Method for mineralizing and sealing CO2 in waste roadway coal gasification ash full-solid waste filling material

Abstract

The invention belongs to the technical field of coal mine filling and solid waste resource utilization, and particularly relates to an abandoned roadway coal gasification ash full-solid waste filling material CO2 mineralization storage method which comprises the following steps that stability evaluation is conducted on a target abandoned roadway, and the roadway end of the target abandoned roadway is blocked; preparing a filling material; the prepared filling material is filled into a target abandoned roadway, and a reserved gas injection pipe and a roadway side gas injection pipe are arranged in the filling material in the filling process; cO2 is injected into the filling material through the reserved gas injection pipe and the laneway side gas injection pipe; and detecting the CO2 injection pressure and concentration to complete mineralization sealing. According to the method, by evaluating the stability of the target abandoned roadway, preparing the coal gasification ash full-solid waste filling material and carrying out CO2 gas injection storage, CO2 mineralization storage of the coal gasification ash full-solid waste filling material of the abandoned roadway is achieved, and coal-based solid waste resource utilization and negative carbon efficient filling popularization and utilization can be promoted.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal mine filling and solid waste resource utilization, and particularly relates to a method for COmineralization and storage of a fully solid waste filling material made from gasification ash and slag in abandoned roadways. Background Art

[0002] As one of the main underground spaces in mines, abandoned roadways have both heavy governance challenges and broad utilization values. At the same time, a large amount of coal-based solid waste and CO 2 are generated during the process of coal mining and utilization. The coal-based solid waste and CO 2 emissions cause a series of environmental problems such as land pollution, greenhouse effect, and extreme weather. Therefore, under the condition of having a large amount of underground abandoned space resources, carrying out green and efficient disposal of coal-based solid waste and CO 2 is an important topic for achieving carbon neutrality and high-quality development.

[0003] By utilizing the characteristics of gasification ash and slag rich in metal oxides, based on the alkali activation process and the preparation process of filling slurry, a fully solid waste filling material made from gasification ash and slag can be obtained. Combining with CO 2 capture and storage utilization technology, CO 2 mineralization and storage of the fully solid waste filling material made from gasification ash and slag are carried out to achieve multiple benefits such as utilization of underground abandoned space, solid waste resource utilization, and control of roadway surrounding rock. However, there is currently no perfect process method for synergistic CO 2 sealing in gasification ash and slag filling.

[0004] Therefore, it is necessary to design a method for CO 2 mineralization and storage of a fully solid waste filling material made from gasification ash and slag in abandoned roadways to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for CO 2 mineralization and storage of a fully solid waste filling material made from gasification ash and slag in abandoned roadways. By evaluating the stability of the target abandoned roadway, preparing the fully solid waste filling material made from gasification ash and slag, and injecting gas for storage, CO 2 mineralization and storage of the fully solid waste filling material made from gasification ash and slag in abandoned roadways are realized, which helps to promote the resource utilization of coal-based solid waste and the popularization and utilization of negative carbon and efficient filling. 2 To achieve the above purpose, the present invention provides the following solution: A method for CO

[0006] mineralization and storage of a fully solid waste filling material made from gasification ash and slag in abandoned roadways, comprising the following steps: 2 Evaluating the stability of the target abandoned roadway and blocking the end of the target abandoned roadway;

[0007]

[0008] ​Preparing a filling material;

[0009] Filling the prepared filling material into the target abandoned roadway, and arranging a reserved gas injection pipe and a roadway side gas injection pipe inside the filling material during the filling process;

[0010] Injecting CO into the filling material through the reserved gas injection pipe and the roadway side gas injection pipe 2 ;

[0011] Detecting the CO 2 injection pressure and concentration to complete mineralization and sealing.

[0012] Preferably, the step of evaluating the stability of the target abandoned roadway includes:

[0013] Establishing an evaluation matrix based on geological factors, abandoned roadway structure factors, environmental factors, mining disturbance factors, and internal monitoring factors of the abandoned roadway, and conducting stability evaluation through the entropy method.

[0014] Based on a CO 2 mineralization and sealing method of a fully solid waste filling material for gasified ash slag in abandoned roadways of the present invention, the step of sealing the ends of the target abandoned roadway includes:

[0015] Sealing the near and far ends of the target abandoned roadway through a closed filling retaining wall.

