Across
- 4. Coal that contains greater energy content per volume than lignite and is frequently used as an industrial fuel, for space heating, and for the generation of electricity. This coal is full black in color and is categorized as a “soft” coal.
- 7. A device that works by positively charging waste particles and attracting them to a negatively charged electrode. The solid particles are then washed off the electrode and collected
- 9. An underground rock formation that acts as a reservoir for large quantities of water. It is used to store gas from pipelines.
- 10. another term for Oil
- 12. A large tower in which crude oil is separated into various products.
- 14. The restoration of land to a usable condition after strip mining has taken place.
- 15. Coal that is hard and brittle. It appears shiny on the surface and has a high carbon content. Because it burns cleaner than other forms of coal, it is often used for home heating. It does not have as much energy content per volume as bituminous coal.
- 17. 40–50 million-year-old sedimentary rock containing an oily substance.
- 19. The mining or removing of coal close to the earth’s surface. It is done mainly with the use of large pieces of machinery, such as mechanical shovels and bulldozers. Also called surface mining.
- 20. A solid waste by-product produced by burning coal.
Down
- 1. Oil in its natural state.
- 2. The first step in the formation of coal. It is formed from water and the decomposition of organic materials.
- 3. A mining operation that uses shafts and special machinery to remove the coal from deep below earth’s surface.
- 5. An organization that supports the monitoring of acid rain in the United States.
- 6. A device that works like a bag on a vacuum cleaner, trapping all solid particles in the waste streem prior to the hot wasted gases exiting through the smokestack of a power plant.
- 8. An oily substance contained by 40–50 million-year-old sedimentary rock.
- 11. A type of coal containing some woody decomposition that can be recognized as peat, but it has a higher energy content than peat. It contains a large amount of moisture and is brownish in color, as opposed to the black substance typically recognized as coal.
- 13. Gas usually found within the vicinity of petroleum reserves.
- 16. A source of crude oil. The sand is mined and mixed with hot water or steam to extract the thick oil known as bitumen.
- 18. Coal with a high carbon content. It is denser and blacker than most other forms of coal. This type of coal is principally used for the production of electricity