Mine venting method and device
FIELD: mining, particularly to vent ore and rock mines.
SUBSTANCE: method involves mixing fresh and exhaust air by blasting fuel mixture; forming suction jet, which discharges exhaust air outside the mine. Fuel mixture components are supplied by compressed nitrogen. Air mixing is performed with the use of mixture including sodium permanganate and hydrogen peroxide taken in ratio of 1:(3-10). The suction jet is formed by exhaust air ejection. Venting plant is arranged at bottom mine level. Device comprises body with nozzle arranged over fuel mixture and control panel. The device additionally has nitrogen, sodium permanganate and hydrogen peroxide vessels. Venting pipeline is secured to body nozzle. The venting pipeline is provided with jets to supply hydrogen peroxide and sodium permanganate connected with compressed nitrogen cylinder through control panel. The venting pipeline is composed of separate sections put one on another and provided with conical flares. The flares and adjacent sections define annular air suction slots.
EFFECT: provision of independent operation, simplified structure, increased operational safety and reduced power inputs for mine venting.
1 cl, 1 tbl, 2 cl
The invention relates to mining and can be used for artificial ventilation of mines (quarries), which is the extraction of metallic and non-metallic minerals.
The known method of intensification of exchange in career (RF patent No. 2099537, IPC 7 E 21 F 1/00, epubl). The invention consists in a secure exchange between the stagnant zone and the surface of a career with any degree of stability of its atmosphere. To achieve these objectives the inventive method includes the cyclical movements in the airspace career from its surface to the stagnant zone and back gatavodama shell large volume, with each cycle is accompanied by the placement of the inside of the shell portion of fresh air, his substitution in the stagnant zone of the polluted air and the subsequent moving of a portion of the contaminated air to the surface of the career and replace with fresh. The disadvantages of this device are manufacturing complexity and low efficiency of ventilation.
There is a method of ventilation of the mine adopted for the prototype in terms of method (patent RF №2162944, IPC 7 E 21 F 1/00, epubl). The method includes cascading horizontal placement of ventilation systems, mixing of fresh and exhaust air. As ventilation systems use installation is, creates an air-fuel mixture. Mixing of fresh and exhaust air produced by the detonation of fuel-air mixture. For the formation of the suction jet issuing the exhaust air outside of the quarry, blast first air-fuel mixture in the upper horizon, and then sequentially to the bottom. The number of cascades, the amount of fuel supplied to the fuel-air mixture, and undermine uniformity between the cascades determined empirically. The disadvantage of this method is the necessity to use for ventilation multiple venting installations.
A device for ventilation of deep pits (RF patent No. 2143076, E 21 F 1/00, epubl.) The device includes a flexible exhaust pipe with toroidal chambers stiffness, spaced along its length and filled with light inert gas, a device to move the device, electric heating elements mounted on the supporting frame, a power plant in the form of a turbine and motor-generator and Teploobmennik made of screened films. Additionally the device has a vertical telescopic hollow shaft, which strengthened wheel with curved blades and impeller. The profile of the lower wing surface of the impeller and the profile of the upper surface of the curvilinear Palast the wind turbine is designed in such a way that form in the joint motion of the cavity in the form of a tapering cone of rotation. The axis of the cone coincides with the axis of the telescopic hollow shaft. Between the impeller and propeller in the hollow shaft holds the outlet and the turbine inlet provided window. The disadvantage of this device is the inability of Autonomous work, complexity, and low efficiency of ventilation.
A device to ventilate mines, adopted as a prototype of the device (the application for the invention of the Russian Federation No. 94040233, IPC E 21 F 1/00, epubl). The inventive device to ventilate mines is the case with the power mechanism and the remote control, connected to a communication with him. The lift mechanism is made of two parts. The lower part has a cumulative seizure with an explosive charge. The top separated from the bottom of the jumper and made of slow-burning fuel mixture. The housing has a nozzle placed above the fuel mixture. The enclosure is suspended on a wire cable, United telecommunications fuzes, placed on the upper and lower parts of the power mechanism. After running the nozzle enters the channel, undermining the fuel mixture and the cumulative part of creating atmospheric shock wave directed to the bottom of the quarry. Dragged the net atmospheric flows down vytesnyayut from the pit of stagnant gas environment. The disadvantage of this device is the inability of Autonomous work, the complexity and high risk operation.
