Write two points of similarities between calcination and roasting.

Explanation

### Step-by-Step Solution:

1. **Definition of Calcination and Roasting**:
- **Calcination**: It is the process of converting an ore into its oxide by heating it below its melting point, typically in the absence or limited supply of air. This process is commonly used for carbonates and hydroxides.
- **Roasting**: This is the process of converting an ore into its oxide by heating it above its melting point in the presence of excess air. It is primarily used for sulfide ores.

2. **Similarity 1: Conversion of Ore into Oxide**:
- Both calcination and roasting are processes aimed at converting ores into their respective oxides. In calcination, carbonates and hydroxides are converted to oxides, while in roasting, sulfide ores are converted to oxides.
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