A method of filling a mine underground delamination space

Abstract

The application discloses a kind of filling methods of underground bed separation space of mine, belong to mine filling technical field, to solve the problem of existing technology in mine tailings pollution environment or goaf influence mine safety production.The filling method includes that gangue is collected in feed unit;Gangue in feed unit is transported to crushing unit and is crushed, and gangue particles are obtained;Gangue particles are transported to pulping unit and are ground to generate slurry, then, slurry is supplied into stirring pool and is stirred, and qualified slurry is prepared;The stratum above underground bed separation space is drilled, and grouting hole is formed;Qualified slurry is pumped into underground bed separation space by grouting hole using grouting unit.The filling method can be used for the filling of underground bed separation space of mine.

Description

Technical Field

[0001] This invention belongs to the field of mine filling technology, and specifically relates to a method for filling underground delamination space in mines. Background Technology

[0002] Mining-induced overburden abscission mainly occurs below key strata, with the maximum development height of the abscission ending below the main key strata. The movement of key strata controls the formation, development, and spatiotemporal distribution of mining-induced overburden abscission. Preventing the main key strata from fracturing is crucial to ensuring no surface subsidence.

[0003] Mine tailings contain a large amount of organic components, as well as metals and sulfides, and are a source of inorganic salt pollution. They can pollute the environment through atmospheric precipitation.

[0004] On the one hand, the rapid changes in the environment caused by the transportation of mine tailings from underground or surface processing workshops to the surface for disposal accelerate their weathering, promote the dissolution of soluble components, and aggravate the environmental pollution of tailings mines. On the other hand, coal mining can cause the presence of abscission water above the goaf, which seriously affects the safe production of the mine. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a method for filling underground delamination spaces in mines, in order to solve the problems of environmental pollution from mine tailings or the impact of goaf areas on safe production in existing technologies.

[0006] The objective of this invention is mainly achieved through the following technical solutions.

[0007] This invention provides a method for filling underground delamination spaces in mines, comprising the following steps:

[0008] Step 1: Collect the gangue in the feeding unit;

[0009] Step 2: The gangue in the feeding unit is transported to the crushing unit for crushing to obtain gangue particles;

[0010] Step 3: The gangue particles are transported to the pulping unit for grinding and pulping to generate slurry. Then, the slurry is fed into the mixing tank for stirring to produce qualified slurry.

[0011] Step 4: Drill holes in the rock strata above the underground separation space to form grouting holes;

[0012] The qualified grout is pumped into the underground separation space through the grouting hole using a grouting unit.

[0013] Furthermore, in step 1, the particle size of the gangue is ≤200mm.

[0014] Furthermore, step 2 includes the following steps:

[0015] Step 21: The gangue in the feeding unit is transported to the jaw crusher and crushed to a particle size ≤40mm to obtain primary particles;

[0016] Step 22: The primary particles are fed to a double-roll crusher and crushed to a particle size of ≤10mm to obtain gangue particles.

[0017] Furthermore, the gangue is sandy mudstone, and the qualified slurry has a water-cement ratio of 1.3–1.7:1, a water weight of 585–765 g, a cement weight of 450 g, a slurry volume of 775–955 ml, a viscosity of 15.5–19.5 Pa·s, and a density of 1.25–1.40 g / cm³. 3 The ash content ranges from 37% to 43.5% by mass.

[0018] Furthermore, the underground delamination space is located above the water-conducting fracture zone of the mine.

[0019] Furthermore, the spacing between adjacent grouting holes is calculated using the following formula:

[0020] L j ≤2k j R k

[0021] In the formula: L j The distance between adjacent grouting holes is in meters (m); k j For safety, we take 0.5; R k Where is the slurry diffusion radius, m; M is the mining height, in meters.

[0022] Furthermore, in step 4, the grouting pressure is greater than or equal to the natural pressure of the strata above the underground separation space.