The technical result of the invention is the possibility of the autonomy of the device, simplifying the design and improving the safety of operation.
The technical result is achieved in that in the method of ventilation of the mine ventilation system, consisting in mixing of fresh and exhaust air through detonation of the mixture, the formation of the suction jet issuing the exhaust air outside of the quarry, according to the invention the components to undermine served with compressed nitrogen, and the stirring of air is realized by using a mixture comprising sodium permanganate and hydrogen peroxide at a ratio of 1:(3÷10), while the suction jet is formed due to the effect ejection of exhaust air, and the air handling unit is placed on the lower elevation of the mine.
The technical result in part of the device is achieved in that the device for ventilation of a mine, comprising a housing with a nozzle placed above the fuel mixture, remote control, according to the invention it is provided with tanks for nitrogen, hydrogen peroxide and sodium permanganate, ventilazione pipeline, mounted on the nozzle body, which is equipped with nozzles for supplying PE is ekici hydrogen and sodium permanganate, connected through remote control with capacity of compressed nitrogen with a ventilation pipe made of composite of wearing each other sections with tapered sockets, forming with the adjacent sections of the ring slit for air leaks.
The use of the invention in comparison with the prototype provides Autonomous operation of the device, to simplify the design and increase the safety of operation.
The method of ventilation of the mine and the device for its implementation is illustrated in the drawing, where:
1 - body;
2 - nozzle body 1;
3 - nozzle for supplying hydrogen peroxide;
4 - injector for the supply of sodium permanganate;
5 - supply hoses;
6 - capacity with sodium permanganate;
7 - capacity with hydrogen peroxide;
8 - remote control;
9 - tank of compressed nitrogen;
10 is a section of vent pipe;
11 - conical funnel sections 10;
12 is an annular slit;
13 - the direction of the flow.
The method is designed for ventilation of deep mines and quarries and is carried out as follows. On the lower elevation of the mine (quarry) place the ventilation device. Then carry out periodic undermining mixture consisting of sodium permanganate and hydrogen peroxide. The number of interacting sodium permanganate and hydrogen peroxide accept what I see when following their ratio of 1:(3÷ 10). The uniformity of undermining by mixing hydrogen peroxide and sodium permanganate determined empirically depending on the desired intensity of the ventilation of the mine. When periodic detonation of the mixture along the length of the vent pipe occurs, the air moving, which is due to effect ejection podsushivaet exhaust air and promotes mixing of fresh and otrabotanny air. Using detonation of the mixture and the resulting detonation of gas-vapor mixture, form due to the effect ejection of the suction jet issuing the exhaust air outside of the mine. The lower limit of the ratio of permanganate sodium to hydrogen peroxide to 1:10 passed from the condition of minimum effective temperature of the gas mixture, and the upper limit of 1:3 adopted from conditions thermal resistance of the material of the body 1 and the nozzle 2. Data on the temperature of the gas mixture given in the table.
|Hydrogen peroxide pieces||11||10||6||4||3||2|
|The sodium permanganate, parts||1||1||1||1||1||1|
|The temperature of the gas mixture, °||1090||990||780||250||220|
Device for ventilation of the mine is as follows. In case 1 placed in the upper part of the nozzle 2 is fed through a nozzle 4 for supplying sodium permanganate, and a nozzle 3 for supplying hydrogen peroxide, respectively, sodium permanganate and hydrogen peroxide. In the nozzle 3 and 4 hydrogen peroxide and permanganate sodium pump on the inlet hose 5 from the tank 7 with hydrogen peroxide and a capacity of 6 with sodium permanganate. To create pressure in the system and adjust the flow of reagents used compressed nitrogen, inert to hydrogen peroxide and sodium permanganate supplied from the tank 9 with compressed nitrogen through the control panel 8. Remote control 8 doses portions of the reactants and the frequency of their submission to adjust the intensity of the ventilation of the mine. When mixing hydrogen peroxide and sodium permanganate reaction occurs, accompanied by a large selection of gas-vapor mixture, which, moving on vent pipe causes mixing of exhaust air and forms due to the effect ejection of the suction jet moving in the direction of flow 13. Section 10 of the vent pipe have tapered sockets 11, forming a conical slit 12 along the length of the vent pipe. The depth of the dressing neighboring s is s 10 in each other determine empirically secure effect ejection, causing a leak of exhaust air and carrying it outside of the mine.
