Abstract: A method for disposing of biomass waste. The method includes locating an abandoned mine having a first well drilled into or through the abandoned mine. Water is removed from a mine cavity through a second well drilled into or through the abandoned mine. The water from the mine is combined with a biomass waste that is at least 70 wt. % carbon to provide biomass waste entrained in the water. The biomass waste entrained in the water is pumped through the first well into the mine cavity to fill the mine cavity. As the biomass waste settles in the mine cavity, the water used to entrain the biomass waste is recirculated to combine with additional biomass waste.

Abstract: An underground longwall mining method includes drilling a main shaft and an auxiliary shaft from a ground to a coal bed and exploiting in the coal bed first and second connection laneways. The first connection laneway is in communication with the main shaft, and the second connection laneway is in communication with the auxiliary shaft. The method further includes communicating the first and second connection laneways, and using a communication part between the first connection laneway and the second connection laneway as a first open-off cut; and by using a direction of the first open-off cut further away from the connecting line connecting the main shaft and the auxiliary shaft as a first direction, and exploiting by cutting a coal wall in the first direction using a coal mining machine.

Abstract: A coal mining method is provided without coal-pillar leaving and without laneway excavation in a full mining area. The coal mining method includes drilling a main shaft, an auxiliary shaft and a return air shaft from a ground to a coal mining layer; by a coal mining machine, forming a first mining face with a first direction as an advance direction; by the coal mining machine, cutting out a first haulageway and a first return airway while cutting the coal wall at the first mining face, and preserving the first haulageway and the first return airway. In this method, the first haulageway and the first return airway are located on two sides of the first mining face, the first haulageway is in communication with both of the main and auxiliary shafts, and the first return airway is in communication with the return air shaft.

Abstract: Provided is a method for radially mining open-pit end slope pressed coal, including: L-shaped or U-shaped main tunnel arrangements, and radially mining; branch tunnels are formed by excavating tunnels in directions perpendicular to or obliquely crossing the main tunnel from the L-shaped or U-shaped main tunnel; In the mining method, a coal mining system and a transportation system both adopt a remote control mode, a tunneling machine excavates a tunnel to product coal; a rubber belt conveyor conveys coal; the main tunnel adopts an exhaust ventilation mode, the branch tunnels adopt a blowing ventilation mode; the lengths of the branch tunnels do not exceed a farthest control distance of a remote control system; the length of each main tunnel needs to ensure that all the end slope pressed coal is mined under the premise that the branch tunnels do not exceed the farthest control distance of the remote control system.

Abstract: Provided is a method for recovering room-type coal pillars by cemented filling of reserved roadways, which is especially suitable for safe and efficient recovery of left coal pillars in room-type mining faces in mining areas where the ecological system is fragile, such as in western China. In the method, by constructing reserved roadways in two adjacent rows of room-type goafs, excavating coal pillar roadways in room-type coal pillars, and finally interconnecting the reserved roadways with the coal pillar roadways to form a U-shaped working face, room-type left coal pillars are recovered. Thus, not only the workload of roadway excavation is reduced, but also the recovery ratio of the coal resources is maximized. The method provides a novel technical model for the recovery of room-type left coal pillars in mining areas, such as in western China.

Abstract: A similar simulation experimental device of hydraulic energy-absorbing roadway support is provided. A similar model is placed in a model box, a roadway is excavated in the similar model, and hydraulic energy-absorbing support devices are placed in the roadway on the periphery of the roadway. Front and rear ends of the hydraulic energy-absorbing support device are connected to supporting plates, left and right sides of the model box are provided with horizontal hydraulic cylinders, and front ends of the horizontal hydraulic cylinders are connected to pressure plates. One or several cushion blocks are placed at the top of the model box, and an upper pressure plate is placed above the cushion block(s). Vertical hydraulic cylinders are installed at both ends of the upper pressure plate. An impact rod passing through the upper pressure plate is placed above the cushion block to apply vertical impact load to the similar model.

Abstract: A mine exploitation method based on stoping, separation and filling control is disclosed herein. The method includes deploying a gangue-less coal mining system; choosing a suitable coal and gangue separation method according to a separation requirement; choosing a suitable filling method according to mine geology, production conditions and rock stratum control requirement; reversely calculating a filling rate according to gangue discharge requirement and control indexes by utilizing theoretical calculation, simulation and experiment; determining a filling process and a separation process according to the filling rate; and feeding back and adjusting the filling process and separation process parameters by monitoring filling and control effect indexes.

