c6.1.9 biological metal extraction

Question 1

bioleaching

Answer 1

bacteria oxidise iron and sulfide ions and use the energy transferred. during this, sulphuric acid is made, in the presence of water and oxygen. the sulphuric acid is used to break down copper sulfide ions releasing metal ions

Question 2

advantages and disadvantages of bioleaching

Answer 2

advantages:
cheaper than traditional mining
doesn’t release any harmful substances into the atmosphere

disadvantages:
slow

Question 3

phytoextraction

Answer 3

plants absorb dissolved ions through their roots
these plants grow and then they are burned
metal can then be extracted from the ash

Question 4

advantages and disadvantages of phytoextraction

Answer 4

advantages:
cheaper
carbon-neutral
produces less waste

disadvantages:
slow