The application of this method of ventilation of the mine and device for its implementation provides the following benefits:
- autonomy of operation of devices of this type;
- simplify the design of the device.
- improving the safety of operation;
- reducing energy consumption for ventilation of the mines.
1. The method of ventilation of the mine ventilation system, consisting in mixing of fresh and exhaust air through detonation of the mixture, the formation of the suction jet issuing the exhaust air outside of the mine, characterized in that the components to undermine served with compressed nitrogen, and the stirring of air is realized by using a mixture comprising sodium permanganate and hydrogen peroxide at a ratio of 1:(3÷10), while the suction jet is formed due to the effect ejection of exhaust air, and the air handling unit is placed on the lower elevation of the mine.
2. Device for ventilation of a mine, comprising a housing with a nozzle placed above the fuel mixture, remote control, characterized in that it is equipped with tanks for nitrogen, hydrogen peroxide and sodium permanganate, vent pipe, mounted on the nozzle body, which is equipped with nozzles for supplying peraki and hydrogen and sodium permanganate, connected through remote control with capacity of compressed nitrogen with a ventilation pipe made of composite of wearing each other sections with tapered sockets, forming with the adjacent sections of the ring slit for air leaks.
FIELD: mining industry.
SUBSTANCE: invention is designed for use in development of minerals with systems involving filling mined-out space with solidifying stowing mix. The latter is composed of broken lime-containing binder in the form of active aluminosilicate material (5.6-33.2%) and fired carbonate rocks (1.0-16.7%), tempering water with phlegmatizer (10.6-27.5%), and filler. Carbonate rocks are fired at 900-1200°C, contain active calcium-magnesium oxides CaO+MgO at least 40% and not more than 9.1% based on the total weight of mix, which are broken to screen residue 0.08 mm not more than 15%. Active aluminosilicate material is fired marl or fired clay, or fired kimberlite ore concentration tails, or granulated blast furnace slag. Tempering water contains phlegmatizer in amounts found from formula [Ph] = (0.005-0.021)*Cr/Cw, where [Ph] amount of water in 1 L tempering water, kg; (0.005-0.021) coefficient taking into account proportion between phlegmatizer and fired carbonate rocks in mix; Cr amount of carbonate rocks in mix, kg; and Cw experimentally found consumption of tempering water with mix, L. When indicated amount of CaO+MgO in mixture is exceeded, CaO and MgO are converted into hydroxides by spraying with water in amount not higher than 20% of the weight of fired carbonate rocks (on conversion to active CaO+MgO). As carbonate rocks, host rocks of kimberlite deposits are used; as filler, sand and/or concentration tails, and/or broken aluminosilicate rock; and, as phlegmatizer, industrial-grade lignosulfonate or superplasticizer.
EFFECT: improved workability of mix and reduced cost.
5 cl, 4 dwg, 3 tbl
FIELD: mechanical engineering; conveyors.
SUBSTANCE: invention relates to conveyors with multichain traction member. Proposed scraper conveyor contains endless traction member consisting of parallel traction chains, two outer chains and one inner chain, closed in vertical plane on end sprockets and resting on guides of panline flight. It is provided with scrapers secured in turn by ends on outer chains, alternating with scrapers freely fitted with clearances between outer chains and attached by ends on inner chain. Scrappers secured on outer chains are provided with cavities for accommodating inner chain. Traction member is furnished with additional inner chain, both inner chains being arranged in middle part of panline flight symmetrically to each other relative to longitudinal axis of conveyor, and scrapers being secured by ends on both inner chains. Distance between outer and inner chains is set less than distance between inner chains.
EFFECT: increased length of flight owing to increased summary breaking force of traction member chains.
FIELD: mining, particularly for underground ore deposit and kimberlite pipe development.
SUBSTANCE: ore pass comprises shaft, loading mouth and sieve. The ore pass shaft is provided with conveyer belts suspended to sieve grate so that distances between adjacent conveyer belts are different and defined by maximal dimensions of rock pieces passing between the belts. Sealed elastic shell is arranged in lower ore pass part. The sieve is installed at α=17° - 45° angle to horizontal plane. Lower conveyer belt ends are provided with weights.
EFFECT: reduced degree of rock grinding, increased service life of ore pass members.
FIELD: mining, particularly to prevent underflooding of ground areas to be shifted during underground mining performing.
