Ores & Extraction

Very unreactive metals are found in their natural states. More reactive metals have reacted with other elements to form compounds in rocks.

The process of obtaining a metal from a compound is extraction.

Ways of extracting metals:

Heating an ore with Carbon:

• Used if the metal being extracted is under Carbon in the reactivity series.
• The carbon displaces the metal.
• Iron Oxide + Carbon ---) Iron + Carbon Dioxide

Electrolysis of a molten compound:

• Used if the metal being extracted is higher than Carbon in the reactivity series.
• Decomposes the compound.
• Aluminium ---) Aluminium + Oxygen

Advanced ways of extracting metals:

Bioleaching - Using bacteria to extract metals from their ores. Produces solution with metal ions.

Bioleaching uses bacteria on low grade ore. The bacteria produce a solution containing copper ions, called a leachate. Copper is extracted from leachate by displacement using scrap iron, then purified by electrolysis.

This method can also be used to extract Nickel, Cobalt and Zinc.

Phytoextraction - Using plants to extract metals by absorbing the compounds.

Phytoextraction involves growing plants that absorb metal compounds. The plants are burnt to form ash, from which the metal is extracted.