A kind of full coal filling method and near full coal filling material for high coal face passing empty roadway in outburst mine

Abstract

A kind of outburst mine fully mechanized caving face passes through empty lane nearly full coal filling method and nearly full coal filling material belong to mine filling material technical field, including the following steps: S1, obtaining coal and rock stratum physical mechanics parameters and mining technical parameters of fully mechanized caving face;S2, obtain the basic characteristics of old goaf, including the section shape, section size, roadway length, inclination, azimuth angle of old goaf, the distance between the roof and floor of old goaf and the roof and floor of coal seam, the support method and parameters of old goaf and the type and concentration of gas in old goaf;S3, determine the in-situ filling method and material of outburst mine fully mechanized caving face passing through old goaf: use lump coal, coal, coal slime water and coal powder slag formed by drilling as main raw materials to prepare filling material applicable to different scenes, which realizes local material and local filling, and reduces the influence of filling body on coal mining efficiency and coal quality, greatly reduces the filling cost and washing cost of mine.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of mine filling materials, and particularly relates to a near-full-coal filling method and near-full-coal filling material for a fully-mechanized caving face of an outburst mine passing through an empty roadway. BACKGROUND

[0002] In recent years, with the continuous growth of energy demand in China, some coal mines are mined in disorder, expanded, even cross-layered, cross-border, and privately mined, which not only causes damage to the original coalfield, but also leaves a large number of old airways, bringing great difficulties to the normal mining of the mining face. In addition, due to changes in mining connection, mining design, etc., or overlong working face passing through the middle cut, etc., the mining face needs to pass through the old airway. At present, the most commonly used technical method for the mining face passing through the airway is to fill the airway with cement slurry, gangue-fly ash-cement slurry, coal gangue, blocks, etc. However, due to the fact that some old airways are perpendicular or oblique to the working face, or there are multiple old airways within the working face mining range, a large amount of space needs to be filled, that is, the filling body needs to be continuously cut during the mining process, which not only increases the difficulty of crushing and washing, reduces the coal quality, but also aggravates the wear of the cutting pick of the coal mining machine, reduces the mining speed, produces cutting sparks, and affects the safe and efficient production of the mine. In addition, for the fully-mechanized caving face, when the old airway is located in the upper caving area, after filling with cement slurry, gangue-fly ash-cement slurry, etc., due to its large solidification strength and high integrity, it is difficult to be caved, which is specifically manifested in the actual production process as follows: the filling block body blocks the caving opening, the filling body suspends the top for a long distance, the filling body collapses in a large area and in a whole, etc., which brings about the reduction of the mining rate, the abnormal appearance of the mine pressure, the death of the support, the blocking of the rear scraper, the stop of the end head, and other major safety accidents in production.

[0003] On the other hand, for high-gas and outburst mines, using bedding boreholes or cross-layer boreholes to pre-drain coal seam gas is the most commonly used and effective gas control method. According to incomplete statistics, the annual extraction drilling footage of a single mine in China reaches 300-500 million meters, and the generated drilling coal powder slag reaches 35-60 tons. However, due to the fact that it cannot be effectively utilized, at present, the mine almost does not recycle it, thus causing a large amount of resource waste.

[0004] Therefore, for the fully-mechanized caving face of the outburst mine passing through the old airway, it has become a major technical problem for the development of China's coal industry to research and develop a near-full-coal roadway filling method and near-full-coal filling material that can utilize the underground raw coal and drilling coal powder slag. SUMMARY

[0005] In order to overcome the problems mentioned in the above background, the present application provides a near-full-coal filling method for a fully-mechanized caving face of an outburst mine passing through an empty roadway, which at least partially solves the above problems.

[0006] According to the technical scheme of the present application, a method for filling a near-full coal of a goaf passing lane of a fully-mechanized caving face in a outburst mine is provided, which comprises the following steps:

[0007] S1, obtaining physical and mechanical parameters and mining technical parameters of the coal and rock strata of the fully-mechanized caving face;

[0008] S2, obtaining basic characteristics of the goaf, including a section shape, a section size, a length, an inclination angle and an azimuth angle of the goaf, a distance between a roof and a floor of the goaf and a roof and a floor of the coal seam, a support mode and parameters of the goaf, and a type and a concentration of gas in the goaf;

[0009] S3, determining an in-situ filling method and materials for the goaf passing lane of the fully-mechanized caving face in the outburst mine:

[0010] when b≥N and a≤S, the filling method is selected as a paste filling material to fill in a paste filling method;

[0011] when b≥S and a≤M, the filling method is selected as a block coal and grouting filling material to fill in a combined filling method of throwing and grouting;

[0012] wherein, a is a roof elevation of the goaf, b is a floor elevation of the goaf, M is a roof elevation of the coal seam, N is a floor elevation of the coal seam, and S is a top boundary elevation of a machine mining range of the fully-mechanized caving face, and the paste filling material, the block coal and the grouting filling material are all prepared by using underground raw coal and drill cuttings coal powder residue as raw materials.