SUBSTANCE: method involves forming contour trench-like cutoff curtain in ground; creating drainage devices inside the contour and removing water from ground movement trough. The contour trench-like cutoff curtain is arranged along predicted horizontal line of ground surface relief formed after ground subsidence and height mark thereof is higher than that of maximal ground water level in spring. Necessary throughput Q of drainage devices is set on the base of mathematical expressions.
EFFECT: increased safety of underground mineral mining.
2 dwg, 1 ex
FIELD: mining industry, particularly to develop mineral deposit along with backfilling of worked-out areas.
SUBSTANCE: backfill mix comprises cement, grinded granulated blastfurnace slag, filler and water. The backfill mix additionally has shredded straw. Grinded diabase is used as the filler. All above components are taken in the following amounts (% by weight): cement - 2.9-5.07, grinded granulated blastfurnace slag - 15.21-16.91, grinded diabase - 52.24-53.22, shredded straw - 0.02-0.076, water - remainder.
EFFECT: increased strength and crack-resistance.
FIELD: mining industry, particularly to remove water from deep pits, especially in going to underground excavation in upper part of ore body.
SUBSTANCE: system comprises main pipeline, pumping unit with pumping pipe and power supply members. The system is additionally provided with lowering-and-lifting device arranged on pit side and tightening device provided with rope. The first rope end is connected with tubular case in which submersed pumping unit is installed. Submersed end of the case has throughput orifices for liquid passage. Through orifice formed at outlet case end communicates with pumping pipe orifice, which in turn is connected with inlet end of the main pipeline through connection pipe and connection flange. Outlet end of the main pipeline is secured in the lifting-and-lowering device.
EFFECT: reduced material consumption and increased efficiency of water drainage from water-filled deep pits.
FIELD: mining industry, particularly methods or devices for drawing-off gases.
SUBSTANCE: method involves taking methane concentration in characteristic mining face points by sensors, wherein the characteristic points are selected in accordance with requirements fixed by Safety Rules; recording and processing methane sensor readings in central station; transmitting the methane sensor readings to signal receiving block; performing primary processing of the received signals and de-energizing bottomhole mechanisms; inputting safety factor, namely maximal value of gaseous methane content, which is less than critical methane concentration value and takes into consideration response time of methane emission control system; automatically forming commands aimed at cutter-loader output regulation by reducing or increasing speed of cutter-loader feeding if one sensor detects methane concentration reduction or growth from zero to maximal value after the received signal processing to provide safe operation in the mining face until critical methane concentration is reached in mining face atmosphere without bottomhole mechanism de-energizing. If above methane emission control system can not provide maximal methane content in mine face atmosphere the system will de-energize all bottomhole mechanisms with taking into consideration of response time of methane emission control system.
EFFECT: prevention of critical explosive methane concentration in mine without bottomhole mechanism operation stoppage.
FIELD: mining industry; mine plants.
SUBSTANCE: invention is designed for selective transportation of mineral resources. Proposed conveyor contains rigidly mounted on buntons chute-like section guide conductors with curvilinear sections, articulated members with two load-carrying units freely suspended from axles and arranged symmetrically on each member and provided with gear wheels for selective transportation of load, and guide rolling supports on axles of members for engagement with said guide conductors. Rolling elements of rolling supports are made in form of balls. Conveyor is furnished also with distributed linear hydraulic drive. Guide rolling supports are provided with metal journals with rectangular seats on free places of which detachable inserts are installed accommodating said rolling elements in form of balls. Detachable inserts are installed for corrective displacement by means of pressure spring to adjust distance between guide rolling supports and inner surfaces of chute-like section guide conductors.
EFFECT: provision of reliable operation of conveyor.
FIELD: mining industry, particularly to form venting system, which controls thermal mine conditions during combined mining.
SUBSTANCE: method involves forming overburden haulage inclined out of the pit extending across the strike up to interface between exposed and underground mines; extracting mineral from the haulage; constructing venting means and mounting support in approach mine; erecting heat-exchanging mines during opened mining.
EFFECT: elimination of time intervals during venting system construction and mining performing, simplified people evacuation in emergency and possibility to use heat-exchanging mines for other purposes.
FIELD: mining industry, particularly ventilation of mines or tunnels during bauxite deposit development.
