What is gangue in chemistry?

Gangue is the unwanted material or impurities that are found with ore during mining and extraction of metals.

When ores are mined, they are mixed with impurities like sand, clay, and rock. These impurities do not contain any valuable metal and are called gangue. Before extracting metal, gangue must be removed by various physical or chemical methods.

Methods to Remove Gangue

• Gravity separation: Based on differences in weight.
• Magnetic separation: Uses magnets to remove magnetic gangue.
• Froth flotation: Used for sulfide ores using bubbles.

Example

In iron ore, silica (SiO₂) and sand are gangue. In copper ore, clay may act as gangue material.