CN111441773B

CN111441773B - Retention method for mining ore pillar by room-pillar method for slowly-inclined medium-thickness ore body

Info

Publication number: CN111441773B
Application number: CN202010225820.6A
Authority: CN
Inventors: 张非; 孙庆和; 张东
Original assignee: Hebei Dabaiyang Gold Mine Co ltd
Current assignee: Hebei Dabaiyang Gold Mine Co ltd
Priority date: 2020-03-26
Filing date: 2020-03-26
Publication date: 2021-08-06
Anticipated expiration: 2040-03-26
Also published as: CN111441773A

Abstract

The invention discloses a retention method for stoping an ore pillar by a gentle dip medium-thickness ore body pillar method, which belongs to the technical field of mining, wherein a panel distribution area is selected, ore blocks are selected to be arranged in a way of being vertical to the trend of an ore body, and the ore blocks are divided into ore rooms and ore pillars; cutting a chamber, namely drilling and blasting shallow holes on the surfaces of the divided ore blocks to perform shallow hole blasting ore falling operation; stoping in a chamber, namely stoping by adopting a segmented open stope method; and (3) performing cemented filling, and filling the filling material into the chamber in sections by using the grouting device according to claim 1. According to the invention, by designing the pillar structure, filling the mined-out chamber in a sectional manner, monitoring and controlling the grouting pressure and monitoring the ground pressure of the mining area by adopting a 5G technology in the filling process, the ground pressure is effectively controlled, and differential settlement and roof collapse accidents of the mining area are prevented and reduced.

Description

Retention method for mining ore pillar by room-pillar method for slowly-inclined medium-thickness ore body

Technical Field

The invention belongs to the technical field of mining, and particularly relates to a retention method for stope pillars of a gentle dip medium-thickness ore body room-pillar method.

Background

The slowly inclined medium-thick ore body is an ore body with an inclination angle of 5-30 degrees and a thickness of 4-15m, and the ore body occupies a certain proportion in China. In the proven 105 hundred million t phosphorite resources, the ore accounts for 86 percent, the iron ore reserves account for 18 percent, the nonferrous metals account for 5 to 9 percent, the copper is taken as the main component, and the lead, the zinc, the molybdenum, the antimony and the like are taken as the secondary components. In addition, the manganese ore, clay ore, pyrite and alum ore resources have a considerable proportion, according to the statistics of domestic slow-inclined medium-thick ore body mines, the room-pillar mining method accounts for 50%, the chassis-funnel mining method accounts for 35%, and foreign ore bodies mainly adopt a room-pillar method, and the proportion of the ore bodies reaches 61%.

The exposed area of the mined out-of-place area of the slowly inclined medium-thickness ore body mined by the room-pillar method is large, and the overburden stratum is easy to generate large moving deformation due to inappropriate room-pillar method deformation schemes and stope parameters, so that the ground surface is subjected to large deformation settlement.

Disclosure of Invention

The invention aims to provide a grouting device which is used for grouting and backfilling in the room pillar mining process to keep the stability of a stope, ensure the safety production, simultaneously realize the full filling of a stope by grouting fillers and avoid the problem that cracks exist in the room pillar and rock mass in the stope due to the overlarge pressure of grouting on the rock mass.

The technical scheme adopted by the invention for realizing the first purpose is as follows: a grouting device comprising:

a material buffering box is arranged at the front end of the material buffering box,

at least two main feeding pipes which penetrate through the hollow buffer tank and discharge the second filler from the pipe body of the main feeding pipe positioned outside the buffer tank,

a feeding auxiliary pipe which penetrates through the buffer box and discharges the first filler from a pipe body positioned outside and inside the buffer box, and can discharge the discharged first filler from a discharge hole I of the buffer box to be mixed with the second filler,

wherein, slip casting device still includes: a circulating pipe for adjusting the pressure of the second filler in the at least two feeding main pipes, wherein the circulating pipe is arranged in a snake shape between the at least two feeding main pipes, the feeding/discharging end of the circulating pipe is connected with the liquid circulating pump,

wherein, slip casting device still includes: and the fastening sleeve body is arranged on the surface of the feeding main pipe in the buffer box and is used for controlling the linear distance between two points on the feeding main pipe and the pipe diameter.

The invention utilizes the buffer bin to discharge the first filler fed in the feeding auxiliary pipe into the chamber, the feeding main pipe sprays the second filler outside the buffer bin, the first filler and the second filler are ejected from different positions to realize the mixing of the fillers, so that a multi-directional ejection effect and a filling range are obtained, the filler after mixing is in full contact with the rock mass, the problem that the rock mass is cracked due to overlarge ejection impact pressure on the rock mass caused by overlarge ejection pressure caused by one-directional ejection is solved, the deformable hose is formed by utilizing the circulating pipe of the internally circulating flowing liquid in the process of feeding the filler into the feeding main pipe, the pressure of the filler flowing in the feeding main pipe relative to the circulating pipe can be absorbed by the circulating pipe or the proper filler injection pressure can be regulated and controlled, the filler flowing effect in the feeding main pipe is changed, and the filler injection effect is improved.

According to an embodiment of the present invention, the grouting device further includes:

and a flow restricting sleeve which is sleeved on the feeding auxiliary pipe in the buffer tank, is provided with a first annular part with the inner diameter equal to the outer diameter of the feeding auxiliary pipe and a second annular part with the inner diameter smaller than the outer diameter of the feeding auxiliary pipe, and reduces the flow surface of the mounting point by arranging the flow restricting sleeve on the feeding auxiliary pipe so as to expand the flow velocity of the fluid passing through the flow surface.

According to one embodiment of the invention, the flow limiting sleeve is sleeved on the feeding auxiliary pipe in the feeding direction of the buffer box and is used for expanding the flow speed of the filler in the feeding auxiliary pipe in the buffer box so as to ensure that the first filler is discharged from the discharge hole I of the buffer box and is mixed with the second filler.

According to one embodiment of the invention, the flow limiting sleeve is sleeved on the feeding auxiliary pipe in the discharging direction of the buffer box and is used for increasing the flow speed of the filler in the feeding auxiliary pipe outside the buffer box so as to ensure the integral filling speed of the filler.

According to an embodiment of the present invention, the fastening sleeve body is composed of at least two annular elastic fastening ring bodies and a fastening strip which is used for connecting adjacent fastening ring bodies and can be deformed in a stretching manner. The fastening ring body is sleeved on the feeding auxiliary pipe in the buffer box, the arranged fastening strip is arranged on the fastening sleeve body in a surrounding mode, uniform gaps are formed in the fastening sleeve body, the mode that the fastening sleeve body is arranged on the feeding main pipe in the buffer box is used for reducing the too strong pressure of the first filler in the buffer box to the feeding main pipe so as to avoid reducing the flow area of a certain point position of the feeding main pipe in the buffer box.

