PDU-scale testing of microbubble flotation
In previous test work, bubble size, countercurrent wash water addition rate, aeration rate and column length-to-diameter ratio have been identified as important parameters in microbubble column flotation. Test work this past quarter focused primarily on Task 1.1.3 (Scale-up Testing) and Task 1.1.4 (Modeling) in order to develop scale-up procedures and relationships for each of these parameters. Scale-up test work was conducted on columns of 1-, 2- and 4-inch diameter using a micronized run-of-mine Elkhorn No. 3 coal from Kentucky. Results of the best selectivity, is achieved at a superficial velocity of approximately 20 cm/min. It was further observed that the aeration rate should be as high as possible in order to achieve a high recovery. However, a superficial velocity of approximately 120 cm/min was found to be adequate. The results of this investigation further suggest that mixing within the column may not be as significant as bubble size and residence time in determining column performance. Improved recovery can be obtained by decreasing bubble size which increases the flotation rate constant, and also by increasing L/D which increases residence time for a fixed column volume. Scale-up relationships for L/D, bubble size, flotation rate constant and residence time have been established which make it possible to predict throughputs for larger columns. 13 refs., 3 figs., 3 tabs.
- Research Organization:
- Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (USA). Dept. of Mining and Minerals Engineering
- Sponsoring Organization:
- DOE; USDOE, Washington, DC (USA)
- DOE Contract Number:
- AC22-86PC91274
- OSTI ID:
- 5902563
- Report Number(s):
- DOE/PC/91274-T13; ON: DE91012260
- Country of Publication:
- United States
- Language:
- English
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PDU-scale testing of microbubble flotation
PDU-scale testing of microbubble flotation
Related Subjects
010300* -- Coal
Lignite
& Peat-- Preparation-- (1987-)
AERATION
BUBBLES
CARBONACEOUS MATERIALS
CLEANING
COAL
COAL FINES
COAL PREPARATION
DEASHING
DOCUMENT TYPES
ENERGY SOURCES
FLOTATION
FLOW RATE
FOSSIL FUELS
FUELS
FUNCTIONAL MODELS
MATERIALS
PILOT PLANTS
PROGRESS REPORT
SEPARATION EQUIPMENT
SEPARATION PROCESSES
WASHING