Abstract: A stress-transfer method in tunnel with high ground pressure based on fracturing ring. According to the stress source of the tunnel, fracturing by drilling holes to form artificial weaken zones in surrounding rocks, that's named fracturing ring. The fracturing ring is the weaken zone with some width, whose inner boundary is the protective circle. The fracturing ring with small width is called the cutting and interruption circle and the cutting or interruption arc. The radius of the protective circle is determined by setting a certain width of safety coal pillar barriers at the edge of a support body. The radius of the fracturing ring is determined by the surrounding rock structure and the stress conditions as well as the construction technology. Usually, the higher the stress, the wider the radius of the fracturing ring. The cutting and interruption circle or arc could cut off all of the targeted rock which transmits the stress.

Abstract: Provided is a filling mining method for a fully-mechanized top coal caving working face, which relates to the field of mining engineering technologies. The method solves the technical problems of roof control of the fully-mechanized top coal caving working face and a large ground deformation of top coal caving mining.

Abstract: A method of recovering a room-and-pillar coal pillar by using external replacement supports. In the recovery of a room-and-pillar coal pillar, a cement material wall is formed by performing pouring around a coal pillar having a width to height ratio of less than 0.6, by means of a single-pillar sack arrangement technique, such that a coal pillar resource may be mined while a wall made from a cement filling material supports an overlying stratum. After mining is complete, a coal pillar goaf region is filled with the cement filling material, and after the cement filling material solidifies and is stable, the single pillar can be recovered.

Abstract: An apparatus and method for protecting a person servicing a longwall shear such changing bits on a drum, embodiments relating to a base plate to be secured to an underside of a shield canopy and a slide plate movably connected to the underside of the base plate such that the slide plate can advance out from the shield canopy to allow a person to service a longwall shear while being protected by the slide plate from falling rock and other debris, and the slide plate can then retract back under the shield canopy.

Abstract: Disclosed is a multi-section non-pillar staggered protected roadway for a deep inclined thick coal seam (DITCS) and a method for coal pillar filling between sections. The multi-section non-pillar staggered protected roadway includes a floor, a coal seam, an immediate roof, and a basic roof in a multi-section coal seam, where the floor is disposed below the coal seam, a hydraulic support is disposed in a section between the floor and the immediate roof; a return airway and a transportation roadway are respectively disposed on a left side and a right side of each section; the return airway and the transportation roadway in each section are communicated with each other through a working face; and non-pillar staggered layout is used for a return airway of a next section and a transportation roadway of a current section.

Abstract: A mine field layout method suitable for fluidized mining of coal resources is provided. A main shaft and an air shaft are provided in the mine field, the bottom of the main shaft is located in the shallow horizontal coal seam zone, and the bottom of the air shaft is located in the deep horizontal coal seam zone. The horizontal main roadways are arranged at two boundaries along the strike of the coal seam, and inclined main roadways are arranged at two boundaries along the dip direction of the coal seam. Connecting roadways are located inside the mine field and are in communication with the horizontal main roadways. In the coal mining stage, the coal resources can be converted into the fluidized energy product and/or electricity by an unmanned automatic mining machine.

Abstract: An apparatus and method for protecting a person servicing a longwall shear such changing bits on a drum, embodiments relating to a base plate to be secured to an underside of a shield canopy and a slide plate movably connected to the underside of the base plate such that the slide plate can advance out from the shield canopy to allow a person to service a longwall shear while being protected by the slide plate from falling rock and other debris, and the slide plate can then retract back under the shield canopy.

Abstract: Provided is a method of forming a roadway by filling gangue paste during wide roadway excavation of a thick coal seam belonging to the technical field of mining industry. The method comprises: firstly designing a width of a filing strip and a width of a new excavation roadway according to a geological condition of a coal seam; secondly, determining a length of each filling, i.e.

Abstract: Provided are a drill-power-based directional hydraulic fracturing system for downhole quick slotting and a method thereof. The directional hydraulic fracturing system includes a water injection pump, a high pressure rubber pipe arranged on the water injection pump is in communication with a drill, a dedicated sealing drill rod for hydraulic fracturing is arranged on the drill, a front segment of the drill rod may be connected with a directional borehole sealer through threads and a sealing ring is provided at the threaded connection. The main steps include drilling, slotting, borehole sealing and fracturing. Firstly, a drill-cut integrated tool is installed at a front end of the drill rod. After drilling is completed, hydraulic slotting, permeability improvement and pressure relief are performed without changing a drill bit. After slotting is completed, the drill bit is retreated, and the directional borehole sealer is installed and pushed to a predetermined position for efficiency sealing.

