Technical System And Practice Of Near Net Mining Of Coal Resources

At present,the coal recovery rate of coal resources in China is generally low,and most of the protected coal mine design,construction and "three" on the next coal influence,quite a number of hard coal mine resources to maximize production,with the international,especially,for example Australia generally over 80%,recovery rate of coal resources is quite a gap.How to leave less or no coal pillar in the process of coal mining and maximize the coal resources with nearly clean degree,that is,the near net mining of coal resources,is an urgent direction to tackle at present.In this paper,by studying the gob retention technology of the whole resource of zero coal pillar and the mining pressure monitoring and support technology of near net mining of coal resources,it is expected to achieve the maximum recovery rate of coal resources.The main conclusions are as follows:(1)The gob-side entry retention technology with zero coal pillar resources and the mining pressure monitoring and support technology of near clean mining of coal resources are studied,and mining area layout and working face design of near clean mining of coal resources are carried out with No.5 coal seam of Lao Mu Po Mine as the engineering background.(2)zero pillar mining technology for all resources along the core for the cutting of combination security technology,the key is to cut the top bracket design,this paper based on the cutting roof strength,lateral strength,combination and quantity of the hydraulic support scalable base area calculation,with reasonable design,cut the top bracket to achieve zero for all resources along the coal pillar mining in coal mine.(3)The commonly used method of gob-side entry retention mining technology with zero coal pillar resources is natural roof cutting.A variety of gob-side entry retention methods were analyzed by grey correlation method,and the natural roof cut gob-side entry retention method was selected as the first choice.Then the influencing factors and weight analysis of natural gob entry retention were studied.The orthogonal test scheme was calculated one by one through FLAC numerical simulation,and the weight of each influencing factor was obtained as follows: buried depth>Lane high>Roof lithology >Mining height are broken>Lane width.AHP model was established to verify the consistency of the test results,which ensured the credibility of the results.(4)Analyze the economic benefit of the gob-side entry retention with natural roof cut in 5101 working face of Lao Mu Po Coal Mine,and explain the necessity of gob-side entry retention with zero coal pillar resources.And by testing the key parameters of near net mining of coal resources,data support is provided for numerical simulation,and the roof lithology is obtained to determine the difficulty of roof cutting.The coal resource near-net mining guarantee technology is used to monitor the mine pressure of the gob-side entry retaining.The results show that it is feasible to use the natural gobside entry retaining technology in Lao Mu Po Mine.Therefore,zero coal pillar full resource gob-side entry retention mining technology is feasible.There are 36 figures,27 tables and 100 references in this paper.