SUBSTANCE: method involves supplying pure air from field haulage roadway through blind drift of transport horizon into ore rising one due to mine depression; feeding part of air from rising horizon in intermediate blind drift; directing remaining pure air in layered air supply drift and then to entry ways for venting thereof; removing contaminated air through previously developed entry ways in layered venting drifts arranged in exhausted space at deposit ground along the strike; directing contaminated air through venting rises arranged in exhausted space along block boundaries at deposit ground to field venting drift drilled under deposit ground along the strike at venting horizon level and blind drift of venting horizon to field venting drift; supplying pure air from intermediate blind drift to field rise and then to field venting drift through blind drift of venting horizon. Intermediate blind drift and field rise are adapted to evacuate miners in emergency conditions.
EFFECT: increased efficiency and miner's safety due to changing pure and contaminated air mass flow within the boundaries of the block.
FIELD: mining industry.
SUBSTANCE: pipeline has sections made in form of hermetically interconnected outer and inner covers, mounted with space relatively to each other, and main ventilator. On different ends of pipeline flow meter and additional ventilator are mounted, the latter having adjustable characteristics and being connected to inter-pipe space by branch pipe. In inner cover apertures are made placed along radius and along length of cover. Air comes from apertures to air channel and forms additional air flow near walls of inner cover, which lowers or heightens aerodynamic resistance of ventilation pipeline.
EFFECT: higher efficiency, higher safety, lesser costs.
FIELD: oil and gas extractive industry.
SUBSTANCE: method includes use of device providing for manufacturability of assemblage of casing and drilling columns and concurrent drilling by two columns, provided with independent drives, and drilling, by casing column, of non-stable rock solids performed with frequency no greater than one calculated from formula
where Vmec - mechanical drilling speed, m/min, Fr - friction forces against rotation, Ften - friction forces against linear displacement, R - casing column radius, m, α - angle between vectors of directions of linear and rotating movements.
EFFECT: higher effectiveness, higher productiveness, higher reliability.
2 cl, 5 dwg, 1 ex
FIELD: mining industry.
SUBSTANCE: method for extraction and underground use of coal includes cleaning extraction and dumping of coal, fixing and controlling ceiling and transporting coal along face to drift. On the drift, in moveable generator, coal is pulverized for intensive burning with use of jets in water boiler firebox, where high temperature of steam is achieved (about 1400 C°), enough for decomposition of water on oxygen and hydrogen. These are separated, then oxygen is fed back to jets, and hydrogen is outputted along pipes and hoses in drifts and shaft. Variants of underground generator for realization of this method are provided. Also provided is method for extraction of disturbed coal beds by short faces. It includes extraction and dumping of coal on face conveyor, fixing of ceiling behind combine, moving conveyor line and support sections in direction of cleaning face displacement, control of ceiling with destruction and partial filling. Extraction of coal is performed in short curvilinear faces by long stripes along bed, in straight drive without forwarding drifts, with preservation and reuse of ventilation and conveyor drifts, equipped with mounting manipulator robots, with fixing behind combine by automatically operating support deflectors without unloading and displacing sections in area of coal extraction. Extraction and transporting of coal is performed by fast one-drum combine and curvilinear reloading conveyor, supplying coal to drift conveyor or immediately to underground gas or energy generator placed immediately on drift. Also proposed is face scraper conveyor for realization of said method, wherein pans are made with step along front face profile, greater, than along back one, while forming common line curved towards face with constant curvature. Also proposed is a method for controlling complex for unmanned coal extraction.
EFFECT: higher efficiency, effectiveness, broader functional capabilities.
8 cl, 5 dwg
FIELD: gas, oil, oil refining and other industries.
SUBSTANCE: invention relates to building and operation of underground reservoir in stable rocks, for instance, soluble salt deposits. Method includes delivery of water and putting out brine along water feed and brine lifting pipes placed one inside the other, charging and storing of gas in underground reservoir. After brine lifting, reservoir is dried and then is filled up with alternating layers of absorbent and inert porous material, volume ratio 2:1, delivered along clearance between water feed and brine lifting pipes. Brine lifting pipe is perforated in lower part in height of reservoir and it is installed in lower part of reservoir. Difference between angles of repose of absorbent and inert material does not exceed 10 degrees. This done, reservoir is filled with gas delivered along perforated brine lifting pipe.
EFFECT: increased productive volume of reservoir owing to sorption of gas on surface of absorbent, reduced cost of gas storing.
FIELD: mining industry.
