New
New
Year 11
Edexcel
Higher

Alternative methods of extracting metals: phytoextraction and bioleaching

I can describe how metals are extracted by phytoextraction and bioleaching and compare different methods of metal extraction.

New
New
Year 11
Edexcel
Higher

Alternative methods of extracting metals: phytoextraction and bioleaching

I can describe how metals are extracted by phytoextraction and bioleaching and compare different methods of metal extraction.

Lesson details

Key learning points

  1. In phytoextraction, metal is extracted from a crop of plants that absorb metal ions through their roots.
  2. In bioleaching, metal is extracted from bacteria that extract metal from an ore.
  3. Electrolysis is a process used to separate metals from their compounds.
  4. There are advantages and disadvantages associated with each method of extracting metals.

Common misconception

Students struggle to distinguish between phytoextraction and bioleaching.

Reinforce that the term 'phyto' is a combining form meaning 'plant'.

Keywords

  • Low-grade ore - An ore is a rock that contains metals or metal compounds. A low-grade ore contains a lower percentage of metal or metal compound than a high-grade ore.

  • Phytoextraction - Phytoextraction is a method of extracting metals by growing plants in soil containing low-grade ore.

  • Displacement - Displacement is where a more reactive element takes the place of a less reactive element in a compound.

  • Electrolysis - Electrolysis is a process that uses electricity to break down a compound.

  • Bioleaching - Bioleaching is a method of extracting metals by growing bacteria on low-grade ores to produce a leachate.

This lesson provides a good opportunity to discuss the importance of reusing and recycling products to reduce the amount of metal we need to extract from ores.
Teacher tip

Equipment

None required.

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
What is meant by the term 'finite resource'?
Correct answer: a limited resource that is being used faster than it is being made
a resource in a plentiful supply
a renewable resource
an infinite resource that will never run out
Q2.
Which of the following are examples of finite resources?
Correct answer: rocks such as limestone and sandstone, used in construction
Correct answer: natural gas, used as a fuel
Correct answer: metal ores, used to provide metals
cotton, used in clothing
the Sun, used as a renewable energy resource
Q3.
What scientific term is used to describe a reaction where a more reactive element takes the place of a less reactive element in a compound?
Correct Answer: displacement, displacement reaction
Q4.
Why can iron be used to extract copper from a copper compound?
An image in a quiz
Correct answer: iron is more reactive than copper
iron is less reactive than copper
Correct answer: iron will displace copper in a copper compound
copper will displace iron in a copper compound
Q5.
Which of the following are disadvantages of traditional mining?
Correct answer: noise pollution
Correct answer: loss of habitats
requires plant growth which is a slow process
bacteria used in the process produce toxic substances
Correct answer: large machinery produce pollutants
Q6.
What is the name of the process that uses electricity to break down a compound?
Correct Answer: electrolysis

6 Questions

Q1.
What is the name of the method of extracting metals by growing bacteria on low-grade ores?
Correct Answer: bioleaching
Q2.
Which of the following are advantages of bioleaching?
Correct answer: conserves high-grade ores
produces toxic substances that can cause environmental damage
it is a slow process
Correct answer: reduces air pollutants released during traditional mining
Correct answer: can be used to extract metals from low-grade ores
Q3.
Which of the following are part of the method for phytoextraction?
Correct answer: Grow plants in soil containing low-grade ore.
Grow bacteria on low-grade ores.
Correct answer: Burn plants to produce ash rich in metal compounds.
Correct answer: Dissolve the ash in acid to produce a leachate.
Bacteria break down the ore to produce a leachate.
Q4.
How can a metal such as copper be extracted from a leachate?
heating with a less reactive metal, such as gold
Correct answer: using electrolysis
Correct answer: displacement reaction using scrap iron
growing bacteria on the leachate
growing plants in the leachate
Q5.
Which of the following are disadvantages of phytoextraction?
creates an eyesore and noise pollution
Correct answer: process is slow
Correct answer: weather dependent
process destroys habitats
Correct answer: more expensive than traditional mining
Q6.
Which of the following statements about copper ores are correct?
Correct answer: low-grade ores contain a lower percentage of copper than high-grade ores
low-grade ores contain a higher percentage of copper than high-grade ores
Correct answer: high-grade ores are becoming more difficult to find
Correct answer: the percentage of copper found in ores has been decreasing
the percentage of copper found in ores has been increasing