Page 13 - Curriculum Visions Dynamic Book

refining: separating a mixture into the simpler substances of which it is made. In the case of a rock, it means the extraction of the metal that is mixed up in the rock. In the case of oil it means separating out the fractions of which
it is made.
 In this aluminium smelter (in Lochaber, Scotland) the power is provided by an on-site hydroelectric power plant. You can see the pipes that carry water to the power station turbines behind the main works. It takes about 20 kilowatt-hours of electricity to produce a kilogram of aluminium.
 Because of the low percentage of aluminium in the bauxite ore from which it is extracted, large machines with bucket scoops have to be used to gain economies of scale.
This bauxite from Ghana is awaiting processing into alumina.
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