According to one embodiment of the invention, one end parts of at least two main feeding pipes are connected with a grouting pump through a multi-way pipe fitting, the other end parts of the at least two main feeding pipes are arranged in a buffer ball body with a cavity structure, a second pressure monitor is arranged outside the buffer ball body, a first pressure monitor is arranged at the grout outlet end of the grouting pump, and the first pressure monitor and the second pressure monitor are respectively connected with a pressure control unit for controlling the grouting pump. The outer wall of the feeding main pipe connected with the buffer box is provided with a sealing ring. The mode that sets up the second pressure monitor on feeding main pipe tip setting buffer ball body obtains the packing pressure signal that fills in the stope and accomplishes data transmission to the pressure control unit through 5G communication network, and the pressure control unit control grouting pump stops work or adjusts grouting pump operating parameter.

The second purpose of the invention is to provide a retention method for stoping the stope by the room-column method of the gently inclined medium-thickness ore body, design the structure of the stope, fill the stope in a sectional mode after the stope is empty, monitor and regulate the grouting pressure by adopting a 5G technology in the filling process, monitor the ground pressure of a mining area, effectively control the ground pressure, and prevent and reduce differential settlement and roof collapse accidents of the mining area.

The technical scheme adopted by the invention for realizing the second purpose is as follows: a retention method for stoping an ore pillar by a room-pillar method of a slowly-inclined medium-thickness ore body comprises the following steps:

selecting a distribution panel, selecting ore blocks to be arranged in a direction perpendicular to the direction of an ore body (the thickness of the ore body is more than or equal to 10m), and dividing the ore blocks into ore rooms and ore pillars;

cutting a chamber, and drilling and blasting shallow holes on the surface of the divided ore blocks to perform shallow hole blasting ore falling operation;

stoping in a room, stoping by a segmented open stope method;

cementing and filling, namely filling the filling materials into the chamber in sections by using a grouting device.

In order to prevent a large number of goafs and deep mining work from occurring in a mining area, the method adopts a room-pillar method to mine ore blocks and adopts a mode of retaining ore pillars to ensure the stability of the mining area, and further adopts a mode of filling fillers to ensure the stability of the mining area, thereby preventing and reducing the occurrence of disastrous accidents such as rock burst, rock stratum caving and the like.

According to one embodiment of the invention, the width of a chamber is 10-15m, the width of a pillar is 4-6m, the chamber is divided into 5 sections along the height of the chamber, the height of each section is 10m, a 7m high top pillar is reserved, the pillar is divided into 5 sections, the height of each section is 10m, each section is divided into 3 layers, and each layer connects the layers with a section roadway through a layer connecting channel. The method is mining by a pillar method, the mining is carried out by dividing the ore blocks and specifically designing the widths of the ore rooms and the pillars, the stress migration and displacement change at the top plate are lower in the mining process under the size, two steps of mining are carried out after the division of the ore blocks is finished, the divided ore rooms are mined firstly in the first step, the mined ore rooms are backfilled in the second step, and the mining work of the next depth is carried out until the mining of the ore blocks in the mining area is finished after the backfilled filler is condensed and the maintenance strength meets the conditions.

According to an embodiment of the invention, the filler comprises, in relative parts by mass with respect to the cement: 100 portions of cement, 300 portions of fine sand, 100 portions of slag, 160 portions of slag, 0.2 to 0.55 portion of water reducing agent, 20 to 35 portions of silica fume, 0.4 to 0.6 portion of defoaming agent, 0.1 to 0.23 portion of accelerating agent and 0.4 to 0.55:1 of water-cement ratio.

According to one embodiment of the invention, the slag is waste ore which is crushed and poured into slag with a square or round section, and the particle size of the slag is 1.5-4 mm; the method selects the slag and waste rocks generated by mining to be crushed into the slag with smaller granularity, and pours the slag by adopting a pouring mode.

According to one embodiment of the invention, the 28 d-age compressive strength of the filler is more than or equal to 37.4MPa, the 28 d-age destructive load is more than or equal to 828.3/KN, the filler is proportioned and filled in an empty stope, higher compressive strength is obtained after the filler is condensed, the filler with the performance is used for reducing differential settlement occurring at each area position of the stope and simultaneously ensuring the support of a top plate of a filling area, and the stability of the stope is ensured by filling the filler when the tensile failure or the shear failure of a rock mass occurs in the area range of the filled stope.

According to one embodiment of the invention, when the chamber is filled in sections, the first filling is adopted for the first section filling: the second filler is 1:4 filler, and the other part adopts the first filler: the second filler is a filler with the ratio of water to cement of 1:5-10, the ratio of the first filler to the water to cement is 0.4:1, the ratio of the second filler to the water to cement is 0.5:1, the ratio of the first filler to the second filler is reduced by reducing the ratio of the first filler to the second filler in order to ensure the strength, durability and a series of physical and mechanical properties of the first filler in the first segmented filling process, so that the rheological property, the cement paste coagulation structure and the compactness after hardening of the finally mixed filler are ensured, and the dosage ratio of the first filler to the second filler can be properly enlarged in the subsequent segmented filling process under the condition of ensuring the support strength and stability of a mine area of the filler, so that the filling cost is reduced.

According to an embodiment of the invention, the cross section of the ore pillar for dividing the chamber in the shallow hole blasting ore-breaking operation is an L-shaped/inverted T-shaped structure, for a mining area, the ore pillar support is the core of a stope support system, the stope stability is important through the reasonably designed ore pillar structure, the size and the structure of the ore pillar are designed according to the load-displacement relational expression of the ore pillar, the displacement of the ore pillar under the load is reduced, and the stability of the stope is ensured, and the specific calculation formula is as follows:

wherein k is the initial rigidity of the pillar, and k is EbA/D₁；

u₀The rock mass top plate sinking amount corresponding to the peak value strain;

a is the cross-sectional area of the pillar, and A ═ Z₁×D₁+Z₂×D₂，Z₁Is the width of the vertical part of the pillar, Z₂Is the width of the extended part of the ore pillar,

D₁to the height of the chamber, D₂Is the height of the extending part of the ore pillar; the initial rigidity of the ore pillar is improved by changing the cross-sectional area of the ore pillar, particularly by arranging an extension part at the bottom of the ore pillar, the extension part can downwardly disperse the pressure concentrated on the ore pillar to the extension part in the process of bearing the self weight of the rock roof and the pressure of the overlying rock stratum, and the stress of the vertical part of the ore pillar is reduced by utilizing the expansion of the contact area of the extension part and the ore room so as to reduce the pressure instability and even the loss of the supporting capability of the ore pillar, so that the design has better buffering effect on the sudden roof caving of the stope, the stress change occurring instantaneously is borne by the ore pillar main body and the extension part, so that the accidents of instantaneously burying the roadway and the stope are avoided, certain reaction time is provided for personnel in a stope area, the design of the extension part also enlarges the ratio of the area of the ore pillar to the total area of a stope dead zone, and the stability of the stope is ensured when the area ratio of the ore pillar is more than 30 percent.

