PILOT SCALE DEMONSTRATION AND EVALUATION OF INNOVATIVE NON-DESLIMED NON-CLASSIFIED GRAVITY-FED HM CYCLONE

• Main Author: Zhang, Yumo
• Format: Others
• Published: UKnowledge 2015
• Subjects: Dense Medium Cyclone; Three Products; Fine Coal Separation; Parametric Evaluation; Tracer Tests; Mining Engineering; Process Control and Systems
• Online Access: http://uknowledge.uky.edu/mng_etds/19; http://uknowledge.uky.edu/cgi/viewcontent.cgi?article=1021&context=mng_etds

Coal preparation plants are required in some cases to produce a high-grade product using a low specific gravity cut-point. For these situations, a second higher gravity separation would be desirable to generate a mid-grade product that can be utilized for electricity generation thereby maximizing coal recovery. A study was conducted to evaluate the potential of achieving efficient separations at two different density cut-points in a single stage using a three-product dense medium cyclone. Variations in density cut-point and process efficiency values were quantified as a function of the feed medium density, feed medium-to-coal ratio, and feed pressure using a three-level experimental design program. Results indicate the ability to effectively treat coal over a particle size range from 6mm to 0.15mm while achieving both low- and high-density cut-points up to 1.95 relative density. Ash content decreased from 27.98% in the feed to an average of 7.77% in the clean coal product and 25.76% in the middlings product while sulfur content was reduced from 3.87 to 2.83% in the clean coal product. The overall combustible recovery was maintained above 90% while producing clean coal products with ash and total sulfur content as low as 5.85 and 2.68%, respectively. Organic efficiency values were consistently about 95% and probable error values were in the range of 0.03 to 0.05, which indicates the ability to provide a separation performance equivalent to or better than traditional coal cleaning technologies.