a mixture of:
(a)- Copper (II) sulfide and iron (II) sulfide
(b)- Copper (II) sulfide and iron (III) sulfide
(c)- Copper (I) sulfide and iron (II) sulfide
(d)- Copper (I) sulfide and iron (III) sulfide
Solution
Copper sulfide is oxidized with a metal that is more reactive than the copper element. Smelting is also involved in this process. Arsenic and antimony are the impurities that are present during the refining. Copper matte is made of Cu2Sand FeS.
Complete step by step answer:
The sulfide ore i.e., copper pyrites after the concentration by froth flotation process is roasted in a reverberatory furnace when copper pyrites are converted into a mixture of FeS$$$$C{{u}_{2}}S and which, in turn, are partially oxidized.
2FeCuS2+O2→Cu2S+2FeS+SO2
2FeS+3O2→2FeO+2SO2
2Cu2S+3O2→2Cu2O+2SO2
Since iron is more reactive than the copper, FeS is preferentially oxidized to FeO thanCu2S to Cu2O. If at all any Cu2O is formed, it combines withFeS and is changed back to Cu2S.
Cu2O+FeS→Cu2S+FeO
Thus, the roasted ore mainly contains Cu2S and along with unreacted FeS
The roasted ore is then mixed with silica (flux) and some powdered coke and heated strongly in a blast furnace. This process is called smelting. During smelting combines with silica to form fusible ferrous silicate slag.
FeO+SiO2→FeSiO3
At the temperature of the furnace, the entire mass melts, and two layers of molten mass are formed. The slag being lighter makes the upper layer which can be withdrawn from the slag whole from time to time. The lower molten layer is called copper matte. It chiefly consists of Cu2S of and some unchanged FeS.
So, the copper matte has Copper (II) sulfide and iron (II) sulfide.
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Therefore, the correct answer is an option (a)- Copper (II) sulfide and iron (II) sulfide**
Note: Recovery of copper from matte:
To obtain pure copper from matte, the molten matte is transferred to a besimmer converter which is a pear-shaped furnace made up of steel and lined inside with silica. It is mounted on a horizontal axle and can be tilted in any position. It is fitted with small pipes called tuyeres through which a blast of hot air and fine sand is admitted.