chemistry.html

Note: Chemical analysis by atomic absorption, ICP, or "wet" methods. Much of SiO2, Al2O3 and Fe2O3 is present in glassy amorphous form. SO3 is usually present as calcium sulfate or alkali sulfates. Most of the CaO/MgO is not free. LOI is presumed to be carbon (check with LECO Carbon Analyzer.) Class C fly ashes are usually self-cementing (hydraulic.)

Class F fly ash has a glassy phase and inert crystalline phases: quartz, mullite, magnetite spinel, hematite. For example, it has been reported for a high-Fe Class F fly ash from Eastern Canadian bituminous coal : 9.6% quartz, 20.4% mullite, 4.5% magnetite spinel, 5.4% hematite, and 58% glass.(Hemmings, Berry, Cornelius, Sheetz, "Speciation in Size and Density Fractionated Fly Ash. Characterization of a Low-Calcium, High-Iron Fly Ash", Materials Research Society Symposia Proceedings, Fly Ash and Coal Conversion By-Products: Characterization, Utilization and Disposal, Vol. 86, 1987.)

Class C fly ash may have the above as well as: anhydrite, alkali sulfates, dicalcium silicate, tricalcium aluminate (the cementitious component), lime (Portlandite if ash has been exposed to moisture), melilite, merwinite, periclase, sodalite. For example, it has been reported for a low-Ca Class C fly ash from western Canadian subbituminous coal: 6% quartz, 14% mullite, and 80% glass.(Berry, Hemmings, Cornelius, "Speciation in Size and Density Fractionated Fly Ash. The Influence of HCL Leaching on the Glassy constituents of a High-Ca Fly Ash", Materials Research Society Symposia Proceedings, Fly Ash and Coal Conversion by-Products: Characterization, Utilization and Disposal, Vol.113, 1988.)

See properties of Japanese fly ash.

• • Chemical Composition of SRM Fly Ash Samples and Lignite Coal Ash (in Weight %)

  • SRM 1633a is from bituminous coal. SRM 2689 is from bituminous coal from Western Kentucky. SRM 2690 is from subbituminous coal from Craig, Colorado. SRM 2691 is from subbituminous coal from Gillette, Wyoming. The lignite coal source is from North Dakota:

Trace Elemental Analysis Coal Fly Ash (Class F)

in mg/kg (NA= Not Available)