Method for cemented filling of waste rocks after shallow hole shrinkage

Abstract

The invention relates to a method for cemented filling of waste rocks after shallow hole shrinkage, and relates to the technical field of mining filling. According to the shallow hole shrinkage subsequent waste rock cemented filling method, the supporting bottom plate structure is formed by filling the cement mortar for one time, a compact bottom plate structure can be formed at the bottom of a goaf, and the bearing capacity of a goaf foundation is improved; the goaf is subjected to secondary filling by directly using underground barren rocks, the utilization rate of mining area resources can be effectively improved, and after the goaf is subjected to grouting filling through the filling system, solidified cement mortar can form a cementitious body with the barren rocks and broken stones, so that the stability of the goaf can be effectively enhanced; according to the method, the goaf is filled and contacted through layered cemented filling, filling of the goaf can be completed, the stability of the goaf is effectively improved, the problems of bottom plate sinking, collapse and the like are avoided, the efficiency and safety of filling operation are improved, the lifting and transporting cost is reduced, and the amount of waste rocks going out of a well is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of mining and filling, and in particular to a method for cementing and filling waste rocks after leaving a shallow hole for mining. Background Art

[0002] After mining, the goaf needs to be filled to avoid accidents such as roof falls, mine tremors, and surface collapse, so as to ensure the safety of mining production.

[0003] For most lead and zinc mining areas that have been mined for many years, the shallow hole ore-leaving method is usually adopted for mining. There are many goafs, some of which are high in height and large in volume. There are safety risks such as goaf collapse, which leads to a low primary recovery rate of subsequent ore and a large loss of ore resources. As the scale of mining gradually expands, the safety hazards brought by goafs have become a problem that mines must solve.

[0004] At present, the filling work of the goaf is mostly done by mixing waste rock with cement and then pumping it for filling to ensure the safe production of the mine. However, this method of mixing and pumping has the problem of clogging the pumping equipment due to excessively large particles or excessively high viscosity during the pumping process, which affects the filling efficiency. In addition, the mixing of waste rock and cement requires the use of many equipments, the production process is long, the process is complex, and the construction cost is high. At the same time, for goafs with high heights and large volumes, the lack of support for the floor of the goaf may cause the floor to sink, resulting in the inability to effectively ensure the safety of the mining construction. Summary of the invention

[0005] In order to solve or partially solve the problems existing in the related technology, the present application provides a method for shallow hole ore retention and subsequent waste rock cementation filling, which can complete the filling of the goaf, effectively improve the stability of the goaf, avoid problems such as bottom plate sinking and collapse, and improve the efficiency and safety of the filling operation.

[0006] The method for shallow hole ore retention and subsequent waste rock cementation filling provided in the present application comprises the following steps:

[0007] Step 1: Seal the goaf to be filled to prevent leakage of filling materials;

[0008] Step 2: Fill the goaf to be filled by pumping cement mortar, and wait for the cement mortar to solidify to form a supporting floor structure;

[0009] Step 3: After the supporting floor structure is formed, the goaf to be filled is refilled with waste rock, with a filling height of 5 meters;

[0010] Step 4: After the secondary filling is completed, the goaf to be filled is grout-filled by the filling system in the form of direct spraying, with a filling height of 5 meters, so that the cement mortar and waste rock are mixed to form a cementitious filling;

[0011] Step 5: Repeat step 3 and step 4 to perform layered cementation filling on the goaf to be filled until the goaf to be filled is completed.

[0012] Optionally, in some embodiments of the present application:

[0013] The goaf to be filled is filled once by pumping cement mortar, wherein the mix ratio of cement, sand and water in the cement mortar used for the primary filling is 1:2.68:0.63, and the sand is medium sand with a crushing rate of 40% to ensure the strength of the supporting base plate structure.

[0014] Optionally, in some embodiments of the present application:

[0015] The filling height of the primary filling shall not be less than 5m;

[0016] The filling height of the primary filling corresponds to the overall height of the goaf to be filled. When the overall height of the goaf to be filled is higher, the filling height of the primary filling increases accordingly.

