Dissolution of lime into synthetic coal ash slags

Journal Article · Tue Dec 31 04:00:00 EST 1996 · Preprints of Papers, American Chemical Society, Division of Fuel Chemistry

OSTI ID:430307

Elliott, L; Wang, Shen Mao; Wall, T; Lucas, J ^[1]

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1. Newcastle Univ. (Australia); and others

One of the alternate processes presently being investigated to produce electrical power from coal is Integrated Gasification Combined Cycle (IGCC). The ash that remains when the coal is gasified in this process, is removed by granulating the molten ash at 1400 - 1500{degrees}C, To reduce the melting temperature of the coal ash to this level, a flux, usually limestone, is added with the cow to the gasifier. The rate of dissolution of the flux is uncertain. This paper reports the investigation of the rate of time dissolution into synthetic coal ashes, consisting of SiO{sub 2}, Al{sub 2}O{sub 3} and CaO. Results previously reported have shown that the free dissolution of fine particles (50-200 {mu}m) is mass transfer controlled. To investigate forced dissolution, a high temperature viscometer was used to rotate a cylinder of lime in the molten slag for a given period. At temperatures between 1450{degrees}C and 1656{degrees}C, reaction products of 3CaO.SiO{sub 2}/3CaOAl{sub 2}O{sub 3}, 2CaO.SiO{sub 2}/3CaO.Al{sub 2}O{sub 3}/12CaO,7Al{sub 2}O{sub 3} form around the lime pellet. The concentration gradient involved in the mass transfer was defined, and initial studies of the diffusion coefficients were completed.

• OSTI ID: 430307
• Report Number(s): CONF-960376--
• Journal Information: Preprints of Papers, American Chemical Society, Division of Fuel Chemistry, Journal Name: Preprints of Papers, American Chemical Society, Division of Fuel Chemistry Journal Issue: 2 Vol. 41; ISSN 0569-3772; ISSN ACFPAI
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
ASHES
CALCIUM OXIDES
COAL
COAL GASIFICATION
COMBINED CYCLES
DISSOLUTION
LIMESTONE
MASS TRANSFER
MELTING
SLAGS
TEMPERATURE DEPENDENCE