Lesson 3: Alternative methods of extracting metals/ Reducing use of resources

Question 1

What 3 things reduce the use of limited resources, use of energy sources, waste and environmental impacts?

Answer 1

1.) Reduction in use of materials.
2.) Reuse of materials.
3.) Recycling materials.

Question 2

What 4 factors are reduced when materials are used less, reused and recycled (at the end of their life-time?)

Answer 2

1.) The use of limited resources.
2.) Use of energy sources.
3.) Waste.
4.) Environmental impacts

Question 3

Give 5 products that are produced from limited raw materials.

Answer 3

1.) Metals.
2.) Glass.
3.) Building materials
4.) Clay ceramics
5.) Most plastics

Question 4

What are the 2 issues with obtaining raw materials from the earth by quarrying and mining?

Answer 4

• Much of energy (needed to extract these materials) are produced from limited/ finite resources.
• Environmental impacts (damaging habitats.)

Question 5

Give an example of a product that can be reused.

Answer 5

• Glass bottles.

Question 6

What process do glass bottles go through so that they can be reused?

Answer 6

• Glass bottles can be crushed and melted to make different glass products.

Question 7

What happens to products that cannot be reused?

Answer 7

• The products are recycled for a different use.

Question 8

How can metals be recycled?

Answer 8

• Melt.
• Recast/ reform metal into different products.

Question 9

What does the amount of separation (from other mateials) required for recycling depend on?
Give an example of two metals that can be recycled by reacting together.

Answer 9

• Depends on the material and the properties required of the final product.
• For example, some scrap steel can be added to iron (from a blast furnace) - reducing the amount of iron that needs to be extracted from iron ore.

Question 10

True or False

There are PLENTY of metal ores that will last for ages!

Answer 10

• False.
• The Earth’s metal ores are limited.

Question 11

What solutions have been made to resolve the fact that copper ores are becoming scarce?

Answer 11

• New ways of extracting copper from low- grade ores:
• Phytomining
• Bioleaching

Question 12

What is the advantage of extracting copper from low- grade ores (ie. phytomining/ bioleaching?)

Answer 12

• Methods avoid traditional mining methods of: digging, moving and disposing of large amounts of rock (as most copper is found reacted with oxygen in ores/ compounds.)

Question 13

How does phytomining work?

Answer 13

• Phytomining uses plants to absorb metal compounds.
• The plants are harvested and then burned to produce ash that contains metal compounds.
• (Ash dissolved in acid to produce solution of copper compound) - mark schem.
• Metal compounds processed to obtain the metal.

Question 14

How does bioleaching work?

Answer 14

• Bioleaching uses bacteria to produce leachate solutions that contain
  metal compounds.
• Metal compounds processed to obtain the metal.

Question 15

In bioleaching and phytomining, how are metal compounds (of copper) processed in order to obtain the metal - copper?

2 ways….

Answer 15

• Copper can be obtained from solutions of copper compound by electrolysis OR by displacement reaction - involving scrap iron.