According to one embodiment of the invention, in the backfilling process of the stope, the grouting pressure is monitored and controlled, the ground pressure of the mining area is monitored, and the whole monitoring and controlling process is completed by transmitting data and/or control instructions through a 5G communication network. The 5G communication network has the characteristics of high bandwidth, high capacity, high reliability, low time delay and low power consumption, compared with the 4G communication network, the 5G communication network has the performance superior to the 4G communication network in the indexes of transmission rate, time delay and the like, the rapid transmission can be realized for massive monitoring data, the alarm response time for early warning accidents in a mining area can be greatly shortened, the escape rate and the survival rate of personnel in the mining area can be greatly improved, and the 5G communication network can be used for realizing the real-time maintenance of the pressure stability of the filling filler in the process of monitoring the filling filler.

Compared with the prior art, the invention has the beneficial effects that: the invention adopts a room-pillar method to mine ore blocks and adopts a mode of reserving ore pillars and backfilling filler to ensure the stability of an ore area, thereby preventing and reducing the occurrence of disastrous accidents such as rock burst, rock stratum caving and the like.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 shows a cross-sectional view A-A of a gently sloping medium thickness ore body mining process as set forth in an embodiment of the present application;

FIG. 2 illustrates a cross-sectional view of C-C during mining of a gently sloping medium thickness ore body as set forth in an embodiment of the present application;

FIG. 3 illustrates a cross-sectional view B-B of a gently sloping medium thickness ore body mining process as set forth in an embodiment of the present application;

fig. 4 shows a schematic diagram of pillar mining and a room according to the room and pillar method proposed in the embodiment of the present application;

fig. 5 shows a schematic view of a grouting device proposed in an embodiment of the present application;

FIG. 6 shows a schematic structural diagram of a fastening sleeve proposed by an embodiment of the present application;

FIG. 7 shows an enlarged schematic view of section a of FIG. 5;

FIG. 8 is a schematic diagram showing the connection of the first and second pressure monitors, the pressure control unit, and the grouting pump according to the embodiment of the present application;

fig. 9 shows a structure diagram of a 5G communication network proposed in the embodiment of the present application;

fig. 10 shows a flow chart of a retention method for pillar extraction of a gently inclined medium-thickness ore body by a room-pillar method according to an embodiment of the application;

FIG. 11 shows the compressive strength of a filler in test example 2 proposed in the examples of the present application;

fig. 12 shows that the examples of the present application propose the filler permeation resistance in experimental example 2.

Description of reference numerals: 10-a chamber; 11-a stoping route; 12-blasting shallow holes; 13-segmented contact lane; 14-ore pass; 15-segmenting a roadway; 16-a middle-section transportation vein-passing roadway; 17-ore; 18-a return air shaft; 19-a top plate; 20-pillar; 30-a filler; 40-a circulating pump; 41-circulation pipe; 50-buffer box; 51-a discharge hole I; 52-sealing ring; 53-auxiliary feed pipe; 54-a discharge hole II; 60-multi-way pipe fittings; 61-main feed pipe; 62-a fastening sleeve body; 621-a fastening ring body; 622-fastening the strip body; 63-a discharge hole III; 64-a buffer sphere; 70-a second pressure monitor; 80-flow limiting sleeve.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

An embodiment of the present invention provides a grouting device, including:

the material buffering box (50) is arranged on the machine,

at least two main feeding pipes 61, wherein the at least two main feeding pipes 61 penetrate through the hollow buffer tank 50 and discharge the second filler from the pipe body of the main feeding pipe 61 positioned outside the buffer tank 50,

a feeding sub-pipe 53 which penetrates the buffer tank 50, discharges the first filler from a pipe body located outside the buffer tank 50, and can discharge the discharged first filler from a discharge hole I51 provided in the buffer tank 50 to mix with the second filler,

wherein, slip casting device still includes: a circulating pipe 41 for adjusting the pressure of the second packing in the at least two main feeding pipes 61, the circulating pipe 41 being arranged in a serpentine shape between the at least two main feeding pipes 61, the inlet/outlet end of the circulating pipe 41 being connected to the liquid circulating pump 40,

wherein, slip casting device still includes: and a fastening sleeve body 62 which is arranged on the surface of the feeding main pipe 61 in the buffer tank 50 and is used for controlling the linear distance pipe diameter of two points on the feeding main pipe 61.

The invention respectively feeds filler into a main feeding pipe 61 and an auxiliary feeding pipe 53 through two grouting pumps, the filler mixing effect in a filled chamber is improved by the mode, specifically, a buffer tank 50 is utilized to discharge first filler fed in the auxiliary feeding pipe 53 into the chamber, the main feeding pipe 61 sprays second filler outside the buffer tank 50, the first filler and the second filler are ejected from different parts to realize the mixing of the fillers, a multi-direction spraying effect and a filling range are obtained, the mixed filler is beneficial to the full contact between rock masses, the problem that the rock masses are cracked due to overlarge spraying impact pressure caused by overlarge spraying pressure intensity caused by one-direction spraying is avoided, meanwhile, in order to regulate and control the spraying speed of the main feeding pipe 61, a deformable hose is formed by a circulating pipe 41 of internally circulating flowing liquid in the process of feeding the main feeding pipe 61 to feed the filler, the pressure of the filler flowing in the feeding main pipe 61 relative to the circulating pipe 41 can be absorbed by the circulating pipe 41 or the proper filler injection pressure can be regulated and controlled, the filler flowing effect in the feeding main pipe 61 is changed, the injection effect of the filler is improved, the outer diameter of the circulating pipe 41 can be adjusted along with the pressure, so that the internal flow area of different points on the feeding main pipe 61 can be adjusted to reduce the probability of blockage, and the mode that the fastening sleeve body 62 is arranged on the feeding main pipe 61 in the buffer tank 50 is used for reducing the excessive pressure of the first filler in the buffer tank 50 on the feeding main pipe 61 so as to avoid reducing the flow area of a certain point of the feeding main pipe 61 in the buffer tank 50.

The selected main feeding pipe 61 and the selected auxiliary feeding pipe 53 are rubber pipes, specifically rubber pipes prepared by taking polyurethane and butyl rubber as main raw materials, the working pressure is 2.5-7.5MPa at normal temperature, the circulating pipe 41 is a PVC hose, and the internal circulating flowing medium is water.