[0016] Based on a CO 2 mineralization and sealing method of a fully solid waste filling material for gasified ash slag in abandoned roadways of the present invention, the step of preparing the filling material includes:

[0017] Adding gasified ash slag, coal gangue, and fly ash into a mixer for mixing and stirring to form a gasified ash slag filling base material, and adding water, cement, and an alkali activator into the gasified ash slag filling base material for mixing and stirring to form a fully solid waste filling material for gasified ash slag.

[0018] Based on a CO 2 mineralization and sealing method of a fully solid waste filling material for gasified ash slag in abandoned roadways of the present invention, the components of the gasified ash slag filling base material include 30 - 40 parts of gasified ash slag, 15 - 25 parts of coal gangue, and 10 - 15 parts of fly ash by weight.

[0019] Based on a CO 2 mineralization and sealing method of a fully solid waste filling material for gasified ash slag in abandoned roadways of the present invention, the components of the fully solid waste filling material for gasified ash slag include 5 - 15 parts of cement, 20 - 30 parts of water, and 0.5 - 3 parts of alkali activator by weight.

[0020] Based on a CO 2Mineralization and sequestration method, wherein the alkali activator is a mixture of sodium silicate and sodium hydroxide.

[0021] Based on an all-solid waste filling material for gasified ash of abandoned roadway gasification in the present invention, CO 2 Mineralization and sequestration method, wherein the reserved injection pipe is located at the bottom of the all-solid waste filling material for gasified ash of abandoned roadway gasification, the diameter of the reserved injection pipe is 5 - 10 cm, and the distance between any two adjacent reserved injection pipes is 1 - 2 m;

[0022] The roadway side injection pipe is located in the middle of the all-solid waste filling material for gasified ash of abandoned roadway gasification, the diameter of the roadway side injection pipe is 5 - 10 cm, and the distance between any two adjacent roadway side injection pipes is 5 - 10 m.

[0023] Based on an all-solid waste filling material for gasified ash of abandoned roadway gasification in the present invention, CO 2 Mineralization and sequestration method, CO 2 The injection concentration is 80 - 100%, the injection pressure is 8 - 10 Mpa, and the CO pressure at the pipe orifices of the reserved injection pipe and the roadway side injection pipe is 2 - 3 Mpa. 2 The pressure is 2 - 3 Mpa.

[0024] Based on an all-solid waste filling material for gasified ash of abandoned roadway gasification in the present invention, CO 2 Mineralization and sequestration method, CO is injected 0.5 - 24 h after the initial setting of the all-solid waste filling material for gasified ash of abandoned roadway gasification 2 .

[0025] Compared with the prior art, the present invention has the following advantages and technical effects:

[0026] The present invention makes full use of the space resources of underground abandoned roadways, effectively disposes of coal-based solid wastes such as gasified ash, reduces the cement consumption by adding an alkali activator to modify the gasified ash, prepares an all-solid waste filling material for gasified ash of abandoned roadway gasification with low cost and environmental friendliness, and can achieve efficient and safe sequestration of CO during the filling process. This method has strong engineering practicability and obvious beneficial effects, and is conducive to promoting the utilization of underground abandoned spaces and the construction of waste-free mines. 2 The method has strong engineering practicability and obvious beneficial effects, and is conducive to promoting the utilization of underground abandoned spaces and the construction of waste-free mines. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings without creative efforts:

[0028] Figure 1 It is a schematic diagram of the whole of the present invention.

[0029] Among them, 1. Target abandoned roadway; 2. Sealing and filling retaining wall; 3. Coal gasification ash residue; 4. Coal gangue; 5. Fly ash; 6. Mixer; 7. Filling pump; 8. Water; 9. Cement; 10. Alkali activator; 11. Slurry conveying system; 12. Roadway filling system; 13. Reserved gas injection pipe; 14. Gas injection pipe for roadway sidewall; 15. CO2 storage tank; 16. CO2 gas injection system; 17. Adjacent mining disturbed space. Specific implementation manners

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0032] Referring to Figure 1 as shown, the present invention provides a method for CO 2 mineralization and storage of a fully solid waste filling material for coal gasification ash residue in an abandoned roadway, including the following steps:

[0033] Conduct a stability assessment on the target abandoned roadway 1, and seal the end of the target abandoned roadway 1.

[0034] Prepare the filling material.

[0035] Fill the prepared filling material into the target abandoned roadway 1, and set a reserved gas injection pipe 13 and a gas injection pipe 14 for the roadway sidewall inside the filling material during the filling process.

