Incinerator bottom ash (IBA) is a form of ash produced in

incineration Incineration is a waste treatment process that involves the combustion of substances contained in waste materials. Industrial plants for waste incineration are commonly referred to as waste-to-energy facilities. Incineration and other high ...

facilities. This material is discharged from the moving grate of

municipal solid waste Municipal solid waste (MSW), commonly known as trash or garbage in the United States and rubbish in Britain, is a waste type consisting of everyday items that are discarded by the public. "Garbage" can also refer specifically to food waste ...

incinerators. Once IBA is processed by removing contaminants, it can be used as an aggregate. Following processing, the material is termed ''IBA aggregate'' or ''processed IBA''. The aggregate uses include: * Bulk fill *

Asphalt Asphalt, also known as bitumen (, ), is a sticky, black, highly viscous liquid or semi-solid form of petroleum. It may be found in natural deposits or may be a refined product, and is classed as a pitch. Before the 20th century, the term ...

Cement A cement is a binder, a chemical substance used for construction that sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel ( aggregate) together. Cement mi ...

bound materials * Lightweight blocks * Pavement

concrete Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wid ...

Alternatively, if there are no local markets for the IBA the material is disposed of in a landfill.

Recovery

IBA is a secondary source of

ferrous In chemistry, the adjective Ferrous indicates a compound that contains iron(II), meaning iron in its +2 oxidation state, possibly as the divalent cation Fe2+. It is opposed to " ferric" or iron(III), meaning iron in its +3 oxidation state, suc ...

and non-ferrous (NFe) metals. Between 5-15% of the bottom ash is made up of ferrous materials, and 1-5% is NFe. Despite

glass Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling ( quenching ...

making up 10-30% of IBA, it is not systematically recovered in any processing plants. On average, 63 kg of ferrous materials are removed from a single tonne of ash.

Risks

Foam concrete made from IBA led to an explosion in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...

in 2009. It was discovered that the

aluminum Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It ha ...

in the concrete can form

hydrogen gas Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, a ...

deposits while the concrete sets. The Health and Safety Executive updated their guidelines to suggest IBA aggregates can only be poured in open air, in well ventilated areas, and no spark generating tools, such as disc cutters and angle grinders, can be used during setting.

References

{{DEFAULTSORT:Incinerator Bottom Ash Concrete Incineration

Recovery

Risks

See also

References