Limestone

Description

Limestone, or calcium carbonate-made of the skeletons of billions of sea creatures-is mined in large quantities. Carefully blasted out of the ground, it is first crushed with huge pestles to eliminate large boulders, then passed through a series of sieves to separate large chunks for further crushing. When sufficiently small, it is washed to remove clay, dust, and sand. The grades are separated: some for road-building, others for processing into sodium carbonate for glass-making. The sand from the wash is separated out and can be made into quicklime and subsequently into slacked lime; the remainder is processed to make cement powder.

Runtime

20 min

Series

Subjects

Geography

Genre

Date of Publication

[2007], c1987

Database

Films on Demand

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