Study of Process Efficiency for High-Ash Fine Coal Cleaning in a Kelsey Centrifugal Jig

Abstract

Processing of ultrafine (< 300 µm), high-ash (> 50 %) coal was investigated in a laboratory Kelsey Jig. A set of experiments were designed through design expert software. Four different process parameters were considered for the present study, including pulse frequency, spin frequency, feed flow rate, and ragging size, while other parameters were kept constant. In a single pass through a KCJ, an absolute 8% reduction in the ash with 53% yield was obtained. Statistical modeling studies and process optimization were also performed. Two different process schemes were studied to process the high-ash coal fines involving (a) a Kelsey Jig and (b) a hydrocyclone followed by a Kelsey Jig. It was observed that the removal of particles below 45 µm by a desliming process results in a reduction of 12% ash with 60% yield at the optimized condition. The Ecart probable value was estimated for particle sizes of 300 x 45 micron. The Ecart probable value 0.08 over a particle-size range of 300 µm x 45 µm with a separation density value of 1.86 is indicative of the good separation performance achievable from a Kelsey Jig for high-ash feed coal.