Extracting Metals From Ores

Question 1

What are the 6 steps as to how Phytomining works?

Answer 1

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.
5. An acid is added to the ash to produce a solution containing dissolved metal compounds (leachate).
6. Copper can be obtained from these solutions by displacement using scrap iron or by electrolysis.

Question 2

How does Bioleaching work?

Answer 2

Certain bacteria can break down low-grade ores to produce an acidic solution containing dissolved copper compounds (leachate).
Electrolysis or scrap iron can be used to displace copper from the leachate.

Question 3

What are some advantages and disadvantages of Bioleaching?

Answer 3

Advantages:
1. Doesn’t release greenhouse gases.
2. Can extract from low grade ores.
Disadvantages:
1. Slow
2. Can produce toxic chemicals that can run into rivers + water supplies.

Question 4

What are some advantages and disadvantages of Phytomining?

Answer 4

Advantages:
1. Can extract from low grade ores.
2. Less impact on the environment
Disadvantages
1. The copper you get isn’t pure, and it isn’t energy efficient to purify it.
2. Slow

Question 5

What does it mean if the species of metal is being oxidised?

Answer 5

It is gaining oxygen.

Question 6

What does it mean if the species of metal is being reduced?

Answer 6

It is losing oxygen.