SUBSTANCE: invention can be used for transportation of rock in underground mines for reloading of rock from one conveyor to the other installed at one level. For this purpose device is used containing pair of flight conveyors, forced-draught and suction fans, air chamber with air inlet hole provided with cyclone installed over flight conveyor to be loaded. Air chamber is arranged between conveyors and is furnished with air collector made in form of screen with cells, housing and brushes from side of conveyors. Additional hole is made in bottom of air chamber to deliver air jet at angle to direction of material movement.
EFFECT: device of simple design providing effective and safe reloading of rock from one conveyor to the other installed at one level.
FIELD: mining industry.
SUBSTANCE: method includes use of screw-drilling machine for driving of several first ventilation shafts in ore body and driving several second shafts, while second and each second shaft crosses, at least, one matching first shaft, forming first support walls, supporting ceiling. First supporting ceilings consist of ore body zones between neighboring second shafts, each first support wall has portion of at least one first shaft, passing horizontally through it. Horizontal channels are formed, each of which is placed transversely to matching second shaft between appropriate portions of first shaft, formed in adjacent support walls, for forming of group of continuous ventilation shafts. Second shafts are filled for forming second supporting walls, supporting well ceiling, and first supporting walls are extracted. First ventilation shafts can be made parallel to each other. Second shafts may be directed perpendicularly relatively to first ventilation shafts. In ore body air-outlet and air-inlet ventilation mines can be formed, placed at distance from each other along horizontal line, while first or each first ventilation shaft passes through portion of ore body between air-inlet and air-outlet ventilation mines. Driving of second or each second shaft can be performed by cutting machine, or by drilling or explosive mining.
EFFECT: higher efficiency.
7 cl, 11 dwg
FIELD: mining industry.
SUBSTANCE: method includes partial filling of extracted space of side and central mains by filling stripes from lava extracting shafts. At center of semi-lava on the side of massive, wherein next extractive column will be cut, filling shaft is additionally driven, wherefrom full filling of space between central fill stripe and fill stripe on the side of massive is performed. Preparation of next extraction column is performed under protection of erected fill stripes.
EFFECT: higher safety, higher efficiency.
FIELD: mining industry.
SUBSTANCE: method includes erection of rows of main platforms along bed length in staggered order with length equal or divisible by step value for support displacement, and placing filling material thereon. Along length of main platforms between ceiling and bed soil post support is mounted, upon which filling material is fed. After that between main platforms additional platforms are erected with wedge supporting, and main platforms are rotated counter-clockwise towards pneumatic support and it is displaced for one drive step. During that filling material, while lowering, unwedges wedge support between ceiling and bed soil and forms artificial supports. After that additional platforms are rotated counter-clockwise towards pneumatic support. After movement of cleaning face for two drive steps operations for constructing artificial supports are repeated. Distance between main platforms along bed fall line are selected from mathematical expression.
EFFECT: higher efficiency.
FIELD: mining industry.
SUBSTANCE: invention relates to vibrating facilities and it can be used for letting out ore or other materials and their separation. Proposed vibrating feeder has resilient supports, working member consisting of charging and discharge parts and vibrating drive consisting of two shafts with unbalance weight and motors, one per each unbalance weight. Place of arrangement of vibrating drive is determined basing on the fact that line of connection of axles of unbalance weights is located in area limited by two straight lines square to direction of vibration, one of which passed through center of mass, and the other is located at a distance from center of mass of 1/10L to side of charging part of working member. Axle of unbalance weights are located at different sides from line of direction of vibration passing through center of mass at distance equal to not less than 1/8 where L is distance between resilient supports in horizontal direction.
EFFECT: improved stability of operation of vibrating feeder at unstable supply and impact loads on working member at discharging.
FIELD: mining industry.
SUBSTANCE: method includes preparation and well extraction of resources of chambers with partial backfill of extraction space. Blocks of upper level relatively to blocks of lower level are placed in staggered order, while blocks are made in form of a stretched upwards hexahedron. Resources of block within one hexahedron are separated on two chambers, one of which, placed along periphery of hexahedron, after extraction and removal of ore from it is filled by hardening backfill. Second order chamber is made of hexahedron-like shape, extracted and removed under protection from artificial block on all six sides of this chamber. Removal of ore from first order chambers is performed through one removal mine - end of level ort and cross-cut in lower portion of block and intermediate sub-level cross-cuts.
EFFECT: higher efficiency.