WO2019085052A1 - Method for filling coal mining to recover residual coal pillar and controlling stability of waterproof key layer - Google Patents

Method for filling coal mining to recover residual coal pillar and controlling stability of waterproof key layer Download PDF

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Publication number
WO2019085052A1
WO2019085052A1 PCT/CN2017/112100 CN2017112100W WO2019085052A1 WO 2019085052 A1 WO2019085052 A1 WO 2019085052A1 CN 2017112100 W CN2017112100 W CN 2017112100W WO 2019085052 A1 WO2019085052 A1 WO 2019085052A1
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coal
filling
mining
key layer
stability
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PCT/CN2017/112100
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French (fr)
Chinese (zh)
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张吉雄
孙强
周楠
张强
姜淑印
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中国矿业大学
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    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21F—SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, OR DRAINING IN OR OF MINES OR TUNNELS
    • E21F15/00—Methods or devices for placing filling-up materials in underground workings
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21C—MINING OR QUARRYING
    • E21C41/00—Methods of underground or surface mining; Layouts therefor
    • E21C41/16—Methods of underground mining; Layouts therefor
    • E21C41/18—Methods of underground mining; Layouts therefor for brown or hard coal

Definitions

  • the invention relates to the field of filling coal mining and recovering left coal pillars, and particularly relates to a method for filling coal mining and recovering residual coal pillars and controlling the stability of the water-storing key layer.
  • Filling coal mining is a green mining technology that has been developed and widely used in recent years. This technology is a green mining and mining method with high recovery rate, which can make coal mine operations better adapt to local mining conditions, especially effective. Avoid mining damage to the ecological environment.
  • This technology is a green mining and mining method with high recovery rate, which can make coal mine operations better adapt to local mining conditions, especially effective. Avoid mining damage to the ecological environment.
  • filling materials such as meteorites and fly ash in the western mining area, and the abundant conditions of aeolian sand on the surface, how to maximize the use of surface aeolian sand materials for safety and environmental protection to improve the recovery rate of coal resources for local economic and social development Significance.
  • the object of the present invention is to provide a safe, efficient, high resource recovery rate of residual coal pillar recovery, while controlling the stability of the water-critical key layer.
  • the method for filling the recovered coal pillars of the present invention and recovering the stability of the water-storing key layer comprises the following steps:
  • the cementation filling material mainly composed of aeolian sand is used for cementing filling of the goaf in the first mining face;
  • the cemented filling material in the step a is filled with a certain bearing capacity and deformation resistance, the remaining coal pillars in the mining working face are recovered; the cementing filling material reaches a certain bearing capacity and the deformation resistance capability refers to cementation filling.
  • the material plays an effective supporting role on the top plate, and the cemented filling material is not easily deformed under the action of the upper load;
  • step b transporting the raw coal recovered in step b to the ground using transportation equipment
  • the mining is stopped, and the isolation protection coal pillar is set.
  • the certain distance L refers to the initial pressure and the falling step of the basic top.
  • the side roadway formed by the coal mining room in the first mining working face is used as the material conveying lane
  • the cementing filling pumping device is arranged in the conveying lane
  • the material is cemented and filled on both sides of the conveyance lane by a cement filling pumping device.
  • the cementing filling material achieves certain bearing capacity and anti-deformation ability, which means that the cementing filling material plays an effective supporting role on the top plate, and the cementing filling material is not easily deformed under the upper load.
  • the other side roadway formed by the coal mining room in the first mining working face is used as the coal transportation lane, and the recovered raw coal is transported to the ground through the coal transportation lane.
  • the aerated sand-based cementing filling material is selected by mixing natural aeolian sand in the western region with cement, fly ash and additives.
  • the filling rate ⁇ of the aeolian sand throwing filling in the step d is determined according to the position of the water-retaining key layer and the strength stability breaking condition.
  • the method of the invention firstly fills the cemented filling material mainly composed of aeolian sand according to the geological conditions of the mine, the ratio of the cementing material and the surrounding rock control of the working face, and the residual coal pillar is subjected to a certain bearing capacity and deformation resistance capability after the filling body reaches a certain bearing capacity and deformation resistance capacity.
  • Safety recovery then, a high-speed throwing machine and a bulldozer are used to fill a single aeolian sand in the goaf, and the filling rate of the secondary aeolian sand is determined according to the position of the aquifer and the breaking stability of the strength.
  • the method of the invention is mainly directed to the two aspects of the stability of the surrounding coal pillars and the stability control of the key layer of the water-retaining coal pillars in the western mining area, and the object is strong.
  • the stability control of the remaining coal pillars and the key layer of the water separation is carried out by cement filling and aeolian sand high-speed casting combined filling method.
  • the secondary filling is aimed at long-term stability of the key layer of water separation, and is filled with a high-speed throwing machine and a bulldozer;
