Low melting metals like lead in tin are refined by .............. .

Answer

**Step-by-Step Text Solution:**

1. **Identify the Process**: The question asks about the refining process for low melting metals like lead and tin. The correct term for this process is "liquidation."

2. **Understanding Liquidation**: Liquidation is a refining process specifically used for metals with low melting points. In this process, crude metal is placed on a sloping hearth.

3. **Heating the Hearth**: The sloping hearth is gently heated. As the temperature increases, the low melting metal begins to melt.

4. **Flow of Metal**: Once the metal melts, it flows down the slope into a receiver. This allows for the collection of the purified metal.

5. **Separation of Impurities**: While the molten metal flows down, the impurities remain on the hearth. This separation is a key aspect of the liquidation process.

6. **Diagram Representation**: To visualize the process, one can draw a simple diagram showing the sloping hearth, the crude metal placed on it, the receiver for the molten metal, and the impurities left behind.

7. **Conclusion**: Therefore, low melting metals like lead and tin are refined by the process of liquidation.

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