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प्रश्न
State the role of silica in the metallurgy of copper.
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उत्तर १
In the metallurgy of copper, silica (SiO2) acts as an acidic flux during smelting and Bessemerisation.
During smelting, the roasted ore contains ferrous oxide (FeO) as an impurity. Silica combines with FeO to form ferrous silicate (FeSiO3), which is a fusible slag.
\[\ce{FeO + SiO2 -> FeSiO3}\]
The slag (FeSiO3) being lighter, floats on the surface of the molten matte and is removed easily.
Similarly, during Bessemerisation, FeO formed again reacts with SiO2 to form FeSiO3 slag, purifying the molten copper.
Hence, the role of silica is to remove iron impurities by forming a fusible slag of FeSiO3.
उत्तर २
During roasting, copper pyrites are converted into a mixture of FeO and Cu2O. Thus, acidic flux silica is added during smelting to remove FeO (basic). FeO combines with SiO2 to form famous silicate (FeSiO3) slag, which floats over molten matte.
संबंधित प्रश्न
The reaction,
Cr2O3 + 2Al → Al2O3 + 2Cr
(ΔGθ = -421kJ) is thermodynamically feasible as is apparent from the Gibbs energy value. Why does it not take place at room temperature?
Is it true that under certain conditions, Mg can reduce SiO2 and Si can reduce MgO? What are those conditions?
The choice of a reducing agent in a particular case depends on thermodynamic factor. How far do you agree with this statement? Support your opinion with two examples.
How will you convert the following:
Zinc blende to Zinc metal
The impurity that is added externally to remove the impurity already present in the ore is known as ____________.
In the extraction of copper from its sulphide ore, the metal is formed by the reduction of \[\ce{Cu2O}\] with ______.
Choose the correct option of temperature at which carbon reduces \[\ce{FeO}\] to iron and produces \[\ce{CO}\].
Below point ‘A’ \[\ce{FeO}\] can ______.
For the reduction of \[\ce{FeO}\] at the temperature corresponding to point D, which of the following statements is correct?
For the metallurgical process of which of the ores calcined ore can be reduced by carbon?
(i) Haematite
(ii) Calamine
(iii) Iron pyrites
(iv) Sphalerite
Explain the following:
Generally sulphide ores are converted into oxides before reduction.
Explain the following:
Silica is added to the sulphide ore of copper in the reverberatory furnace.
A cuprous ore among the following is:-
Heating of MgCl2 6H2O in absence of HCl gives ______.
Carbon deposition reaction taking place in ______.
Assertion: For the extraction of iron, haematite ore is used.
Reason: Haematite is a carbonate ore of iron.
