Which of the following statements is incorrect?a)Cassiterite ore of ti...
Incorrect Statement: Reducing agent of haematite in blast-furnace is coke in the upper part and CO in the lower part of the furnace.
Explanation:
1. Cassiterite Ore and Impurities:
- Cassiterite is the main ore of tin, and it often contains impurities such as wolframite.
- Wolframite is a tungsten mineral that is often found associated with tin deposits.
- To separate the impurities from cassiterite, an electromagnetic separator is used. This device uses magnetic properties to separate the different minerals.
2. Carbon Reduction of Tin:
- Tin metal is obtained by the carbon reduction of tin oxide, also known as black tin.
- Black tin is heated with carbon (usually in the form of coal or coke) in a furnace.
- The carbon reacts with the oxygen in the tin oxide, producing carbon dioxide gas and leaving behind the pure tin metal.
3. Extraction of Lead from Galena:
- Galena is the main ore of lead, and it is a sulfide mineral.
- In the extraction of lead from galena, two main steps are involved: roasting and self-reduction.
- Roasting involves heating the galena in the presence of air, which converts the lead sulfide into lead oxide and sulfur dioxide gas.
- Self-reduction is carried out in the same furnace but at different temperatures.
- In this process, the lead oxide is reduced by the carbon monoxide gas produced during roasting, resulting in the formation of metallic lead.
4. Reduction of Haematite in Blast Furnace:
- Haematite is an iron ore that contains iron(III) oxide (Fe2O3).
- In the blast furnace, iron ore is reduced to iron metal using a combination of coke and carbon monoxide gas (CO).
- The reduction process occurs in different zones of the furnace.
- In the upper part of the furnace, coke (carbon) is the main reducing agent.
- Coke reacts with the oxygen in the haematite, producing carbon dioxide gas and leaving behind iron metal.
- In the lower part of the furnace, carbon monoxide gas (CO) is the main reducing agent.
- Carbon monoxide reacts with the remaining iron(III) oxide, further reducing it to iron metal.
Conclusion:
The incorrect statement is option 'D' because it states that coke is the reducing agent in the upper part of the furnace and carbon monoxide (CO) is the reducing agent in the lower part. In reality, coke is the main reducing agent throughout the furnace, while carbon monoxide plays a role in the reduction process in the lower part of the blast furnace.