Question

Give the balanced equations for the conversion of argentite (Ag₂S) to metallic silver. 

Give the equations for the conversion of argentite (Ag₂S) to metallic silver.

Answer 1

Concentration of the ore: Argentite, being a sulphide ore, is concentrated by the froth flotation process. The powdered ore is mixed with water and pine oil, and air is blown through it. The ore particles attach to the froth and rise to the surface, while the impurities settle down.

Roasting: The concentrated argentite is roasted in the presence of air. During roasting, a part of silver sulphide is oxidised to silver oxide and sulphur dioxide.

\[\ce{2Ag2S + 3O2 -> 2Ag2O + 2SO2}\]

Reduction: On further heating, the remaining silver sulphide reacts with silver oxide to form metallic silver and sulphur dioxide gas.

\[\ce{Ag2S + 2Ag2O -> 6Ag + SO2}\]

Overall reaction: Combining both steps, the overall reaction can be represented as:

\[\ce{2Ag2S + 3O2 -> 4Ag + 2SO2}\]