Heating the ore in the presence of excess supply of air below its melting point is called

Options

A. roasting
B. calcination
C. smelting
D. liquation

Explanation

To solve the question, we need to identify the process described when heating an ore in the presence of excess air below its melting point. Let's break it down step by step:

### Step-by-Step Solution:

1. **Understanding the Process**: The question asks about heating an ore in the presence of excess air below its melting point. This indicates a chemical reaction involving the ore and oxygen.

**Hint**: Consider the role of air (oxygen) in the transformation of ores.

2. **Identifying the Type of Ore**: The process described typically involves sulfide ores. These are ores that contain sulfur in combination with a metal.

**Hint**: Think about the common types of ores and their compositions.

3. **Chemical Reaction**: When sulfide ores are heated in the presence of oxygen, they undergo a reaction that converts them into their corresponding metal oxides. This is a crucial part of the process.

**Hint**: Recall the general reaction of sulfide ores when they react with oxygen.

4. **Naming the Process**: The specific term for this process, where sulfide ores are heated with excess air to form metal oxides, is known as "roasting."

**Hint**: This term is commonly used in metallurgy; think about the processes used to extract metals from their ores.

5. **Conclusion**: Therefore, the correct answer to the question is that the process of heating the ore in the presence of excess air below its melting point is called "roasting."

### Final Answer:
The process is called **roasting**.