RU2411360C1 - Method of underground mining of massive steep ore deposits - Google Patents

Abstract

FIELD: mining. ^ SUBSTANCE: during canopy installation for cylindrical sections there used are pipes that are put close to one another. The pipes are connected by flexible coupling at cross-section. The pipes are arranged along the ore body with the connection of neighbouring sections by couplings that rigidly fix pipe sections in relation to each other. Elastic material is used as a net, for example, nonwoven geotextile fabric that is covered by the layers of clay. The quantity of clay layers that are separated by geotextile fabric layers is taken more than three, the height of each clay layer is taken more than one metre. ^ EFFECT: increase of work safety, increase of range of application of this method, the possibility of use in ores of mean and small stability, raising the total performance of working off of the operational block during clearing excavation of chambers of the second sequential queue. ^ 3 cl, 6 dwg, 1 tbl

Description

The invention relates to the mining industry and can be used to develop powerful, tens and hundreds of meters, steeply falling ore deposits in conditions in which it is necessary to prevent breakthrough of water, quicksand and other fluids into the working space of the mine (for example, under the bottoms of pits, reservoirs, thickness flooded Quaternary sediments).

A known method of developing powerful steep-dipping deposits of weak ores (RF patent No. 22448448, E21C 41/22, publ. 2005.03.20). The method includes sinking ventilation and filling and boring loading gates, excavation of minerals oriented in crosswise direction by rhombic or ellipsoid shaped chambers, with displacement of the chambers of adjacent floors by half their width, with excavation of ore by blasting of wells and laying of mined-out space. Directly above the upper floor, a protective ceiling is constructed with a slope of 5-7 ° in the direction of the hanging side of the deposit. The width, height of the chambers and the height of the chambers of the upper floor, the angle of inclination of the side walls of the chambers are determined from mathematical expressions, based on a stable calculated span of the protective overlap, the width of the loading unit and the angle of internal friction of the ore mass. After the construction of a protective overlap, the ore in the chamber is developed by blast holes in a squeezed medium, and the next run is worked out after laying the previous run. In unstable, prone to collapse ores slaughtering treatment chambers give a slope corresponding to the angle of repose of the ore mass. In ores with rock layers, the slope of the treatment chambers is given a slope corresponding to the angle of incidence of the ore deposit.

The disadvantage of this invention is the high risk of work under objects that are dangerous for breakthroughs of fluids, since due to the inevitable shrinkage of the filling material, as well as possible underfilling when filling the chambers with filling material, the filling of the filling array, as well as covering ores and rocks, with a violation of their waterproofing properties, which can lead to breakthrough fluids.

There is a method of layer mining buried diamondiferous placers with the presence in the contours of mine fields of depressions with diamond ore (RF patent No. 2345219, E21C 41/16, E21D 19/02, publ. 2009.01.27). The method of layer mining of buried diamond-bearing placers with the presence of cavities with diamond-containing ore in the contours of mine fields includes mechanized mining of the upper layer by chambers, followed by working out of the pillars and installation of a flexible ceiling, working out of a block caving system for the lower layer, including hollows with diamond-containing ore. Flexible overlap is mounted only over the hollows with diamond ore. First, a flexible ceiling is mounted on the soil of the processed chambers simultaneously with their development, then - on the soil of the processed support pillars simultaneously with their development, after which the flexible ceilings of adjacent chambers and support pillars are connected to each other.

The disadvantage of this invention is the high risk of work under objects that are dangerous for breakthroughs of fluids, since due to the inevitable shrinkage of the filling material, as well as the possible under-filling when filling the chambers with filling material, the filling of the filling array, as well as covering ores and rocks, with a violation of their waterproofing properties, which can lead to breakthrough fluids.

A known method of developing powerful steep coal seams, adopted as a prototype (RF patent No. 2085739, E21C 41/18, publ. 1997.07.27). The inventive method includes conducting drifts, installation of a flexible ceiling, consisting of two parallel branches made up of cylindrical sections, the ceiling branches are fastened together via rigid ties, on top of which a metal mesh is laid. Sections in each branch at the ends are connected by a flexible connection. Bypassing the overlap is carried out as the coal mining of the underlying floors, and dismantled on the accumulating drift.

The disadvantage of this invention is the high risk of work under objects that are dangerous for breakthroughs of fluids, since due to the inevitable shrinkage of the filling material, as well as the possible under-filling when filling the chambers with filling material, the filling of the filling array, as well as covering ores and rocks, with a violation of their waterproofing properties, which can lead to breakthrough fluids.