[0013] Further, the preparation method of the paste filling material is as follows: the raw coal produced by the underground mining and the roadway excavation is sorted to separate out coal fines and coal slime water with a particle size less than 7mm;

[0014] The coal slime water is subjected to sedimentation and dehydration treatment to obtain concentrated coal slime water with a water content of 20%-25%;

[0015] The drill cuttings coal powder residue formed by the drilling in the mine is screened to remove impurities;

[0016] The coal fines, the concentrated coal slime water and the coal powder residue are mixed and stirred, cement, additives and mine water are added in the stirring process, and the paste filling material with a slurry concentration of 77%-86% is prepared after uniform stirring.

[0017] Further, the preparation method of the block coal and grouting filling material is as follows:

[0018] The raw coal produced by the underground mining and the roadway excavation is sorted to separate out coal fines and coal slime water with a particle size of 9-11cm;

[0019] The coal slime water is subjected to sedimentation and dehydration treatment to obtain concentrated coal slime water with a water content of 20%-25%;

[0020] Screening the drill cuttings and coal powder residue formed by drilling in the mine to remove impurities;

[0021] Mixing and stirring the thickened coal slurry and the coal powder residue, adding cement and additives and mine water in the stirring process, and preparing a grouting filling material with a slurry concentration of 68% to 75% after uniform stirring.

[0022] Further, the method for paste filling comprises the following steps:

[0023] Arranging the filling columns: a plurality of filling columns are arranged in the old roadway by injecting the filling material into the vertical filling bag, and the distance between adjacent filling columns is the same;

[0024] Retracting the anchor: starting from the end of the old roadway close to the open-off cut of the fully-mechanized caving face, the lock, tray, anchor net, steel belt and the like of the roof and two sides of the old roadway are sequentially disassembled and recovered by the anchor retractor;

[0025] Establishing the filling body: after the single retraction of the anchor is completed, the filling body is established in the old roadway within the single retraction distance range by the paste filling material until the old roadway is completely filled.

[0026] Further, the vertical filling bag is formed by intercepting a mine waste old air duct with the same length as the roadway height of the old roadway, and the opening of one end of the air duct is sealed by air duct cloth.

[0027] The opening end of the filling bag is hung on the area of the roof of the old roadway without anchor rod anchor cable by the anchor nail, the paste filling material is injected into the vertical filling bag to form the filling column,

[0028] The paste filling material is pumped into the vertical filling bag by the grouting hose to form the filling column, and a filling column is established at every other distance in the same way.

[0029] Further, the old air duct with the same length as the roadway width of the old roadway is intercepted, the opening of one end of the intercepted air duct is sealed by air duct cloth, the other end is sealed by air duct cloth and a grouting hole is left to form a horizontal filling bag, the horizontal filling bag is placed horizontally on the floor of the old roadway, the two ends of the horizontal filling bag contact the two sides of the old roadway, the paste filling material is pumped into the horizontal filling bag by the grouting hose to make the horizontal filling bag swell freely, the grouting is stopped when the paste filling material slurry starts to overflow from the upper grouting hole, the grouting hole is closed, and the two ends of the horizontal filling bag are fixed on the two sides of the roadway by the anchor nail.

[0030] A second horizontal filling bag is established by construction in the same way next to the first horizontal filling bag which has been grouted, a third horizontal filling bag is established by construction at the middle position above the two filling bags after the two filling bags are consolidated, and the three horizontal filling bags form a filling retaining wall with a height of 0.9-1.1m.

[0031] Through the grouting hose, grout filling material slurry is injected into the space between the filling retaining wall and the old roadway or the filling body, until the slurry liquid level is flush with the top surface of the retaining wall.

