Question

Among the following options, a process for liquid-liquid separation is

• A. Smelting
• B. Roasting
• C. Sintering
• D. Calcination

Hint:

Associate key transformations with each metallurgical process: Smelting \(\rightarrow\) Melting \& Reduction (liquid metal + liquid slag); Roasting \(\rightarrow\) Oxidation (solid + gas); Calcination \(\rightarrow\) Decomposition (solid + gas); Sintering \(\rightarrow\) Agglomeration (solid).

Answer 1

The Correct Option is A

Step 1: Concept of Liquid-Liquid Separation in Metallurgy:
Liquid-liquid separation occurs when two immiscible liquid phases with different densities form and separate into layers. This phenomenon is commonly observed in high-temperature metallurgical processes.
Step 2: Evaluation of Each Process:

• Smelting: In smelting, the ore is heated above its melting point in the presence of a reducing agent. This produces molten metal and molten slag. These two liquids are immiscible and separate due to density differences, enabling liquid-liquid separation.
• Roasting: Roasting involves heating sulfide ores in the presence of oxygen, mainly resulting in gas-solid reactions.
• Sintering: Sintering is a solid-state process where fine particles are fused below their melting point.
• Calcination: Calcination is a thermal decomposition process of carbonates or hydroxides in the solid state.

Step 3: Final Conclusion:
Only smelting produces two distinct liquid phases (metal and slag) that separate naturally. Therefore, it is the correct process for liquid-liquid separation.