[0023] Furthermore, the injection pressure of qualified grout into the grouting hole is controlled by controlling the injection pressure at the upper opening of the grouting hole:

[0024] p 孔 =p 注 -H1γ1≥p 地 -H1γ1=H1(γ-γ1) where: p 注 The grouting pressure is expressed in kPa; p 地 The natural pressure of the strata above the underground separation space, in kPa; p 孔 H1 is the grouting pressure at the top of the grouting hole, in kPa; H1 is the depth from the surface to the underground separation space, in m; γ is the overall specific gravity of the strata above the underground separation space, in kN / m³. 3 γ1 is the specific gravity of the qualified slurry, in kN / m³. 3 .

[0025] Furthermore, step 4, drilling into the rock strata above the underground ablation space includes the following steps:

[0026] Step 41: Perform initial drilling, drill into the bedrock, run in the first casing, and cement the well to form a cementing layer on the outer wall of the first casing;

[0027] Step 42: Using a second casing, drill to a depth of 20-30m from the top of the underground separation space.

[0028] Furthermore, in step 4, before pumping the qualified grout into the underground separation space through the grouting hole using the grouting unit, the following steps are also included:

[0029] The grouting rate is calculated using the following formula:

[0030] Q = AHv c

[0031] In the formula: Q is the grouting speed, m 3 / h; A is the subsidence coefficient; H is the width of the mining face, m; v c m is the advance speed of the mining face. 2 / h.

[0032] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects.

[0033] A) The filling method for underground delamination space in mines provided by the present invention can process gangue into qualified slurry and then inject the qualified slurry into the underground delamination space, thereby realizing the treatment and effective utilization of gangue and solving the problems of mine tailings polluting the environment and goaf affecting mine safety production in the prior art.

[0034] B) The filling method for underground delamination space in mines provided by this invention has the following advantages: First, this filling method can return gangue to nature without affecting the normal production of the mine. Second, by filling all the underground delamination space in the mine with gangue, the groundwater in the underground delamination space is "squeezed out" to eliminate the threat of mine water hazards. Third, the qualified slurry of pressurized gangue is filled into the underground delamination space. The weight of the qualified slurry can accelerate the fracture above the coal seam, thereby reducing the probability of inducing rockburst disasters.

[0035] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained through the embodiments described and the accompanying drawings, which are particularly pointed out. Attached Figure Description

[0036] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0037] Figure 1 A flowchart illustrating a method for filling underground delamination spaces in a mine, as provided in Embodiment 1 of the present invention;

[0038] Figure 2 A schematic diagram illustrating the principle of the method for filling underground delamination space in a mine according to Embodiment 1 of the present invention;

[0039] Figure 3 This is a schematic diagram of the filling device in the filling method for underground delamination space in a mine provided in Embodiment 1 of the present invention;

[0040] Figure 4 This is a schematic diagram of the grouting hole structure in the method for filling underground delamination space in a mine according to Embodiment 1 of the present invention;

[0041] Figure 5 This is a schematic diagram of the conveying unit in the method for filling underground delamination space in a mine according to Embodiment 1 of the present invention.

[0042] Figure label:

[0043] 1-Feeding unit; 2-Crushing unit; 3-Pulping unit; 4-Grouting unit; 5-Grouting hole; 51-Cementing layer; 52-First casing; 53-Second casing; 6-First-stage conveyor belt; 7-Second-stage conveyor belt; 8-Third-stage conveyor belt; 9-Drive block; 10-Lower guide protrusion; 11-Upper guide protrusion. Detailed Implementation

[0044] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0045] Example 1

[0046] This embodiment provides a method for filling underground delamination spaces in mines, see [link to relevant documentation]. Figure 1 It includes the following steps:

[0047] Step 1: Collect the secondary waste (i.e. gangue, size ≤200mm) that has no utilization value generated after coal washing and processing in the coal preparation plant into the feeding unit 1 via a belt conveyor;

[0048] Step 2: The gangue in feeding unit 1 is transported by truck to a jaw crusher for crushing to a particle size ≤40mm, and then enters a double roller crusher for crushing to a particle size ≤10mm to obtain gangue particles.