[0032] Further, the method of combined filling by throwing and grouting is specifically:

[0033] The old roadway is sequentially divided into multiple filling sections with the same filling step;

[0034] Starting from the end of the old roadway close to the open-off cut of the fully-mechanized caving face, the locks, trays, anchor nets, steel belts, etc. of the roof and two sides of the old roadway are sequentially disassembled and recovered through the anchor withdrawing device;

[0035] After single anchor withdrawal, the lump coal is first thrown and scattered in the single layer, and then the grouting filling material is injected into the gap between the lump coal until the slurry liquid level is flush with the top surface of the lump coal, and the filling is completed after complete solidification.

[0036] Further, the filling section is divided into multiple filling areas with the same height, and the unblocked side of the single layer is provided with a retractable withdrawing plate;

[0037] During the throwing and scattering process, the lump coal in the filling area is pushed and compacted and leveled by the movement of the gangue filling machine and the extension and retraction of the push plate, and when the thickness of the coal in the filling area reaches the required thickness, the bottom of the push plate is fixed to the ground, and extension plates are arranged on both sides of the withdrawing plate to make the extension plates completely contact the two sides of the old roadway.

[0038] Further, when filling the filling area close to the top wall of the old roadway, the position of the push plate is adjusted so that the front of the push plate is tightly attached to the side of the filling body below and the upper part is connected to the top, and a slot is dug in the roof above the push plate, and the nozzle of the filling pipeline is inserted into the filling space along the slot to realize the top filling of the filling area.

[0039] Still further, the application further provides a near-full-coal filling material for a fully-mechanized caving face passing through an empty roadway in a protruding mine, which comprises a paste filling material and a pipe.

[0040] The paste filling material comprises the following components in percentage by weight: 15-30% of coal fines, 10-25% of concentrated coal slurry, 20-35% of coal powder slag, 5-15% of cement, 0.5-1.5% of early strength agent, and 0.5-1.5% of water reducing agent.

[0041] The grouting filling material comprises the following components in percentage by weight: 15-30% of concentrated coal slurry, 25-40% of coal powder slag, 10-20% of cement, 0.5-1.5% of early strength agent, and 0.5-1.5% of water reducing agent.

[0042] Compared with the prior art, the present application has the following advantages:

[0043] The present application uses lump coal, coal slime water and coal powder slag formed by drilling as main raw materials to prepare filling materials applicable to different scenes, uses near-full coal filling materials to fill the old goaf in the mining face, realizes local material and local filling, reduces the influence of the filling body on the mining efficiency and coal quality, and greatly reduces the mine filling cost and washing and selecting cost.

[0044] The grouting filling material in the present application forms a heterogeneous filling body when cementing lump coal, and can produce a delamination effect to form a loose body under the action of mine pressure and support load, that is, equivalent to forming a prefabricated crack for top coal, which plays an important role in promoting the smooth release of top coal. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 is a flowchart of the full-coal filling method of the present application through the goaf of the fully-mechanized caving face;

[0046] Figure 2 is a schematic diagram of the present application when the paste filling is completed to form a filling retaining wall;

[0047] Figure 3 is a schematic diagram of the present application when the first layer of paste filling material is injected;

[0048] Figure 4 is a schematic diagram of the present application when the filling retaining wall is completed above the solidified first layer of filling body;

[0049] Figure 5 is a schematic diagram of the present application when the grouting of the roadway in the range of the first segment of the anchor length s is completed;

[0050] Figure 6 is the laboratory property test result of the paste filling material in embodiments 1-6 of the present application;

[0051] Figure 7 is the laboratory property test result of the grouting filling material in embodiments 1-6 of the present application;

[0052] Figure 8 is the laboratory property test result of the cemented body formed by the lump coal and the grouting material in embodiments 1-6 of the present application.

[0053] In the figure: 1-wind pipe cloth, 2-filling column, 3-filling retaining wall, 4-old goaf, 5-paste filling body. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments; based on the embodiments, all other embodiments obtained by a person of ordinary skill in the art without creative effort fall within the protection scope.

