P2 2e extraction and uses of metals Flashcards
what is galena?
lead sulphate PbS
what is haematite ?
iron oxide Fe2O3
what is bauxite?
aluminium oxide Al2O3
what is used in the blast furnace?
haematite, coke (carbon) and limestone (CaCO3)
everything above carbon gets?
extracted by electrolysis
what is anode?
positive
what is a cathode?
negative
what is used for the anodes and cathodes?
graphite bc its a good conductor
what is an ore?\
when metals are chemically combined with other substances
how can metal be extracted from ores?
blast furnace, electrolysis or by reacting it with a more reactive metal
how do metals get extracted when they are too reactive?
by electrolysis
how do metals get extracted when they are less reactive?
blast furnace
how do silver and gold get extracted?
they dont, they are found as pure elements because they are very un-reactive
what do metals above carbon get extracted by?
electrolysis
what are uses of aluminium?
aeroplane bodies, overhead power cables, saucepans, food cans, window frames
what are the uses of copper?
electrical wires and water pipes
what are the uses of mild steel?
car body panels and wires
what are the uses of high carbon steel?
tools and chisels
what are the uses of low alloy steel?
construction, bridges, high speed tools
what are the uses of stainless steel?
cutlery and sinks, chemical plants
what are alloys?
mixture of metals where the metals are mixed physically but not chemically combined
what are properties most alloys have?
strength
hardness
resistance to corrosion
extreme temps
why are alloys harder than normal metals?
they have atoms of different size which distorts the regular arrangement of atoms and creates uneven layers making it harder to slide over each other
why is limestone used in a blast furnace?
to remove impurities
what is coke?
an impure form of carbon
what happens in a blast furnace?
zone 1
- coke burns in the hot air forming carbon dioxide
zone 2
- at high temps more coke reacts with CO2 forming carbon monoxide
zone 3
- CO reduces iron oxide in the iron ore to form iron
- it will melt and collect at the bottom
- limestone is added and is decomposes to form calcium oxide
- slag which is calcium silicate collects at the bottom
