Pilot Demonstration of Technology for the Production of High Value Materials from the Ultra-Fine (PM 2.5) Fraction of Coal Combustion Ash. Semi-Annual Report. January 1-July 31, 2004.

Robl, T. L. ; Henke, K. R. ; Groppo, J. G.

Technical Information Center Oak Ridge Tennessee

关键词: Coal;    Dispersants;    Fly ash;    Adsorption;    Sedimentation;   

RP-ID  :  DE2004833430

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

Broad range dispersants, including naphthalene sulfonate-formaldehyde condensates (NSF) and polycarboxylate based products, were tested on both wet and dry fly ash samples from the LG&E Energy Corp. plants in the study. Tests included both total adsorption and measurement of sedimentation rate via time density relationships. A wide range of dosages were required, ranging from 0.3 to 10 g/kg. In general the ponded ash required less dispersant. Leaching tests of 5% ash solutions by weight revealed a wide range of soluble salts to be present in the ash, and found a relationship between calcium ion concentration and dispersant dosage requirement. Other parameters measured included SO(sub 4), Cl, F, NO(sub 3), PO(sub 4), Al, Ca, Mg, K, Na and alkalinity. An assessment was made of the available software to digitally model the overall process circuit. No prefabricated digital model was found for hydraulic classification or froth flotation. Work focused on building a model for hydraulic classification in an Excel spread sheet based on Stokes Law. A pilot plant scale hydraulic classifier was fabricated and operated. The performance of the hydraulic classifier was found to be forecastable within reasonable bounds, and work to improve both are ongoing.