[0049] Step 3: The gangue particles are conveyed to the pulping unit 3 (e.g., an overflow ball mill) for grinding and pulping to generate slurry. Then, the slurry is fed into the mixing tank for stirring to produce qualified slurry.

[0050] Step 4: Use a drilling machine to drill holes in the rock strata above the underground separation space to form grouting holes 5; use a grouting unit 4 (e.g., a grouting pump) to pump qualified grout into the underground separation space through the grouting holes 5, and inject the grout into the underground separation space.

[0051] Compared with the prior art, the filling method for underground delamination space in mines provided by the present invention can process and effectively utilize gangue by making qualified slurry from gangue and then injecting the qualified slurry into the underground delamination space, thereby solving the problems of environmental pollution from mine tailings and the impact of goaf on safe production in mines in the prior art.

[0052] Specifically, on the one hand, this filling method can return gangue to nature without affecting the normal production of the mine; on the other hand, filling all the underground separation space in the mine with gangue can "squeeze out" the groundwater in the underground separation space and eliminate the threat of mine water hazards; furthermore, the qualified slurry of pressurized gangue is filled into the underground separation space, and the weight of the qualified slurry can accelerate the fracturing above the coal seam, thereby reducing the probability of inducing rockburst disasters.

[0053] Step 2 above includes the following steps:

[0054] Step 2 includes the following steps:

[0055] Step 21: The gangue in feeding unit 1 is transported to a jaw crusher and crushed to ≤40mm to obtain primary particles;

[0056] Step 22: The primary particles are fed to a double-roll crusher and crushed to ≤10mm to obtain gangue particles.

[0057] For example, the gangue is sandy mudstone with a particle size of 100-120 mesh. The proportions of the qualified slurry are as follows: water-cement ratio of 1.3-1.7:1, water weight of 585-765g, cement weight of 450g, slurry volume of 775-955ml, viscosity of 15.5-19.5Pa·s, and density of 1.25-1.40g / cm³. 3 The ash content (i.e., gangue particles) has a mass concentration of 37–43.5%.

[0058] The specific slurry ratio is shown in Table 1 below.

[0059] Table 1 Summary of Slurry Proportioning Test

[0060]

[0061] Specifically, the spacing between adjacent grouting holes 5 is calculated using the following formula:

[0062] L j ≤2k j R k

[0063] In the formula: L j The distance between adjacent grouting holes is in meters (m); k j For safety, we take 0.5; R k Where is the slurry diffusion radius, m; M is the mining height, in meters.

[0064] Regarding the determination of the grouting pressure for injecting qualified grout into grouting hole 5, the grouting pressure should not be less than the natural ground pressure of the strata above the underground separation space. This ensures that the underground separation space is not damaged while also promoting its development. Specifically, the grouting pressure is expressed as...

[0065] p 注 ≥p 地

[0066] In the formula: p 注 The grouting pressure is expressed in kPa; p 地 The pressure is the natural pressure of the strata above the underground separation space, in kPa.

[0067] In actual construction, the grouting pressure p at the upper opening of grouting hole 5 can be controlled. 孔 (kPa) is used to control the grouting pressure within the grouting hole 5 to ensure the injection of qualified grout.

[0068] p 孔 =p 注 -H1γ1≥p 地 -H1γ1=H1(γ-γ1)

[0069] In the formula: H1 is the depth from the surface to the subsurface separation space, in meters; γ is the overall specific gravity of the strata above the subsurface separation space, in kN / m³. 3 γ1 is the specific gravity of the qualified slurry, in kN / m³. 3 .

[0070] For example, H1 = 522.6m, γ = 25kN / m 3 γ1=13kN / m 3 Correspondingly, the grouting pressure p at the top of the grouting hole... 孔 ≥6.26MPa.

[0071] To ensure drilling quality, step 4 above, drilling into the rock strata above the underground separation space, includes the following steps:

[0072] Step 41: Start drilling.

[0073] The first drilling was carried out using a roller cone drill bit to enter the bedrock, and the first casing 52 was run in for cement cementing, forming a cementing layer 51 on the outer wall of the first casing 52.

[0074] Step 42: Second drilling.

