Metal Extraction

Question 1

What is Phyto mining?

Answer 1

Using plants to extract metal from the ground.

Question 2

What is bioleaching?

Answer 2

using bacteria to extract metals from ore.

Question 3

What is the process for Phyto mining?

Answer 3

-Specific plants (Hyperaccumulators) absorb metal ions from soil are grown in soils containing low grade metal ores.
-Through roots take up metal ions which is transported to roots and stems
-When plants are grown they are harvested, dried and incinerated.
-Remaining ash contains metal compounds that can be processed into pure metals
-Extracted ash heated with carbon in furnace as carbon is reactive.

Question 4

What is the process of bioleaching?

Answer 4

-Bacteria such as ferrooxidans can oxidise metal sulphides into soluble metal ions
-Copper sulphide ores treated with bacteria forming leachate
-Dissolved metal extracted from leachate via displacement.

Question 5

What are pros and cons of Phyto mining?

Answer 5

+Used to extract metal from concentrated soils(low concentration of metal)
+Valuable in areas of polluted land and cleans up environment.
-Slow process due to plant growth
-Only works for metals plants can absorb

Question 6

What are pros and cons of bioleaching?

Answer 6

+Allows ores which would be discarded to have metal extracted low-energy option.
-Slow and requires control of environment conditions like temperature and PH for bacteria to remain alive
-Solutions from bioleaching are often acidic.