In an embodiment of the present invention, the grouting device further includes:

and a flow restricting sleeve 80 which is fitted around the auxiliary feed pipe 53 in the buffer tank 50, the flow restricting sleeve 80 having a first annular portion with an inner diameter equal to an outer diameter of the auxiliary feed pipe 53 and a second annular portion with an inner diameter smaller than the outer diameter of the auxiliary feed pipe 53, the flow restricting sleeve 80 being provided on the auxiliary feed pipe 53 to narrow a flow surface of a mounting point to increase a flow rate of a fluid passing through the flow surface, the flow restricting sleeve 80 preferably being made of a metal material and having a hardness higher than that of the auxiliary feed pipe 53.

In an embodiment of the present invention, the flow-limiting sleeve 80 is sleeved on the feeding secondary pipe 53 in the feeding direction of the buffer bin 50, and is used for increasing the flow speed of the filler in the feeding secondary pipe 53 in the buffer bin 50 to ensure that the first filler is discharged from the discharge hole I51 of the buffer bin 50 and mixed with the second filler.

In an embodiment of the present invention, the flow limiting sleeve 80 is sleeved on the feeding sub-pipe 53 in the discharging direction of the buffer box 50, and is used for increasing the flow speed of the filler in the feeding sub-pipe 53 outside the buffer box 50 to ensure the overall filling speed of the filler.

In an embodiment of the present invention, the fastening sleeve 62 is composed of at least two annular elastic fastening ring bodies 621 and a fastening strip 622 capable of being deformed in a stretching manner for connecting the adjacent fastening ring bodies 621. The fastening ring body 621 is sleeved on the feeding auxiliary pipe 53 in the buffering box 50, the fastening strips 622 are arranged on the fastening sleeve body 62 in a surrounding manner and have uniform gaps, and the mode that the fastening sleeve body 62 is arranged on the feeding main pipe 61 in the buffering box 50 is used for reducing the overlarge pressure of the first filler in the buffering box 50 on the feeding main pipe 61 so as to avoid reducing the flow area of a certain point of the feeding main pipe 61 in the buffering box 50.

In an embodiment of the present invention, one end of at least two main feeding pipes 61 is connected to the grouting pump through a multi-way pipe 60, the other end of at least two main feeding pipes 61 is disposed in a buffer sphere 64 having a cavity structure, a second pressure monitor 70 is disposed outside the buffer sphere 64, a first pressure monitor is disposed at a grout outlet end of the grouting pump, and the first pressure monitor and the second pressure monitor are respectively connected to a pressure control unit for controlling the grouting pump. The outer wall of the feeding main pipe 61 connected with the buffer tank 50 is provided with a sealing ring 52. The mode that the second pressure monitor 70 is arranged on the buffering ball 64 arranged at the end part of the feeding main pipe 61 is used for obtaining a filling pressure signal in a filling chamber and completing data transmission to the pressure control unit through a 5G communication network, the pressure control unit receives feedback data of the first pressure monitor and the second pressure monitor in real time and compares the feedback data, when the second pressure monitor or the first pressure monitor reaches a preset value, the pressure control unit controls the grouting pump to stop working or adjusts the operation parameters of the grouting pump (the initial filling pressure is 4MPa, and the grouting pressure is adjusted to be 1.5-2.5MPa), so that the grouting pressure in the filling chamber is stable, and the problem that the rock body is cracked due to overlarge injection impact pressure caused by overlarge injection pressure on the rock body is solved.

An embodiment of the present invention provides: a retention method for stoping an ore pillar by a room-pillar method of a slowly-inclined medium-thickness ore body comprises the following steps:

s10, selecting a panel distribution area, selecting ore blocks to be arranged perpendicular to the trend of the ore body (the thickness of the ore body is more than or equal to 10m), dividing the ore blocks into ore rooms and ore pillars, wherein the mining preparation engineering mainly comprises a mining area slope way, a segmented roadway, a segmented connecting way, a layered connecting way (ore room), a chute, a filling small well (ore room), a filling return air well (ore pillar), a smooth road water filtering well (ore pillar) and a mining approach (ore room), and the cutting engineering mainly comprises a cutting drift and a cutting raise;

s20, cutting the chamber, and drilling and blasting the shallow holes 12 on the surface of the divided ore blocks to perform shallow hole blasting ore falling operation;

s30, stoping the chamber, stoping by a segmented open stope method, drilling fan-shaped shallow holes in a segmented roadway by a YGZ-90 rock drill when stoping the chamber, wherein the row spacing is 1.5-1.8m, the hole bottom spacing is 2-2.3m, the mined ores are transported to a mining area drop shaft through a mining approach by a scraper conveyor, stoping the pillars layer by layer from bottom to top by a rock drilling trolley when stoping the chamber, the exploded ores are transported to the mining area drop shaft through the mining approach by the scraper conveyor, controlled blasting is adopted for coping, the top plate is guaranteed to be flat and stable, the chamber is ventilated in an upward air flow through manner, and the chamber and the pillars are ventilated with local fan assistance, so that a good operation environment is guaranteed;

s40, when ore is removed, the ore which is removed in sections is shoveled and loaded in the mining route by a shoveling and transporting machine and then is unloaded to the ore pass out of the vein, after the last subsection is finished, the ore which is not removed completely is cleaned by a remote control shoveling and transporting machine, and the ore is shoveled and taken by the remote control shoveling and transporting machine and then is directly unloaded to the ore pass out of the vein. When the ore pillar is removed, the scraper is unloaded into the extravenous draw shaft after the ore is shoveled and loaded by the stoping route. Finally, the ore in the draw shaft is transported to a bottom yard of the main shaft through an electric locomotive and is lifted to the ground surface through the main shaft;

and S50, performing cemented filling, and filling the filling materials into the chamber in sections by adopting a grouting device.

Note: the size of the cross section of the approach path is 3m × 4.2m (width × height).

In one embodiment of the invention, the width of the chamber is 10-15m, the width of the pillar is 4-6m, the chamber is divided into 5 subsections along the height of the chamber, the height of the subsections is 10m, meanwhile, a 7m high top pillar is reserved, the pillar is divided into 5 subsections, the height of the subsections is 10m, each subsection is divided into 3 layers, and each layer is connected with a subsection roadway 15 through a layer connecting channel 13. The method is mining by a pillar method, the mining is carried out by dividing the ore blocks and specifically designing the widths of the ore rooms and the pillars, the stress migration and displacement change at the top plate are lower in the mining process under the size, two steps of mining are carried out after the division of the ore blocks is finished, the divided ore rooms are mined firstly in the first step, the mined ore rooms are backfilled in the second step, and the mining work of the next depth is carried out until the mining of the ore blocks in the mining area is finished after the backfilled filler is condensed and the maintenance strength meets the conditions.

