What is the link?

1. What is the link?

2. Limestone: is it worth it?

3. Today we are finding out…… • Why we need limestone • Where limestone comes from • The impact quarrying has on • The local community • The economy • The environment

4. List 5 things you have done today……

5. What is Limestone? • Limestone is made up of shells of dead sea creatures. It contains carbon that has been locked away for millions of years. • Layers of these built up over millions of years, and were squashed together until they formed limestone. • It is a sedimentary rock, it is porous and often contains fossils.

6. Types of Limestone There three different types of limestone: • Chalkis a very soft (formed under low pressure) and high purity CaCO3 • Marbleis a metamorphic rock it is the hardest form of limestone, as it was subjected to lots of pressure when it was formed. (no fossils!) • Limestone is the third type and is formed at a medium pressure. It is often coloured by other chemicals e.g. iron compounds.

7. Chemical Stuff • Limestone is made of calcium carbonate (CaCO3). • Calcium carbonate is insolublein water. • It is a base. (It will react with acids) • Acid rain erodes limestone • H2SO4 + CaCO3 CaSO4 + CO2 + H2O

8. and its uses Limestone

9. Where do we find Limestone? • Sedimentary rock formed in shallow tropical seas millions of years ago • The Yorkshire Dales and the Peak District have a lot of high purity Limestone from coral reefs and other sea creatures! • It is permeable and susceptible to weathering Karst scenery is spectacular Tourism Limestone caves Malham Cove, Yorkshire Dales

10. What else can limestone be used for? Limestone is fairly resistant, but it is still easy to cut making it ideal for use as a building material. • Building walls • Building houses • Limestone is also used to make glass, mortar, cement and concrete

11. More about limestone • Limestone is dug up out of the ground in quarries • About 150 million tonnes of limestone are quarried in Britain each year, for many different uses…

12. 1. Building Stuff • Limestone has been used for building for many centuries. • Many old buildings are made out of limestone. (the Pyramids, St Paul’s etc) • Very little limestone quarried is used in this way

13. 2. Aggregate (crushed stone) • Aggregate is the largest use of limestone • Crushed stone is used to make concrete • Aggregate is used as roadstone • Limestone is not the best material to use, but it is one of the easiest to extract.

14. 3. 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.

15. 4. Concrete • 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. • Reinforced concrete has steel bars in it

16. 5. Glass • Typical everyday glass is called soda lime glass. • It is mostly made from sand, but limestone is also added to it before it is heated up. • It also contains sodium carbonate (which is itself made from limestone)

17. 6. The chemicals industry • High grade limestone is used as a raw material for the chemical industry • It is used in… • water treatment • manufacture of tablets, paper, leather and plastics, toothpaste, soaps and detergents • food as an additive to increase calcium content (for humans and animals!) • To make other useful chemicals, e.g. sodium carbonate

18. 7. Agriculture • Acid rain can make soil acidic. Limestone is used to neutraliseit. • This is because calcium carbonate is a base (an insoluble alkali) • It is also used to supply plants with calcium, plants cannot grow well without calcium as it is needed to make cell walls.

19. 8. Neutralising acid lakes • Burning fossil fuels gives off sulfur dioxide • Sulfur dioxide dissolves in rain to form sulfuric acid • Acid rain pollutes lakes • Lime is added to neutralise it

20. 9. Desulfurisation • Fossil fuels are burnt to generate electricity in power stations. • This releases sulfur dioxide into the atmosphere. • Waste gases can be desulfurised by passing them through a slurry of limestone (or slaked lime)

21. 10. Making steel • Limestone is added to the blast furnace to remove acidic impurities in the iron ore. • The liquid slag formed floats on top of the molten iron, it is poured away leaving the iron behind.

22. What has limestone ever done for us? Rank the uses of limestone in order of importance, be prepared to justify your choices!

23. Quarrying Limestone

24. Quarrying and Mineral extraction • Before the industrial revolution quarrying was used to provide limestone as a building material, by men with axes. • Nowadays the rock is blasted with explosives to provide crushed rock to make cement, and for aggregate. • To build1km of road around 500 lorry loads of crushed stone are needed!

25. Is there an alternative? • Most Limestone comes from the national parks, Why? • Cheap and easy to extract • Very abundant • Hard and resistant • Huge demand.

26. Quarry aerial photos • http://www.webbaviation.co.uk/gallery/v/environment/quarries/

27. Case study: Topley Pike Quarry • Your mission (that you are choosing to accept whether you like it or not!!!) is to weigh up the pros and cons for the proposed extension to the quarry, and write a letter to the National Park Authority explaining your views…… • To be continued….. (for homework!!)

28. What are the effects on… • The local community? (jobs, noise, traffic, amenities…) • The economy? (tourism, jobs, industry, small businesses…) • The environment? (wildlife, pollution, regeneration…)