Which of the following metals can be extracted through alkali leaching technique ?

Options

A. `Cu`
B. `Au`
C. `Pb`
D. `Sn`

Answer

To determine which metals can be extracted through the alkali leaching technique, we can follow these steps:

### Step 1: Understand Alkali Leaching
Alkali leaching is a hydrometallurgical process used to extract metals from their ores using alkaline solutions. Common leaching agents include sodium hydroxide (NaOH) and potassium cyanide (KCN).

### Step 2: Identify Metals Extracted by Alkali Leaching
The metals that can typically be extracted using alkali leaching include:
- Gold (Au)
- Silver (Ag)
- Aluminium (Al)

### Step 3: Analyze the Given Options
The question provides the following options:
1. Gold
2. Lead
3. Tin

### Step 4: Match Options with Extractable Metals
- **Gold**: Can be extracted through alkali leaching.
- **Lead**: Typically not extracted through alkali leaching; it is usually extracted via pyrometallurgical methods.
- **Tin**: Also not commonly extracted through alkali leaching; it is usually extracted from its ores using other methods.

### Step 5: Conclusion
From the analysis, the only metal from the given options that can be extracted through alkali leaching is **Gold**.

### Final Answer
**Gold** is the metal that can be extracted through alkali leaching technique.

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