The technical result of the invention is to increase the safety of mining powerful steeply falling ore deposits occurring under objects that are dangerous for fluid breakthroughs, the underworking of which is associated with the danger of fluid breakthrough into the working space of the mine.

The technical result is achieved by the fact that in the method of underground mining of powerful steep-dipping ore deposits, including the excavation of preparatory and rifled mine workings, installation of an overlap consisting of parallel branches of cylindrical sections fastened together, covered with a grid, mining within the excavation field of mineral resources of primary and secondary chambers using blasting, filling the spent space of the primary and secondary chambers with a bookmark according to the invention with mounting Even overlapping pipes are used as cylindrical sections, stacked close to each other, fastened together in cross section by flexible connections, moreover, the pipes are arranged along the strike of the ore body with the adjoining sections joined by adapters that rigidly fix the pipe sections relative to each other, and use elastic material, for example, a non-woven geotextile fabric, on top of which clay layers are poured, the number of clay layers being separated from each other by layers of geotextile fabric take more than three, and the height of each clay layer takes more than one meter.

The technical result is also achieved by the fact that as a geotextile web, dornite is used.

The technical result is also achieved by the fact that as a geotextile fabric using spunbond.

The application of the proposed method in comparison with the prototype allows to increase the safety of mining powerful steeply falling ore deposits lying under objects that are dangerous for breakthroughs of fluids, the underworking of which is associated with the danger of breakthrough fluids into the working space of the mine.

The method of underground mining of powerful steep-dipping ore deposits is illustrated by the drawings, Fig. 1 shows a vertical section along the line CC, Fig. 2 shows a vertical section along the line A-A, the stage of breaking primary chambers under the protection of the floor, Fig. 3 shows section along the line BB, figure 4 shows a vertical section along the line BB, the release horizon, figure 5 shows a view of D, the structure of the floor, where:

1 - layered drift;

2 - ore passing;

3 - running uprising;

4 - treatment approach across the strike;

5 - output development;

6 - recoil drift;

7 - ventilation uprising;

8 - ventilation drift;

9 - drill drift;

10 - recoil unit;

11 - overlap;

12 - embedded cameras;

13 - flooded Quaternary sediments;

14 - ceiling;

15 - pipe sections, for example steel;

16 - layers of geotextile fabric, for example spunbond or mandrel;

17 - clay layers;

h - vertical floor height 11, m;

L is the length of the block, m;

b is the width of the chambers;

h _bl - block height;

h _Tr - the height of the output;

m is the length of the chamber, m;

l _lb is the distance from the chamber to the lying side of the ore deposit;

l _WB - the distance from the camera to the hanging side of the ore deposit.

The development of reserves of powerful steeply falling ore bodies lying under the bottoms of quarries or under the thickness of flooded Quaternary sediments is fraught with the danger of fluid breakthrough into the working space of the mine. The use of development systems with the laying of the mined-out space cannot guarantee the integrity of the protective floor created due to shrinkage processes, which inevitably manifests itself in filling arrays of all types. The shrinkage of the filling array is aggravated by the possible actual under-laying of fillings and layers, which again can lead to the destruction of the protective floor due to its sagging and the creation of an emergency with various kinds of damage. The proposed design of the overlap will allow to mine ore reserves by chamber development systems with subsequent laying with guaranteed protection against the penetration of fluids into the working space of the mine. This is achieved through the use of the plastic properties of clay and the bearing capacity of an elastic material - geotextile paintings (geotextiles). Currently, geotextiles are used in all areas of construction. Geotextiles optimize clay compaction so that bulk material (clay) does not penetrate the bookmark. Used as a filter between the bookmark and clay. Geotextile, preventing the collapse of slopes, allows for the construction of roads even on poorly bearing soil, so it is advisable to use it for the construction of floors. It is recommended to use the following types of geotextile fabric - dornite or spanbond.

Dornite is a needle-punched non-woven geotextile fabric. Dornite is an environmentally friendly non-woven material made from endless polypropylene fibers using the needle-punched method, which ensures its high chemical resistance and resistance to thermo-oxidative aging. The material is not susceptible to decay, mold and mildew. Operating temperature range: -60 ° С + 100 ° С. The structure of the material provides good strength and filtering properties. Due to the optimal combination of its characteristics, Dornit geotextiles, in addition to traditional applications in road, drainage and anti-erosion structures, are widely used in the construction of roofs, foundations, drainages, land management, etc. In this regard, the main functions of geotextiles are performed - separation, reinforcing, filtering, drainage, as well as their combination. Geotextiles perfectly fulfill these functions due to a combination of their properties: high modulus of elasticity, due to which the material can absorb significant loads and perform the function of reinforcing at relatively small deformations; large elongations at break (depending on the density of the material - up to 45%), i.e. local damage does not lead to destruction of the material, and it continues to fulfill its functions; universal filtering ability, due to the specific structure of the material, which eliminates the penetration of soil particles into the pores and their clogging. Thus, it allows to ensure good stability of the filtering quality of the material under soil pressure and in conditions of strong vibration; high tear and puncture resistance, which is especially valuable when laying; does not form any by-products, environmentally friendly material.