[0036] Fill the prepared filling material into the target abandoned roadway 1 through the filling pump 7, the slurry conveying system 11, and the roadway filling system 12.

[0037] Inject CO 2 ;

[0038] Detect the CO 2 injection pressure and concentration to complete mineralization and storage.

[0039] Further, the step of conducting a stability assessment on the target abandoned roadway 1 includes:

[0040] Establish an evaluation matrix based on geological factors, abandoned roadway structure factors, environmental factors, mining disturbance factors, and internal monitoring factors of the abandoned roadway, and conduct a stability assessment through the entropy method.

[0041] Geological factors include stratigraphic structure and lithology, geological structure, in-situ stress conditions, and groundwater conditions. Abandoned roadway structure factors include the cross-sectional shape of the abandoned roadway, the cross-sectional size of the abandoned roadway, the support structure, and the roadway layout. Environmental factors include groundwater changes, temperature changes, dynamic loads, and the time effect of rock mass and support materials. Mining disturbance factors include blasting intensity, the size of adjacent mined-out spaces, and the mining method of adjacent mined-out spaces. Internal monitoring factors of the abandoned roadway include displacement and deformation, stress changes, crack and leakage monitoring, and gas concentration.

[0042] Furthermore, the steps for plugging the ends of the target abandoned roadway 1 include:

[0043] Plugging the near and far ends of the target abandoned roadway 1 with the airtight filling wall 2.

[0044] Using single hydraulic props, filling back panels, concrete, and sealing cloth materials to build the airtight filling wall 2 to plug the near and far ends of the target abandoned roadway 1.

[0045] Furthermore, the steps for preparing the filling material include:

[0046] Adding coal gasification ash 3, coal gangue 4, and fly ash 5 into the mixer 6 for mixing and stirring to form a coal gasification ash filling base material, and adding water 8, cement 9, and alkali activator 10 into the coal gasification ash filling base material for mixing and stirring to form a coal gasification ash all-solid waste filling material.

[0047] The stirring time of the coal gasification ash 3, coal gangue 4, and fly ash 5 is 5 - 10 min, and the stirring time of the water 8, cement 9, and alkali activator 10 with the coal gasification ash filling base material is 5 - 10 min.

[0048] Furthermore, the components of the coal gasification ash filling base material include 30 - 40 parts by weight of coal gasification ash 3, 15 - 25 parts by weight of coal gangue 4, and 10 - 15 parts by weight of fly ash 5.

[0049] Furthermore, the components of the coal gasification ash all-solid waste filling material include 5 - 15 parts by weight of cement 9, 20 - 30 parts by weight of water 8, and 0.5 - 3 parts by weight of alkali activator 10.

[0050] Furthermore, the alkali activator 10 is a mixture of sodium silicate and sodium hydroxide.

[0051] Furthermore, the reserved injection pipe 13 is located at the bottom of the coal gasification ash all-solid waste filling material, the diameter of the reserved injection pipe 13 is 5 - 10 cm, and the distance between any two adjacent reserved injection pipes 13 is 1 - 2 m;

[0052] The rib injection pipe 14 is located in the middle of the fully solid waste filling material of coal gasification ash residue. The diameter of the rib injection pipe 14 is 5 - 10 cm, and the distance between any two adjacent rib injection pipes 14 is 5 - 10 m.

[0053] The rib injection pipe 14 is set in the target abandoned roadway 1 through the adjacent mining space 17.

[0054] Further, the injection concentration of CO 2 is 80 - 100%, the injection pressure is 8 - 10 Mpa, and the CO 2 pressure at the pipe orifices of the reserved injection pipe 13 and the rib injection pipe 14 is 2 - 3 Mpa.

[0055] Further, CO is injected 0.5 - 24 h after the initial setting of the fully solid waste filling material of coal gasification ash residue. 2 .

[0056] The injected CO 2 enters the reserved injection pipe 13 and the rib injection pipe 14 from the CO 2 storage tank 15 through the CO 2 injection system 16.

[0057] Test example:

[0058] Weigh 3.5 parts of coal gasification ash residue 3, 2 parts of coal gangue 4, 1 part of fly ash 5, 0.5 part of cement 9, 2.5 parts of water 8 and 0.08 part of alkali activator 10, add them to the mixer 6 and stir to obtain the fully solid waste filling material of coal gasification ash residue. Put the obtained fully solid waste filling material of coal gasification ash residue into the CO 2 mineralization stirring device, mix and stir for 30 min. Additionally, set up a group of fully solid waste filling material of coal gasification ash residue without CO 2 added and put it into the CO 2 mineralization stirring device, mix and stir for 30 min. Calculate the CO 2 mineralization sealing amount according to the mass change of the fully solid waste filling material of coal gasification ash residue before and after stirring. The CO 2 sealing amount of the test group is 2.76%, and that of the control group is 0.12%.

