Published on January 14, 2008
Uses of Limestone: Uses of Limestone By Sandy Mill 10TS What is Limestone?: What is Limestone? Limestone is made up of the shells of millennia old dead sea creatures. Layers of these built up over millions of years, and were squashed together until they formed limestone. This means it is a sedimentary rock. Types of Limestone: Types of Limestone There three different types of limestone: chalk is a very soft form of limestone which has had less pressure put on it whilst it was being formed. Marble is the hardest form of limestone, as it was subjected to lots of pressure when it was formed Limestone is the third type and is formed at a medium pressure. Chemical Stuff: Chemical Stuff Chalk, Limestone and Marble are made of the same things, so share a chemical formula. All forms of limestone are made up of calcium carbonate (CaCO3). Calcium carbonate is an insoluble chemical, and is also a base. Limestone Cycle: Limestone Cycle Limestone Lime Slaked Lime Lime Water Heat CO2 H2O H2O CO2 H2O Key Added to substance Taken away from substance Used to detect for the presence of CO2. Turns cloudy if CO2 is bubbled trough it Calcium oxide (CaO) Calcium hydroxide (Ca(OH)2 Calcium Hydroxide (AQ) Ca(OH)2 Glass: Glass Glass is mostly made from sand, but limestone is also added to it before it is heated up. Glass is used for many everyday things such as windows, glasses and mirrors. Paper!?: Paper!? Paper is made of wood pulp. To make this, acid is used to break the wood down. Limewater is used to neutralise the acid, and also helps to whiten the paper. It is also used as a bulking agent, so less trees are cut down to make the paper. Steel: Steel When steel is made, the impurities in the iron must be got rid of so other materials can be added to it to turn it into steel. Limestone mixes with the impurities in the iron in the blast furnace, and forms a substance known as slag. The slag is separated from the iron, and taken away, leaving pure molten iron which can be made into steel. Building Stuff: Building Stuff Limestone has been used for building for many centuaries. Many old buildings are made out of limestone. However, it can be gradually dissolved by acid rain. Neutralisation: Neutralisation Water and soil are turned slightly acidic when they are affected by acidic rain Limestone is used to neutralise this acidity and revert the substance to its normal P.H. This is because calcium carbonate is a base (an insoluble alkali), and so can neutralise the positive hydrogen ions in the acid. Cement: Cement When limestone is heated with clay it forms cement, a substance that sets gradually when it reacts with water. Cement can be made into mortar by adding sand and water. Mortar is used to set the bricks in walls, as when it dries it acts as an adhesive between the bricks. Cement (cont): Cement (cont) Cement can also be made into concrete by adding water, sand and small stones or gravel. Concrete is used for all kinds of building work, including paths, walls and large buildings. Summary: Summary Limestone is made of layers of dead sea creature’s shells Chemical formula - CaCO3 (calcium carbonate) Limestone is used to make many things in our everyday lives, such as glass, cement, paper and buildings.