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Title: Ash reduction in clean coal spiral product circuits

Abstract

The article describes the Derrick Corporation's Stack Sizer{trademark} technology for high capacity fine wet cleaning with long-lasting high open-area urethane screen panels. After field trials, a Stack Sizer fitted with a 100-micron urethane panel is currently processing approximately 40 stph of clean coal spiral product having about 20% ash at McCoy-Elkhorn's Bevin Branch coal preparation plant in Kentucky, USA. Product yield is about 32.5 short tons per hour with 10% ash. The material is then fed to screen bowl centrifuges for further processing. At Blue Diamond Coal's Leatherwood preparation plant similar Stacker Sizers are achieving the same results. 2 figs., 3 tabs., 2 photo.

Authors:
Publication Date:
OSTI Identifier:
20923756
Resource Type:
Journal Article
Resource Relation:
Journal Name: Coal People Magazine; Journal Volume: 29; Journal Issue: 9
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; DEASHING; COAL; SPIRAL CONFIGURATION; DESIGN; SCREENING; SCREENS; FUEL SLURRIES; PERFORMANCE TESTING; URETHANE; ASH CONTENT; FIELD TESTS; USA; COAL PREPARATION PLANTS; KENTUCKY

Citation Formats

Brodzik, P. Ash reduction in clean coal spiral product circuits. United States: N. p., 2007. Web.
Brodzik, P. Ash reduction in clean coal spiral product circuits. United States.
Brodzik, P. Sun . "Ash reduction in clean coal spiral product circuits". United States. doi:.
@article{osti_20923756,
title = {Ash reduction in clean coal spiral product circuits},
author = {Brodzik, P.},
abstractNote = {The article describes the Derrick Corporation's Stack Sizer{trademark} technology for high capacity fine wet cleaning with long-lasting high open-area urethane screen panels. After field trials, a Stack Sizer fitted with a 100-micron urethane panel is currently processing approximately 40 stph of clean coal spiral product having about 20% ash at McCoy-Elkhorn's Bevin Branch coal preparation plant in Kentucky, USA. Product yield is about 32.5 short tons per hour with 10% ash. The material is then fed to screen bowl centrifuges for further processing. At Blue Diamond Coal's Leatherwood preparation plant similar Stacker Sizers are achieving the same results. 2 figs., 3 tabs., 2 photo.},
doi = {},
journal = {Coal People Magazine},
number = 9,
volume = 29,
place = {United States},
year = {Sun Apr 15 00:00:00 EDT 2007},
month = {Sun Apr 15 00:00:00 EDT 2007}
}
  • The article discusses the successful introduction of Derrick Corporation's Stack Sizer technology for removing minus 200 mesh slimes from 6-inch coal hydrocyclone underflow prior to froth flotation or dewatering by screen bowl centrifuges. In 2006, the James River Coal Company selected the Stack Sizer fitted with Derrick 150 micron and 100 micron urethane screen panels for removal of the minus 100 mesh high ash clay fraction from the clean coal spiral product circuits. After this application proved successful, Derrick Corporation introduced new 75 micron urethane screen panels for use on the Stack Sizer. Evaluation of feed slurry to flotation cellsmore » and screen bowl centrifuges showed significant amounts of minus 75 micron that could potentially be removed by efficient screening technology. Removal of the minus 75 micron fraction was sought to reduce ash and moisture content of the final clean coal product. Full-scale lab tests confirmed that the Stack Sizer fitted with Derrick 75 micron urethane screen panels consistently reduced the minus 75 micron percentage in coal slurry from 6-inch clean coal hydrocyclone underflow that is approximately 15 to 20% solid by-weight and 30 to 60% minus 75 micron to a clean coal fraction that is approximately 13 to 16% minus 75 micron. As a result total ash is reduced from approximately 36 to 38% in the hydrocyclone underflow to 14 to 16% in the oversize product fraction form the Stack Sizers. 1 fig., 2 tabs., 5 photos.« less
  • In 2006, the James River Coal Co. selected the Stack Sizer to remove the minus 100 mesh high ash clay fraction from the clean coal spiral product circuits at the McCoy-Elkhorn Bevins Branch prep plant and at the Blue Diamond Leatherwood prep plant in Kentucky. The Stack Sizer is a multi-deck, high-frequency vibrating screen capable of separations as fine as 75 microns when fitted with Derrick Corp.'s patented high open area urethane screen panels. Full-scale lab tests and more than 10 months of continuous production have confirmed that the Stack Sizer fitted with Derrick 100 micron urethane screen panels consistentlymore » produces a clean coal fraction that ranges from 8 to 10% ash. Currently, each five-deck Stack Sizer operating at the Bevins Branch and Leatherwood prep plants is producing approximately 33 tons per hour of clean coal containing about 9% ash. This represents a clean coal yield of about 75% and an ash reduction of about 11% from the feed slurry. 3 figs. 2 tabs.« less
  • The potential for mercury (Hg) releases to the air and water from three soils, two subbituminous coal fly ashes, and mixtures of these materials as stabilized soil was assessed. In addition, the potential for Hg release from crushed stabilized material mixed into soil simulating degradation over time was investigated. In general, atmospheric Hg deposition was measured for the ash and materials made using the ash with the higher Hg concentration, whereas the second ash material and materials generated using this ash exhibited emission as the dominant flux. Fluxes measured from stabilized material were less than that measured for the puremore » ash material but of the same direction. Although the stabilized and degraded stabilized materials exhibited Hg fluxes that were significantly different from base soils, values were within the range reported for low Hg-containing background soils. Because of limitations of the experimental design (i.e., reduced light exposures and measurement of flux from dry materials) reported fluxes are most likely underestimates of that which would occur in the natural environment. Materials made to simulate degradation of the stabilized material did not exhibit higher releases than the stabilized material alone. Synthetic Precipitation Leaching Procedure (SPLP; EPA method 1312) results showed that the chemistry of a soil, especially pH, may influence the amount of Hg released to soil solutions, with more acidic soils potentially enhancing Hg release. 25 refs., 9 figs., 4 tabs.« less