Preparation of super-clean coal: improvements in recovery and selectivity. Technical progress report for the seventh and eighth quarters, March 15-September 14, 1985

Technical Report · Tue Jan 01 04:00:00 EST 1985

OSTI ID:6277311

Yoon, R H; Adel, G T; Luttrell, G H

It has been shown previously that in cleaning ultrafine coal by flotation, the use of microbubbles improves both recovery and selectivity as compared to the conventional flotation process. In this investigation, the increased recovery associated with microbubbles has been found to result from the improved hydrodynamic conditions for bubble-particle collision. The improved selectivity, on the other hand, can be attributed to the absence of a wake behind the rising bubbles. It has been found that when using larger bubbles, particles are entrained in the wake volume, which results in reduced selectivity. The benefits of using microbubbles have been demonstrated in a series of continuous flotation experiments using a column-type flotation cell. A model for the flotation rate constant has been developed by combining flotation due to adhesion and flotation due to entrainment. The rate constants determined experimentally using a frothless flotation cell have been found to be in good agreement with those predicted by the model over a wide range of bubble sizes. 13 refs., 11 figs.

• Research Organization: Virginia Polytechnic Inst. and State Univ., Blacksburg (USA). Dept. of Mining and Minerals Engineering
• DOE Contract Number: FG22-83PC60806
• OSTI ID: 6277311
• Report Number(s): DOE/PC/60806-T4; ON: DE86005368
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
013000* -- Coal
Lignite
& Peat-- Transport
Handling
& Storage
BUBBLES
CARBONACEOUS MATERIALS
CLEANING
COAL
COAL FINES
DATA
ENERGY SOURCES
ENTRAINMENT
EXPERIMENTAL DATA
FLOTATION
FOSSIL FUELS
FUELS
INFORMATION
MATERIALS
MATHEMATICAL MODELS
NUMERICAL DATA
PARTICLE SIZE
RESEARCH PROGRAMS
SEPARATION PROCESSES
SIZE