10.5 Phytomining and bioleaching
5 exam questions worth 8 marks. Write your answer, open the mark scheme, then give yourself the marks you earned. Your answers are saved on this device.
0 / 8
In phytomining, what happens to the plants after they have absorbed metal compounds?
Choose one answer.
Correct Not quite: the answer is They are burned to produce ash
Mark scheme
C
Model answer
C: the plants are harvested and burned, and the ash contains the metal compounds.
Describe how bioleaching is used to extract copper.
Mark scheme
- bacteria are used to break down low-grade ore (1)
- producing a leachate (solution) of copper compounds (1)
Model answer
Bacteria break down the low-grade ore, producing a leachate that contains copper compounds.
Explain why scrap iron is used to obtain copper from a solution of copper sulfate.
Mark scheme
- iron is more reactive than copper, so it displaces copper (1)
- scrap iron is cheap (1)
Model answer
Iron is more reactive than copper, so it displaces copper from the solution, and scrap iron is cheap.
Give two advantages of phytomining compared with traditional mining.
Mark scheme
any two from:
- uses low-grade ores (1)
- less damage to landscape / less waste rock (1)
- uses less energy (1)
- can clean contaminated land (1)
Model answer
It can extract copper from low-grade ores, and it does less damage to the landscape.
Give one disadvantage of biological methods of extracting metals.
Mark scheme
- very slow / need large areas of land / produce small amounts / toxic leachate (1)
Model answer
They are very slow.
Found a mistake?