Abstract: A method for removing wellbore deposits includes the steps of providing a first treatment solution comprising a nitrite salt and a second treatment solution comprising sulfamic acid into the wellbore, allowing the first and second treatment solutions to mix and form a cleaning fluid, and maintaining the first and second treatment solutions in reactive connection. The first and second treatment solutions are maintained in reactive connection to initiate reaction of the sulfamic acid and the nitrite salt to generate an acidic bisulfate salt, heat, and nitrogen gas; remove organic and inorganic deposits from the wellbore; and stimulate the walls of the wellbore by dissolving minerals in the walls of the wellbore with the generated acidic bisulfate salt. Organic and inorganic deposits are removed from the wellbore by liquefying the organic deposits upon elevation of the temperature with the generated heat and breaking down the inorganic deposits with the acidic bisulfate salt.

Abstract: This invention relates to an injection tool which comprises a longer smaller diameter pipe assembled movable inside a shorter larger diameter pipe, a connection piece assembled at the first end of the smaller diameter pipe, a projecting part connected to the smaller diameter pipe near the connecting piece, the projecting part having an opening or groove for a bolt, a projecting part connected near to the first end of the larger diameter pipe the projecting part having threaded opening for the bolt, the bolt connecting the projecting parts and the bolt having a fixed stopper plate, a nose piece assembled to the second end of the smaller diameter pipe, a press plate assembled to the second end of the larger diameter pipe and a sealing rubber around the smaller diameter pipe situated between the nose piece and the press plate.

Abstract: A method for recovering room-mining coal pillars by solid filling in synergy with artificial pillars. Solid materials and cementing materials on the ground are conveyed through a feeding well and a pipeline to a room-and-pillar goaf, a plurality of artificial pillars is cast at an interval in a coal room area, and gangue is cast to fill other regions of the coal room using a gangue casting machine. Under joint support by the artificial pillars and the coal room filler, coal pillars are recovered using a continuous coal mining machine, artificial pillars are cast in the original coal pillar area after recovery, and gangue is cast to fill the original coal pillar area using the gangue casting machine. A system for recovering room-mining coal pillars by solid filling in synergy with artificial pillars mainly includes a material conveying system, a joint support system, and a coal pillar recovery system.

Abstract: A longwall N00 mining method includes performing a no-entry excavation and non-pillar mining in N working faces of a new district, and the whole district is provided with an air-return dip, a haulage dip and a track dip, wherein the air-return dip and the track dip are located on one end of the district, and the haulage dip is connected to the other end of the district, and connected to the air-return dip. This method can not only ensure ventilation of the whole coal cutting are, but also when mining is performed in each working face in the district, entries can be automatically formed due to top-cutting pressure release by using a part of a gob area, and thereby it is not required to separately excavate any gateroad entry during mining coal nor need to retain any coal pillar, so as to save resources and improve efficiency.

Abstract: The present invention discloses a system for consolidating soft clay by combined anode boosting and electro-osmosis, comprising a vacuum preloading system, wherein the vacuum preloading system comprises anode tubes, cathode tubes, a power supply, a boosting device, sealing cloth and a pumping and drainage device; the sealing cloth is covered above soft clay; air vents are formed on side faces of the cathode tubes and the anode tubes; the cathode tubes and the anode tubes are connected to a boosted pumping and drainage pipe above the soft clay through pipelines; the boosted pumping and drainage pipe is configured with the boosting device and the pumping and drainage device; and, the anode tubes and the cathode tubes are connected to an anode and a cathode of the power supply, respectively. The present invention further provides a method for consolidating soft clay by using the system for consolidating soft clay by combined anode boosting and electro-osmosis.

Abstract: The present invention relates to a tunneling method, and particularly, to a tunneling method by installing an internal pre-support member and a corresponding post support member in an alternate manner or by installing an external pre-support member and a corresponding post support member in an alternate manner, and an apparatus, respectively, therefor.

