Silver metal is extracted by cyanide process from silver glance `(Ag_(2)S)`. The ore is concentrated through forth floatation process. The concentrated ore is then leached and solution is treated with reducing agent to get spongy silver which is then purified by fusion with an oxidsing agent followed by electrolysis.
Leaching of `Ag_(2)S` is carried out by heating it with a dilute solution of

Options

A. NaCN alone
B. NaCN in presence of `O_(2)`
C. HCl
D. NaOH

Explanation

To extract silver metal from silver glance (Ag₂S) using the cyanide process, we follow these steps:

### Step 1: Concentration of Ore
The first step in the extraction process is the concentration of the ore, which is done through the froth flotation process. In this method, the ore is mixed with water and chemicals to create a froth that selectively separates the valuable minerals from the waste material.

### Step 2: Leaching
After concentration, the concentrated ore is subjected to leaching. This involves heating the concentrated Ag₂S with a dilute solution of sodium cyanide (NaCN) in the presence of oxygen (O₂). The reaction can be summarized as follows:

\[ \text{Ag}_2\text{S} + 4 \text{NaCN} + \text{O}_2 \rightarrow 2 \text{AgCN} + 2 \text{Na}_2\text{S} \]

In this reaction, silver sulfide (Ag₂S) reacts with sodium cyanide and oxygen to form silver cyanide (AgCN) and sodium sulfide (Na₂S).

### Step 3: Reduction to Spongy Silver
The resulting solution containing silver cyanide is treated with a reducing agent (often zinc) to convert the silver cyanide into spongy silver (Ag). The reaction can be represented as:

\[ 2 \text{AgCN} + \text{Zn} \rightarrow 2 \text{Ag} + \text{Zn(CN)}_2 \]

### Step 4: Purification of Silver
The spongy silver obtained is not pure and needs to be purified. This is done by fusion with an oxidizing agent, typically lead oxide (PbO), which helps to remove impurities. The reaction can be summarized as:

\[ \text{Ag} + \text{PbO} \rightarrow \text{Ag} + \text{Pb} \]

After fusion, the pure silver is obtained and can be further purified by electrolysis, where an electric current is passed through a solution containing silver ions, depositing pure silver on the cathode.

### Summary
1. Concentration of ore through froth flotation.
2. Leaching with dilute NaCN and O₂ to form AgCN.
3. Reduction of AgCN to spongy silver using a reducing agent.
4. Purification of silver through fusion and electrolysis.