Cleaning the ore

The idea

Impurities such as soil and sand in a mined ore are called gangue; they are removed before extraction by techniques based on differences between the physical or chemical properties of the gangue and the ore.

Straight from the mine

A mined ore has soil and sand mixed with it.

What should be done before extracting the metal?

• Remove the soil and sand
• Nothing, extract at once
• Add more soil

Remove the gangue

Press Next step.

Why we clean ores

Mined ore is mixed with soil, sand and other impurities. These impurities are called gangue. They must be removed before the metal is extracted. Different separation techniques are used, based on differences between the physical or chemical properties of the gangue and the ore.

Impurities such as soil and sand in a mined ore are called gangue; they are removed before extraction by techniques based on differences between the physical or chemical properties of the gangue and the ore.

Notes

Gangue (soil, sand) is removed from an ore before extraction, using differences in physical or chemical properties of gangue and ore.

Check yourself

Impurities such as soil and sand mixed in a mined ore are called ...

When must the gangue be removed?

The techniques for removing gangue are based on ...

• gangue — correct. Yes!
• minerals. Minerals are the elements or compounds found naturally in the earth's crust.
• anode mud. Anode mud is the insoluble impurity that settles during electrolytic refining.
• After the metal is refined. The book says the impurities must be removed prior to extraction of the metal.
• Before the metal is extracted — correct. Yes!
• It need not be removed. The book says the impurities must be removed from the ore before extraction.
• the price of the ore. The book bases them on differences between physical or chemical properties.
• the age of the mine. The book bases them on differences between physical or chemical properties.
• differences between the properties of the gangue and the ore — correct. Yes!