Abstract: A mine management system to mine ore in a mine including a mining area, and a second mine shaft connecting the mining area and a first mine shaft, the mine management system includes: a transporting machine loading the ore mined in the mining area and transporting the ore to a soil discharge area while traveling in the first mine shaft; a loading machine staying in the second mine shaft while a space for the transporting machine to travel therein is left inside the first mine shaft, excavating the ore in the mining area, conveying the mined ore from the mining area in an opposite direction, and loading the ore on the transporting machine; and a management device determining the mining area toward which the transporting machine is directed so that an operability of the loading machine becomes maximal or an operability of the transporting machine becomes maximal.

Abstract: A mine management system to mine ore in a mine including a mining area, a first mine shaft, and a second mine shaft connecting the mining area and the first mine shaft, the mine management system includes: a transporting machine loading the ore mined in the mining area and transporting the ore to a soil discharge area while traveling in the first mine shaft; a loading machine staying in the second mine shaft while a space for the transporting machine to travel therein is left inside the first mine shaft, excavating the ore in the mining area, conveying the mined ore from the mining area in an opposite direction, and loading the mined ore on the transporting machine; and a management device determining a mining area in which the loading machine is disposed based on a difference between a production plan and an actual production amount of the mine.

Abstract: The present invention improves a work efficiency of an entire system for operating a plurality of working machines. An operation system of the working machine includes a work progress calculating unit 80 which calculates a work progress of a plurality of working machines or a scheduled ending time calculating unit 81 which calculates a scheduled ending time of a work by using the work progress calculated by the work progress calculating unit 80. A working machine of which an operation is switched from automatic control to remote control is determined from among the plurality of working machines by using the work progress or the scheduled ending time, and the operation system includes a centralized operation controller 43 which transmits an operation instruction to the determined working machine.

Abstract: The present invention refers to a set of methods and procedures that may be combined in order to greatly increase the speed of development of an access ramp in a underground hard-rock mine. More particularly, the present invention was designed to target all the bottle-necks comprised by the access operation of a hard-rock mine that employs a RAIL-VEYOR machine. The invention also comprises of an ore production line which consists in the sequential arrangement of a series of mining equipment between the work face and the entrance of a hard-rock mine. The invention also comprises a Hard Rock Mining Access Plan for a hard-rock mine which encompasses two parallel ramps interconnected by cross-cut passageways. Further, invention also comprises a Ground Support Installation method configured to shorten the time required for the installation of ground support inside of a hard-rock mine.

Abstract: Method and apparatus for cribbing a floating roof included in a storage tank whereby a first and a first opposite force are applied between a floor in the storage tank and an internal surface of the floating roof. An additional set of forces are also provided and are constrained according to the first and first opposite force, not only in magnitude, but in position. By constraining these forces to be applied orthogonally to the floating roof, horizontal shear forces can be resisted thus reducing the likelihood of failure of a cribbing unit.

Abstract: Systems and methods are provided for detecting face creep of a longwall mining system. The system includes a detection device mounted in a maingate roadway and coupled to the detection device. The controller determines the position of the beam stage loader-armored face conveyor interface based on a signal from the first indicator device, determines a position of a maingate line based on a signal from a maingate indicator device, and determines a position of a belt conveyor based on a signal from a belt conveyor indicator device. The controller further determines a first distance between the position of the beam stage loader-armored face conveyor interface and a maingate line, and a second distance between the position of the belt conveyor and the maingate line. The controller generates an indication of face creep based on the first distance and the second distance.

Abstract: A transportation main roadway and stope branch roadways are arranged by adopting a wangeviry coal mining method. A plurality of stope branch roadways are divided into multiple mining stages, based on which the stope branch roadways are skip-mined; and coal pillars are not reserved among the stope branch roadways. The transportation main roadway is a main transportation channel, and the stope branch roadways are coal mining roadways. All the stope branch roadways are sequentially stoped in a skip-mining manner according to the designed mining sequence and are sequentially and timely filled. The coal never stoped or the filled stope branch roadways is/are used as supports for controlling roofs at the two sides of the stope branch roadways, and the stope branch roadways are sequentially stoped according to a plurality of mining stages, and finally the coal pillar-free mining is realized.

Abstract: A pumpable mine ventilation stopping wall structure comprised of a pumpable bag having spaced walls of generally parallel nonporous and flexible sheets with the sheets retained in spaced relationship with spaced flexible cross ties. The perimeter of the spaced walls may be closed off with a permeable mesh having a mesh size which will permit restricted flow of cementitious grout therethrough for sealing the wall structure to surrounding rough mine faces. The bag is provided with at least one grout fill port for filling the bag by pumping cementitious grout into the bag.

