Resources Flashcards
Iron rust
Iron+water+oxygen —> hydrated iron(III) oxide
Only happens on the surface, where it is exposed to air
Flakes off when rusted to let more rust
Aluminium corrosion
Aluminium also corrodes in air
The aluminium oxide doesn’t flake off
Produces a protective layer
How to prevent rusting
Barrier e.g. plastic, electroplating (electrolysis to coat it in a non-corrosive material), oiling with moving parts
Sacrificial methods to put a more reactive metal instead so the water an air reacts with that
Renewable resources
Reform at a similar rate or faster than we use them
Improvements in sustainability
- stop using energy from finite resources to extract renewable
- develop/adapt processes that use less finite resources e.g. catalysts
Copper
Bioleaching- use bacteria to produce a leachate containing copper ions, which can then be extracted
Phytomining- grow plants in soil containing copper. Builds up in the leaves as they can’t use or get rid. Plants are harvested, dried and burned in a furnace. The ash contains solid copper compounds
Recycling metals
Less energy than mining and extracting
Recycled by melting and casting
Separation depends on what it will be used for after
Glass recycling
Glass bottles can be reused
Others can’t so are recycled by colour and chemical composition
Crushed and melted for reuse in other glass products
Life cycle assessment
Rating the environmental costs of a product in each stage of its life cycle
Life cycle assessment phases
Raw materials Manufacture Use Disposal All transport throughout
Issues with LCAs
Hard to quantify
Based on people’s opinions- need lots of people
Selective LCAs can be used by companies to deliberately support them and positively advertise
What metals rust?
ONLY iron and its alloys (e.g. steel)
Why use bioleaching or phytomining?
When the ore isn’t copper-rich so it can’t be extracted by carbon
Where do resources come from?
Earth
Air
Sea
Renewable resources
Timber, fresh water, food