[0017] Optionally, in some embodiments of the present application:

[0018] The cement mortar is produced and pumped through a filling system;

[0019] The filling system comprises: a tailings feeding line, a cement storage feeding line, a water supply line and a mixing and conveying line, and the cement, sand and water are mixed and pumped through the filling system.

[0020] Optionally, in some embodiments of the present application:

[0021] The filling system uses a pipe with a diameter of 125 mm as the downhole filling pipe. The pipe layout of the downhole filling pipe has a filling multiple of 7. When cement mortar is pumped through the filling system, the pumping pressure is controlled to be 8 Mpa through the filling system.

[0022] Optionally, in some embodiments of the present application:

[0023] A displacement meter and a pressure gauge are arranged on the mixing and conveying line to monitor the conveying condition of the filling slurry.

[0024] Optionally, in some embodiments of the present application:

[0025] The waste rock is used for secondary filling of the goaf to be filled, wherein the waste rock is the waste rock produced by the excavation of the upper and middle sections of the working face, and the waste rock is transported to the goaf to be filled and falls into the goaf to be filled through the filling well to realize the filling of the goaf to be filled.

[0026] The waste rock is used to carry out secondary filling of the goaf to be filled, including:

[0027] According to the density of the waste rock in the goaf, crushed rock is sent underground to reduce the gaps and holes between the waste rocks to increase the density; wherein the crushed rock is obtained by crushing the waste rock;

[0028] The particle size of the crushed stone is 40 mm.

[0029] Optionally, in some embodiments of the present application:

[0030] Step 1: seal the goaf to be filled to ensure effective filling, including:

[0031] An iron funnel is installed at the opening of the ore discharge funnel in the goaf to be filled, and the iron funnel is sealed with a steel plate;

[0032] During filling, wooden boards are used to block and close all passages in the goaf to be filled.

[0033] Optionally, in some embodiments of the present application:

[0034] For the long goaf of abandoned tunnels, segmented filling is adopted, with each segment being 30-50m long and each segment being built with masonry filling retaining walls;

[0035] For the goaf in the middle section where mining has been completed, one-time filling is adopted.

[0036] The technical solution provided by this application may have the following beneficial effects:

[0037] The present application forms a supporting bottom plate structure by filling cement mortar once, which can form a dense bottom plate structure at the bottom of the goaf, improve the bearing capacity of the foundation of the goaf, and ensure the subsequent layered bonding work. At the same time, it can also ensure the safe recovery of the lower and middle sections of the ore body, providing favorable conditions for filling the lower void area.

[0038] This application improves the efficiency of construction by directly using underground waste rock to perform secondary filling of the goaf, which can effectively improve the utilization rate of mining resources and waste rock, and at the same time reduce the amount of filling slurry, control and increase transportation costs, and reduce the amount of waste rock out of the well. At the same time, after the goaf is grouted and filled by the filling system, the solidified cement mortar can form a cemented body with the waste rock and crushed stone, which can effectively enhance the stability of the goaf.

[0039] The present application completes the filling and capping of the goaf by performing layered cementation filling, which can complete the filling of the goaf, effectively improve the stability of the goaf, avoid problems such as bottom plate sinking and collapse, improve the efficiency and safety of the filling operation, reduce lifting and transportation costs, and reduce the amount of waste rock out of the well.

[0040] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The above and other objects, features and advantages of the present application will become more apparent through a more detailed description of exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0042] Figure 1 It is a structural schematic diagram of a method for shallow hole ore retention and subsequent waste rock cementation filling in an embodiment of the present application;

[0043] Figure 2 It is a structural schematic diagram of the filling system in the embodiment of the present application. DETAILED DESCRIPTION

[0044] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0045] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0046] In the description of the present application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0047] Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0048] For most lead and zinc mining areas that have been mined for many years, the shallow hole ore-leaving method is usually adopted for mining. There are many goafs, and the height of some goafs is relatively high. The existing safety risks such as goaf collapse also lead to a low primary recovery rate of subsequent ore and a large loss of ore resources. As the scale of mining gradually expands, the safety hazards brought by goafs have become a problem that mines must solve.