Abstract: A safe haven wall for use in defining a safe haven in an underground mine comprising a lower section and an upper section, wherein said upper section is slidingly engaged to the lower section.

Abstract: The present invention provides a mining method. The method includes: dividing a mining region into a plurality of federated mining regions; performing an open-pit mining operation in each of the federated mining regions and forming a pit in each of the federated mining regions; performing an underground mining operation on a slope of the pit and forming a plurality of excavated tunnels; and backfilling a pit of a previous federated mining region with a spoil of a subsequent federated mining region.

Abstract: Utilization of mine methane produced by mining a non-combustible ore, such as trona, as an energy source for heat, steam, and/or power generation. Such utilization is beneficial for a surface appliance which is close to surface outlet(s) of mine methane recovery system(s). A method for reducing greenhouse gas emissions generated during mining of a non-combustible ore uses the combustion of co-produced mine methane. The mine methane is recovered in a mine ventilation air exhaust with very low methane content, and may be additionally recovered in a drainage gas, such as gob gas, with much higher methane content. The surface appliance may be selected from the group consisting of calciner, dryer, boiler, kiln, furnace, engine, turbine, power generation unit, co-generation unit, and any combinations thereof. Benefits may include reduction in energy purchases, reduction in greenhouse emissions, and/or gain through sale of carbon credits to the carbon market by registering carbon reductions.

Abstract: A method includes obtaining at least first, second and third data corresponding to an industrial plant, wherein the first data is indicative of a performance of equipment of the industrial plant, the second data is indicative of a process of the industrial plant, and third data is indicative of a reliability of the industrial plant, analyzing the first, second and third data with respect to predetermined metrics of the industrial plant, and generating a signal indicative of a recommendation for at least one of use of the equipment or implementation of the process based on a result of the analyzing.

Abstract: The invention relates to a load support (1) comprising a container (2) manufactured from a flexible material, having at least one side wall (4), a top panel (3), a bottom panel (5), and a filler aperture (13). The side wall (4) has a predetermined height selected to be greater than the installation height of the support (1), operatively to allow for vertical expansion of the top of the container (2) into contact with the roof upon filling of the container (2) with a filler material.

Abstract: A method of degassing a coal seam by directionally drilling a borehole in a rock formation that is adjacent the coal seam, or between two different coal seams. The borehole is then pressurized to fracture the adjacent coal seam(s) to enhance the permeability thereof and allow fluids to flow from the coal seam to the borehole and be extracted from the coal seam.

Abstract: The present invention provides a device useful for supporting underground mine/tunnels. The device continuously monitors the roof load coming over the canopy and correspondingly yielding/convergence indicated by the pointer on graduate scale. The roof load coming on the canopy (9) is transmitted to the prop via a set of steel disc springs (5) to increase the yielding and longevity of the present device. The present invention has mechanism for preloading upto the desired load. It is a simple, easily transportable and user friendly device having quick release mechanism from a safe distance.

Abstract: A screen-handling stinger extends and retracts hydraulically from within a bore of a hydraulic stinger of a rock bolter. The screen-handling stinger has a finger that engages a screen. The screen-handling stinger retracts the screen until it snugly abuts the front face of a pad of the stinger. The screen can then be rotated by the rotation motor of the stinger.

Abstract: A system for mining includes the use of a stope fill barrier having a fluid-fillable bladder for temporarily filling a portion of a stope void directly adjacent to ore to be mined and creating a barrier between the stope void and adjacent ore. The stope fill barrier is installed and positioned in the stope void from below the adjacent ore.

Abstract: Methods and equipment have been developed that combine the use of continuous miners, flexible conveyor trains, and longwall mining techniques to provide flexible and efficient removal of resources from subterranean formations. Some systems include: a main gate; and a tailgate connected to the maingate by an active mine face; wherein the active mine face extends at an angle between 95° and 135° relative to the maingate.

