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प्रश्न
Write down the reactions taking place in different zones in the blast furnace during the extraction of iron.
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उत्तर
During the extraction of iron, the reduction of iron oxides takes place in the blast furnace. In this process, hot air is blown from the bottom of the furnace, and coke is burnt to raise the temperature up to 2200 K in the lower portion itself. The temperature is lower in the upper part. Thus, it is the lower part where the reduction of iron oxides (Fe2O3 and Fe3O4) takes place.
The reactions taking place in the lower temperature range (500 − 800 K) in the blast furnace are:
\[\ce{3Fe2O3 + CO -> 2Fe3O4 + CO2}\]
\[\ce{Fe3O4 + 4CO -> 3Fe + 4CO2}\]
\[\ce{Fe2O3 + CO -> 2FeO + CO2}\]
The reactions taking place in the higher temperature range (900-1500 K) in the blast furnace are:
\[\ce{C + CO2 -> 2CO}\]
\[\ce{FeO + CO -> Fe + CO2}\]
The silicate impurity of the ore is removed as slag by calcium oxide (CaO), which is formed by the decomposition of limestone (CaCO3)
\[\ce{CaCO3 -> CaO + CO2}\]
\[\ce{CaO + SiO2 -> \underset{(Slag)}{\underset{Calcium silicate}{CaSiO3}}}\]
संबंधित प्रश्न
How is ‘cast iron’ different from ‘pig iron’?
Why is the extraction of copper from pyrites more difficult than that from its oxide ore through reduction?
State the role of silica in the metallurgy of copper.
The impurity that is added externally to remove the impurity already present in the ore is known as ____________.
In the metallurgy of aluminium ______.
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
Wrought iron is the purest form of iron. Write a reaction used for the preparation of wrought iron from cast iron. How can the impurities of sulphur, silicon and phosphorus be removed from cast iron?
How is copper extracted from low grade copper ores?
The purest form of iron is prepared by oxidising impurities from cast iron in a reverberatory furnace. Which iron ore is used to line the furnace? Explain by giving reaction.
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.
Carbon deposition reaction taking place in ______.
Assertion: For the extraction of iron, haematite ore is used.
Reason: Haematite is a carbonate ore of iron.
\[\ce{Au + CN^- + H2O + O2 -> [Au(CN)2]^- + OH^-}\]
The number of CN− ions involved in the balanced equation is ______.