  • the layer position and strength stability breaking conditions determine the filling rate of the secondary aeolian sand and control the sinking deformation of the key layer of the water barrier.
  • the technical method of the invention can utilize the surface abandonment of aeolian sand material to the maximum extent, has low cost, improves the recovery rate of coal resources, and effectively controls the long-term stability of the key layer of the quaternary clay water-separating layer and maintains the ecological environment of the local surface vegetation. It provides a new technical model for the control of high-strength mining and recovery of residual coal pillars and water-removing key layers in western mining areas of China. It is a green and efficient way to acquire resources. It has great significance in science and engineering and has broad application prospects.
  • the remaining coal pillars of the first mining working face can be recovered, and the coal resource recovery rate reaches over 90%.
  • the measured results show that the cemented filling material with a uniaxial compressive strength of 2.83 MPa or more and a filling rate of 85 %
  • the above aeolian sand throwing joint filling is combined, and the development height of the water guiding fracture zone is less than 40m, which can ensure the long-term stability of the quaternary clay aquifer at 70m position on the working surface.
  • Figure 1-1 is a plan view showing the arrangement of the working surface of the present invention.
  • Figure 1-2 is a cross-sectional view taken along line A-A of Figure 1-1;
  • Figure 2-1 is a plan view showing the filling process of the goaf of the coal house of the present invention
  • Figure 2-2 is a cross-sectional view taken along line B-B of Figure 2-1;
  • Figure 3-1 is a plan view showing the process of recycling the remaining coal pillars of the working face of the present invention
  • Figure 3-2 is a cross-sectional view taken along line C-C of Figure 3-1;
  • Figure 4-1 is a plan view showing the secondary filling process of the aeolian sand of the working face of the present invention
  • Figure 4-2 is a cross-sectional view taken along line D-D of Figure 4-1;
  • Figure 5-1 is a plan view showing the recovery of a single-cycle remaining coal pillar in the working face of the present invention
  • Figure 5-2 is a cross-sectional view taken along line E-E of Figure 5-1;
  • Figure 6-1 is a plan view of the first working face of the present invention after all the remaining coal pillars are recovered and filled;
  • Figure 6-2 is a cross-sectional view taken along line F-F of Figure 6-1.
  • a method for filling coal mining to recover residual coal pillars and controlling stability of water-storing key layers comprising the following steps:
  • the cementation filling material mainly composed of aeolian sand is used for cementing filling of the goaf in the first mining face;
  • the cemented filling material in the step a is filled with a certain bearing capacity and deformation resistance, the remaining coal pillars in the mining working face are recovered; the cementing filling material reaches a certain bearing capacity and the deformation resistance capability refers to cementation filling.
  • the material plays an effective supporting role on the top plate, and the cemented filling material is not easily deformed under the action of the upper load;
  • step b transporting the raw coal recovered in step b to the ground using transportation equipment
  • the side roadway formed by the coal mining room in the first mining face is used as the material conveying lane, and the cementing filling pumping device is arranged in the conveying lane, and the cementing filling material mainly composed of aeolian sand is cemented.
  • Filling pumping device transports coal pillars along The gob area on both sides of the roadway is cemented and filled. This filling method is more efficient and simpler.
  • the mining is stopped, and the isolation protection coal pillar is set; and the other side roadway formed by the coal mining room in the first mining working face is used as the coal transportation lane.
  • the certain distance L refers to the initial pressure and the stepping distance of the basic top.
  • a high-speed power-spraying machine can be used for the throwing machine.
  • the aerated sand-based cementing filling material is selected from natural aeolian sand in western China with cement, fly ash and a small amount of additives, and has high strength and good durability.
  • the bearing capacity and deformation resistance requirement of the aeolian sand-based cementing filling material are determined according to the geological conditions of the mine, the ratio of cementing materials and the surrounding rock control of the working face.
  • the mechanical calculation method of the elastic foundation of the rock beam is used to determine the filling rate ⁇ of the aeolian sand throwing filling in the step d, which can reduce soil erosion and water inrush disaster.
  • each adjacent two columns of coal pillars shall be arranged with a working face with a working height of 4.5 m and a working face length of 800 m.
  • the inclined length is 70m, and a partition wall 2 is left between adjacent working faces, as shown in Figure 1-1 and Figure 1-2;
  • the ground natural aeolian sand is transported to the underground and transported by the belt conveyor 5 to the secondary filling work.
  • the high-speed power-spraying machine 4 throws the aeolian sand 11 into the goaf, and when the aeolian sand 11 is piled up to a certain height, the high-speed power-spraying machine 4 is rotated, and the material is thrown to the other side of the gob;
  • the bulldozer 6 is started, and the natural aeolian sand 11 after the throwing is pushed and filled to make it topped; under the cooperation of the high-speed power-spraying machine 4 and the bulldozer 6, the sand casting and the tamping are repeated.
  • the top process is shown in Figure 4-1, Figure 4-2, Figure 5-1, Figure 5-2;
  • the remaining coal pillars of the first mining face can be recovered, and the recovery rate of coal resources reaches over 90%.
  • the measured results show that the cemented filling materials with a uniaxial compressive strength of 2.83 MPa or more and the enrichment rate are 85%.
  • the above aeolian sand throwing joint filling is combined, and the development height of the water guiding fracture zone is less than 40m, which can ensure the long-term stability of the quaternary clay aquifer at 70m position on the working surface.