[0049] At present, the filling work of the goaf is mostly done by mixing waste rock with cement and then pumping it for filling to ensure the safe production of the mine. However, this method of mixing and pumping has the problem of clogging the pumping equipment due to excessively large particles or excessively high viscosity during the pumping process, which affects the filling efficiency. In addition, the mixing of waste rock and cement requires the use of many equipments, the production process is long, the process is complex, and the construction cost is high. At the same time, for goafs with high heights and large volumes, the lack of support for the floor of the goaf may cause the floor to sink, resulting in the inability to effectively ensure the safety of the mining construction.

[0050] In response to the above problems, an embodiment of the present application provides a method for shallow hole ore retention and subsequent waste rock cementation filling, which can complete the filling of the goaf, effectively improve the stability of the goaf, avoid problems such as bottom plate sinking and collapse, and improve the efficiency and safety of the filling operation.

[0051] The technical solution of the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0052] Figure 1 It is a structural schematic diagram of a method for shallow hole ore retention and subsequent waste rock cementation filling in an embodiment of the present application;

[0053] Figure 2 It is a structural schematic diagram of the filling system in the embodiment of the present application.

[0054] See also Figure 1-2 The method for shallow hole ore retention and subsequent waste rock cementation filling in the embodiment of the present application comprises the following steps:

[0055] S100: Step 1: Seal the goaf to be filled to prevent leakage of filling material.

[0056] Specifically, it includes:

[0057] An iron funnel is installed at the mouth of the ore-discharging funnel in the goaf to be filled, and the iron funnel is sealed with a steel plate; specifically, the thickness of the steel plate is 5 mm. By using the steel plate to weld and fix the iron funnel, the mouth of the ore-discharging funnel can be effectively sealed. At the same time, the strength of the steel plate can withstand the pressure of the subsequent filling colloid to ensure the sealing of the filling.

[0058] When filling, wooden boards are used to block and close all passages in the goaf to be filled, which can avoid leakage of slurry during the filling process and ensure the safety and effectiveness of the operation.

[0059] In this embodiment, by sealing the goaf to be filled, leakage of filling materials can be avoided, thereby ensuring the effectiveness and safety of subsequent filling operations.

[0060] S200: Step 2: Fill the goaf to be filled once by pumping cement mortar, and wait for the cement mortar to solidify to form a supporting bottom plate structure.

[0061] Specifically, the mix ratio of cement, sand and water in the cement mortar used for the primary filling is 1:2.68:0.63, and the sand is medium sand with a crushing rate of 40% to ensure the strength of the supporting base plate structure.

[0062] In the mix ratio of cement mortar, the ratio of cement, sand and water directly affects the strength of the final mixture. This embodiment conducts a slurry strength performance experiment, performs strength property detection on slurry sampling test blocks with different mix ratios, analyzes the primary and secondary factors affecting the slurry strength and their degree of influence, and ensures the stability of the slurry mix ratio. Among them, the slurry strength performance experiment is specifically as follows: build a surface filling ring pipe, sample the test block at the filling pump tank and the filling pipe outlet, sample 3 groups of different cement mortar mix ratios, 9 blocks in each group, and the sampling mold box size is 150mm*150mm and 70mm*70mm triple mold boxes. The test block is tested for strength properties after 28 days at room temperature.

[0063] In this embodiment, by testing and analyzing parameters such as the concentration, slump, consistency and stratification of the slurry, the stability, plasticity and fluidity of the slurry were analyzed and studied, and it was found that when the mix ratio of cement, sand and water was 1:2.68:0.63, the cement mortar had good strength and tensile strength, which could effectively ensure the bearing capacity of the supporting base structure, and had good fluidity, which was convenient for subsequent pumping and filling construction. At the same time, it could minimize the proportion of cement while ensuring the strength, and effectively control the production cost.

