Extraction of Metals

04/01/2023

Two ways of extracting copper from low-grade ores

Phytomining and bioleaching

What happens in phytomining?

1. Plants are grown in soil containing low-grade copper ores
2. The plants are harvested
3. The plants are burned to produce ash containing metal compounds
4. Sulfuric acid is added to the ash to dissolve the copper compounds
5. This produces copper sulfate
6. Copper can be obtained from this by using electrolysis or by a displacement reaction using scrap iron

What happens in bioleaching

1. Bacteria are added to low-grade copper ores
2. The bacteria feed on the ores producing leachate containing soluble copper compounds
3. Copper can be obtained from this by using electrolysis or by a displacement reaction using scrap iron

What is used in phytomining to remove copper from low-grade ore?

Plants

What is added to the ash from phytomining to dissolve the copper compound?

Sulfuric acid

Give two ways of obtaining copper from copper sulfate solution or leachate

Electrolysis or a displacement reaction using scrap iron

What is added to the low-grade ores in bioleaching

Bacteria

What is the solution that contains the water soluble compounds from bioleaching?

Leachate

What advantages do phytomining and bioleaching have over more traditional methods of mining.

1. Less CO2 produced
2. Less waste produced
3. Digging up ores is not required

What occurs when a metal oxide is heated with carbon

The carbon removes the oxygen from the metal to form carbon dioxide

What is the equation for when carbon removes oxygen from a metal

metal oxide + carbon → metal + carbon dioxide

What is it called when a metal oxide is reduced to the metal by a chemical reaction

reduction

What are limited resources called

Finite resources

How do you extract metals less reactive than carbon

metals less reactive than carbon can be extracted from their oxides by reduction with carbon

What are most metals found as in the Earth

Compounds that require chemical reactions to extract the metals

What type of metals can be found in the Earth

Unreactive metals like gold can be found as the metal itself not the compound