-Limestone's quarried out of the ground-it's great for making into blocks for building with.
-Limestone is mainly calcium carbonate. CaCO3
-Limestone goes through a cycle.
- When it is heated it thermally decomposes to make calcium oxide and carbon dioxide. Calcium Carbonate--->Calcium Oxide+ Carbon Dioxide CaCO3 CaO CO2
- When you add water to calcium oxide you get calcium hydroxide. Calcium oxide+water---> Calcium hydroxide CaO H2O Ca(OH)2
- Calcium hydorxide is an alkali which can be used to neutralise acidic soil in fields.
- Calcium Hydroxide can also be used to test for carbon dioxde. If you make a solution of calcium hydroxide in water (called limewater) and bubble gas through it, the solution will turn cloudy, if there;s carbon dioxide in the gas. The cloudiness is caused by the formation of calcium carbonate. Calcium hydroxide+ carbon dioxide--->calcium carbonate+water Ca(OH)2 CO2 CaCO3 H2O
- Calcium Carbonate also reacts with acid to make calcium salt, carbon dioxide and water: Calcium Carbonate+Sulfuric acid--->Calcium sulfate+carbon dioxide+water CaCO3 H2SO4 CaSO4 CO2 H2O
- The type of salt produced depends on the type of acid. For example, a reaction with hydrochloric acid would make a chloride.
- Other carbonates that react with acids are magnesium, copper, zinc and sodium.
- Powdered limestone is heated in a kiln with powdered clay to make CEMENT
- Cement can be mixed with sand and water to make mortar. Mortar is the stuff you stick bricks together with. You can use calcium hydroxide to mortar.
- Or you can mix cement with sand and aggregate (water and gravel) to make CONCRETE.
- Reinforced concrete
- Makes huge ugly holes-permenant
- Makes a lot of noise and dust- in quite scenic areas.
- Destroys habitats
- The limestone needs to be transported away from the quarry-usually in lorries. This causes more noise and pollution.
- Waste materials produce unsightly tips.
Making stuff from Limestone
- Cement factories make a lot of dust, which can cause breathing problems.
- Energy is needed to produce cement and quicklime. The energy is likely to come from burning fossil fuels, which causes pollution.
- Provides things that people want-houses,roads. Chemicals used in making dyes, paints and medicenes
- Limestone products csn be used to neutalise acidic soil. Acidity in lakes and rivers caused by acid rain is also neutalised.
- Used in power station chimneys to neutralise sulfur dioxide, which is a cause of acid rain.
- The quarry and assocaiated businesses provide jobs, and bring money into the local economy.
- Landscaping and restoration of the area is normally requiresd as part of the planning permission
Limestone Products: Advantages
-Limestone is widely available.
-Cheaper than granite or marble.
-Easy rock to cut.
-Hardwearing, but also looks attractive.
-Concrete can be poured into moulds to make blocks or panels that can be joined together. It is very quick and cheap way of constructing buildings.
-Limestone,concrete, and cement do not rot when they get wet like wood does. They cannot be gnawed away by insects or rodents eithe. They are also fire resistant too.
-Concrete does not corrode like lots of metals do. It can be reinforced with steel bars.
Limestone Products: Disadvantages
-Cocnrete is the most unattractive building material.
-Concrete has a fairly low tensile strength and can crack.