[0064] Specifically: the filling height of the primary filling is 5m; the filling height of the primary filling corresponds to the overall height of the goaf to be filled, and when the overall height of the goaf to be filled is higher, the filling height of the primary filling increases accordingly.

[0065] In this embodiment, after determining the mix ratio of cement, sand and water, the bearing capacity of the supporting floor structure can be evaluated by analyzing the strength of the cement mortar and the filling height of the primary filling. When the filling height of the primary filling is set to 5m, the stability and bearing capacity of the supporting floor structure can be guaranteed to bear the cementing filling work of most of the existing goafs. When the overall height of the goaf to be filled is relatively high, the stability and bearing capacity of the supporting floor structure can be effectively enhanced by correspondingly increasing the filling height of the primary filling. Specifically, when the overall height of the goaf to be filled is greater than 50m, the filling height of the primary filling increases by 0.5m for every 10m increase in the overall height of the goaf to be filled.

[0066] Specifically: the cement mortar is produced and pumped through a filling system;

[0067] The filling system includes: a tailings feeding line, a cement storage feeding line, a water supply line and a mixing and conveying line, through which the cement, sand and water are mixed and pumped. In this embodiment:

[0068] The tailings feeding line transports tailings from the tailings pond to the filling station for stacking by car. 3 The loader shovels the tailings to the mixing port;

[0069] The cement storage feeding line transports cement to the filling station through bulk cement tank trucks, and unloads cement into the cement storage tank through the soot blowing pipe. The cement storage tank has a capacity of 150t. A φ219-11m double-tube screw conveyor is installed at the bottom of the cement storage tank. When filling, the gate valve of the double-tube screw conveyor is opened. The double-tube conveyor can be turned on to add cement to the mixer. At the same time, the cement delivery amount is controlled by the batching controller of the cement scale to meet the filling ratio requirements;

[0070] The water of the water supply line comes from the underground drainage of the mine area and the water supply pipeline of the high-level water pool. A time relay is installed on the water supply line to control the water supply through the time relay;

[0071] The mixing and conveying line conveys tailings, cement and water from different feeding lines into the mixer through the feed hopper, and the filling slurry is prepared by the mixer. The mixer uses the JS1000 mixer, which is connected to the conveying pump through a chute. The filling material is continuously stirred evenly to prepare a filling slurry with moderate concentration and good fluidity, which then enters the feeding hopper through the chute and is finally pumped into the underground filling pipe network system to the goaf for filling.

[0072] In this embodiment, a filling system is established near the surface of the mine pit entrance. Through the filling system, efficient and continuous cement mortar preparation and pumping are achieved, which can effectively ensure the production stability and production efficiency of the filling operation. In addition, the filling system of this embodiment is easy to build, occupies a small area, and has a simple process flow. It can better adapt to the environmental requirements of the mine site and ensure the normal progress of the filling work.

[0073] Specifically: the filling system uses a pipe with a diameter of 125mm as the downhole filling pipe, the pipe arrangement filling multiple of the downhole filling pipe is 7, and when the cement mortar is pumped through the filling system, the pumping pressure is controlled by the filling system to be 8Mpa.

[0074] In this embodiment, for the cement mortar mix ratio used in this embodiment, the consistency of the cement mortar can be obtained. According to its consistency, the diameter of the downhole filling pipeline is determined, the filling multiple is arranged, and the pumping pressure is controlled, which can effectively avoid clogging of the filling slurry and ensure the production continuity and stability of the filling operation.

[0075] Specifically: a displacement meter and a pressure gauge are arranged on the stirring and conveying line to monitor the conveying condition of the filling slurry.

[0076] In this embodiment, the delivery volume of the filling slurry is monitored in real time by the displacement meter, and the delivery rate can be adjusted in time to ensure the stability and uniformity of the filling process. At the same time, the pressure change in the delivery pipeline is monitored in real time by the pressure gauge, so the flow state of the slurry during the delivery process can be judged, and possible blockage or leakage problems can be discovered in time to ensure the safety and reliability of the filling slurry delivery.

