C10-Using resources Flashcards
What are finite resources?
Resources that are used up at a faster rate which they can be replaced.
What are renewable resources?
Resources that are used up at the same rate in which they can be replaced.
What are some examples of finite resources?
- Metal ores used to extract metals
- Crude oil used to make polymers
- Limestone to make petrol and concrete
- Crude oil to make the petrol, diesel and kerosene we use for transport
What are the methods of extracting metals from their ores and how do they work?
- Smelting (Then electrolysis)
- Displacement using scrap iron to extract copper
- Bioleaching (Having bacteria feed on the low-grade metal ore-this obtains a solution of copper ions-leachate)
- Phytomining (Plants are planted in soil containing a low percentage of copper ore, absorm it and are burnt in air-the ash contains high percentage of copper compound-then electrolysis)
What are the 4 stages in a life-cycle assessment?
- Raw material extraction
- Manufacture
- Use/Reuse/Maintainance
- Recycle/Waste management
What is potable water?
Water that is safe to drink
How is water made safe to drink?
- By firstly passing the untreated water through filter beds of sand and gravel to remove insoluble particles
- Sterilising the water (via chlorine or ozone to kill microorganisms or by passing UV light through the water)
What is a method to purify salty water?
Desalination via distillation or reverse osmosis
What is reverse osmosis?
Where water is put under high pressure and passed through a membrane that prevents most ions from passing through
How is waste water treated?
- Screening and grit removal to remove large particles
- Sedimentation to allow tiny particles to settle out from still water which produces sludge and effluent
- The sewage sludge is digested anaerobically by specific bacteria
- The effluent is treated with aerobic bacteria
What are the uses of ‘sludge’?
As a fertiliser of burnt to generate electricity
How can the effluent be made safer?
By filtering it one more time through a bed of sand and/or sterilised by UV light or chlorine
What is needed for the corrosion of iron?
Oxygen and water
What is the formula for rusting?
Iron + Oxygen + Water –>hydrated iron(III) oxide
What are ways to prevent rusting?
- Paint
- Oil or grease
- Plastic
- A less/more reactive (sacrificial metal)
What is a sacrificial method for protecting iron?
Adding zinc (galvanising)
What is a mixture of metal called?
Alloys
Why are alloys useful?
The differently-sized metal ions make it harder for the layers to slip-they are jammed in position
What are examples of Copper alloys?
- Bronze (copper and tin)
- Brass (copper and zinc)
What is gold mixed with?
Silver, copper and zinc-enables it to be stronger
What are examples of steel alloys?
- Low carbon steel
- High carbon steel
- Alloy steels-stainless steel contains chromium and nickel
What is the main glass we use?
Soda lime glass
How is soda lime glass made?
By melting a mixture of silicon dioxide (sand), sodium carbonate and limestone