Optimization Of Coal Pillar Size And Fire Prevention Technology In Yang Chang Wan Coal Mine

Mining by means of fully mechanized sublevel caving can effectively increase production efficiency for highly spontaneous combustion thick coal seam,but it also brings a serious threat of spontaneous combustion.Setting the working face with narrow coal pillars can not only improve the resources recovery,but also be beneficial to the support of coal pillar and roadways.Due to the coal pillar is narrow,the threat of spontaneous combustion is increased in the well development fracture zone.Therefore,this paper first studied the size of coal pillar in highly spontaneous combustion tendency coal seam,especially optimized the design of coal pillar by thinking about the ventilation,and clarified the "three zones" of spontaneous combustion in the gob.The fire prevention and control technology for different mining periods are constructed.This paper firstly studies the theoretical calculation methods of pressure-bearing pillar and yield coal pillar of Yang Chang Wan coal mine and the calculation method of peak stress position of coal pillar,and determines the scope of the size of narrow pillars.Using FLAC3D numerical simulation to establish the model,respectively,6m,8m,35m three kinds of coal pillar scheme for simulation,from the stress distribution during the excavation of roadways and the working face mining and prevention and control of disaster prevention,three aspects of the comprehensive analysis.It is determined that the 6m coal pillar can be in the spray-strengthening mode under the stress distribution,prevention and control of water and other work,and can maximize the recovery of coal,so as to determine the 6m pillar plan for the proposed scheme.Secondly,the dangerous area of goaf in the fully mechanized caving face of extremely easy spontaneous combustion thick seam is divided,the "three zones" distribution of spontaneous combustion in goaf of fully mechanized caving face is heat dissipation zone(0～10m),oxidation zone(10m～150m),suffocative zone(>150m),and the minimum safety mining speed is calculated according to the division of "three zones".According to the actual mining process of 130205 mining face,specific fire prevention and control technology have been designed for different mining phases.Among them,gel foam is used in the normal mining process to prevent fire extinguishing,temperature and beam monitoring,and comprehensive mechanization work measures such as gas drainage in the goaf During the slow mining period,measures were taken to set up a fly ash-cement foam insulation wall,reduce the amount of wind at the working surface,strengthen grouting in the goaf area,and temperature beam monitoring;During the retreat of the working face,spray mist inhibitors,optimized ventilation,smart gel injection and other measures were adopted.By fire prevention and control technology in the fully mechanized top coal caving face of spontaneous combustion in thick coal seam,an system of effective warning and control of fire hazards has been achieved,which ensures the safe production of the working face and the mine.