British Sign Language Glossaries of Curriculum Terms

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BSL Environmental Science Glossary - Tar sands definition

Definition: Tar sand is a mixture of sand and very viscous crude oil. It is found very deep in Earth (see image). We can extract the thick crude oil/sand mixture by quarrying using large excavators – see 1st photograph. The tar sand is then treated with hot water. This will produce an emulsion of oil droplets that will float on top of the water, and sand falls to the bottom of the tank. The waste sand is then returned to the mine to fill the holes. About 75% of the oil is recovered, which is a lot. However, tar sand is being extracted from a vast area in Canada. It is the same size as England. It is affecting the environment in Canada.