C1.3 Flashcards
What is an ore?
An ore is a rock that contains enough of a metal to make its extraction economical
What may happen over time that changes the price of metals?
Over time, metal prices may rise and the low-grade ores (the rocks that contain little metal) may become useful
Why aren’t low-grade ores being used at the moment?
Because they contain little amounts of metal, the extraction isn’t worthwhile (the cost of extracting the metals is greater than the value of the metal itself)
What certain metals can be extracted by reduction and why only them?
Metals that are less reactive that carbon can be extracted by reduction
What methods are used to extract metals that are more reactive that carbon?
Electrolysis
Explain the process of smelting.
Smelting involves heating copper ores in a furnace.
For example, copper sullied is heated in air to produce copper. However this is the traditional method and has major environmental impacts (it also produces sulphur dioxide, which can lead to acid rain)
Why do we need to use other extraction methods?
Because the high-grade ores are running out
Explain the process of phytomining.
Metals compounds absorbed by roots->plant concentrates metals compounds in its shoots and leaves ->plants burned->ash contains metal compounds
Explain the process of bioleaching
Certain bacteria absorb metal compounds to produce a solution called leachate. This has a high concentration of metal compounds. Scrap iron may be used to displace copper metal from these solutions.
Name some disadvantages of extracting metals from their ores.
- uses up limited resources
- uses a lot of energy
- damages the environment
Name some advantages of recycling metals.
- metal ores will last longer
- less energy need d to recycle metals than to mine ores and extract metals
- fewer quarries and mines used
- Less noise and dust produced
- less land needed for landfill sites
Name some disadvantages of recycling metals
- used metal items must be collected and transported to recycling centre
- different metals must be removed from used items and sorted
- recycling saves different amount of energy depending on the metal involved
What is cast iron?
Iron oxide is reduced to iron in a blast furnace is about 96% pure. The impurities it contains make the iron brittle and this limits its uses.
Blast furnace iron is used as cast iron.
What happens to most iron?
Most iron is converted into steel
Where can you find a transition metal on the periodic table?
The elements in the central block of the periodic table are called the transitions metals.