In one embodiment of the present invention, the filler 30 includes, in relative parts by mass with respect to the cement: 100 portions of cement, 300 portions of fine sand, 160 portions of slag, 0.2 to 0.55 portion of water reducing agent, 20 to 35 portions of silica fume, 0.4 to 0.6 portion of defoaming agent, 0.1 to 0.23 portion of accelerating agent, the water-cement ratio is 0.4 to 0.55:1,

the invention meets the standard requirements by using the physical property and the mechanical property of the filling filler, the mixture in the filling filler has good spraying uniformity and can not fall off, the mixture can be firmly combined with the rock surface to effectively reduce the phenomenon of shrinkage joints generated by filler solidification, the filler has better compressive strength and higher water seepage resistance after being solidified, and the mining area differential settlement and roof fall accidents after the filling are prevented and reduced, preferably, the cement is preferably P.O42.5 common portland cement, preferably, the particle size of fine sand is 0.25-0.35mm, preferably, slag is formed by pouring the crushed waste ore into square or round slag with the section of 1.5-4 mm; selecting the silica fume with the grain diameter of 0.1-0.3 mu m; preferably, the water reducing agent is at least one compound selected from the group consisting of lignosulfonate, polyol derivative, naphthalene sulfonic acid-formaldehyde condensate, and polymer having polyoxyalkylene group and anionic group, and defoaming agent such as glycerin, polyvinyl alcohol, sodium aluminosilicate, sulfanilic acid, casein, and the like. Preferably, the defoaming agent is mineral oil defoaming agent, and preferably, the accelerating agent is inorganic salt accelerating agent, in particular to monascus I type. In order to further improve the water seepage prevention performance of the filled filler, in an embodiment of the invention, the backfilled filler further comprises, in relative parts by mass relative to the cement: 0.03-0.05 part of allantoin. The addition of the allantoin can also reduce and improve the compressive strength of the filler, and specifically realizes that the compressive strength of the filler at 28d age is more than or equal to 37.4MPa, and the breaking load at 28d age is more than or equal to 828.3/KN.

In one embodiment of the invention, the slag is waste ore which is crushed and poured into slag with a square or round section, and the particle size of the slag is 1.5-4 mm; the method selects the slag with the particle size of 0.1-0.3 mu m, crushes the slag and waste rocks generated by mining to form the slag with smaller particle size, and pours the slag in a pouring mode, and aims to reduce the influence of the slag on the stirring performance of a filler in a mixing process and the flowability of the formed filler in a conveying process, relatively improve the mixing and stirring speed of the filler and the flowability of the filler, particularly improve the shearing action of the slag on filler slurry in a flowing process of the filler by the regularly-shaped slag, and is better in the flowability of the filler with a square or circular cross section compared with the irregular slag, thereby being beneficial to improving the mechanical properties of the condensed filler, such as the compressive strength and the like.

In one embodiment of the invention, the 28 d-age compressive strength of the filler is more than or equal to 37.4MPa, the 28 d-age destructive load is more than or equal to 828.3/KN, the filler is proportioned and filled in an empty stope, higher compressive strength is obtained after the filler is condensed, the filler with the performance is used for reducing differential settlement occurring at each area position of the stope and simultaneously ensuring the support of a top plate of a filling area, and the stability of the stope is ensured by filling the filler when the tensile failure or the shear failure of a rock mass occurs in the area range of the filled stope.

In one embodiment of the present invention, when the chamber is filled in sections, the first filling is used for the first section filling: the second filler is 1:4 filler, and the other part adopts the first filler: the second filler is a filler with the ratio of water to cement of 1:5-10, the ratio of the first filler to the water to cement is 0.4:1, the ratio of the second filler to the water to cement is 0.5:1, the ratio of the first filler to the second filler is reduced by reducing the ratio of the first filler to the second filler in order to ensure the strength, durability and a series of physical and mechanical properties of the first filler in the first segmented filling process, so that the rheological property, the cement paste coagulation structure and the compactness after hardening of the finally mixed filler are ensured, and the dosage ratio of the first filler to the second filler can be properly enlarged in the subsequent segmented filling process under the condition of ensuring the support strength and stability of a mine area of the filler, so that the filling cost is reduced.

In an embodiment of the present invention, the pillar section that partitions the room during the shallow hole blasting ore-breaking operation is an L-shaped/inverted T-shaped structure, for the mining area, the pillar support is the core of the stope support system, the pillar structure that is reasonably designed has an important effect on the stope stability, the pillar size and structure are designed according to the load-displacement relational expression of the pillar to reduce the displacement of the pillar under load, and the stability of the stope is ensured, and the specific calculation formula is as follows:

wherein k is the initial rigidity of the pillar, and k is EbA/D₁；

In one embodiment of the invention, in the backfilling process of the chamber, the grouting pressure is monitored and controlled, the ground pressure of the mining area is monitored, and the whole monitoring and controlling process is completed by transmitting data and/or control instructions through a 5G communication network. The 5G communication network has the characteristics of high bandwidth, high capacity, high reliability, low time delay and low power consumption, compared with the 4G communication network, the 5G communication network has the performance superior to the 4G communication network in the indexes of transmission rate, time delay and the like, the rapid transmission can be realized for massive monitoring data, the alarm response time for early warning accidents in a mining area can be greatly shortened, the escape rate and the survival rate of personnel in the mining area can be greatly improved, and the 5G communication network can be used for realizing the real-time maintenance of the pressure stability of the filling filler in the process of monitoring the filling filler.

The used 5G communication network mainly consists of a core network, a macro base station and a micro base station, as shown in fig. 9, the core network is the "brain" of the communication system and is responsible for the control of the system and the transmission of information data, and calls or data requests of different ports are connected to the corresponding network. The macro base station is a central nerve of the communication system, is connected with a core network through optical fibers or microwaves, and transmits information to the macro base station, the micro base station and users corresponding to different areas through wireless communication. The macro base station has large transmitting power and wide coverage radius. The single carrier transmission power is generally larger than 10W, and the coverage radius is generally more than 200 m. The micro base station is the peripheral nerve of the communication system, the transmitting power of the micro base station is low, the coverage radius is small, the cooperative coverage of a large number of micro base stations can ensure the signal intensity of each area, and the wireless connection density is improved.

The monitoring and debugging operations of the grouting pressure of the filler during filling are as follows: the pressure data acquired by the first pressure monitor and the second pressure monitor are received and fed back to the pressure control unit through the 5G communication network, the acquired data and the preset value are compared and processed by the pressure control unit, and when the acquired value is larger than the preset value, the grouting pump is controlled to stop working or the injection pressure of the grouting pump is adjusted, so that the grouting pressure in the filled chamber is stable, and the problem that the rock body is cracked due to overlarge injection impact pressure caused by overlarge injection pressure to the rock body is solved.

