Settling characteristics and separation features in a CrossFlow separator for fine coal beneficiation

ABSTRACT

An in-depth analysis of the separation features in a CrossFlow Separator was performed with reference to fine coal (1.4 x 0.1 mm) beneficiation. How various particle sizes respond to the separation in CrossFlow Separator was also investigated. A detailed experimental program was designed using response surface methodology (RSM) to unravel the beneficiation behavior. The process responses were estimated in terms of mass yield, product ash levels, and combustible recovery. The experimental data were analyzed to arrive at statistically significant correlations for the response variables as functions of the operating variables and optimized. Under optimum conditions, the feed coal with 33% ash was treated to obtain 24% ash in the clean coal with ~63% mass yield and over 70% combustible recovery. It was found that a ratio of 10:1 between the top and the bottom sizes of the particles may be acceptable in the feed coal for processing in the CrossFlow Separator. Overall Ep and effective specific gravity of separation were observed to be 0.34 and 1.81, respectively. The process features have been described phenomenologically vis-à-vis the experimental observations. Such understanding may be easily extended for the treatment of other coals and fine particles using the CrossFlow Separator.

KEYWORDS:

• Fine coal
• hindered settling
• CrossFlow separator
• liquid fluidization
• gravity concentration
• optimization

Acknowledgments

The authors gratefully acknowledge the research support by the Research Office of Montana Tech through the Undergraduate Research Program.