extraction of metals from their ores

What is an ore?

A compound often made of metal oxide in the earth's crust which contains a metal

Examples of ores

Bauxite containing Al2O3, haemanite containing Fe2O3

How is metals less reactive than carbon extracted?

Reduction using C or CO cheaply

How is metals more reactive than carbon extracted?

Compounds are stable and are extracted by electrolysis of molten compounds

Bioleaching

Bacteria is grown on low grade copper ores. The bacteria makes a solution that contains copper ions (leachate).Scrap ions is used to displace the copper ions forming copper metal which is purified using electrolysis

Phytoextraction

Plants abosrobing metal compounds are grown. Metals are extracted from ash formed when plants are burnt

Advantages of bioleaching

No harmful gas produced, less damage to landscape compared to mining, does not require high temperature, conserve supply of higher grade ores

Disadvantage of bioleaching

Very slow, can produce toxic substance and sulfuric acid damaging the environment

Advantage of phytoextraction

No harmful gases produced, less damage to landscape compared to mining, can extract metals from contaminated soil, conserve supply of higher grade ores

Disadvantages of phytoextraction

Very slow, more expensive than mining, pant growth is weather dependent

Advantages of recycling metals

Natural metal ore resources will last longer if not mined, less waste metal end up in landfills, less energy required to recycle, less pollutants gas formed, less mining so less damage to the landscape