Optimization of a Compound Spiral for Cleaning High Sulfur Fine and Ultrafine Coal
Conventional spirals are capable of providing excellent clean coal recovery, although at a relatively high ash content. Compound spirals, which provide two stages of spiral cleaning in a single taller unit, have been commercialized in recent years to improve upon the cleaning performance obtained from conventional spirals. The present study aimed at optimizing the performance obtained from a compound spiral for cleaning especially high sulfur free and ultrafme coal.Industrial-scale spiral units were utilized for this study in a pilot-scale facility at the Illinois Coal Development Park. A statistically designed experimental program was conducted to optimize ash and sulfur cleaning performance of the compound spiral. It was found that significant cleaning of ultrafine coal (i.e., 150 microns × 45 microns and even 45 microns × 25 microns size coal) is achievable with the compound spiral. However, operating conditions for cleaning finer coal fractions (-150 microns size coal) have to be significantly different from those used to clean coarser coal fractions (+150 microns size coal). The sulfur rejection trends were different from ash separation efficiency trends in all size fractions except 45 microns × 25 microns. The probable error (Ep) and effective specific gravity of separation (SG50c) determined for the compound spiral cleaning of the overall particle size were as low as 0.07 and 1.62, respectively. However, the bypass of a small percentage of clean coal to the tailings stream of the compound spiral, may need further adjustment of the key process parameters.
Compound Spiral Performance optimization Parametric study Fine coal cleaning
B. J. Zhang F. Yang P. Sahoo M. K. Mohanty X. X. Zhang
Department of Mining and Mineral Resources Engineering, Southern Illinois University Carbondale, USA School of Chemical Enginecring &Technology, China University of Mining and Technology, Xuzhou, China
国际会议
XXIV International Mineral Processing Congress(第24届国际矿物加工大会)
北京
英文
653-662
2008-09-24（万方平台首次上网日期，不代表论文的发表时间）