Abstract
The results of a research study on airborne dust generation and entrainment in longwall faces are presented. The study encompassed determination of the size analysis of shearer-mined coal, the amount of adhering fines to the coarse coal fractions, the amount of dust entrained, and the relationship among these factors. Descriptions of the longwall faces, the sampling schemes employed in the mines, the laboratory procedures for both the mined-coal size analyses, and the determination of the amount of fine coal attached to the coarse sizes are presented. Amount of airborne dust is estimated on the basis of measured air quantity flow rates and the dust concentrations at stations along the faces. According to this study the differences in the size distribution of the coal mined in different faces are significant, the amount adhering is very size dependent, and the amount of dust airborne is a very small fraction of that which is generated. The results reveal the important role of agglomeration and adhesion in the process of generation and entrainment.