[0055] Embodiment 1

[0056] As Figure 1 shown, when the old goaf 4 is completely located in the fully-mechanized mining height range (b≥N and a≤S), a near-full coal filling method and near-full coal filling material for a fully-mechanized caving face passing through an empty roadway in a prominent mine are provided, and the specific steps are as follows:

[0057] (1) The raw coal produced by underground working face mining and roadway excavation is transported to the underground TDS intelligent sorting system for sorting, and the coal fines and slime water with a particle size less than 7 mm are sorted out; the slime water is subjected to sedimentation and dewatering treatment to obtain concentrated slime water with a water content of 25%; the drill cuttings and coal powder residues formed by the gas bedding drilling, gas drainage drilling and water exploration drilling are screened to remove impurities; the prepared coal fines, concentrated slime water and coal powder residues are mixed and stirred, cement, additives and mine water filtered through a sedimentation tank are added during the stirring process, and the filling material with a slurry concentration of 85% is prepared after stirring, wherein the mass percentage of each component in the filling material is: coal fines 30%, concentrated slime water 10%, coal powder residues 33%, cement 12%, early strength agent 1%, water reducing agent 1.5%, and the balance is mine water;

[0058] (2) A 1000mm diameter air duct is cut off underground, and the cutting length is equal to the height of the old goaf; the opening of one end of the air duct is sealed with air duct cloth 1 to form a vertical filling bag, the opening end of the filling bag is hung in the area of the old goaf roof without anchor rod anchor cable by using anchor nails, and the grouting material is pumped into the filling bag through a 50mm diameter grouting hose to form a filling column 2, and a filling column 2 is established at a distance of L in the same way.

[0059] (3) After the filling column 2 is consolidated for 3 days, the lock, tray, anchor net and steel belt of the old goaf roof and two sides anchor rod cable are disassembled and recycled from the roadway end close to the fully-mechanized caving face cut hole by using a retainer, and the retainer length of the roadway is 50m;

[0060] (4) Establish a filling retaining wall 3 composed of wind pipe filling bags at the boundary of the unanchoring range, specifically: cut a waste 1000mm diameter wind pipe of a length equal to the roadway width of the old goaf 4, seal the opening at one end of the cut wind pipe with wind pipe cloth 1, and leave only a grouting hole at the other end after sealing with wind pipe cloth 1 to form a horizontal filling bag, place the filling bag horizontally on the roadway floor, with the two ends of the filling bag contacting the two sides of the roadway, pump the grouting material into the filling bag through a 50mm diameter grouting hose to make the filling bag freely expand, stop grouting when the slurry starts to overflow from the upper grouting hole, close the grouting hole, and fix the two ends of the filling bag to the two sides of the roadway with anchor bolts. A second filling bag is established next to the grouting completed filling bag in the same way, and after the two filling bags are consolidated for 24 hours, a third filling bag is established above the middle of the two filling bags, thus forming a filling retaining wall 3 with a height of about 1m;

[0061] (5) After the third filling bag is solidified for 3 days, start grouting into the space surrounded by the filling retaining wall 3 using a 120mm diameter grouting hose, and end the grouting when the slurry surface is level with the top surface of the retaining wall.

[0062] (6) After the slurry is solidified for 3 days, a paste filling body 5 is formed, and steps d-e are repeated to continuously establish filling retaining walls 3 above the consolidated filling material and grout, achieving dense roof filling of the roadway within the 50m range of the unanchoring length.

[0063] (7) After grouting of the first segment of the roadway within the s range of the unanchoring length is completed, steps c-f are repeated to fill the roadway within the s range behind, and the cycle is repeated until the entire old goaf 4 is fully filled.

[0064] As shown in Figure 1 when the old goaf 4 is completely within the range of the coal caving height (b≥s and a≤M), a method for passing through an empty roadway near full coal filling at a fully mechanized coal caving face in a mine and a near full coal filling material, the specific steps of which are as follows:

[0065] (1) The raw coal produced by underground working face mining and roadway excavation is transported to the underground TDS intelligent sorting system for sorting, and block coal and coal slurry with a particle size of about 10cm are sorted out; the coal slurry is treated by sedimentation and dewatering to obtain concentrated coal slurry with a water content of 25%; the drill cuttings and coal powder residue formed by the gas bedding drilling, gas drainage drilling and water exploration drilling are screened to remove impurities; the concentrated coal slurry and coal powder residue prepared above are mixed and stirred, cement, additives and mine water filtered through a sedimentation tank are added during the stirring process, and after stirring, a filling material with a slurry concentration of 73.5% is prepared, wherein the mass percentage of each component in the filling material is: concentrated coal slurry 25%, coal powder residue 37%, cement 18%, early strength agent 1%, water reducing agent 1%, and the balance is mine water;

[0066] (2) Improvements to the existing gangue filling machine: First, install a new type of onboard temporary support mechanism. Specifically, weld a lifting jack to the track walking frame on both sides of the gangue filling machine, fix a crossbeam above the two lifting jacks, and fix several multi-stage telescopic rods to the crossbeam. After the multi-stage telescopic rods are extended and the front end is fixed, a support shelter can be formed. Second, install a gangue pushing and slurry blocking device. That is, weld a fixed block to the track walking frame on both sides of the gangue filling machine, install a pushing jack and a turning jack on the fixed block, and install two retractable push plates in front of the pushing jack. The height of the retractable push plates is 1.2m. Its structure and working principle are the same as the existing jacks, and will not be described in detail here.