The process of laying geotextile material is simple and technological. This is due to the following features of the geotextile fabric: the material rolls are small, due to which transport and storage costs are reduced, as well as labor costs; the material does not absorb water, when used in wet conditions of mines and mines, the weight of the rolls remains unchanged; The material is characterized by resistance to natural acids and alkalis, etc. When laying, it is necessary to overlap 10-12 cm of adjacent rows to each other. The use of geotextiles (Dornite) in the proposed method greatly simplifies the task of isolating fluids. The main advantages of using geotextile: geotextile performs the function of separating layers and allows you to redistribute stress at the base of the embankment, increase the bearing capacity of the base during shrinkage of the filling mass, the stability of slopes, improve the compaction conditions of the clay canvas to increase its waterproofing properties. Also, when using the material in this method, the reinforcing function is performed when designing embankments from clay of high humidity. The geotextile layer is rolled out in the longitudinal and transverse directions along the entire width of the primary or secondary chamber. Cloths are interconnected by gluing or stitching. The clay is poured in layers, taking into account the described conditions, directly onto the geotextile web using mobile or self-propelled throwing filling machines.

It is widely known that wet clays are weaker than dry ones, and fine-grained ones are weaker than coarse-grained ones. In this case, geotextiles will: prevent a decrease in bearing capacity, preventing the mixing of small particles of soil with a poured base (filling array); increase the bearing capacity, preventing clay from being pressed into the soft base, and thus providing an increased degree of compaction. Delayed tiny particles (finely dispersed inclusions) act like a sponge that expands when moistened. It should also be noted that geotextiles (Dornit) are resistant to damage during installation. It is known that 95% of all damage to geotextiles (other brands) usually occurs during the laying process when filling and compacting clay. The combination of high initial elastic modulus and elongation allows this material to absorb more energy compared to other geotextiles. This provides him with increased resistance to damage during installation.

Geotextile (Dornite) is an isotropic material, its properties are the same in all directions. This is reflected in the stress-strain parameters characteristic of its use as a separation layer. It is manufactured with a very high level of uniformity with continuous current x-ray inspection. In this case, the geotextile performs the function of reinforcing, distributing the load over the entire area of the overlap (filling array). Geotextiles also prevent clay loss in silty soils and provide effective protection against mechanical damage. Also, geotextiles (Dornite) prevent the washing out of smaller particles of soil into the drainage aggregate, thus maintaining the uniformity of the drainage properties. Geotextiles have the following advantages: lower total costs, since the use of coarse-grained, cheaper materials is allowed; reduced installation costs due to time savings.

Spunbond geotextile fabric - thermally bonded non-woven geotextile fabric. Spunbond geotextile is a non-woven material made of thermally bonded endless fibers made of 100% polypropylene, which provides geotextile resistance to moisture and chemical compounds, in particular to alkalis, acids, fungi and mold. The structure of geotextiles provides good strength and filtering properties. The main functions of geotextiles are used: separation, reinforcement, filtering, drainage, as well as their combination. Material (spanbond) is widely used in various industries and agriculture: construction; covering, greenhouse and mulching material for agriculture; medicine and hygiene; leather goods; furniture; footwear; container and packaging; sewing and quilting; wide range filters; decorative decoration, etc. An assortment of materials is presented below in tabular form in the range from 10 to 150 g / m ² . According to the technical specifications, the material may deviate from the stated density (± 10%), in practice this figure is ± 3-5%. The maximum roll width can be 4200 mm.

The main technical characteristics of the material spunbond Indicators RANGE Surface density, g / m ² 10 17 25 40 60 80 one hundred 150 Breaking load longitudinal, N twenty 22 thirty 60 80 one hundred 120 180 Breaking load transverse, N 17 twenty 25 40 60 80 one hundred 130 Elongation at break longitudinal,% 120 150 150 150 150 180 200 200 Elongation at break transverse,% 120 150 150 150 150 180 200 200 Fiber Diameter, Tex 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Breathability l / dm ² / min 4000 4000 3500 2000 1300 700 320 one hundred Hydrophilic properties, (transit time, sec) 3 3,5 four - - - - - Hydrophobic properties, (buoyancy) hour - - - 24 24 24 24 24