[0075] Using the second casing 53, directional drilling was carried out according to the design of each hole, and the drilling was carried out to a distance of 20-30m from the top of the underground separation space.

[0076] Core drilling was carried out using a core drill bit, and the drilling was carried out to a depth of 4-5m from the top of the underground separation space. The third casing was then installed, and cement was used for well cementing.

[0077] It should be noted that by using the above drilling method and performing cement cementing twice, the hydraulic connection between the upper and lower formations can be effectively prevented, ensuring the stability of grouting hole 5 during the grouting process.

[0078] The theoretical basis for ground subsidence grouting is the delamination theory. Delamination has a process of occurrence, development, and eventual closure, and the best time for grouting is during the period of greatest delamination development. Therefore, in step 4 above, before injecting qualified grout into the grouting hole 5 using the grouting pump in the borehole grouting unit 4, the following steps are also included:

[0079] The grouting rate is calculated to ensure sufficient grouting strength when the delamination opening is at its maximum, and this is used as the basis for selecting the grouting pump.

[0080] Specifically, the grouting speed is calculated using the following formula:

[0081] Q = AHv c

[0082] In the formula: Q is the grouting speed (i.e., pump flow rate), m 3 / h; A—Subsidence coefficient, which can be determined based on observations in practical applications; H is the width of the mining face, in meters; v c m is the advance speed of the mining face. 2 / h.

[0083] Specifically, the design pressure of grouting unit 4 should be greater than the pressure required for the pipeline connecting grouting unit 4 and grouting hole 5. The pressure required for the pipeline connecting grouting unit 4 and grouting hole 5 is calculated using the following formula:

[0084] Pk=ρ k ·gH+ρ s gi k L+P j +P n +P z

[0085] In the formula: Pk is the pressure required for grouting through the connecting pipeline, kPa; g is the acceleration due to gravity, m / s². 2 H represents the geometric height of the conveyed qualified slurry, in meters; ρ k For qualified slurry density, kg / m³ 3 ;ρ s The density of water is kg / m³ 3 i k Frictional loss along the connecting pipeline for qualified slurry, mH2O / m; P j The local friction loss of the connecting pipeline is expressed in kPa; P n The friction loss of pipe components within the grouting unit is expressed in kPa; P z The remaining head of the qualified slurry at the terminal is given in kPa.

[0086] The calculation formulas for the inner diameter and wall thickness of the connecting pipe between grouting unit 4 and grouting hole 5 are as follows:

[0087]

[0088] In the formula: D is the inner diameter of the connecting pipe, in meters; Q is the grouting speed (i.e., pump flow rate), in meters. 3 / h; V is the qualified slurry flow rate, m / s.

[0089]

[0090] Where: t is the wall thickness of the straight pipe section connecting the grouting unit and the grouting hole, mm; D is the inner diameter of the connecting pipe, m; K is the design coefficient, generally 0.72 outside the pump station, and 0.6 inside the pump station, large crossing pipe sections, urban centers, suburban residential areas, commercial areas, industrial areas, planning areas and other densely populated areas; σ s The minimum yield strength of the connecting pipeline, in MPa; The weld coefficient of the connecting pipeline is taken according to the relevant provisions of the current national standard "Code for Design of Oil Pipeline Engineering" GB50253; C is the annual wear corrosion rate, mm / a; S is the design service life of the connecting pipeline, a year.

[0091] To prevent the underground separation space from connecting with the goaf, the underground separation space is located above the water-conducting fracture zone.

[0092] For example, the filling method for the underground delamination space in the above-mentioned mine adopts a filling device with the following structure, see [link to details]. Figures 2 to 3Specifically, the filling device includes a feeding unit 1, a crushing unit 2, a water supply unit, a slurry preparation unit 3, a grouting hole 5, and a grouting unit 4. The feeding unit 1, crushing unit 2, slurry preparation unit 3, grouting unit 4, and grouting hole 5 are connected in sequence. The water outlet of the water supply unit is connected to the water inlet of the slurry preparation unit 3, and the grout outlet of the grouting hole 5 is connected to the underground separation space formed by coal mining.