[0077] In this embodiment, by filling cement mortar once to form a supporting bottom plate structure, a dense bottom plate structure can be formed at the bottom of the goaf, thereby improving the bearing capacity of the foundation of the goaf and ensuring subsequent layered bonding work. At the same time, it can also facilitate the subsequent recovery of the bottom pillars of the mining area, providing favorable conditions for filling the upper void area.

[0078] S300: Step 3: After the supporting bottom plate structure is formed, waste rock is used to carry out secondary filling of the goaf to be filled, and the filling height is 5 meters.

[0079] Specifically: the waste rock is the waste rock produced by excavation of the upper and middle sections of the working face. The waste rock is transported to the goaf area to be filled, and falls into the goaf area to be filled through the filling well to achieve the filling of the goaf area to be filled.

[0080] Specifically: the use of waste rock to carry out secondary filling of the goaf to be filled also includes: according to the density of the waste rock in the goaf, assisted by sending crushed stone underground, reducing the gaps and holes between the waste rocks to increase the density; wherein the crushed stone is obtained by crushing the waste rock, and the stone particle size of the crushed stone is 40mm.

[0081] In this embodiment, by filling the gaps and holes between the waste rocks with crushed stones, the overall density of the filling structure can be effectively increased, the stability of the goaf after filling can be improved, and the risk of settlement can be reduced. At the same time, by using crushed stones with a particle size of 40 mm, after mixing with the prepared cement mortar, the filling structure has good strength, which can effectively ensure the strength of the filling structure.

[0082] In this embodiment, the goaf is refilled directly with underground waste rock, which improves the efficiency of construction, effectively improves the utilization rate of mining resources, improves the utilization rate of waste rock, and reduces the amount of filling slurry, thereby controlling construction costs.

[0083] S400: Step 4: After the secondary filling is completed, the goaf to be filled is grout-filled by means of direct spraying through the filling system, with a filling height of 5 meters, so that the cement mortar and waste rock are mixed to form a cementitious filling.

[0084] In this embodiment, after the goaf is grout-filled by the filling system, the solidified cement mortar can form a cementing body with the waste rock and crushed stone, which can effectively enhance the stability of the goaf.

[0085] S500: Step 5: Repeat step 3 and step 4 to perform layered cementation filling on the goaf to be filled until the goaf to be filled is completed.

[0086] In this embodiment, the filling and capping of the goaf is completed by performing layered cementation filling, which can complete the filling of the goaf, effectively improve the stability of the goaf, avoid problems such as surface subsidence and collapse, improve the efficiency and safety of the filling operation, and reduce construction costs.

[0087] Specifically: For the goaf of abandoned tunnels with longer lengths, segmented filling is adopted, with each segment being 30-50m long and each segment being filled with a retaining wall; for the goaf in the middle section where mining has been completed, one-time filling is adopted.

[0088] In this embodiment, for longer lengths, a segmented filling method is adopted to ensure the filling stability of each segmented goaf. For the goaf in the middle section where mining has been completed, the construction safety risk is relatively high. One-time filling can ensure that the filling material quickly forms a stable supporting structure, thereby ensuring safety during construction.

[0089] The technical solution in the embodiment of the present application includes the following beneficial effects:

[0090] In this embodiment, by filling cement mortar once to form a supporting bottom plate structure, a dense bottom plate structure can be formed at the bottom of the goaf, thereby improving the bearing capacity of the foundation of the goaf and ensuring subsequent layered bonding work. At the same time, it can also ensure the safe recovery of the lower and middle sections of the ore body, providing favorable conditions for filling the lower void area.

[0091] In this embodiment, by directly using underground waste rock to perform secondary filling of the goaf, the efficiency of construction is improved, the utilization rate of mining resources and waste rock can be effectively improved, and the amount of filling slurry can be reduced, the transportation cost can be controlled and increased, and the amount of waste rock out of the well can be reduced. At the same time, after the goaf is grout-filled by the filling system, the solidified cement mortar can form a cementing body with the waste rock and crushed stone, which can effectively enhance the stability of the goaf.

