In calcination, ore is heated strongly in the absence of air

Explanation

**Step-by-Step Solution:**

1. **Understanding the Process of Calcination:**
- Calcination is a thermal treatment process in which ores are heated to a high temperature. This process is typically carried out in the absence of air or in a limited supply of air.

2. **Identifying the Key Characteristics of Calcination:**
- The main characteristics of calcination include:
- Heating of the ore.
- Absence of air or limited oxygen supply.
- Heating is done below the melting point of the ore.

3. **Example of Calcination:**
- A common example of calcination is the heating of zinc carbonate (ZnCO3).
- When ZnCO3 is heated, it decomposes to form zinc oxide (ZnO) and carbon dioxide (CO2):
\[ \text{ZnCO}_3 \xrightarrow{\text{heat}} \text{ZnO} + \text{CO}_2 \]

4. **Conclusion:**
- Since calcination involves heating ores in the absence of air or with limited air supply, the statement "In calcination, ore is heated strongly in the absence of air" is true.

**Final Answer:**
The statement is true.

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