[0093] To ensure grouting efficiency, for example, the distance between two adjacent grouting holes 5 is 300-500m.

[0094] To ensure the stability of grouting hole 5 during the grouting process, the structure of grouting hole 5 is described in detail below. Figure 4 Specifically, the grouting hole 5 includes a cementing layer 51, a first casing 52, and a second casing 53. The cementing layer 51 is located on the outer wall of the first casing 52, and the first casing 52 and the second casing 53 are connected in sequence along the direction gradually away from the ground.

[0095] For ease of construction, the inner diameter ratio of the first sleeve 52 to the second sleeve 53 is 1.5 to 2.0.

[0096] It is worth noting that there is a change in the inner diameter between the first casing 52 and the second casing 53. In order to prevent the qualified grout injected into the underground separation space from flowing back into the first casing 52, the first casing 52 is sealed to the second casing 53 by a grout stop plug.

[0097] Based on the structure of the grouting hole 5, the grouting unit 4 includes a grouting pipe and a grouting valve provided on the grouting pipe. Grouting is controlled by controlling the opening and closing of the grouting valve.

[0098] Considering the different particle sizes of gangue, the characteristics of the underground delamination space and the required slurry ratio are also different. However, if the gangue particles are directly crushed to a smaller particle size, multiple crushing operations with a roller crusher are required, resulting in energy waste. Therefore, for example, the above-mentioned filling device also includes a conveying unit. The crushing unit 2 is connected to the slurry preparation unit 3 through the conveying unit. The conveying unit includes a primary conveyor belt 6, a secondary conveyor belt 7, a tertiary conveyor belt 8, a primary particle bin, a secondary particle bin, and a tertiary particle bin. See [link to relevant documentation]. Figure 5The primary conveyor belt 6, secondary conveyor belt 7, and tertiary conveyor belt 8 are arranged in parallel along the vertical direction. The particle input ends of the primary conveyor belt 6, secondary conveyor belt 7, and tertiary conveyor belt 8 are connected to the particle outlet of the crushing unit 2, respectively. The particle output end of the primary conveyor belt 6 is connected to the feed inlet of the primary particle bin, the particle output end of the secondary conveyor belt 7 is connected to the feed inlet of the secondary particle bin, and the particle output end of the tertiary conveyor belt 8 is connected to the feed inlet of the tertiary particle bin. The discharge outlets of the primary, secondary, and tertiary particle bins are connected to the feed inlet of the pulping unit 3, respectively. Screen holes are opened on the primary conveyor belt 6 and the secondary conveyor belt 7, but no screen holes are opened on the tertiary conveyor belt 8. The screen hole diameter on the primary conveyor belt 6 is larger than the screen hole diameter on the secondary conveyor belt 7. In this way, by setting up the primary conveyor belt 6, the secondary conveyor belt 7 and the tertiary conveyor belt 8, the gangue particles can be transported and classified by particle size at the same time. The gangue particles of different particle sizes are then stored in different particle bins (i.e., primary particle bin, secondary particle bin and tertiary particle bin), so that the appropriate slurry formula can be selected according to the gangue particles of different particle sizes.

[0099] Considering that the primary, secondary, and tertiary pellet bins are all connected to the feed inlet of pulping unit 3, in order to ensure that only one of the pellet bins is connected to pulping unit 3, the discharge outlets of the primary, secondary, and tertiary pellet bins are equipped with discharge components. The discharge components control one of the primary, secondary, and tertiary pellet bins to be connected to pulping unit 3.

