Zusammenfassung der Ressource
C1.2 Limestone And Building Materials
- C1.2.1 Calcium Carbonate
- Limestone is a naturally occurring resource that provides a
starting point for the manufacture of cement and concrete.
- There are many benefits with using limestone as a building
material: it is cheap and easy to quarry; it is a plentiful
resource; no special, rare or dangerous chemicals are
required to make it into a useful product and limestone can be
made into numerous other products.
- Quarrying creates jobs, provides income to local councils
through taxation, good communications are needed for
transporting the products of quarrying and so as a result
many remote rural areas benefit from improved access.
- However, habitats are destroyed, valuable agricultural land is
taken away, pollution is caused from dust which can lead to
problems with health, it is noisy, the landscape is left scarred
deterring tourists and limestone is a non-renewable resource.
- Limestone, mainly
composed of the
compound calcium
carbonate (CaCO3),
is broken down by
heat to make calcium
oxide and carbon
dioxide.
- Calcium oxide reacts
with water forming
calcium hydroxide; an
alkali.
- A solution of calcium hydroxide in water
(limewater) reacts with carbon dioxide to produce
calcium carbonate. Limewater is used as a test for
carbon dioxide, which turns it cloudy.
- Carbonates react with acids to produce
carbon dioxide, a salt and water.
Limestone is damaged by acid rain.
- Limestone is heated with clay to make
cement. Cement is mixed with sand to
make mortar and with sand and aggregate
to make concrete.