Optimization of the Drawing Process of Low–Middle-Thickness Top Coal Based on a Simulation

Abstract

Based on a theoretical analysis and simulation, the automated drawing characteristics for low–middle-thickness top coal are investigated, and the drawing process of top coal is optimized. For top coal with a 3 m thickness, a comparison is made between traditional and automated drawing process of top coal, which is used to highlight the superiority of automated drawing process. Then, for the automated top coal drawing, the effects of the round number on the drawing results of the entire working face are investigated, and the advantages and disadvantages of the multi-round drawing process are compared. Finally, the coal drawing results combined with automated and traditional methods are discussed, and an ideal optimized coal drawing process is proposed. The research results indicate that, for top coal with a 3 m thickness, the recovery rate of top coal by automated one-round drawing is slightly higher than that of traditional drawing, the drawing amount and drawing time of various drawing openings are relatively uniform for automated drawing, while the traditional coal drawing process shows fluctuating characteristics. For automated multi-round drawing, the top coal recovery rate decreases with an increase in the round number; however, the rock mixed rate in the drawn top coal is lower, and the drawing results at various drawing openings become more uniform. The combined automated–traditional drawing can achieve layered drawing of the top coal, avoid gangue drawing, and maintain a relatively high recovery rate, which is the optimal drawing process for this research project.