[0100] To enable vibratory screening of the primary conveyor belt 6 and the secondary conveyor belt 7, the conveying unit further includes multiple sets of vibration drive components. Each set of vibration drive components includes a drive block 9, a lower guide protrusion 10, and an upper guide protrusion 11. The lower guide protrusion 10 is provided on both sides of the lower surface of the primary conveyor belt 6, and the upper guide protrusion 11 is provided on both sides of the upper surface of the secondary conveyor belt 7. Along the conveying direction, the cross-sectional shape of the lower guide protrusion 10 is a right-angled triangle, with one right-angled side connected to the primary conveyor belt 6 and the other right-angled side located behind the hypotenuse. Along the conveying direction, the cross-sectional shape of the upper guide protrusion 11 is a right-angled triangle, with one right-angled side connected to the secondary conveyor belt 7 and the other right-angled side located behind the hypotenuse. The drive block 9 is located between the upper guide protrusion 11 and the lower guide protrusion 10 and slides in contact with both of them. In this way, the drive component is stationary relative to the mounting surface, while the primary conveyor belt 6 and the secondary conveyor belt 7 are in motion. When the upper guide protrusion 11 and the lower guide protrusion 10 pass the drive component, the drive component slides into contact with the upper guide protrusion 11 and the lower guide protrusion 10, causing the distance between the primary conveyor belt 6 and the secondary conveyor belt 7 to gradually increase. The upper guide protrusion 11 and the lower guide protrusion 10 continue to move. At the instant the drive component disengages from the upper guide protrusion 11 and the lower guide protrusion 10, the distance between the primary conveyor belt 6 and the secondary conveyor belt 7 will suddenly decrease, followed by reciprocating vibration, thereby realizing the vibrating screening of the primary conveyor belt 6 and the secondary conveyor belt 7. It should be noted that the vibrating screening in the prior art all rely on the reciprocating motor to drive the reciprocating motion, while the vibrating drive component in this embodiment does not require any electrical equipment and can realize vibrating screening only through structural design.

[0101] It is understandable that grouting pressure directly affects grouting efficiency and grouting effect. In order to monitor grouting pressure in real time, the above-mentioned filling device also includes a grouting pressure gauge installed in the grouting hole 5. The grouting pressure is monitored in real time by the grouting pressure gauge, and the grouting pressure is adjusted according to different grouting stages and the grouting pressure measured by the grouting pressure gauge.

[0102] Specifically, in order to automatically adjust the grouting pressure, the above-mentioned filling device also includes a central control center. The central control center receives the real-time grouting pressure collected by the grouting pressure gauge and determines whether the real-time grouting pressure is equal to the preset pressure of a certain grouting stage. If it is not equal, the central control center adjusts the grouting unit 4 according to the preset pressure so that the real-time grouting pressure is equal to the preset pressure.

[0103] Considering that the grouting pressure of qualified grout injected into the grouting hole 5 can be controlled by controlling the grouting pressure at the upper opening of the grouting hole 5, the grouting pressure gauge is set at the upper opening of the grouting hole 5.

[0104] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for filling underground delamination spaces in a mine, characterized in that, The process includes the following steps: Step 1: Collecting gangue in the feeding unit; Step 2: Transporting the gangue from the feeding unit to the crushing unit for crushing to obtain gangue particles; Step 3: Transporting the gangue particles to the slurry preparation unit for grinding and slurry preparation to generate slurry, and then feeding the slurry into the mixing tank for stirring to produce qualified slurry; Step 4: Drilling holes in the rock strata above the underground abscission space to form grouting holes; using the grouting unit to pump the qualified slurry into the underground abscission space through the grouting holes; The filling device used in the filling method includes a crushing unit, a pulping unit, and a conveying unit. The conveying unit includes a primary conveyor belt, a secondary conveyor belt, a tertiary conveyor belt, a primary pellet bin, a secondary pellet bin, a tertiary pellet bin, and multiple sets of vibration drive components. The primary, secondary, and tertiary conveyor belts are arranged in parallel along the vertical direction. The particle input ends of the primary, secondary, and tertiary conveyor belts are connected to the particle outlets of the crushing unit, respectively. The particle output end of the primary conveyor belt is connected to the feed inlet of the primary pellet bin, the particle output end of the secondary conveyor belt is connected to the feed inlet of the secondary pellet bin, and the particle output end of the tertiary conveyor belt is connected to the feed inlet of the tertiary pellet bin. The discharge outlets of the primary, secondary, and tertiary pellet bins are connected to the feed inlet of the pulping unit, respectively. Screen holes are opened on the primary and secondary conveyor belts, but no screen holes are opened on the tertiary conveyor belt. The screen hole diameter on the primary conveyor belt is larger than that on the secondary conveyor belt. Each set of vibration drive components includes a drive block, a lower guide protrusion, and an upper guide protrusion. The lower guide protrusions are provided on both sides of the lower surface of the primary conveyor belt, and the upper guide protrusions are provided on both sides of the upper surface of the secondary conveyor belt. Along the conveying direction, the cross-sectional shape of the lower guide protrusion is a right-angled triangle, with one right-angled side connected to the primary conveyor belt and the other right-angled side located behind the hypotenuse. Along the conveying direction, the cross-sectional shape of the upper guide protrusion is a right-angled triangle, with one right-angled side connected to the secondary conveyor belt and the other right-angled side located behind the hypotenuse. The drive block is located between the upper guide protrusion and the lower guide protrusion and slides in contact with both of them.