[0067] (3) According to the direction of the fully mechanized mining face, the old working roadway 4 is divided into several filling sections with a filling step distance of 30m.

[0068] (4) Connect the extendable belt conveyor to the feeding belt of the gangue filling machine, and place the grouting pipe opening in the pipe ring below the crossbeam of the temporary support mechanism of the gangue filling machine. Through the remote control function of the gangue filling machine, the gangue filling machine drags the extendable belt conveyor and the filling pipe together to one end of the old roadway near the cutting direction of the fully mechanized mining face.

[0069] (5) Based on the stopping position of the gangue filling machine, five holes are drilled at the top of the wall at one end of the old tunnel 4. The holes are 500mm deep and 110mm in diameter. The temporary support mechanism of the gangue filling machine is opened so that the telescopic rod can be extended and enter the bottom of the holes.

[0070] (6) Use anchor removal devices to dismantle and recycle the locks, trays, anchor nets, steel strips, etc. of the roof slab and the two sides of the old roadway.

[0071] (7) The 10cm lump coal produced by the sorting chamber is transported to the gangue filling machine by a retractable belt conveyor and scattered. During the scattering process, the lump coal in the filling area is pushed, compacted and leveled by the movement of the gangue filling machine and the forward and backward extension of the push plate. When the thickness of the coal in the filling area reaches 1m, the push plate is remotely controlled to make its bottom ground, and the telescopic plates on both sides of the push plate are opened so that the telescopic plates are fully in contact with the two sides of the roadway.

[0072] (8) Move the grouting pipeline and hang the pipe opening on the telescopic rod of the temporary support structure so that the pipe opening is in the middle of the filling area. Turn on the grouting pump to deliver the filling material into the gaps of the scattered coal. When the grout level reaches the height of the coal pile, stop grouting.

[0073] (9) After the slurry is coagulated for 3 days, the push plate and the telescopic plate are withdrawn, the height of the gangue filling machine throwing belt is adjusted, and the lump coal above the filling body is thrown and scattered. During the throwing and scattering process, the lump coal in the filling area is pushed and compacted and leveled by the movement of the gangue filling machine and the forward and backward telescoping of the push plate. When the thickness of the falling coal reaches 1 m, the push plate is stopped at the edge above the filling body by remote control, and at the same time, the telescopic plates on both sides of the push plate are opened, so that the telescopic plates completely contact the two sides of the roadway.

[0074] (10) The grouting pump is started, and the filling material is transported into the void of the thrown and scattered lump coal. When the slurry liquid level reaches the height of the lump coal accumulation, the grouting is stopped.

[0075] (11) Steps i-j are repeated to increase the filling height layer by layer. When the last layer of filling is completed and the thrown and scattered lump coal is about to reach the roof, the telescopic rod of the temporary support mechanism and the grouting pipeline are withdrawn, the position of the push plate is adjusted so that the front of the push plate is tightly attached to the filling body, the upper part is connected to the roof, and a slot is dug in the roof above the push plate. The nozzle of the filling pipeline is inserted into the filling space along the slot, and the roof filling of the first filling section of the roadway space is realized.

[0076] (12) The gangue filling machine is retreated by one filling step, and steps e-k are repeated to complete the filling work of the second section, the third section, and the entire roadway.

[0077] Example 2

[0078] According to the method of Example 1, the difference is that the paste filling material I is prepared by mixing: 25% of foamed coal, 20% of concentrated coal slurry, 34% of coal powder residue, 10% of cement, 1% of additive, and the rest is mine water, with the total mass percentage of each substance being 100%. The near-full coal paste filling material has a slurry concentration of 83%.

[0079] According to the method of Example 1, the difference is that the grouting filling material II is prepared by mixing: 25% of concentrated coal slurry, 31% of coal powder residue, 16% of cement, 1.5% of additive, and the rest is mine water, with the total mass percentage of each substance being 100%. The near-full coal grouting filling material has a slurry concentration of 72%.