The underground mining method of powerful steeply falling ore deposits, for example steeply falling ore bodies, is as follows. The steeply falling ore body is divided into blocks with a length L and a vertical height h _bl . Blocks are prepared with the necessary preparatory and rifled workings. Retreating 6 drifts and ventilation 8 drifts of ore pass, connect them with retractable 10 orts, outline the block with them. Of drifts 6 and 8 are running 3 uprising, ore passes 2, ventilation 7 uprising. Drilling rigs 9 drifts and lay drifts 1 pass. In each chamber, work outs of 5 issues are made out as the chamber is worked out or ahead of schedule. Prior to the beginning of the mining excavation, the ore reserves located between the lines can be advanced l _lb is the distance from the chamber to the lying side of the ore deposit and l _wb is the distance from the chamber to the hanging side of the ore deposit, for example, using treatment openings 4 located across the strike. After working off the indicated sections above the design circuit of each chamber, workings pass in which the ceiling 11 is mounted. The ceiling 11 is created as follows. As the cylindrical sections using pipe 15, stacked in rows close to each other. Pipes 15 are fastened together in cross section by flexible connections, for example tapes. The pipe sections 15 are arranged along the strike of the ore body with the connection of adjacent pipe sections with adapters that rigidly fix the pipe sections 15 relative to each other. As the mesh, an elastic material is used — a non-woven geotextile fabric 16, for example spunbond or mandrel, over which layers of clay 17, for example montmorillonite or any other, are poured. The height h of the overlap is determined on the basis of the mining and geological conditions in this area. The number of clay layers, separated from each other by layers of geotextile fabric, take more than three, and the height of each clay layer is more than one meter. In necessary cases, the number of clay layers is determined by experimental, experimental, or analytical methods. Observance of the above-described conditions will make it possible to restrain the significant pressure of the fluids when they break through the water-proof layer. After mining the reserves of the chamber under the protection of the floor 11, filler material is fed into them and the primary chamber 12 is formed. Between the flooded Quaternary 13 deposits and the floor 11, a ceiling 14 of ore or host rocks is left. Development system parameters, namely the length of the block L, m; the width b of the primary and secondary chambers; height h _bl block; height h _tp output production; the length m of the chamber across the strike, m, is determined on the basis of mining and mining and geological conditions of development by experimental, experimental, or analytical methods. The release of ore from the block during mining of primary and secondary chambers is as follows. A loading and delivery machine (not shown conditionally in the drawing) calls in to develop output 5 through a loading run, scoops up the ore, and transports it to the nearest ore pass. In the process of partial release, the output development - trench 5 is left filled to prevent its destruction during breaking of the following layers.

Secondary chambers are supposed, depending on the stability of the enclosing rocks, to lay with a hardening tab or to fill them with cheaper bulk tab (without the use of binders).

During the destruction or cracking of the water-proof stratum and the breakthrough of fluids into the working space of the mine, the liquid phase of the fluids (water) begins to be intensively absorbed by the clay. In this case, its increase in volume and reliable blockage of the water supply channels occur. According to the calculations, the height of the fluid column can be more than 20 m. Thus, due to the creation of waterproofing, all equipment and workers can be removed from the unit in case of a possible emergency.

The application of the proposed underground mining method for powerful steeply falling ore deposits provides the following advantages:

- improving the safety of work when developing deposits under objects dangerous for the breakthrough of fluids, for example, quicksand;

- expanding the scope of this method due to the application on steep and steeply dipping fields;

- the possibility of using in ores of medium and low stability;

- increasing the overall efficiency of the development of the operational unit during the cleaning recess of the chambers of the second stage.

Claims (3)

1. The method of underground mining of powerful steep-dipping ore deposits, including the excavation of preparatory and rifled mine workings, the installation of an overlap consisting of parallel branches of cylindrical sections fastened together, covered with a mesh, working out primary and secondary chambers using a drilling and blasting using a drilling and blasting mineral field blasting, filling the waste space of the primary and secondary chambers with filling material, characterized in that when installing the ceiling as a cylinder The main sections use pipes stacked close to each other, fastened together in cross section by flexible connections, the pipes being placed along the ore body stretch with the adjacent sections connected by adapters that rigidly fix the pipe sections relative to each other, and elastic material is used as a mesh, for example non-woven geotextile fabric, on top of which clay layers are poured, while the number of clay layers separated from each other by layers of geotextile fabric is more than three, and high each layer clays take more than 1 m. 2. The method according to claim 1, characterized in that dornite is used as a geotextile web. 3. The method according to claim 1, characterized in that spunbond is used as the geotextile web.

Images