2. The method for filling underground delamination spaces in mines according to claim 1, characterized in that, In step 1, the particle size of the gangue is ≤200mm.

3. The method for filling underground delamination spaces in mines according to claim 1, characterized in that, Step 2 includes the following steps: Step 21: The gangue in the feeding unit is transported to the jaw crusher and crushed to a particle size ≤40mm to obtain primary particles; Step 22: The primary particles are fed to a double-roll crusher and crushed to a particle size of ≤10mm to obtain gangue particles.

4. The method for filling underground delamination spaces in mines according to claim 1, characterized in that, The gangue is sandy mudstone. The qualified slurry has a water-cement ratio of 1.3~1.7:1, a water weight of 585~765g, a cement weight of 450g, a slurry volume of 775~955ml, a viscosity of 15.5~19.5Pa·s, and a density of 1.25~1.40g / cm³. 3 The ash content is 37-43.5% by mass.

5. The method for filling underground delamination spaces in mines according to claim 1, characterized in that, The underground delamination space is located above the water-conducting fracture zone of the mine.

6. The method for filling underground delamination spaces in mines according to any one of claims 1 to 5, characterized in that, The spacing between adjacent grouting holes is calculated using the following formula: L j ≤ 2 k j R k In the formula: L j The distance between adjacent grouting holes is in meters (m). k j For safety, a factor of 0.5 is used; R k Where is the slurry diffusion radius, R k =90~96 ,m; M The extraction height is measured in meters (m).

7. The method for filling underground delamination spaces in mines according to any one of claims 1 to 5, characterized in that, In step 4, the grouting pressure is greater than or equal to the natural pressure of the strata above the underground separation space.

8. The method for filling underground delamination spaces in mines according to claim 7, characterized in that, The injection pressure of qualified grout into the grouting hole is controlled by controlling the injection pressure at the top of the grouting hole: In the formula: p 注 The grouting pressure is expressed in kPa. p 地 The pressure of the strata above the underground separation space is expressed in kPa. p 孔 H1 is the grouting pressure at the top of the grouting hole, in kPa; H1 is the depth from the surface to the underground separation space, in m; γ is the overall specific gravity of the strata above the underground separation space, in kN / m³. 3 ; γ1 is the specific gravity of the qualified slurry, in kN / m³. 3 .

9. The method for filling underground delamination spaces in mines according to any one of claims 1 to 5, characterized in that, Step 4, drilling into the rock strata above the underground separation space, includes the following steps: Step 41: Perform initial drilling, drill into the bedrock, run in the first casing, and cement the well to form a cementing layer on the outer wall of the first casing; Step 42: Using a second casing, drill to a depth of 20-30m from the top of the underground separation space.

10. The method for filling underground delamination spaces in mines according to any one of claims 1 to 5, characterized in that, Before step 4, which involves pumping qualified grout into the underground separation space through the grouting hole using a grouting unit, the following steps are also included: The grouting rate is calculated using the following formula: Q=AHv c In the formula: Q is the grouting speed, m 3 / h; A is the subsidence coefficient; H is the width of the mining face, m; v c m is the advance speed of the mining face. 2 / h.

Images