[0080] Example 3

[0081] According to the method of Example 1, the difference is that the paste filling material I is prepared by mixing: 22% of foamed coal, 15% of concentrated coal slurry, 32% of coal powder residue, 8% of cement, 1% of additive, and the rest is mine water, with the total mass percentage of each substance being 100%. The near-full coal paste filling material has a slurry concentration of 81%.

[0082] The method of Example 1 is followed, except that the grouting filling material II is prepared by mixing, in mass percentage, 23% of thickened coal slurry, 28% of coal powder residue, 15% of cement, 1% of additive, and the balance being mine water, the total mass percentage of the above substances being 100%, to obtain a near-full coal grouting filling material with a slurry concentration of 70%.

[0083] Example 4

[0084] The method of Example 1 is followed, except that the paste filling material I is prepared by mixing, in mass percentage, 20% of coal slime, 12% of thickened coal slurry, 29% of coal powder residue, 8% of cement, 1% of additive, and the balance being mine water, the total mass percentage of the above substances being 100%, to obtain a near-full coal paste filling material with a slurry concentration of 79.5%.

[0085] The method of Example 1 is followed, except that the grouting filling material II is prepared by mixing, in mass percentage, 22% of thickened coal slurry, 27% of coal powder residue, 14% of cement, 1% of additive, and the balance being mine water, the total mass percentage of the above substances being 100%, to obtain a near-full coal grouting filling material with a slurry concentration of 69%.

[0086] Example 5

[0087] The method of Example 1 is followed, except that the paste filling material I is prepared by mixing, in mass percentage, 18% of coal slime, 15% of thickened coal slurry, 23% of coal powder residue, 7% of cement, 1.5% of additive, and the balance being mine water, the total mass percentage of the above substances being 100%, to obtain a near-full coal paste filling material with a slurry concentration of 78%.

[0088] The method of Example 1 is followed, except that the grouting filling material II is prepared by mixing, in mass percentage, 20% of thickened coal slurry, 26% of coal powder residue, 13% of cement, 1% of additive, and the balance being mine water, the total mass percentage of the above substances being 100%, to obtain a near-full coal grouting filling material with a slurry concentration of 68%.

[0089] Example 6

[0090] The method of Example 1 is followed, except that the paste filling material I is prepared by mixing, in mass percentage, 15% of coal slime, 25% of thickened coal slurry, 20% of coal powder residue, 5% of cement, 1.5% of additive, and the balance being mine water, the total mass percentage of the above substances being 100%, to obtain a near-full coal paste filling material with a slurry concentration of 77%.

[0091] The method of Example 1 is followed, except that the grouting filling material II is prepared by mixing: 15% of thickened slurry, 25% of coal powder residue, 10% of cement, 1.5% of additives, and the rest is mine water, with the mass percentage of each substance totaling 100%, to form a thickened slurry cement filling material with a concentration of 68%.

[0092] Performance detection

[0093] The laboratory performance detection of the paste filling material and the grouting filling material includes flowability and compressive strength tests. The flowability test is performed according to the GB / T8077-2023 test standard, with a metal truncated cone circular mold having a height of 300 mm, an upper diameter of 100 mm, and a lower diameter of 200 mm, and a glass plate having a size of 400x400x5mm.

[0094] The flowability of the paste filling material and the grouting filling material in different proportioning schemes in Examples 1-6 is tested respectively. The flowability test results of the paste filling material in Examples 1-6 are 185 mm, 213 mm, 204 mm, 243 mm, 265 mm, and 240 mm, respectively, as shown in Table 1. Figure 6

[0095] The flowability test results of the grouting filling material in Examples 1-6 are 225 mm, 233 mm, 245 mm, 273 mm, 275 mm, and 291 mm, respectively, as shown in Table 2. Figure 7

[0096] In the compressive strength experiment, a standard cubic test block with a size of 100x100x100mm is first poured, and the test block is placed in a curing box with a temperature of 20±2℃ and a humidity of not less than 90% for curing. After 24h, demolding is performed, and after demolding, curing is continued for 28d. After the curing is completed, a single-axis compressive strength test is performed using an electro-hydraulic servo universal testing machine.