[0059] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0060] The embodiments described above are only descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the spirit of the present invention's design, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for mineralizing and storing CO2 using all-solid waste filling materials of coal gasification ash in abandoned tunnels, characterized in that: The following steps are involved: Conducting a stability assessment on the target abandoned tunnel (1), and sealing the end of the target abandoned tunnel (1); preparing filling materials; Filling the prepared filling material into the target abandoned tunnel (1), and during the filling process, setting a reserved air injection pipe (13) and a tunnel side air injection pipe (14) inside the filling material; Injecting CO2 into the filling material through the reserved gas injection pipe (13) and the lane side gas injection pipe (14); Detect CO2 injection pressure and concentration and complete mineralization storage.

2. The method for CO2 mineralization and storage using all-solid waste filling materials of abandoned tunnel coal gasification ash according to claim 1 is characterized in that: The step of conducting stability assessment on the target abandoned tunnel (1) comprises: An evaluation matrix was established based on geological factors, abandoned tunnel structure factors, environmental factors, mining disturbance factors and internal monitoring factors of abandoned tunnels, and stability assessment was performed using the entropy method.

3. The method for CO2 mineralization and storage using abandoned tunnel coal gasification ash as all-solid waste filling material according to claim 1 is characterized in that: The step of blocking the end of the target abandoned tunnel (1) comprises: The far and near ends of the target abandoned tunnel (1) are blocked by means of a closed filling retaining wall (2).

4. The method for CO2 mineralization and storage using all-solid waste filling materials of abandoned tunnel coal gasification ash according to claim 1 is characterized in that: The step of preparing the filling material comprises: Coal gasification ash (3), coal gangue (4) and fly ash (5) are added to a mixer (6) for mixing and stirring to form a coal gasification ash filling base material, and water (8), cement (9) and an alkali activator (10) are added to the coal gasification ash filling base material for mixing and stirring to form a coal gasification ash all-solid waste filling material.

5. The method for CO2 mineralization and storage using all-solid waste filling materials of abandoned tunnel coal gasification ash according to claim 4 is characterized in that: The coal gasification ash filling base material components include 30-40 parts by weight of coal gasification ash (3), 15-25 parts by weight of coal gangue (4), and 10-15 parts by weight of fly ash (5).

6. The method for CO2 mineralization and storage using all-solid waste filling materials of abandoned tunnel coal gasification ash according to claim 4 is characterized in that: The coal gasification ash all-solid waste filling material comprises, by weight, 5-15 parts of cement (9), 20-30 parts of water (8), and 0.5-3 parts of an alkali activator (10).

7. The method for CO2 mineralization and storage using abandoned tunnel coal gasification ash and solid waste filling materials according to claim 6 is characterized in that: The alkaline activator (10) is a mixture of sodium silicate and sodium hydroxide.

8. The method for CO2 mineralization and storage using all-solid waste filling materials of abandoned tunnel coal gasification ash according to claim 1 is characterized in that: The reserved gas injection pipe (13) is located at the bottom of the coal gasification ash solid waste filling material, the diameter of the reserved gas injection pipe (13) is 5-10 cm, and the distance between any two adjacent reserved gas injection pipes (13) is 1-2 m; The lane side gas injection pipe (14) is located in the middle of the coal gasification ash solid waste filling material, the diameter of the lane side gas injection pipe (14) is 5-10 cm, and the distance between any two adjacent lane side gas injection pipes (14) is 5-10 m.

9. The method for CO2 mineralization and storage using all-solid waste filling materials of abandoned tunnel coal gasification ash according to claim 1 is characterized in that: The injection concentration of CO2 is 80-100%, the injection pressure is 8-10Mpa, and the CO2 pressure at the pipe openings of the reserved gas injection pipe (13) and the lane side gas injection pipe (14) is 2-3Mpa.

10. The method for CO2 mineralization and storage using all-solid waste filling materials of abandoned tunnel coal gasification ash according to claim 4 is characterized in that: CO2 is injected into the coal gasification ash all-solid waste filling material 0.5-24 hours after initial setting.

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