Concentration of carbon types from fly ash by density gradient centrifugation

Conference · Thu Dec 31 04:00:00 EST 1998

OSTI ID:349181

Maroto-Valer, M M; Taulbee, D N; Hower, J C ^[1]

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1. Univ. of Kentucky, Lexington, KY (United States). Center for Applied Energy Research

Although the increasing amount of unburned carbon in fly ash is known to preclude the use of ash in the cement industry, very little is known about the characteristics of the unburned carbon. Three types of carbon particles have been identified microscopically: inertinite, isotropic coke and anisotropic coke. This manuscript describes a method to isolate these three types of carbon. A preliminary enrichment, followed by density gradient centrifugation (DGC) with a high-density polytungstate media (2.85 g/cm{sup 3} max), resulted in an enrichment of inertinites from a starting concentration of 3.8% to 61%, isotropic coke from 13.4% to 65%, and anisotropic coke from 19.2% to 74%. Large scale runs (LS) have been conducted to accumulate sufficient sample for subsequent analyses. The recovery weights and petrography composition of the PS and LS fractions are very similar.

• OSTI ID: 349181
• Report Number(s): CONF-980985--; ISBN 1-890977-15-2
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
CARBONACEOUS MATERIALS
CEMENTS
CENTRIFUGATION
FLY ASH
QUALITATIVE CHEMICAL ANALYSIS
SAMPLE PREPARATION
WASTE PRODUCT UTILIZATION