Limestone

Using limestone

• Limestone is mainly calcium carbonate - CaCO3
• When heated it thermally decomposes to make calcium oxide+ carbon dioxide.
• Calcium carbonate also reacts with acid to make a calcium salt, carbon dioxide and water.
• When you add water to calcium you get calcium hydroxide- Ca(HO)2, which is an alkali used to neutralize acidic soil in field, this way is faster than using powdered limestone.
• If you make a solution of calcium hydroxide in water (limewater) and bubble gas through it, the solution will turn cloudy if there's carbon dioxide in it. Cloudiness is formed by the formation of calcium carbonate.
• Uses of Limestone
• Powdered limestone heated+powdered clay=cement.
• Cement+sand+water=mortar
• Cement+sand+aggregate=concrete
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• Bildunterschrift: Limestone cycle

Quarrying Limestone

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• Bildunterschrift: Quarrying has pros and cons
• Cons:
• Huge ugly hole=permanently wreck landscape.
• Makes lots of noise and dust in quiet areas.
• Destroys habitats of birds and animals.
• Limestone transported in quarries=noisy/pollution.
• Waste materials produce unsightly tips.
• Cement factories produce dust=breathing problems.
• Energy is needed to make cement=quicklime, made by burning fuels, causes pollution.
• Pros:
• Limestone provides houses and roads.
• Chemicals used like dyes, paints, medicines come from limestone.
• Products used to neutralize acidic soil.
• Used in power station chimneys to neutralize sulfur dioxide, caused by acidic rain.
• Provide jobs, bring money to local economy, lead to local improvements in transport,roads, recreation facilities,health.
• Landscaping and restoration of area is required as part of the planning permission.

Limestone products have pros&cons

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• Bildunterschrift: Limestone and concrete are used as building materials.
• Limestone is WIDELY AVAILABLE and is CHEAPER than granite and marble.
• Easy to CUT.
• Some limestone is HARD-WEARING, still ATTRACTIVE.
• Concrete can be poured into MOLDS to make blocks&panels that can be joined together.
• QUICK&CHEAP, but HIDEOUS.
• DOESN'T ROT when wet.
• Can't be gnawed by INSECTS or RODENTS.
• FIRE RESISTANT.
• DOESN'T CORRODE.
• LOW TENSILE STRENGTH.