[0097] The compressive strength test results of the paste filling material in Examples 1-6 are 7.3MPa, 6.6MPa, 6.7MPa, 5.9MPa, 5.3MPa, and 5.1MPa, respectively, as shown in Table 3. Figure 6

[0098] The compressive strength test results of the grouting filling material in Examples 1-6 are 5.7MPa, 5.3MPa, 5.2MPa, 4.6MPa, 4.55MPa, and 4.1MPa, respectively, as shown in Table 4. Figure 7

[0099] During the field application process, the material proportioning can be selected according to the above test results and combined with the actual engineering needs.

[0100] ​​​​The laboratory performance test of the cemented body formed by the lump coal and the grouting filling material includes the compressive strength test and the tensile strength test. First, the cemented body test specimen is prepared: several lump coals with a particle size of about 10 cm are placed in six 50x50x50 cm molds, and the paste filling material slurry in Examples 1-6 is respectively poured into the molds, and the surface is smoothed, and then placed in a standard curing box for curing for 24 h, and then demolded, and then cured for 28 d. The uniaxial compressive strength is tested by using an electro-hydraulic servo universal testing machine.

[0101] The compressive strength test results of the cemented bodies in Examples 1-6 are 3.2 MPa, 3.5 MPa, 2.2 MPa, 2.6 MPa, 3.0 MPa, and 2.8 MPa, respectively. The tensile strength test is tested by using an electro-hydraulic servo universal testing machine, and the tensile strength test results of the cemented bodies in Examples 1-6 are 0.52 MPa, 0.81 MPa, 0.69 MPa, 0.48 MPa, 0.61 MPa, and 0.85 MPa, respectively, as shown in Table 1. Figure 8

[0102] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.​

Claims

1. A method for fully filling a full coal of a high coal mining face of a fully mechanized caving coal face passing through an empty roadway, characterized in that, The method comprises the following steps: S1, obtaining the physical and mechanical parameters of the coal and rock strata and the mining technical parameters of the fully mechanized caving face; S2, obtaining the basic characteristics of the old goaf, including the cross-sectional shape, cross-sectional size, length, inclination angle and azimuth angle of the old goaf, the distance between the roof and floor of the old goaf and the roof and floor of the coal seam, the support method and parameters of the old goaf, and the type and concentration of the gas in the old goaf; S3, determining the in-situ filling method and materials for the fully mechanized caving face of the outburst mine passing through the old goaf: When b is greater than or equal to N and a is less than or equal to S, the filling method selects the paste filling material, and the filling is performed by the paste filling method; When b is greater than or equal to S and a is less than or equal to M, the filling method selects the lump coal and grouting filling material, and the filling is performed by the combined filling method of throwing and grouting; Wherein, a is the roof elevation of the old goaf, b is the floor elevation of the old goaf, M is the roof elevation of the coal seam, N is the floor elevation of the coal seam, and S is the top boundary elevation of the fully mechanized caving face; The paste filling material, the lump coal and the grouting filling material are all prepared by using the raw coal and the drill cuttings coal powder residue produced by the underground mining and roadway excavation; The preparation method of the paste filling material comprises the following steps: The raw coal produced by the underground mining and roadway excavation is sorted to separate the coal fines with a particle size less than 7mm and the coal slurry water; The coal slurry water is subjected to sedimentation and dehydration treatment to obtain the concentrated coal slurry water with a water content of 20% to 25%; The drill cuttings coal powder residue formed by the drilling in the underground mine is screened to remove impurities; The coal fines, the concentrated coal slurry water and the coal powder residue are mixed and stirred, cement, additives and mine water are added in the stirring process, and the paste filling material with a slurry concentration of 77% to 86% is prepared after uniform stirring; The preparation method of the lump coal and grouting filling material comprises the following steps: The raw coal produced by the underground mining and roadway excavation is sorted to separate the lump coal with a particle size of 9-11cm and the coal slurry water; The coal slurry water is subjected to sedimentation and dehydration treatment to obtain the concentrated coal slurry water with a water content of 20% to 25%; 2. The method for full-coal filling of a high coal mining face passing through an empty roadway according to claim 1, characterized in that, The drill cuttings coal powder residue formed by the drilling in the underground mine is screened to remove impurities; The concentrated coal slurry water and the coal powder residue are mixed and stirred, cement, additives and mine water are added in the stirring process, and the grouting filling material with a slurry concentration of 68% to 75% is prepared after uniform stirring. The paste filling method comprises the following steps: Arranging the filling column: a plurality of filling columns are arranged in the old goaf by injecting the filling material into the vertical filling bag, and the distance between adjacent filling columns is the same; 3. The method according to claim 2, characterized in that, Retreating the anchor: starting from the end of the old goaf close to the open-off cut of the fully mechanized caving face, the lock, tray, anchor net and steel belt of the roof and two sides of the old goaf are sequentially disassembled and recovered by the anchor retreating device; Establishing the filling body: after the single anchor retreat is completed, the filling body is established in the old goaf within the single anchor retreat distance range by the paste filling material until the old goaf is completely filled. The vertical filling bag is formed by cutting the length of the old mine waste air duct to be the same as the height of the old goaf, and the opening of one end of the air duct is sealed by air duct cloth to form a vertical filling bag; The opening end of the filling bag is hung on the area without anchor rod anchor cable on the roof of the old goaf by the anchor nail, the paste filling material is injected into the vertical filling bag to form a filling column, The paste filling material is pumped into the vertical filling bag through the grouting hose to form a filling column, and a filling column is established at every other end distance in the same way.

