화학공학소재연구정보센터
Korean Journal of Chemical Engineering, Vol.18, No.4, 531-538, July, 2001
Tribo-Electrostatic Beneficiation of Fly Ash for Ash Utilization
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The study was conducted to obtain the scale-up factor and the optimum design criteria for the development of a commercial scale electrostatic separator using a continuous, bench-scale electroseparator composed of two vertical electrode plates and an ejector-tribocharger. Tests of the charge density and separation efficiency to study the removal possibility of unburned carbon from coal fly ash were evaluated under various operating conditions. It was found that the experimental conditions for obtaining the maximum charge density were an air flow rate of 1.75 m(3)/min and a feed rate of less than 50 kg/hr when operated at lower than 30% relative humidity using a SUS304 ejector tribocharger. Also, the optimum instrument conditions for recovering the clean ash with less than LOI 3% at yield over 65% when operated at above experimental conditions were found to be a diffuser slit gap of 4 mm, and a distance between diffuser slit and splitter of 15 cm. Overall, the feed rate per unit electrode surface area was about 0.074 kg/cm(2) · hr, which can be used as a scale-up factor of the electroseparator.
  1. Cho HC, Kim JK, Geosystem Eng., 2(2), 37 (1999)
  2. Choi JB, Park JH, "A Basic Study on the Utiliation of Fly Ash as a Mineral Admixture in Concrete," KEPRI Technical Report KRC-87H-J07, Korea Electric Power Reserch Institute (1989)
  3. Choi JH, Keum SM, Chung JD, Korean J. Chem. Eng., 16(6), 823 (1999)
  4. Ciccu R, Ghiani M, Peretti R, Serci A, Zucca A, Proc., Int. Ash Util. Symp., Kentucky, USA, 443 (1997)
  5. David RL, "Properties of Solids in CRC Handbook of Chemistry & Physics," 71st Eds., CRC Series, Chemical Rubber Publishing Company Press Inc., 12-23, 12-84 (1990)
  6. Gupta R, Gidaspow D, Wasan DT, Powder Technol., 75(1), 79 (1993) 
  7. Kim JK, Cho HC, Kim SC, Chun HS, J. Environ. Sci. Health Part A-Toxic/Hazard. Subst. Environ. Eng., 35(3), 357 (2000)
  8. Kim JK, Cho HC, Kim SC, Chun HS, J. Korean Institute of Mineral. Energy Res. Eng., 35(5), 481 (1998)
  9. Kim JK, Cho HC, Park OW, Cho BS, "Fly Ash Beneficiation by Classification and Triboelectrostatic Separation," Int'l. Fly Ash Util. Symposium Proceedings, Kentucky, USA, 459 (1997)
  10. Kim JK, Kim SC, "Separation Technology of Unburned Carbon From Coal Fly Ash," KEPRI Technical Report TR.96GJ05.2000.321, Korea Electric Power Research Institute, 104-123, Appendix 123 (2000)
  11. KSL, Fly Ash Standard, 1992, No.5211
  12. Lee MG, Yi G, Ahn BJ, Roddick F, Korean J. Chem. Eng., 17(3), 325 (2000)
  13. Pratt PL, "In the Use of Fly Ash in Concrete-A European View. Fly Ash and Conversion By-Products; Characterization. Utilization and Disposal VI," Materals Research Society Symposium Proceedings, Nov. 29-Decem. 1. 1989, Boston, Boston, Massachusetts, Day, RL and Glasser FP, Eds., Material Research Society, Pittsburgh, Pennsylvania, 178, 177 (1989)
  14. Shin BS, Lee SO, Kook NP, Korean J. Chem. Eng., 12(3), 352 (1995)
  15. Taylor DM, Secker PE, "In Industrial Electrostatics: Fundamental and Measurements," Electrostatics & Electrostatic Applications Series, Research Studies Press LTD., John Wiley & Sons, New York, 13, 185 (1994)