Question

Extraction of metal from the ore cassiterite involves

• A. carbon reduction of an oxide ore
• B. self-reduction of a sulphide ore
• C. removal of copper impurity
• D. removal of iron impurity

Hint:

Crude tin obtained initially contains impurities like iron, copper, lead, and other metals.

Answer 1

The Correct Option is D

The important ore of tin is cassiterite \((SnO_2)\). Tin is extracted from cassiterite ore by carbon reduction method in a blast furnace. Limestone is added to produce a slug with impurities, which can be separated. 
\(SnO_2+2C\rightarrow Sn+2CO\) 
The product often contains traces of iron which is removed by blowing air through the melt to oxidise to FeO which then floats to the surface. 
\(2Fe+O_2\rightarrow 2FeO\)

• Crude tin obtained initially contains impurities like iron, copper, lead, and other metals.
• The crude tin is subjected to a process called liquation, where it is remelted on an inclined furnace.
• Liquation takes advantage of the different melting points of tin and impurities.
• The easily fusible tin melts away and flows down, while the less fusible impurities remain behind.
• The molten tin is then further purified through a process called poling.
• Poling involves stirring the molten tin with green poles of wood in the presence of air.
• During poling, any remaining metal impurities react with oxygen in the air and form scum.
• The scum rises to the surface of the molten tin and is removed, leaving behind purified tin.
• Poling helps in oxidizing and removing the remaining impurities in the molten tin.

Therefore, Options A, C, and D are the correct answers.

Discover More From Chapter: General Principles and Processes of Isolation of Elements

Answer 2

The Correct Answer is (D)

Real Life Applications

1. Cassiterite is the primary source of tin, which is widely used in the manufacturing of solder, tinplate, and other metal alloys. 
2. Extracted tin from cassiterite is crucial in the production of electronic components, such as integrated circuits and transistors. 
3. Tinplate made from tin extracted from cassiterite is used in food packaging, ensuring a protective and hygienic barrier for canned goods. 
4. Cassiterite-derived tin is employed in coating and plating processes for items like steel containers, providing corrosion resistance and aesthetic appeal. 
5. Tin is utilized in the production of solar cells, contributing to the renewable energy sector. 

The extraction of metal from cassiterite ore plays a vital role in diverse industries, ranging from electronics to sustainable energy applications.

Question can also be asked as

1. What is involved in extracting metal from the ore cassiterite? 
2. How is iron impurity removed during the extraction of metal from cassiterite ore? 
3. Explain the process of removing iron impurity during the extraction of metal from cassiterite. 
4. In the extraction of metal from cassiterite ore, what step is taken to eliminate iron impurity? 
5. Describe the procedure of iron impurity removal in the extraction process of metal from cassiterite ore.

Answer 3

The Correct Answer is (D)

Cassiterite ore, a primary source of tin, undergoes a series of extraction steps to obtain the desired metal. Cassiterite, also known as tin stone, is a mineral form of tin oxide (SnO₂) found in various tin-bearing deposits. Tin is extracted from cassiterite ore through a sequence of extraction processes.

Removal of Iron Impurities

• Iron impurities are commonly present in cassiterite ore and need to be removed before further processing.
• Techniques such as magnetic separation or flotation are employed to separate iron-bearing minerals from cassiterite.

Carbon Reduction of an Oxide Ore

• Cassiterite is primarily an oxide ore, and tin extraction involves a carbon reduction process.
• The ore is heated with carbon in a furnace in the presence of a reducing agent, such as coke or charcoal.
• The carbon reacts with the oxygen in the cassiterite, reducing the tin oxide to metallic tin.

Smelting and Refining

• After carbon reduction, the resulting product, called crude tin or tin matte, contains impurities like copper, lead, and other metals.
• The crude tin is then subjected to smelting, where it is melted at high temperatures to separate impurities.
• During smelting, the impurities form a slag layer that floats on top of the molten tin, allowing for their removal.

Removal of Copper Impurity

• Copper impurities are commonly present in the crude tin obtained after smelting.
• To remove copper, the molten tin is stirred with green poles of wood, such as birch or fir.
• The wood reacts with copper, forming a copper oxide that floats to the surface as scum, which is skimmed off.

Purification and Casting

• Once the impurities are removed, the purified molten tin is cast into moulds or ingots for further processing and utilization.
• The cast tin can be further refined through electrolysis or other purification methods to achieve higher purity levels.

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