Respirable dust concentration distribution model on longwall faces — multiple dust source approach

Abstract

A mathematical model is developed for description of the dust concentration distribution on the longwall faces of coal mines involving multiple dust sources of various particle sizes. Longwall mining is an efficient and productive coal-mining method. However, it generates a large quantity of respirable dust in the working area during the shearing and transportation of coal. Multiple dust sources on the longwall face make dust distribution prediction very difficult. In this paper, the primary sources of respirable dust and transportation of dust particles on a longwall face are determined. The dust particle size distributions at various locations of the longwall face are analyzed, classified and incorporated into the dust distribution model. General trends of dust concentration obtained at different working positions on a longwall face are discussed. The mathematical model takes into account the characteristics of airflow, the effect of particle size, various dust sources, and the mechanisms of dust transport along a longwall face. It predicts the dust behaviors and dust distribution in the longwall mining atmosphere under various operating conditions. Computer programs based on the respirable dust distribution model are also developed. The predicted results are compared with the field data from several longwall faces.