The operation of monitoring the ground pressure of the mining area is as follows: the method comprises the steps of installing stress meters and multipoint displacement meters (including filled rooms and pillars) on mined rooms and pillars, selecting Korean 1338VW type borehole stress meters for the stress meters, enabling the multipoint displacement meters to be BOR-EX type borehole multipoint displacement meters, collecting and transmitting data to an industrial personal computer control unit by using a 5G communication network, processing the data by the industrial personal computer control unit, displaying the processed data in a graph and numerical mode, displaying the monitored data in a statistical settlement map, a settlement table and other modes, setting preset values, carrying out alarm operation after the data values reach the preset values, evacuating mine area workers in time and taking corresponding emergency measures. During low-pressure monitoring, two independent monitoring processes are carried out in a linking manner, the monitoring result is used as an initial value of deformation measurement, and then the monitoring process is carried out once every 15 days in the first 6 months, once every month in 7-12 months and once every 2 months later.

Reporting is needed in the monitoring process to facilitate adjustment of the monitoring scheme:

1) the deformation amount or the deformation rate has sudden abnormal change;

2) the deformation of the monitored numerical value reaches or exceeds a critical early warning value, namely the monitored numerical value exceeds a preset value;

3) collapse, rock burst and surface abnormality of each middle section of the mining area;

4) and other abnormal deformation conditions caused by natural disasters such as earthquakes.

Example 1:

referring to fig. 5-8, a grouting device includes: buffer bin 50, be responsible for 61 including two feeding, and a feeding auxiliary pipe 53, the feeding is responsible for 61 and feeding auxiliary pipe 53 body material and pipe diameter unanimously, buffer bin 50 still includes columnar buffer bin 50, the inside cavity setting of buffer bin 50, feeding is responsible for 61 and runs through the buffer bin 50 that cavity set up and is responsible for the body discharge second filler of 61 by the feeding that is located outside buffer bin 50, feeding in buffer bin 50 is responsible for 61 surface mounting and is had the fastening cover body 62, fastening cover body 62 comprises two at least rings form and have elastic fastening ring body 621 and be used for connecting adjacent fastening ring body 621 and the fastener 622 that can stretch out and draw back deformation. The feeding secondary pipe 53 penetrates through the buffer box 50 and discharges first filler from a pipe body positioned in the outer part 50 of the buffer box, the discharged first filler can be discharged from a discharge hole I51 arranged in the buffer box 50 and mixed with second filler, a flow-limiting sleeve body 80 is arranged on the feeding secondary pipe 53 in the buffer box 50, the flow-limiting sleeve body 80 is provided with a first annular part with the inner diameter equal to the outer diameter of the feeding secondary pipe 53 and a second annular part with the inner diameter smaller than the outer diameter of the feeding secondary pipe 53, the flow-limiting sleeve 80 is sleeved on the feeding secondary pipe 53 in the feeding direction of the buffer box 50, one end parts of two feeding main pipes 61 are connected with the grouting pump through a three-way pipe, the feeding secondary pipe 53 is simultaneously connected with a second grouting pump, the other end parts of the two feeding main pipes 61 are arranged in a buffer ball 64 with a cavity structure, a second pressure monitor 70 is arranged outside the buffer ball 64, the slurry outlet ends of the two grouting pumps are respectively provided with a first pressure monitor, and the first pressure monitor and the second pressure monitor are respectively connected with a pressure control unit for controlling the grouting pump, the outer wall of the feeding main pipe 61 connected with the buffer tank 50 is provided with a sealing ring 52.

The selected main feeding pipe 61 and the selected auxiliary feeding pipe 53 are rubber pipes which are prepared by taking polyurethane and butyl rubber as main raw materials, the working pressure is 2.5-7.5MPa at normal temperature, and the circulating pipe 41 is a PVC hose.

When the filling material is grouted and filled into the chamber, the filling material pressure is monitored, and the method specifically comprises the following steps: the pressure data acquired by the first pressure monitor and the second pressure monitor are received and fed back to the pressure control unit through the 5G communication network, the acquired data and the preset value are compared and processed by the pressure control unit, and when the acquired value is larger than the preset value, the grouting pump is controlled to stop working or the injection pressure of the grouting pump is adjusted, so that the grouting pressure in the filled chamber is stable, and the problem that the rock body is cracked due to overlarge injection impact pressure caused by overlarge injection pressure to the rock body is solved.

The initial filling pressure of the grouting pump is 4MPa, and the grouting pressure range is adjusted to be 1.5-2.5MPa by the pressure control unit.

Example 2:

referring to fig. 1-3 and 10, a retention method for mining ore pillars by a gentle dip medium-thickness ore body room pillar method comprises the following steps:

s10, selecting a panel distribution area, selecting ore blocks which are arranged perpendicular to the trend of ore bodies (the thickness of the ore bodies is more than or equal to 10m), dividing the ore blocks into an ore room and an ore pillar, dividing the ore room into 10-15m and the ore pillar into 4-6m, dividing the ore room into 5 subsections along the height of the ore room in the ore room, dividing the subsection height into 10m, reserving a 7m high top pillar, dividing the ore pillar into 5 subsections, dividing the subsection height into 10m, dividing each subsection into 3 layers, and connecting each layer with a subsection roadway 15 through a layering connecting roadway 13, wherein a mining preparation project mainly comprises a mining slope, the subsection roadway, the layering connecting roadway, a layering connecting roadway (the ore room), a chute, a filling small well (the ore room), a filling return air well (the ore pillar), an on-road drainage well (the ore pillar) and a mining approach (the ore room), and a cutting project mainly comprises a cutting level and a cutting raise;

s50, cemented filling, wherein the filling material is filled into the chamber in a segmented manner by adopting a grouting device, and when the chamber is filled in a segmented manner, the first filling material is filled in a segmented manner for the first time: the second filler is 1:4 filler, and the other part adopts the first filler: the second filler is 1:5-10 filler, the water-cement ratio of the first filler is 0.4:1, and the water-cement ratio of the second filler is 0.5: 1.

Note: the size of the section of the approach is 3m multiplied by 4.2m (width multiplied by height), the section of the pillar forming the divided chamber in the shallow hole blasting ore-breaking operation is an inverted T-shaped structure, for the mining area, the pillar support is the core of a stope support system, the pillar structure has important effect on the stope stability through reasonable design, as shown in figure 4, the size and the structure of the pillar are designed according to the load-displacement relational expression of the pillar, the displacement of the pillar under the load is reduced, and the stability of the stope is ensured, and the specific calculation formula is as follows:

wherein k is the initial rigidity of the pillar, and k is EbA/D₁；

a is the cross-sectional area of the pillar, and A ═ Z₁×D₁+Z₂×D₂，Z₁Is the width of the vertical part of the pillar, Z₂For the width of the extended part of the pillar, D₁To the height of the chamber, D₂Is the height of the extending part of the ore pillar;

the filler comprises the following components in relative parts by mass relative to cement: 100 parts of cement, 340 parts of fine sand, 120 parts of slag, 0.35 part of water reducing agent, 28 parts of silica fume, 0.45 part of defoaming agent and 0.18 part of accelerator, wherein the water-cement ratio is 0.45:1, the cement is P.O42.5 ordinary portland cement, the particle size of the fine sand is 0.28mm, the slag is waste ore, the slag is poured into the slag with a circular cross section after being crushed, the particle size of the slag is 2mm, and the particle size of the silica fume is 0.2 mu m; the water reducing agent is a naphthalene sulfonic acid formaldehyde condensation compound, the defoaming agent is glycerin, and the condensation compound is a monascus I type.

