Electrostatic beneficiation of coal fly ash utilizing triboelectric charging with subsequent electrostatic separation

Authors
Citation
Jk. Lee et Sc. Kim, Electrostatic beneficiation of coal fly ash utilizing triboelectric charging with subsequent electrostatic separation, KSME INT J, 15(6), 2001, pp. 804-812
Citations number
13
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Mechanical Engineering
Journal title
KSME INTERNATIONAL JOURNAL
ISSN journal
1226-4865 → ACNP
Volume
15
Issue
6
Year of publication
2001
Pages
804 - 812
Database
ISI
SICI code
1226-4865(200106)15:6<804:EBOCFA>2.0.ZU;2-G
Abstract
triboelectrostatic separation system for removing unburned carbon from coal fly ash is designed and evaluated. Fly ash from a coal-fired power plant i s used as an accepted additive in concrete where it adds strength, sulfate resistance and reduced cost, provided acceptable levels of unburned carbon are maintained. Unfortunately, unburned carbon in coal fly ash absorbs some of other additives and reduces the concrete strength. This paper describes to investigate dry triboelectrostatic process to separate unburned carbon from coal fly ash and utilize it into economically valuable products. The l aboratory-scale triboelectrostatic separation system consists of a particle feeding system, a tribocharger, a separation chamber, and collection syste ms. Particles of unburned carbon and fly ash can be imparted positive and n egative surface charges, respectively, with a copper tribocharger due to di fferences in the work function values of the particles and the tribocharger , and can be separated by passing them through an external electric field. Results showed that fly ash recovery was strongly dependent on the electric field strength and the particle size. 70 wt% of fly ash containing 6.5 wt% of carbon contents could be recovered at carbon contents below 3%. The tri boelectrostatic separation system showed a potential to be an effective met hod for removing unburned carbon from coal fly ash.