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Abstract

Disclosed is a method for filling coal mining to recover a residual coal pillar and controlling stability of a waterproof key layer. A cement-filling pumping device is arranged in a tunnel formed by a mined coal chamber; goafs at two sides are filled with an aeolian sand-based cement-filling material, and the residual coal pillar is stoped after a body to be filled reaches a certain bearing capacity; and after the coal pillar is stoped, secondary filling of goafs by aeolian sand is carried out using a high-speed power throwing machine and a bulldozer. By means of the method, an earth surface natural aeolian sand material can be used to the maximum extent, an overlying waterproof key layer is effectively controlled, and a new technical method is provided for stoping the residual coal pillar in the ecological weak mine area in western China and protecting the ecological environment.

Description

一种充填采煤回收遗留煤柱并控制隔水关键层稳定的方法Method for filling coal mining residual coal pillar and controlling stability of water-storing key layer 技术领域Technical field
本发明涉及充填采煤回收遗留煤柱领域，并具体涉及一种充填采煤回收遗留煤柱并控制隔水关键层稳定的方法。The invention relates to the field of filling coal mining and recovering left coal pillars, and particularly relates to a method for filling coal mining and recovering residual coal pillars and controlling the stability of the water-storing key layer.
背景技术Background technique
随着我国煤炭资源的高强度开采，东部矿区煤炭资源的逐渐枯竭，我国西部矿区已成为煤炭资源开采的主体。“十三五”期间，国家重点建设的大型煤炭基地主要集中在生态环境十分脆弱、水土流失严重的晋、陕、蒙、宁、甘地区。该区域矿区长期以来一直采用房式采煤法，该方法造成大量煤炭资源浪费，煤炭资源开采率不足40％。另一方面，煤层开采后，由于覆岩的长期作用，易引发煤柱失稳破坏，顶板大面积垮落，造成上部第四系中更新统离石黄土和第三系上新统三趾马红土组成的粘土隔水层破坏，水土流失，加重当地生态脆弱环境的破坏。With the high-intensity mining of China's coal resources, the coal resources in the eastern mining areas have gradually dried up, and the western mining areas in China have become the mainstay of coal resource exploitation. During the “Thirteenth Five-Year Plan” period, the large-scale coal bases under construction by the state were mainly concentrated in the Jin, Shan, Meng, Ning and Gan regions where the ecological environment is very fragile and soil erosion is serious. The mining area in this area has long used the house type coal mining method, which has resulted in a waste of coal resources and a coal resource exploitation rate of less than 40%. On the other hand, after coal seam mining, due to the long-term effect of overburden, it is easy to cause instability and damage of coal pillars, and the roof is extensively degraded, resulting in the Upper Quaternary Middle Renewal Sediment and the Tertiary Pliocene Three-toed Horse. The clay aquifer composed of red clay is destroyed, soil erosion is lost, and the damage of the local ecological fragile environment is aggravated.
充填采煤是近年来发展、应用较为广泛的绿色采煤技术，该技术是一种绿色环保、回收率较高的矿井开采方式，能够使煤矿作业更好地适应当地开采条件，特别是能够有效地避免开采对生态环境的破坏。针对西部矿区矸石、粉煤灰等充填材料短缺，而地表赋存风积沙丰富的条件，如何最大限度的利用地表风积沙材料安全、环保的提高煤炭资源回收率对于当地的经济社会发展具有重要的意义。Filling coal mining is a green mining technology that has been developed and widely used in recent years. This technology is a green mining and mining method with high recovery rate, which can make coal mine operations better adapt to local mining conditions, especially effective. Avoid mining damage to the ecological environment. In view of the shortage of filling materials such as meteorites and fly ash in the western mining area, and the abundant conditions of aeolian sand on the surface, how to maximize the use of surface aeolian sand materials for safety and environmental protection to improve the recovery rate of coal resources for local economic and social development Significance.
因此，针对当地的采矿地质条件，研究一种既能保证安全开采，又能解决房式开采遗留煤柱的回收问题的开采技术已成为当地煤矿开采的重大技术难题。Therefore, in view of the local mining geological conditions, researching a mining technology that can ensure safe mining and solve the problem of recycling of residual coal pillars in house mining has become a major technical problem in local coal mining.
发明内容Summary of the invention
本发明的目的是提供一种安全、高效、资源回收率高的遗留煤柱回收，同时控制隔水关键层稳定的方法。The object of the present invention is to provide a safe, efficient, high resource recovery rate of residual coal pillar recovery, while controlling the stability of the water-critical key layer.
为实现上述目的，本发明的充填采煤回收遗留煤柱并控制隔水关键层稳定的方法，包括以下步骤：In order to achieve the above object, the method for filling the recovered coal pillars of the present invention and recovering the stability of the water-storing key layer comprises the following steps:
a.利用风积沙为主的胶结充填材料将首个回采工作面中的采空区进行胶结充填；a. The cementation filling material mainly composed of aeolian sand is used for cementing filling of the goaf in the first mining face;
b.待步骤a中胶结填充后的胶结充填材料达到一定承载能力与抗变形能力后对上述回采工作面内的遗留煤柱进行回采；胶结充填材料达到一定承载能力与抗变形能力是指胶结充填材料对顶板起到有效支撑作用，在上部载荷作用下胶结充填材料不易产生变形；b. After the cemented filling material in the step a is filled with a certain bearing capacity and deformation resistance, the remaining coal pillars in the mining working face are recovered; the cementing filling material reaches a certain bearing capacity and the deformation resistance capability refers to cementation filling. The material plays an effective supporting role on the top plate, and the cemented filling material is not easily deformed under the action of the upper load;
c.利用运输设备将步骤b中回采的原煤运送到地面；c. transporting the raw coal recovered in step b to the ground using transportation equipment;
d.采用高速动力抛投机对上述遗留煤柱回采后形成的采空区进行风积沙抛投充填，采用推 土机将抛投后的风积沙推实，高速动力抛投机与推土机相互配合完成遗留煤柱回采后形成的采空区的充填；d. Using a high-speed power-spraying machine to fill the goaf formed after the mining of the remaining coal pillars, the aeolian sand is thrown and filled, using push The earth machine will push the aerated sand after the throwing, and the high-speed power throwing machine cooperates with the bulldozer to complete the filling of the goaf formed after the mining of the remaining coal pillars;
