metal extraction
metal ores
rocks we obtained metal from
composition of the earths crust
45% oxygen 27% silicon the rest are metals apart from 2% being non-metals
how does extraction depend on reactivity
chemical extraction is needed for highly reactive metals as they have more drive to exist in a compound but for stable elements impurites need to be removed
describe stage 1 of the reactions in a blast furnace
-coke burns giving carbon dioxide and heat -carbon is oxidised
describe the second stage oof the reaction in a blast furnace
-carbon is reduced to carbon monoxide -carbon dioxide is reduced
describe stage 3 of the reaction in a blast furnace
-carbon monoxide reduces the iron (iii) oxide to iron
describe stage 4 of the reaction in a blast furnace
-impuritites are removed -thermal decomposition -slag is formed
steps in extracting bauxite the main ore of aluminium
-screen land to see if it is worth mining -identify bauxite -dig up bauxite -take to plant for impurities to be removed -aluminum oxide is formed and broken down by electrolysis
reactions of electrodes of an electrolysis cell
at cathode - aluminium gains electrons. at anode - oxides lose electrons. overall reaction aluminium oxide breaks down into aluminum
uses of aluminum
electrical cables -foil -aircrafts
properties of aluminum
-conductor -low-density -resists corrosion
uses of copper
-electrical wiring -pipes
properties of copper
-conductor -malleable -corrodes easily
uses of zinc
-coating/galvanising -iron or steel -batteries
properties of zinc
-prevents rusting -gives current when connected to carbon electrode
alloy
mixture of metals with at least one other element
how do alloys affect metals
they change the properties of the metals
key notes on alloys
-new atoms must enter metal lattice -new metal must be melted so the new element dissolves and the alloy cools and hardens -nre atoms can be bigger or smaller than metal -
examples of alloys
brass, bronze, stainless steel
properties of brass
-harder than copper -maleable -does not corrode
properties of bronze
-hard -sonorous -resits corrosison
properties of stainless steel
-strong -resists corrosion -looks attractive
uses of brass
-musical intruments -ornaments -door knobs
uses of bronze
-coins -statues -ship propellers
uses of stainless steel
-cutlery -construction -hospital equipment