Investigation of Coal Properties and Airborne Respirable Dust Generation

摘要

Laboratory crushing experiments were conducted on a range of low- to high-211u001evolatile bituminous coals to investigate the various factors influencing airborne 211u001erespirable dust (ARD) generation. This research was conducted to identify the 211u001eprinciples of ARD liberation from the coal product. Five U.S. bituminous coals 211u001ewere uniformly prepared and processed through a double roll crusher located in a 211u001elow-velocity wind tunnel. Experimental factors studied included inherent coal 211u001eseam constituents, coal grindability, specific energy of crushing, product size 211u001echaracteristics, dust cloud electrostatic field, and specific ARD generated. The 211u001eresults of this investigation indicate that a combination of several factors are 211u001eassociated with ARD generation. One factor is the effect of coal rank, described 211u001eby the inherent moist fuel ratio, on the product size characteristics, defined by 211u001eSchuhmann size function parameters. Another key factor is the effect of air dry 211u001eloss (ADL) moisture in the coal seam on the breakage-induced electrostatic field 211u001eof airborne dust. The effect of these factors is that different percentages of 211u001e<10-micrometers coal particles are dispersed as ARD. A discussion of 211u001eelectrostatic field principles, coal ADL, and its effect on ARD generation is 211u001epresented.