e、重复上述步骤a～d，完成其余回采工作面内遗留煤柱的回采。e. Repeat steps a to d above to complete the recovery of the remaining coal pillars in the remaining mining face.
进一步地，所述步骤c中，当工作面回采至一定距离L时停止回采，设置隔离保护煤柱，所述的一定距离L是指基本顶的初次来压、垮落步距。Further, in the step c, when the working surface is recovered to a certain distance L, the mining is stopped, and the isolation protection coal pillar is set. The certain distance L refers to the initial pressure and the falling step of the basic top.
进一步地，所述步骤a中，将首个回采工作面中已采煤房形成的一侧巷道作为运料巷，在运料巷内布置胶结充填泵送装置，风积沙为主的胶结充填材料通过胶结充填泵送装置将运料巷的两侧采空区进行胶结充填。胶结充填材料达到一定承载能力与抗变形能力是指胶结充填材料对顶板起到有效支撑作用，在上部载荷作用下胶结充填材料不易产生变形。Further, in the step a, the side roadway formed by the coal mining room in the first mining working face is used as the material conveying lane, the cementing filling pumping device is arranged in the conveying lane, and the cementing filling mainly composed of aeolian sand The material is cemented and filled on both sides of the conveyance lane by a cement filling pumping device. The cementing filling material achieves certain bearing capacity and anti-deformation ability, which means that the cementing filling material plays an effective supporting role on the top plate, and the cementing filling material is not easily deformed under the upper load.
进一步地，所述步骤c中，将首个回采工作面中已采煤房形成的另一侧巷道作为运煤巷，将回采的原煤经过运煤巷运送至地面。Further, in the step c, the other side roadway formed by the coal mining room in the first mining working face is used as the coal transportation lane, and the recovered raw coal is transported to the ground through the coal transportation lane.
进一步地，所述的风积沙为主的胶结充填材料选用西部地区天然的风积沙配以水泥、粉煤灰及添加剂混合而成。Further, the aerated sand-based cementing filling material is selected by mixing natural aeolian sand in the western region with cement, fly ash and additives.
进一步地，相邻回采工作面之间留设隔离墙。Further, a partition wall is left between adjacent working faces.
进一步地，根据隔水关键层的位置及强度稳定性破断条件，确定所述步骤d中的风积沙抛投充填的充实率φ。Further, the filling rate φ of the aeolian sand throwing filling in the step d is determined according to the position of the water-retaining key layer and the strength stability breaking condition.
本发明的有益效果在于：The beneficial effects of the invention are:
本发明方法首先是根据矿井地质条件、胶结材料配比及工作面围岩控制确定风积沙为主的胶结充填材料一次充填，待充填体达到一定承载能力与抗变形能力后对遗留煤柱进行安全回采；然后，采用高速抛投机与推土机对采空区进行单一风积沙充填，根据隔水层位置及强度稳定性破断条件，确定二次风积沙充填充实率。本发明的方法主要针对于西部矿区遗留煤柱回采围岩稳定性及隔水关键层稳定性控制两个方面，目的性强。遗留煤柱回采与隔水关键层稳定性控制采用胶结充填与风积沙高速抛投联合充填方式，二次充填以隔水关键层长期稳定为目的，采用高速抛投机与推土机充填；根据隔水层位置及强度稳定性破断条件，确定二次风积沙充填充实率，控制隔水关键层下沉变形。本发明的技术方法可最大限度利用地表废弃风积沙材料，成本低，提高煤炭资源采出率，同时有效控制第四系黏土类隔水关键层的长期稳定，维护当地地表植被的生态环境。为我国西部矿区高强度开采回收遗留煤柱及隔水关键层控制提供了一种全新的技术模式，是一种绿色、高效的资源获取方式，科学与工程意义重大，应用前景广阔。The method of the invention firstly fills the cemented filling material mainly composed of aeolian sand according to the geological conditions of the mine, the ratio of the cementing material and the surrounding rock control of the working face, and the residual coal pillar is subjected to a certain bearing capacity and deformation resistance capability after the filling body reaches a certain bearing capacity and deformation resistance capacity. Safety recovery; then, a high-speed throwing machine and a bulldozer are used to fill a single aeolian sand in the goaf, and the filling rate of the secondary aeolian sand is determined according to the position of the aquifer and the breaking stability of the strength. The method of the invention is mainly directed to the two aspects of the stability of the surrounding coal pillars and the stability control of the key layer of the water-retaining coal pillars in the western mining area, and the object is strong. The stability control of the remaining coal pillars and the key layer of the water separation is carried out by cement filling and aeolian sand high-speed casting combined filling method. The secondary filling is aimed at long-term stability of the key layer of water separation, and is filled with a high-speed throwing machine and a bulldozer; The layer position and strength stability breaking conditions determine the filling rate of the secondary aeolian sand and control the sinking deformation of the key layer of the water barrier. The technical method of the invention can utilize the surface abandonment of aeolian sand material to the maximum extent, has low cost, improves the recovery rate of coal resources, and effectively controls the long-term stability of the key layer of the quaternary clay water-separating layer and maintains the ecological environment of the local surface vegetation. It provides a new technical model for the control of high-strength mining and recovery of residual coal pillars and water-removing key layers in western mining areas of China. It is a green and efficient way to acquire resources. It has great significance in science and engineering and has broad application prospects.
采用本发明的方法后，可实现首采工作面剩余遗留煤柱的回采，煤炭资源回采率达到90％以上，实测结果表明，单轴抗压强度达到2.83MPa以上的胶结充填材料与充实率85％ 以上的风积沙抛投联合充填，导水裂隙带发育高度小于40m，可以保证工作面上部70m位置第四系黏土类隔水层长期稳定性。After adopting the method of the invention, the remaining coal pillars of the first mining working face can be recovered, and the coal resource recovery rate reaches over 90%. The measured results show that the cemented filling material with a uniaxial compressive strength of 2.83 MPa or more and a filling rate of 85 % The above aeolian sand throwing joint filling is combined, and the development height of the water guiding fracture zone is less than 40m, which can ensure the long-term stability of the quaternary clay aquifer at 70m position on the working surface.
附图说明DRAWINGS
