Calcination is the process of heating the ore strongly in the _____of air.

Answer

**Step-by-Step Solution:**

1. **Understanding Calcination**: Calcination is a thermal treatment process. It involves heating ores to high temperatures.

2. **Conditions of Calcination**: The key aspect of calcination is that it occurs in the absence of air or in a limited supply of air. This is crucial because it prevents oxidation of the metal.

3. **Purpose of Calcination**: The primary purpose of calcination is to convert metal carbonates into metal oxides and carbon dioxide. For example, when calcium carbonate (CaCO3) is heated, it decomposes into calcium oxide (CaO) and carbon dioxide (CO2).

4. **Filling in the Blank**: Based on the understanding that calcination occurs in the absence of air, we can fill in the blank in the question.

5. **Final Answer**: Calcination is the process of heating the ore strongly in the **absence** of air.

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