What is flux ? What is the role of flux in the metallurgy of iron and copper ?

Explanation

### Step-by-Step Solution:

**Step 1: Define Flux**
- Flux is a substance that is added during the metallurgical process to facilitate the removal of impurities from the ore. It helps in forming a molten slag that can be easily separated from the metal.

**Step 2: Role of Flux in Metallurgy of Iron**
- In the metallurgy of iron, fluxes such as limestone (calcium carbonate) are commonly used. When limestone is heated, it decomposes to form lime (calcium oxide) and carbon dioxide. The lime reacts with silica (an impurity in iron ore) to form calcium silicate, which is a slag. This slag is less dense than molten iron and can be easily removed, thus purifying the iron.

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