图1-1是本发明工作面布置平面图；Figure 1-1 is a plan view showing the arrangement of the working surface of the present invention;
图1-2是图1-1中A-A方向的剖面图；Figure 1-2 is a cross-sectional view taken along line A-A of Figure 1-1;
图2-1是本发明煤房采空区充填过程的平面图；Figure 2-1 is a plan view showing the filling process of the goaf of the coal house of the present invention;
图2-2是图2-1中B-B方向的剖面图；Figure 2-2 is a cross-sectional view taken along line B-B of Figure 2-1;
图3-1是本发明工作面遗留煤柱回收过程的平面图；Figure 3-1 is a plan view showing the process of recycling the remaining coal pillars of the working face of the present invention;
图3-2是图3-1中C-C方向的剖面图；Figure 3-2 is a cross-sectional view taken along line C-C of Figure 3-1;
图4-1是本发明工作面风积沙二次充填过程的平面图；Figure 4-1 is a plan view showing the secondary filling process of the aeolian sand of the working face of the present invention;
图4-2是图4-1中D-D方向的剖面图；Figure 4-2 is a cross-sectional view taken along line D-D of Figure 4-1;
图5-1是本发明工作面完成单次循环遗留煤柱回收的平面图；Figure 5-1 is a plan view showing the recovery of a single-cycle remaining coal pillar in the working face of the present invention;
图5-2是图5-1中E-E方向的剖面图；Figure 5-2 is a cross-sectional view taken along line E-E of Figure 5-1;
图6-1是本发明首个工作面完成所有遗留煤柱回采及充填后的平面图；Figure 6-1 is a plan view of the first working face of the present invention after all the remaining coal pillars are recovered and filled;
图6-2是图6-1中F-F方向的剖面图。Figure 6-2 is a cross-sectional view taken along line F-F of Figure 6-1.
图中：1-停采线，2-隔离墙，3-胶结充填泵送装置，4-高速动力抛投机，5-带式输送机，6-推土机，7-无轨胶轮车，8-装载机，9-隔离保护煤柱，10-胶结充填材料，11-天然风积沙，12-运煤巷，13-运料巷，14-隔水关键层。In the picture: 1-stop line, 2-wall, 3-cement filling pumping device, 4-high speed power throwing machine, 5-belt conveyor, 6-bulldozer, 7-trackless rubber wheeler, 8-loading Machine, 9-isolated protective coal column, 10-cement filling material, 11-natural wind accumulation sand, 12-transport coal lane, 13-cargo lane, 14-water barrier key layer.
具体实施方式Detailed ways
下面结合具体的实施方式进一步说明。The following is further described in conjunction with specific embodiments.
一种充填采煤回收遗留煤柱并控制隔水关键层稳定的方法，包括以下步骤：A method for filling coal mining to recover residual coal pillars and controlling stability of water-storing key layers, comprising the following steps:
a.利用风积沙为主的胶结充填材料将首个回采工作面中的采空区进行胶结充填；a. The cementation filling material mainly composed of aeolian sand is used for cementing filling of the goaf in the first mining face;
b.待步骤a中胶结填充后的胶结充填材料达到一定承载能力与抗变形能力后对上述回采工作面内的遗留煤柱进行回采；胶结充填材料达到一定承载能力与抗变形能力是指胶结充填材料对顶板起到有效支撑作用，在上部载荷作用下胶结充填材料不易产生变形；b. After the cemented filling material in the step a is filled with a certain bearing capacity and deformation resistance, the remaining coal pillars in the mining working face are recovered; the cementing filling material reaches a certain bearing capacity and the deformation resistance capability refers to cementation filling. The material plays an effective supporting role on the top plate, and the cemented filling material is not easily deformed under the action of the upper load;
c.利用运输设备将步骤b中回采的原煤运送到地面；c. transporting the raw coal recovered in step b to the ground using transportation equipment;
d.采用抛投机对上述遗留煤柱回采后形成的采空区进行风积沙抛投充填，采用推土机将抛投后的风积沙推实，抛投机与推土机相互配合完成遗留煤柱回采后形成的采空区的充填；d. Using the throwing machine to fill the goaf formed after the mining of the remaining coal pillars, and use the bulldozer to push the aerated sand after casting, and the throwing machine and the bulldozer cooperate to complete the mining of the remaining coal pillars. Filling of the formed goaf;
e、重复上述步骤a～d，完成其余回采工作面内遗留煤柱的回采。e. Repeat steps a to d above to complete the recovery of the remaining coal pillars in the remaining mining face.
所述步骤a中，将首个回采工作面中已采煤房形成的一侧巷道作为运料巷，在运料巷内布置胶结充填泵送装置，风积沙为主的胶结充填材料通过胶结充填泵送装置将煤柱沿运料 巷两侧采空区进行胶结充填，这种充填方式效率更高，更加简便。In the step a, the side roadway formed by the coal mining room in the first mining face is used as the material conveying lane, and the cementing filling pumping device is arranged in the conveying lane, and the cementing filling material mainly composed of aeolian sand is cemented. Filling pumping device transports coal pillars along The gob area on both sides of the roadway is cemented and filled. This filling method is more efficient and simpler.
所述步骤c中，当工作面回采至一定距离L时停止回采，设置隔离保护煤柱；并且，将首个回采工作面中已采煤房形成的另一侧巷道作为运煤巷。所述的一定距离L是指基本顶的初次来压、垮落步距。In the step c, when the working surface is recovered to a certain distance L, the mining is stopped, and the isolation protection coal pillar is set; and the other side roadway formed by the coal mining room in the first mining working face is used as the coal transportation lane. The certain distance L refers to the initial pressure and the stepping distance of the basic top.
抛投机可以选用高速动力抛投机。A high-speed power-spraying machine can be used for the throwing machine.
所述的风积沙为主的胶结充填材料选用中国西部地区天然的风积沙配以水泥、粉煤灰及少部分添加剂混合而成，强度大，耐久性好。所述的风积沙为主的胶结充填材料的承载能力与抗变形能力要求，根据矿井地质条件、胶结材料配比及工作面围岩控制确定。The aerated sand-based cementing filling material is selected from natural aeolian sand in western China with cement, fly ash and a small amount of additives, and has high strength and good durability. The bearing capacity and deformation resistance requirement of the aeolian sand-based cementing filling material are determined according to the geological conditions of the mine, the ratio of cementing materials and the surrounding rock control of the working face.
此外，相邻回采工作面之间留设隔离墙。In addition, a wall is placed between adjacent mining faces.
根据隔水关键层的位置及强度稳定性破断条件，利用岩梁弹性地基力学计算方法，确定所述步骤d中的风积沙抛投充填的充实率φ，能够减轻水土流失，突水溃沙灾害。According to the location and strength stability breaking conditions of the key layer of the water barrier, the mechanical calculation method of the elastic foundation of the rock beam is used to determine the filling rate φ of the aeolian sand throwing filling in the step d, which can reduce soil erosion and water inrush disaster.
