Term: Bottom ash
– Ash handling processes
– In a water impounded hopper system, clinker lumps are crushed by grinders and ejected into a trough.
– Modern systems use chain conveyors to continuously remove ash, quenching it in water.
– Municipal waste incinerators produce bottom ash as a byproduct at high temperatures.
– Continuous removal systems are adopted in modern setups for efficient ash handling.
– Clinkers are fed to grinders outside the bottom ash hopper in some arrangements.
– Waste handling
– Ash waste in U.S. facilities is commonly disposed of in ash ponds.
– Some power plants opt for dry disposal systems with landfills.
– Dry ash handling technology can extract and cool bottom ash for reuse.
– Bottom ash can be utilized in making concrete, bricks, and other materials.
– In the UK, furnace bottom ash is distinguished from incinerator bottom ash.
– Environmental impacts
– Coal ash is a significant component of the industrial waste stream in the U.S.
– High levels of toxic elements in coal ash pose risks to human health and the environment.
– Most U.S. power plants lack proper flow controls and liners in ash ponds.
– EPA regulations require retrofitting of unlined ash ponds to prevent environmental contamination.
– Litigation on the CCR regulation is ongoing as of 2021.
– Ash recycling
– Dry bottom ash can be used in various applications, including road construction and cement production.
– Bottom ash can replace earth, sand, or aggregates in different industries.
– Environmental benefits are associated with recycling bottom ash.
– Bottom ash has been historically used in the production of concrete blocks in London.
– Recycling bottom ash reduces environmental impact and promotes sustainability.
– See also
– Coal combustion products are closely related to bottom ash.
– Fly ash is another byproduct of coal combustion.
– Health effects of coal ash are a concern for environmental and public health.
– Industrial wastewater treatment is important in managing ash waste.
– Further research and reading are available on the topic for interested individuals.
This article needs additional citations for verification. (May 2019) |
Bottom ash is part of the non-combustible residue of combustion in a power plant, boiler, furnace or incinerator. In an industrial context, it has traditionally referred to coal combustion and comprises traces of combustibles embedded in forming clinkers and sticking to hot side walls of a coal-burning furnace during its operation. The portion of the ash that escapes up the chimney or stack is, however, referred to as fly ash. The clinkers fall by themselves into the bottom hopper of a coal-burning furnace and are cooled. The above portion of the ash is also referred to as bottom ash.
Most bottom ash generated at U.S. power plants is stored in ash ponds, which can cause serious environmental damage if they experience structural failures.