Rocks and builiding 1.2 Limestone and it’s uses

Learning objectives Know some of the different uses of limestone Know some of the different uses of limestone Understand what happens during the thermal decomposition of limestone Understand what happens during the thermal decomposition of limestone

What are they made of?

Uses of Limestone Making glass Improving soil fertility And even the tourist trade… Making concrete Buildings

Calcium Carbonate Formed from tiny animals from millions of years ago Formed from tiny animals from millions of years ago Can be quarried from ground Can be quarried from ground Cut into blocks Cut into blocks Used as building material Used as building material Powered limestone Powered limestone Heated with powdered clay – cement Heated with powdered clay – cement Can be used to make concrete Can be used to make concrete

Glass Powdered limestone Powdered limestone Heated with sand and soda Heated with sand and soda Produces glass Produces glass Liquid Liquid Flows over 100’s of years Flows over 100’s of years Or does it? Or does it?

Uses of limestone Produce an A4 advert for limestone Produce an A4 advert for limestone Powerpoint or word Powerpoint or word Must include: Must include: Where limestone comes from Where limestone comes from The chemical name The chemical name 3 uses and how it is used 3 uses and how it is used Limestone!!! It’s great!!! Blah Blah Blah etc etc etc What is it etc What’s it for etc

Heating limestone Limestone – Calcium carbonate CaCO 3 Limestone – Calcium carbonate CaCO 3 Which atoms? Which atoms? Heat strongly – breaks down into quicklime (CaO) Heat strongly – breaks down into quicklime (CaO) Releases carbon dioxide Releases carbon dioxide Thermal decomposition Thermal decomposition Lime Kiln Lime Kiln Calcium carbonatecalcium oxide + carbon dioxide LimestoneQuicklime

Lime kiln

Key points Limestone is mainly made of calcium carbonate Limestone is mainly made of calcium carbonate Limestone is widely used in building Limestone is widely used in building Limestone breaks down when you heat it strongly (thermal decomposition) to make quicklime and carbon dioxide Limestone breaks down when you heat it strongly (thermal decomposition) to make quicklime and carbon dioxide