实施例1Example 1
某西部矿井原采用短壁条带房式开采，导致大量煤柱遗留井下，造成大量煤炭资源浪费，且近年来发现部分煤柱失稳与自燃发火严重，进而引发地表大面积塌陷，严重影响了当地的生态环境。为解决上述难题，结合本专利发明内容，针对首采工作面遗留煤柱的回采叙述具体实施方式如下：In a western mine, short-wall strip-type mining was used, resulting in a large number of coal pillars remaining underground, resulting in a large amount of coal resources was wasted. In recent years, some coal pillars were found to be unstable and spontaneously ignited, causing large-scale collapse of the surface, which seriously affected The local ecological environment. In order to solve the above problems, combined with the content of the patent of the present invention, the specific implementation manner of the mining description of the remaining coal pillars in the first mining working face is as follows:
(1)针对一盘区首采工作面已开采区域，沿垂直于大巷的方向，将每相邻的两列煤柱布置一个回采工作面，工作面采高4.5m，工作面走向长度800m，倾斜长度为70m，相邻回采工作面之间留设隔离墙2，如图1-1和图1-2所示；(1) For the mining area of the first mining face in a panel, along the direction perpendicular to the main road, each adjacent two columns of coal pillars shall be arranged with a working face with a working height of 4.5 m and a working face length of 800 m. The inclined length is 70m, and a partition wall 2 is left between adjacent working faces, as shown in Figure 1-1 and Figure 1-2;
(2)沿垂直于大巷的方向，将隔离墙左侧的第一列已采煤房作为运料巷13，第二列已采煤房作为运煤巷12；(2) along the direction perpendicular to the main road, the first column of coal mining room on the left side of the wall is used as the transport lane 13 and the second column has been used as the coal lane 12;
(3)在运料巷13内布置胶结充填泵送装置3的输送管路，将地面配制好的以风积沙为主的胶结充填材料10输送至工作面煤房采空区进行充填，通过控制胶结充填泵送装置3的管口位置、高度以及物料流速使胶结充填材料逐步密实接顶，旋转胶结充填泵送装置3的输送管路进入另一侧采空区进行同样工艺胶结充填工作，如此反复地向前推进至停采线(1)位置结束充填作业，如图2-1和图2-2所示；(3) Arranging the conveying pipeline of the cementing filling pumping device 3 in the conveying lane 13, and conveying the cement filling material 10 mainly composed of aeolian sand to the working area coal mining area for filling. Controlling the position, height and material flow rate of the cement filling pumping device 3, the cement filling material is gradually compacted, and the conveying pipeline of the rotating cement filling pumping device 3 enters the other side goaf for the same process cementing filling work. Repeatedly advance to the stop line (1) position to end the filling operation, as shown in Figure 2-1 and Figure 2-2;
(4)待胶结充填材料达到一定强度及抗变形能力后，采用打眼放炮的方式对运煤巷12、运料巷13之间工作面的遗留煤柱进行***，利用矿用防爆装载机8将***落下的煤装载到无轨胶轮车7上，然后由无轨胶轮车7经运煤巷12将煤运送到地面，当工作面回采至距离L为120m左右距离时，设置隔离保护煤柱9，如图3-1和图3-2所示；(4) After the cemented filling material reaches a certain strength and resistance to deformation, the remaining coal pillars of the working face between the coal transportation lane 12 and the transportation material lane 13 are blasted by means of eye-opening and shooting, and the mining explosion-proof loader 8 will be used. The coal that has fallen from the blasting is loaded onto the trackless rubber wheel vehicle 7, and then the coal is transported to the ground by the trackless rubber wheel vehicle 7 through the coal transportation lane 12. When the working surface is recovered to a distance of about 120 m, the isolation and protection coal pillar is set. , as shown in Figure 3-1 and Figure 3-2;
(5)遗留煤柱回采后，将地面天然风积沙运输至井下，由带式输送机5运至二次充填工作 面，利用高速动力抛投机4向采空区抛投风积沙11，当风积沙11堆积至一定的高度后，旋转高速动力抛投机4，向采空区的另一侧抛投物料；同时启动推土机6，对抛投后的天然风积沙11进行推压充填，使其接顶；在高速动力抛投机4与推土机6的配合下，如此反复的进行抛投风积沙以及夯实接顶工艺，如图4-1、图4-2以及图5-1、图5-2所示；(5) After the remaining coal pillars are recovered, the ground natural aeolian sand is transported to the underground and transported by the belt conveyor 5 to the secondary filling work. In the surface, the high-speed power-spraying machine 4 throws the aeolian sand 11 into the goaf, and when the aeolian sand 11 is piled up to a certain height, the high-speed power-spraying machine 4 is rotated, and the material is thrown to the other side of the gob; At the same time, the bulldozer 6 is started, and the natural aeolian sand 11 after the throwing is pushed and filled to make it topped; under the cooperation of the high-speed power-spraying machine 4 and the bulldozer 6, the sand casting and the tamping are repeated. The top process is shown in Figure 4-1, Figure 4-2, Figure 5-1, Figure 5-2;
(6)当采空区两侧均被密实风积沙充填体11充满后，停止带式输送机5以及高速动力抛投机，至此，首个工作面的遗留煤柱回收以及采空区充填作业完成，如图6-1和图6-2所示；(7)重复上述步骤(2)、(3)、(4)、(5)、(6)进行下一回采工作面内的一次胶结充填、遗留煤柱回收、二次抛投充填的循环作业。(6) When both sides of the goaf are filled with the dense aeolian sand filling body 11, the belt conveyor 5 and the high-speed power throwing machine are stopped. At this point, the remaining coal pillars of the first working face are recovered and the goaf filling operation is completed. Completion, as shown in Figure 6-1 and Figure 6-2; (7) Repeat steps (2), (3), (4), (5), (6) for the first time in the next mining face Cycling operations for filling, remaining coal pillar recovery, and secondary throwing and filling.
采用该技术方法后，可实现首采工作面剩余遗留煤柱的回采，煤炭资源回采率达到90％以上，实测结果表明，单轴抗压强度达到2.83MPa以上的胶结充填材料与充实率85％以上的风积沙抛投联合充填，导水裂隙带发育高度小于40m，可以保证工作面上部70m位置第四系黏土类隔水层长期稳定性。 After adopting this technical method, the remaining coal pillars of the first mining face can be recovered, and the recovery rate of coal resources reaches over 90%. The measured results show that the cemented filling materials with a uniaxial compressive strength of 2.83 MPa or more and the enrichment rate are 85%. The above aeolian sand throwing joint filling is combined, and the development height of the water guiding fracture zone is less than 40m, which can ensure the long-term stability of the quaternary clay aquifer at 70m position on the working surface.

