Optimization of coal drawing method for improving top coal recovery rate in low level fully-mechanized caving face
In response to the problem of the top coal recovery rate in the low level fully-mechanized top caving face of Gucheng Coal Mine,taking the No.S1306 low level fully-mechanized caving face as the background,the existing coal caving methods were analyzed.Firstly,by establishing PFC numerical calculation models for different coal caving methods and coal caving mouth lengths,the top coal recovery rate was analyzed under different coal drawing mouth lengths and the same coal drawing mouth lengths;secondly,a dual port interval dynamic coal drawing method was proposed,and the top coal recovery rates of single port sequential coal drawing,dual port se-quential coal drawing,and dual port interval dynamic coal drawing were compared and analyzed;finally,the impact of different mining and drawing ratios on the top coal recovery rate of three coal drawing methods was studied.Research shows that the recovery rate of top coal in low level fully-mechanized caving face gradually decreases with the increase of the length of the coal drawing port;when the length of the coal drawing port is fixed,the top coal recovery rate of single port sequential coal drawing is greater than that of dual port sequential coal drawing;the recovery rate of top coal in dynamic coal drawing with double port interval has increased by about 8.44％compared to single port sequential coal drawing,saving 46％in coal drawing time,and the coal drawing balance is better than that of single port sequential coal drawing and dual port sequential coal drawing;the top coal recovery rate of dual port interval dynamic coal drawing and single port interval sequential coal drawing both increase with the increase of mining ratio.When the mining ratio is less than 1∶1,the top coal recovery rate of dual port interval dynamic coal drawing is greater than that of single port interval sequential coal drawing.When the mining ratio is greater than 1:1,the difference between the two is significantly reduced,but the time for dual port in-terval dynamic coal drawing is greatly reduced.Therefore,the dual port interval dynamic coal drawing method combines the advantages of high top coal recovery rate and short coal drawing time of the single port coal drawing method under the conditions of low level fully-mechanized caving face.
万方数据
维普
