Hydroacoustic Cavitation for Reclaiming Anthracite Fines from Waste Silt Slurry

Open Access
Liu, Shang
Graduate Program:
Environmental Engineering
Master of Science
Document Type:
Master Thesis
Date of Defense:
November 19, 2014
Committee Members:
  • Fred Scott Cannon, Thesis Advisor
  • Mark Stephen Klima, Thesis Advisor
  • Anthracite
  • processing
  • hydroacoustic
  • cavitation
Hydroacoustic cavitation treatment, coupled with cyclone and spiral separation, were tested to reclaim anthracite fines from a silt-coal slurry. This waste slurry had been received from an anthracite producer, and it contained approximately 36% combustible material (i.e. fuel). Control experiments that did not include hydroacoustic treatment were also conducted. When hydroacoustic treatment was included, this process reclaimed 68.8% of all the fuel (i.e. non-ash volatiles: carbon, hydrogen, and oxygen) as a sellable product. The hydroacoustic cavitation process apparently dislodged the coal from silt particles so that they could be better separated through the cyclone and spiral. When hydroacoustic cavitation treatment was not included (Control test), the cyclone and spiral reclaimed only 14.3% of all the fuel. The spiral included seven splitter box divisions (i.e. exit ports) -- three inner ports combined as refuse, two middlings ports, and two outer clean coal ports. When hydroacoustic treatment was included, the two clean coal ports plus one middlings port yielded coal that averaged less than 8.5% ash in the -16+100 U.S. mesh size range. In comparison, for the Control experiments (no hydroacoustic cavitation treatment), only the clean coal ports (1 and 2) yielded coal that averaged less than 8.5% ash for the same size fraction. In another set of tests, ozone and hydrogen peroxide were coupled with hydroacoustic cavitation treatment that preceded cyclone, spiral, and simulated sieve bend separation. In this case, two clean coal ports plus one middlings port produced coal with 8.5% ash. The total recovery of this material was 72.4% or an increase of 3.6% of the available fuel that was reclaimed without ozone and hydrogen peroxide addition.