Example 3:

the difference from example 2 is that: the filling material also comprises 0.04 part of allantoin; the 28 d-age compressive strength of the filler is more than or equal to 37.4MPa, the 28 d-age destructive load is more than or equal to 828.3/KN, and the slag is formed by crushing waste ore and pouring the crushed waste ore into slag with rectangular cross section.

Example 4:

the invention selects the 5G communication network which has the characteristics of high bandwidth, high capacity, high reliability, low time delay and low power consumption, compared with the 4G communication network, the 5G communication network has the performance superior to the 4G communication in the indexes of transmission rate, time delay and the like, the rapid transmission can be realized for massive monitoring data, the alarm response time for early warning accidents in a mining area can be greatly shortened, the escape rate and the survival rate of personnel in the mining area can be greatly improved, and the 5G communication network can be utilized to realize the real-time maintenance of the pressure stability of the filling filler in the process of monitoring the filling filler.

1) the deformation amount or the deformation rate has sudden abnormal change;

Comparative example 1: the difference from the embodiment 1 is that: the circulation pipe 41 is not provided in the feed main pipe 61;

comparative example 2: the difference from the embodiment 1 is that: and monitoring the filling filler pressure when the filling filler is not grouted and filled into the chamber.

Comparative example 3: the difference from example 2 is that: the slag particle size of the filler used for filling is 6 mm.

Comparative example 4: the difference from example 2 is that: the slag filled with the used filler is obtained by crushing and sieving without pouring, and the obtained particle size is about 8 mm.

Comparative example 5: the difference from example 2 is that: the slag filled with the used filler is poured into a concave shape in section.

Comparative example 6: the difference from example 2 is that: the filler used for filling also comprises 0.04 parts of allantoin and 65 parts of fine aggregate.

Comparative example 7: the difference from example 4 is that: and monitoring the ground pressure of the mining area by adopting a 4G communication network.

Test example 1:

the performance of the injected filler of the grouting device is measured, the grouting devices of example 1, comparative example 1 and comparative example 2 are respectively used for carrying out filling tests on a chamber formed by test rocks, the cracking condition of limestone is observed, the components of the used filler are shown in table 1, and the results are shown in table 2.

TABLE 1 spray Filler stock

Item	Cement (Kg/m)³)	Sand (Kg/m)³)	Water (Kg/m)³)	W/C
					Filler material	600	530	270	0.45

The rock used for the test is Solnhofen limestone, a chamber is formed by using limestone blocks of 30 multiplied by 30cm, and the limestone needs to be soaked by saline water before grouting.

TABLE 2 filling test of the chamber

Test example 2:

determination of the properties of the filling materials:

1) and (3) testing the compressive strength:

the fillers of the examples 2-3 and the comparative examples 3-6 are respectively filled to prepare test pieces with the sizes of 30mm multiplied by 30mm, the mold is removed and the maintenance is carried out for 28d, after maintenance, the compressive strength test is carried out in time, the surface of the test piece and the upper and lower bearing plate surfaces are wiped clean and are placed on a base plate of a hydraulic testing machine, the bearing surface of the test piece is determined to be vertical to the top surface during forming, the center of the test piece is aligned with the center of a lower pressing plate of the testing machine, the testing machine is started, continuously and uniformly loading in the test process, wherein the loading speed is 0.1Mpa/s, loading is carried out until the test piece is destroyed, the destructive load is recorded, the compressive strength of the test piece manufactured by the filler of the embodiment 2 and the comparative examples 4 to 6 is shown in figure 11, it can be seen that the 28-day-old compressive strength of the test piece of example 2 is 36.4MPa, and the 28-day-old compressive strength of the test piece of example 3 is 41.3MPa, which is higher than that of comparative examples 3-6; the compressive strength of the 3 d-old and 14 d-old test pieces of the example 2 is higher than that of the comparative examples 3-6, and the compressive strength of the 3 d-old and 14 d-old test pieces of the example 3 is higher than that of the test piece of the example 2; the above results show that the cast slag used in example 2 can effectively improve the compressive strength of the test pieces at 3d and 14d ages, and the addition of allantoin in example 3 can further improve the compressive strength of the test pieces at 3d, 14d and 28d ages.

The compressive strength calculation formula adopted is as follows:

f_cc＝F/A；

in the formula: f. of_ccThe compressive strength (MPa) of a concrete cubic test piece; f is a time destructive load (N); a is the time bearing area (mm)²)；

2) Impermeability test

And (3) manufacturing a test piece: the test mold size is a cone test piece with the upper opening diameter of 175mm and the lower opening diameter of 185mm and the height of 150 mm. During the test, a test mold is placed near a working surface, the test mold is placed at a wall corner at about 80 degrees, the fillers of examples 2-3 and comparative examples 3-6 are respectively filled to manufacture a test piece, the test piece is transported back to a test room as soon as possible, cement paste films on two end surfaces are cleaned after the mold is removed, and then the test piece is smeared by butter and pressed into an anti-seepage test mold to start the test.

The test process comprises the following steps: during testing, the water pressure is constant to be 0.8MPa +/-0.05 MPa, the test is stopped after 1d, and a test piece is taken out;

longitudinally fracturing a test piece into two parts by using a press machine, tracing a water mark by using a sign pen to obtain the water seepage depth, and measuring and recording data by using a graduated scale;

taking the average value of 8 relatively clear measurement point values as the water seepage height of the test piece;

the relative permeability coefficient (cm/s) was calculated as shown in the following formula:

S_k＝(mD_m ²) (2TH), in the formula,

S_k-relative permeability coefficient (cm/h);

D_m-average water penetration height (cm);

h-water pressure, expressed as water column height (cm);

t-constant pressure lapse time (h);

the water absorption of M-concrete is generally 0.03.

