C14.4 - Extracting metals from ores

Ore

Ore

a rock with enough metal to make extracting the metal worthwhile

Main methods to obtain copper metal from ore

• redox reaction

• electrolysis

Redox reaction

Where a metal oxide reacts with carbon or scrap metal to oxidise the carbon/metal and reduce the metal

Phytomining

1. plants are grown in soil that contains low grade ore

2. the plants absorb metal ions through their roots and concentrate these ions in their cells

3. the plants are harvested and burnt

4. the ash left behind contains metal compounds

Bioleaching

Certain bacteria can break down low-grade ores to produce an acidic solution containing copper ions. The solution is called a leachate.

Advantages of bioleaching and phytomining

• uses less money

• less electricity (and therefore money) so its better for the planet

• conserves supply of high grade ore

• reduces rock waste