Abstract: The present invention relates to a novel method of retrieving gas from a gas-containing subterranean formation, the method including digging a mine shaft to reach the subterranean formation; constructing a ventilated underground control center wherein the center includes a computerized control panel, wherein the computerized control panel controls the movements of a hot head device such as a plasma torch, an electro-chemical apparatus, a hydrogenating solvent or heated ceramic particles; a hollow drill pipe; a movable hydraulic shield; a movable resin roof bolting machine; and a movable waste extrusion device; providing mining personnel to the ventilated underground control center; and allowing the mining personnel to operate the computerized control panel wherein they perform the tasks of moving the hot head device into the subterranean formation, recovering the gas, and extruding waste material into a mined-out space of the subterranean formation.

Abstract: Methods and equipment have been developed that combine the use of continuous miners, flexible conveyor trains, and longwall mining techniques to provide flexible and efficient removal of resources from subterranean formations. Some systems for use in a mining operation include: a continuous miner configured to cut material from a face; a plurality of powered roof supports positioned along the face; and a guidance system operable to receive a location signal based on relative location of the continuous miner along the face and to send a control signal to the plurality of powered roof supports positioned along the face.

Abstract: Methods and equipment have been developed that combine the use of continuous miners, flexible conveyor trains, and longwall mining techniques to provide flexible and efficient removal of resources from subterranean formations. Some mining operations use a powered roof support comprising: a canopy configured to directly contacts a roof of a mine; a base configured to rest on a floor of the mine, the base comprising a spill plate and a push cylinder with a maximum stroke greater than 11 feet; and a pair of hydraulic legs attaching the canopy to the base.

Abstract: Systems for installing roof support sheets on a mine roof. One system includes a support frame, a lifting system, and a feeding system. The support frame holds a plurality of roof support sheets. The lifting system lifts at least one of the sheets from the support frame. The feeding system obtains the at least one sheet from the lifting system and feeds the at least one sheet toward an installation apparatus for installation on the mine roof. The lifting system includes a shoe and at least one arm for moving the shoe to engage and move the at least one sheet. The feeding system includes a drive assembly and a support. The drive assembly engages and moves the at least one sheet toward the installation apparatus, and the support supports the at least one sheet moved by the drive assembly.

Abstract: Methods and equipment have been developed that combine the use of continuous miners, flexible conveyor trains, and longwall mining techniques to provide flexible and efficient removal of resources from subterranean formations.

Abstract: An explosive-resistant mine seal (2) is provided, which includes a pair of block walls (14, 16). An adhesive (22) is provided between adjoining surfaces of the blocks (20) where the adhesive (22) has greater strength properties than the blocks (20) themselves. A core member (18, 18?) is provided between the two walls (14, 16) and is bound thereto. The adhesive (22) may be coated over the walls (14, 16) to increase the strength of the mine seal (2).

Abstract: Methods and equipment have been developed that combine the use of continuous miners, flexible conveyor trains, and longwall mining techniques to provide flexible and efficient removal of resources from subterranean formations. Some methods for use in a mining operation include advancing a continuous miner towards an angled face that extends from a headgate to a tailgate; and performing an angled cutting turn in which the continuous miner turns less than 90°.

Abstract: In a method for lining tunnel walls or ceilings with protective nets or the like, web-shaped protective net material is unwound from a reel and is fastened to the tunnel walls or ceiling by tie bolts. The reel is rotatably arranged. The rotation of the reel about a shaft is controlled in order to unwind the protective net material, the shaft being mechanically moved in steps along the tunnel walls or ceiling together with the reel. The protective net material unwound in each step is preferably stretched and mechanically fastened. The individuals carrying out these processes are thus not exposed to any direct risk, while the lining process can be accelerated.

Abstract: A truss shoe for a roof support system includes a bolt receiving section, an intermediate section, and a housing having a threaded rod engaging section. The threaded rod engaging section has a passageway having a first open end spaced from, and in facing relationship to, the bolt receiving section and an opposite second end. The passageway has a threaded portion extending from the first end of the passageway toward the second end. A stop member is positioned spaced from the first open end of the passageway. With this arrangement, the end of the threaded rod passes through the space between the first open end of the passageway and the stop member into engagement with the stop member, whereby all of the threads of the threaded portion of the passageway are in engagement with the threads of the threaded bar.

Abstract: In a heading or extraction machine (1) including extraction tools that are movable over the working face, and track walling devices such as anchor drilling and setting devices (9), the machine (1) comprises a platform (6) that is displaceable in the longitudinal direction of the machine and carries at least two track walling devices each mounted to be separately displaceable relative to the platform (6).