The test results of permeability coefficient tests are respectively carried out on the test pieces of 3d, 14d and 28d, the test results are shown in figure 7, and compared with comparative examples 3-6, the impermeability of the test piece of example 3 is obviously improved; the concrete of example 2 has no significant change in impermeability compared to example 3. The above results show that the anti-permeability of the test piece can be effectively improved by adding allantoin into the filler of example 3, while the anti-permeability of the test piece of example 2 and comparative examples 3-5 are not changed obviously, the anti-permeability effect of the test piece of comparative example 6 is slightly worse than that of the filler of example 3 due to the addition of allantoin, and the fine aggregate in comparative example 6 may affect the anti-permeability of the test piece, so that the anti-permeability effects of the

test pieces

3d, 14d and 28d of comparative example 6 are slightly lower than that of the test piece of example 3.

Test example 3:

carrying out an earth pressure monitoring test on a mining area in a loess slope copper-zinc mine field, carrying out an earth pressure monitoring simulation test on a goaf at the position of 260m in the middle section of an ore body, carrying out earth pressure monitoring according to the schemes of the embodiment 4 and the comparative example 7 at two adjacent positions respectively, counting data feedback difference values of the two, testing alarm time difference values of the monitoring systems of the embodiment 4 and the comparative example 7 in a mode that personnel press a stress meter in the mining area at the same time, wherein the data feedback time of the comparative example 7 is 0.3 second longer than that of the monitoring system of the embodiment 4 according to a test result, and the monitoring system of the embodiment 4 gives an alarm for 1.5 seconds in the early stage of the monitoring system of the comparative example 7 in the simulation alarm test, so that the escape probability of the personnel in the mining area can be increased.

The above disclosure is only for the purpose of illustrating the preferred embodiments of the present invention, and it is therefore to be understood that the invention is not limited by the scope of the appended claims.

Claims

1. A grouting device comprising:

a buffer box (50),

at least two feeding main pipes (61), wherein the at least two feeding main pipes (61) penetrate through the buffer tank (50) arranged in a hollow manner and discharge second fillers from a pipe body positioned outside the buffer tank (50),

a feeding auxiliary pipe (53) which penetrates through the buffer tank (50), discharges the first filler from a pipe body positioned outside the buffer tank (50), and can discharge the discharged first filler from a discharge hole I (51) of the buffer tank (50) to be mixed with the second filler,

wherein, the slip casting device still includes: a circulating pipe (41) for adjusting the pressure of the second filler in the at least two feeding main pipes (61), wherein the circulating pipe (41) is arranged between the at least two feeding main pipes (61) in a snake shape, the inlet/outlet end of the circulating pipe (41) is connected with a liquid circulating pump (40),

wherein, the slip casting device still includes: and the fastening sleeve body (62) is arranged on the surface of the feeding main pipe (61) in the buffer tank (50) and is used for controlling the linear distance pipe diameter of two points on the feeding main pipe (61).

2. Grouting device according to claim 1, characterised in that: the grouting device further comprises:

a flow-limiting sleeve (80) which is sleeved on a feeding auxiliary pipe (53) in the buffer tank (50),

the flow limiting sleeve (80) is sleeved on a feeding auxiliary pipe (53) in the feeding direction of the buffer box (50);

the flow limiting sleeve (80) is sleeved on the feeding auxiliary pipe (53) in the discharging direction of the buffer box (50).

3. Grouting device according to claim 1, characterised in that: the fastening sleeve body (62) is composed of at least two annular elastic fastening ring bodies (621) and fastening strips (622) which are used for connecting the adjacent fastening ring bodies (621) and can be deformed in a telescopic mode.

4. Grouting device according to claim 1, 2 or 3, characterised in that: at least two feeding are responsible for (61) one end and are connected with the grouting pump through multi-pass pipe spare (60), two at least feeding are responsible for (61) another tip and are located in buffering spheroid (64) that have the cavity structure, buffering spheroid (64) peripheral hardware second pressure monitor (70), first pressure monitor is established to grouting pump grout outlet end, first pressure monitor and second pressure monitor are connected with the pressure control unit who controls the grouting pump respectively.

5. A retention method for stoping an ore pillar by a room-pillar method of a slowly-inclined medium-thickness ore body comprises the following steps:

selecting a distribution panel, selecting ore blocks to be arranged in a direction vertical to the direction of an ore body, wherein the thickness of the ore body is more than or equal to 10m, and dividing the ore blocks into ore rooms and ore pillars;

-cutting the chamber, drilling blasting shallow holes (12) on the surface of the divided blocks to perform shallow hole blasting ore-dropping operation;

stoping in a room, stoping by a segmented open stope method;

-cemented filling, the filling (30) being filled in sections into the chamber using the grouting device according to claim 1.

6. A retention method for pillars in room-pillar extraction of gently sloping medium-thickness ore bodies according to claim 5, characterized in that: the width of the chamber is 10-15m, the width of the pillars is 4-6m, in the chamber, the height of the chamber is divided into 5 sections, the height of the sections is 10m, the height of the pillars is 7m, the pillars are divided into 5 sections, the height of the sections is 10m, each section is divided into 3 layers, and each layer connects the layer with the section roadway (15) through a layer connecting channel (13).

7. A retention method for pillars in room-pillar extraction of gently sloping medium-thickness ore bodies according to claim 5, characterized in that: the filler (30) comprises, in relative parts by mass with respect to cement: 100 parts of cement, 300-430 parts of fine sand, 100-160 parts of slag, 0.2-0.55 part of water reducing agent, 20-35 parts of silica fume, 0.4-0.6 part of defoaming agent, 0.1-0.23 part of accelerator, and the water-cement ratio is 0.4-0.55: 1;

the slag is prepared by crushing waste ore, pouring the crushed waste ore into slag with a square or round cross section, and selecting slag with a particle size of 1.5-4 mm;

the 28 d-age compressive strength of the filler is more than or equal to 37.4MPa, and the 28 d-age breaking load is more than or equal to 828.3/KN.

8. A retention method for pillars in room-pillar extraction of gently sloping medium-thickness ore bodies according to claim 5, characterized in that: when the chamber is filled in a segmented manner, the first filling is adopted for the first segmented filling: the second filler is 1:4 filler (30), and the other part adopts the first filler: (ii) a second filler (30) of 1:5-10, a first filler water-cement ratio of 0.4:1, a second filler water-cement ratio of 0.5: 1.

9. A retention method for pillars in room-pillar extraction of gently sloping medium-thickness ore bodies according to claim 5, characterized in that: and the cross section of an ore pillar for dividing the chamber is of an L-shaped/inverted-T-shaped structure in the shallow hole blasting ore-dropping operation.

10. A retention method for pillars in room-pillar extraction of gently sloping medium-thickness ore bodies according to claim 5, characterized in that: and in the backfilling process of the chamber, monitoring and controlling the grouting pressure and monitoring the ground pressure of the mining area, wherein the whole monitoring and controlling process is realized by transmitting data and/or sending control instructions through a 5G communication network.