The diagrams below show the stages and equipment used in the cement-making process, and how cement is used to produce concrete for building purposes. Summarise the information by selecting and reporting the main features, and make comparisons where relevant.

The diagrams show how

cement

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and concrete are produced.

Overall

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, there are five stages in the production of

cement

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,

while

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the procedure for producing concrete from

cement

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and a few other simple ingredients involves a single stage.

Cement

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production begins when the initial raw materials, namely limestone and clay, are crushed using two rotating drums to make a fine powder which is

then

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mixed in a cylindrical mixer. The next stage involves a tube-like rotating heater with a blowtorch mounted at its bottom opening. The mixed powder is fed from the top and simultaneously heated and blended, after which it is transferred to a grinder using a conveyor belt. There, it is milled to yield the final

cement

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product which is eventually packed in bags.

This

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cement

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is used as raw material in the production of concrete in a second process. An initial mixture comprising 15%

cement

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, 10% water, one-quarter sand and half gravel is fed into a rotating concrete mixer where they are stirred until the concrete mix is ready for construction purposes.