Claims (7)

  1. 一种充填采煤回收遗留煤柱并控制隔水关键层稳定的方法，其特征在于，包括以下步骤：A method for filling coal mining and recovering residual coal pillars and controlling stability of water-storing key layer, characterized in that the method comprises the following steps:
    a.利用风积沙为主的胶结充填材料将一个回采工作面内的采空区进行胶结充填；a. Using a cemented filling material based on aeolian sand to cement the goaf in a working face;
    b.待步骤a中胶结充填后的胶结充填材料达到一定承载能力与抗变形能力后对上述回采工作面内的遗留煤柱进行回采；b. After the cemented filling material in the step a is filled with a certain bearing capacity and deformation resistance, the remaining coal pillars in the mining face are recovered;
    c.利用运输设备将步骤b中回采的原煤运送到地面；c. transporting the raw coal recovered in step b to the ground using transportation equipment;
    d.采用抛投机对上述遗留煤柱回采后形成的采空区进行风积沙抛投充填，采用推土机将抛投后的风积沙推实，抛投机与推土机相互配合完成遗留煤柱回采后形成的采空区的充填；d. Using the throwing machine to fill the goaf formed after the mining of the remaining coal pillars, and use the bulldozer to push the aerated sand after casting, and the throwing machine and the bulldozer cooperate to complete the mining of the remaining coal pillars. Filling of the formed goaf;
    e、重复上述步骤a～d，完成其余回采工作面内遗留煤柱的回采。e. Repeat steps a to d above to complete the recovery of the remaining coal pillars in the remaining mining face.
  2. 根据权利要求1所述的一种充填采煤回收遗留煤柱并控制隔水关键层稳定的方法，其特征在于，所述步骤c中，当工作面回采至一定距离L时停止回采，设置隔离保护煤柱，所述一定距离L指的是基本顶的初次来压垮落步距。The method for charging and recovering residual coal pillars and controlling the stability of the water-storing key layer according to claim 1, wherein in the step c, when the working surface is recovered to a certain distance L, the recovery is stopped, and the isolation is set. The coal pillar is protected, and the certain distance L refers to the initial pressure drop step of the basic top.
  3. 根据权利要求1所述的一种充填采煤回收遗留煤柱并控制隔水关键层稳定的方法，其特征在于，所述步骤a中，将首个回采工作面中已采煤房形成的一侧巷道作为运料巷，在运料巷内布置胶结充填泵送装置，风积沙为主的胶结充填材料通过胶结充填泵送装置将运料巷的两侧采空区进行胶结充填。The method for filling coal mining and recovering residual coal pillars according to claim 1 and controlling the stability of the water-storing key layer, wherein in the step a, the first coal mining room in the first mining face is formed As the material conveying lane, the side roadway is arranged with a cementing filling pumping device in the conveying lane, and the cementing filling material mainly composed of aeolian sand is cemented and filled by the cementing filling pumping device on both sides of the conveying lane.
  4. 根据权利要求3所述的一种充填采煤回收遗留煤柱并控制隔水关键层稳定的方法，其特征在于，所述步骤c中，将首个回采工作面中已采煤房形成的另一侧巷道作为运煤巷，将回采的原煤经过运煤巷运送至地面。The method for filling coal mining residual coal pillars and controlling the stability of the water-storing key layer according to claim 3, wherein in the step c, another coal mining room formed in the first mining working face is formed As one coal roadway, the one side roadway transports the recovered raw coal to the ground through the coal transportation roadway.
  5. 根据权利要求1所述的一种充填采煤回收遗留煤柱并控制隔水关键层稳定的方法，其特征在于：所述的风积沙为主的胶结充填材料选用天然的风积沙配以水泥、粉煤灰及添加剂混合而成。The method for filling coal mining and recovering residual coal pillars according to claim 1 and controlling the stability of the water-storing key layer, characterized in that: the aeolian sand-based cementing filling material is selected from natural aeolian sand. Cement, fly ash and additives are mixed.
  6. 根据权利要求1所述的一种充填采煤回收遗留煤柱并控制隔水关键层稳定的方法，其特征在于：相邻回采工作面之间留设隔离墙。The method for filling and recovering residual coal pillars and controlling the stability of the water-storing key layer according to claim 1, characterized in that: a separation wall is left between adjacent mining working faces.
  7. 根据权利要求1所述的一种充填采煤回收遗留煤柱并控制隔水关键层稳定的方法，其特征在于：根据隔水关键层的位置及强度稳定性破断条件，确定所述步骤d中的风积沙抛投充填的充实率φ。 The method for claiming a residual coal pillar by coal mining and controlling the stability of the water-storing key layer according to claim 1, wherein the step d is determined according to the position and strength stability breaking condition of the water-retaining key layer. The enrichment rate φ of the aeolian sand throwing filling.
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU2018431390B2 (en) * 2018-07-09 2021-05-06 China University Of Mining And Technology Method for recovering room-type coal pillars by cemented filling of reserved roadways
CN114370251A (en) * 2022-01-14 2022-04-19 安徽理工大学 Directional grading and zoning grouting method for overburden bed separation during downward mining of coal seam group
CN114961731A (en) * 2022-07-28 2022-08-30 北京科技大学 Method for filling and recovering ore pillar by inclined thin ore body open-stoping subsequent machine-made sand