4. The method according to claim 3, characterized in that, An old and useless diameter wind pipe with a length equal to the width of the old goaf is cut, the cut wind pipe is opened at one end and sealed with a wind pipe cloth, and the other end is sealed with a wind pipe cloth and a grouting hole is left to form a horizontal filling bag, the filling bag is placed horizontally on the floor of the old goaf, the two ends of the horizontal filling bag contact the two sides of the old goaf, and the paste filling material is pumped into the horizontal filling bag through the grouting hose to make the horizontal filling bag freely expand, when the paste filling material slurry starts to overflow from the upper grouting hole, the grouting is stopped, the grouting hole is closed, and the two ends of the horizontal filling bag are fixed on the two sides of the goaf with anchor nails; A second horizontal filling bag is constructed in the same way next to the first horizontal filling bag which has been grouted, and a third horizontal filling bag is constructed at the middle position above the two filling bags after the two filling bags are consolidated, and the three horizontal filling bags form a filling retaining wall with a height of 0.9-1.1m; The space between the filling retaining wall and the old goaf or the filling body is grouted with paste filling material slurry through the grouting hose until the slurry liquid level is flush with the top surface of the retaining wall.

5. The method for full-coal filling of a high coal mining face passing through an empty roadway according to claim 1, characterized in that, The method for combined filling by throwing and grouting is specifically as follows: The old goaf is sequentially divided into multiple filling sections with the same filling step distance; Starting from the end of the old goaf close to the open-off cut of the fully-mechanized caving face, the locks, trays, anchor nets and steel belts of the roof and two sides of the old goaf are sequentially disassembled and recycled through the anchor withdrawing device; After the single-time anchor withdrawing is completed, the block coal is first thrown and scattered in the filling single layer, and then the grouting filling material is injected into the gap between the block coals until the slurry liquid level is flush with the top surface of the block coal, and the filling is completed after the whole solidification.

6. The method according to claim 5, characterized in that, The filling section is divided into multiple filling areas with the same height; During the throwing and scattering process, the block coal in the filling area is pushed and compacted and leveled by the movement of the gangue filling machine and the extension and retraction of the push plate, when the thickness of the block coal in the filling area reaches the requirement, the bottom of the push plate is fixed to the ground, and extension plates are arranged on both sides of the push plate so that the extension plates completely contact the two sides of the old goaf.

7. The method according to claim 6, characterized in that, When the filling area near the top wall of the old goaf is reached, the position of the push plate is adjusted so that the front of the push plate is tightly attached to the side surface of the filling body below and the upper part is connected to the roof, a slot is dug in the roof above the push plate, the nozzle of the filling pipeline is inserted into the filling space along the slot, and the roof connection filling of the filling area is realized.

8. The method for full-coal filling of a high coal mining face passing through an empty roadway according to claim 1, characterized in that, The paste filling material comprises the following components in percentage by weight: 15%-30% of coal fines, 10%-25% of concentrated coal slurry, 20%-35% of coal powder residue, 5%-15% of cement, 0.5%-1.5% of early strength agent, and 0.5%-1.5% of water reducing agent; The grouting filling material comprises the following components in percentage by weight: 15%-30% of concentrated coal slurry, 25%-40% of coal powder residue, 10%-20% of cement, 0.5%-1.5% of early strength agent, and 0.5%-1.5% of water reducing agent.

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