Inorganic ash spheres

Keywords atmospheric deposition combustion products industrial pollutants inorganic ash spheres sediment dating spheroidal carbonaceous particles... 

Figure 2. SEM photograph of inorganic ash spheres (IASs) from the combustion of coal (From Rose, 1996 reprinted with permission from Elsevier).

Inorganic ash spheres (IAS) Microscopic spheres of inorganic material formed by the fusing of mineral components during fossil-fuel combustion. A component of fly-ash. 

Plerospheres Hollow inorganic ash spheres (cenospheres) containing encapsulated smaller spheres. 

Spheroidal fly-ash particles (SFP) Term occasionally used to describe a combination of spheroidal carbonaceous particles and inorganic ash spheres. 

Spheres. HoUow spherical fillers have become extremely useflil for the plastics industry and others. A wide range of hoUow spherical fillers are currently available, including inorganic hoUow spheres made from glass, carbon, fly ash, alumina, and 2h conia and organic hoUow spheres made from epoxy, polystyrene, urea—formaldehyde, and phenol—formaldehyde. Although phenol—formaldehyde hoUow spheres are not the largest-volume product, they serve in some important appHcations and show potential for future use. 

Rose, N. L. 1996. Inorganic fly-ash spheres as pollution tracers. Envir. Pollut. 91 245-252. 

Ash particles are formed through the thermal decomposition or dehydration of inorganic minerals associated with the coal. Calcium carbonate and clay are the most abundant mineral impurities, with lesser amounts of sulfides, chlorides and oxides also present. The shape of the ash particle is dependent on many factors, two of which are the amount of time and temperature to which the coal is exposed in the combustion chamber (Fisher et al., 1978). The spherical shape, most commonly associated with fly ash particles, shows that complete melting of silicates occurs at high temperature. These spheres may be solid, hollow (cenospheres) or encapsulating spheres (plerospheres). 

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