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109236296B (en) * 2018-08-02 2019-09-13 缪协兴 A kind of design method of safe working water conservation coal column
CN109577982B (en) * 2018-12-12 2020-09-04 中国矿业大学 Wall type continuous mining and continuous filling water-retaining coal mining and water resource migration monitoring and water damage early warning method
CN110306983A (en) * 2019-06-15 2019-10-08 龙口矿业集团有限公司 A kind of corner pillar face recovery method in exploiting field
CN110359910B (en) * 2019-07-11 2020-12-04 新汶矿业集团有限责任公司 Fully mechanized caving high-level filling mining method for thick coal seam strips under coal mine railway
CN110410076B (en) * 2019-08-16 2021-06-08 山东科技大学 Filling mining method for recovering left coal pillars in goaf of old house pillar
CN111206956B (en) * 2020-01-10 2021-03-02 中国矿业大学 Method for filling and reinforcing left coal pillars in goaf by room-type coal mining method
CN113704863B (en) * 2021-10-28 2022-02-18 中煤科工集团西安研究院有限公司 Method for designing key parameters for controlling filling of room-and-column type goaf
CN114687794B (en) * 2022-03-31 2023-11-17 中国矿业大学(北京) Coal mine filling and repeated mining method

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101126316A (en) * 2007-09-19 2008-02-20 中国矿业大学 Long-wall integrated-extraction reclaiming room-type coal column mining method
CN102155226A (en) * 2010-11-30 2011-08-17 淄博市王庄煤矿 Roadway backfill mining method for coal seams with medium-high thickness

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102011611A (en) * 2010-11-30 2011-04-13 淄博市王庄煤矿 Strip-type filling method of high water-swelling material for controlling movement and deformation of overlying strata
CN102926770B (en) * 2012-11-08 2015-01-07 中国神华能源股份有限公司 Underground draining and grouting process in thin bedrock and thick loose sand layer rich water areas
CN103104287A (en) * 2013-01-28 2013-05-15 山东科技大学 Stripe gob filling repeated-mining method
CN103527196B (en) * 2013-10-28 2015-07-01 中国矿业大学 Method for recovery of room-type coal pillar through loess filling

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101126316A (en) * 2007-09-19 2008-02-20 中国矿业大学 Long-wall integrated-extraction reclaiming room-type coal column mining method
CN102155226A (en) * 2010-11-30 2011-08-17 淄博市王庄煤矿 Roadway backfill mining method for coal seams with medium-high thickness

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
AN, BAIFU: "Controlling Mechanism of Surround Rock Stability in Recovering Room Mining Standing Pillars by Consolidated Solid Backfilling Mining", CHINA DOCTORAL DISSERTATIONS FULL-TEXT DATABASE (ENGINEERING SCIENCE AND TECHNOLOGY I), 15 February 2017 (2017-02-15), pages 68 - 92; 114-117 *
FANG, KUN: "Research on Principal Technology of Recovering Room Coal Pillar with Combined Artificial Pillar and Solid Backfill Mining", CHINESE MASTER'S THESES FULL-TEXT DATABASE (ENGINEERING SCIENCE AND TECHNOLOGY I, 15 February 2017 (2017-02-15), pages 15 - 17 *
LI, LIANG: "Basic Study on Flexible Strip Filling in Water Preserving Mining of Shallow Seam", CHINESE MASTER'S THESES FULL-TEXT DATABASE (ENGINEERING SCIENCE AND TECHNOLOGY I, 15 February 2013 (2013-02-15), pages 50 - 66 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU2018431390B2 (en) * 2018-07-09 2021-05-06 China University Of Mining And Technology Method for recovering room-type coal pillars by cemented filling of reserved roadways
CN114370251A (en) * 2022-01-14 2022-04-19 安徽理工大学 Directional grading and zoning grouting method for overburden bed separation during downward mining of coal seam group
CN114370251B (en) * 2022-01-14 2023-08-18 安徽理工大学 Coal seam group downstream mining overlying strata separation layer directional grading zonal grouting method
CN114961731A (en) * 2022-07-28 2022-08-30 北京科技大学 Method for filling and recovering ore pillar by inclined thin ore body open-stoping subsequent machine-made sand

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