[0092] In this embodiment, the filling and capping of the goaf is completed by performing layered cementation filling, which can complete the filling of the goaf, effectively improve the stability of the goaf, avoid problems such as bottom plate sinking and collapse, improve the efficiency and safety of the filling operation, reduce the lifting and transportation costs, and reduce the amount of waste rock out of the well.

[0093] Finally, it should be noted that, in this article, relationships such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms include, include or any other variations are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0094] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. The method of cementing and filling waste rock after leaving the ore in shallow holes. It is characterized in that The following steps are involved: Step 1: Seal the goaf to be filled to prevent leakage of filling materials; Step 2: Fill the goaf to be filled by pumping cement mortar, and wait for the cement mortar to solidify to form a supporting floor structure; Step 3: After the supporting floor structure is formed, the goaf to be filled is refilled with waste rock, and the filling height is 5 meters; Step 4: After the secondary filling is completed, the goaf to be filled is grout-filled by a filling system in a spraying direct spraying manner, with a filling height of 5 meters, so that the cement mortar and waste rock are mixed to form a cementitious filling; Step 5: Repeat steps 3 and 4 to perform layered cementation filling on the goaf to be filled until the goaf to be filled is filled and topped.

2. The method for cementing and filling waste rock after shallow hole ore retention according to claim 1, Features: The goaf to be filled is filled once by pumping cement mortar, wherein the mix ratio of cement, sand and water in the cement mortar used for the primary filling is 1:2.68:0.63, and the sand is medium sand with a crushing rate of 40% to ensure the strength of the supporting base plate structure.

3. The method for cementing and filling waste rock after shallow hole ore retention according to claim 2, Features: The filling height of the primary filling is not less than 5m; The filling height of the primary filling corresponds to the overall height of the goaf to be filled. When the overall height of the goaf to be filled is higher, the filling height of the primary filling increases accordingly.

4. The method for shallow hole ore retention and subsequent waste rock cementation filling according to claim 3, Features: The cement mortar is produced and pumped through a filling system; The filling system comprises: a tailings feeding line, a cement storage feeding line, a water supply line and a mixing and conveying line, and the cement, sand and water are mixed and pumped through the filling system.

5. The method for shallow hole ore retention and subsequent waste rock cementation filling according to claim 4, Features: The filling system uses a pipe with a diameter of 125 mm as the downhole filling pipe. The pipe arrangement and filling multiple of the downhole filling pipe are 7. When cement mortar is pumped through the filling system, the pumping pressure is controlled to be 8 Mpa through the filling system.

6. The method for cementing and filling waste rock after shallow hole ore retention according to claim 5, Features: A displacement meter and a pressure gauge are arranged on the stirring and conveying line to monitor the conveying condition of the filling slurry.

7. The method for shallow hole ore retention and subsequent waste rock cementation filling according to claim 1, Features: The waste rock is used to perform secondary filling on the goaf to be filled, wherein the waste rock is the waste rock produced by excavation of the upper middle section working face, and the waste rock is transported to the goaf to be filled, and falls into the goaf to be filled through the filling well, so as to achieve filling of the goaf to be filled; The method of using waste rock to perform secondary filling on the goaf to be filled also includes: According to the density of the waste rock in the goaf, crushed stone is sent underground to reduce the gaps and holes between the waste rocks to increase the density; wherein the crushed stone is obtained by crushing the waste rock; The stone particle size of the crushed stone is 40 mm.

8. The method for cementing and filling waste rock after shallow hole ore depositing according to any one of claims 1 to 7, Features: The step 1: sealing the goaf to be filled to ensure effective filling, including: An iron funnel is installed at the ore discharge funnel opening of the goaf to be filled, and the iron funnel is sealed by a steel plate; During filling, wooden boards are used to block and close all passages in the goaf to be filled.

9. The method for shallow hole ore retention and subsequent waste rock cementation filling according to claim 8, Features: For the long goaf of abandoned tunnels, segmented filling is adopted, with each segment being 30-50m long and each segment being built with masonry filling retaining walls; For the goaf in the middle section where mining has been completed, one-time filling is adopted.

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