A layered negative carbon grouting method for preventing mine water inrush

Abstract

This invention belongs to the field of mine water control and carbon dioxide sequestration technology, and particularly relates to a layered negative carbon grouting method for preventing mine water inrush. The steps are as follows: S1, injecting a first-order grout to form a first-order grouting area; S2, injecting a first-order carbon dioxide to displace the first-order grout, forming a first-order carbon injection area, where the first-order carbon dioxide reacts with the first-order grout to form a first-order stone layer; S3, injecting a second-order grout, which displaces unreacted first-order carbon dioxide to form a second-order grouting area; S4, injecting a second-order carbon dioxide, where the second-order grout, unreacted first-order carbon dioxide, and second-order carbon dioxide fully react to form a second-order stone layer; repeating S1-S4 until the parameters required for preventing mine water inrush are met, completing the grouting process. This invention simultaneously achieves mine water inrush prevention and carbon dioxide sequestration.

Description

Technical Field

[0001] This invention belongs to the field of mine water control and carbon dioxide storage technology, and particularly relates to a layered negative carbon grouting method for preventing mine water inrush. Background Technology

[0002] Currently, cement-based grouting is a common method for preventing mine water inrush. By drilling and pumping cement slurry into grouting areas such as aquifers and fault fracture zones, the surrounding rock can be cemented and reinforced, and its impermeability improved, thereby achieving the purpose of water plugging. However, with the increase in coal mining depth, extreme conditions such as high stress, high water pressure, and high temperature place higher demands on grouting materials. Traditional cement-based materials are difficult to adapt to extreme environments, resulting in significantly limited grouting effectiveness.

[0003] On the other hand, while geological carbon dioxide sequestration is a key technology for large-scale emission reduction, its widespread application is limited by extremely high geological conditions. It is worth noting that the cement industry, as a major source of carbon emissions, produces traditional cement-based grouting materials that generate significant carbon emissions during production and use, fundamentally conflicting with the green and low-carbon development needs of mines.

[0004] Therefore, a layered negative carbon grouting method for preventing mine water inrush is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a layered negative carbon grouting method for preventing mine water inrush, so as to solve the above-mentioned problems.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] A layered negative carbon grouting method for preventing mine water inrush includes the following steps:

[0008] S1. Inject the first-order grout into the grouting hole, the first-order grout filling the fissures between rocks to form a first-order grouting area; inject the first-order carbon dioxide into the grouting hole, so that the first-order carbon dioxide displaces the first-order grout in the first-order grouting area and forms a first-order carbon dioxide injection area, and the first-order carbon dioxide can react with the first-order grout to form a first-order stone body layer;

[0009] S2. Inject a second-order grout into the grouting hole so that the second-order grout displaces the unreacted first-order carbon dioxide in the first-order carbon injection area and forms a second-order grouting area; inject a second-order carbon dioxide into the grouting hole so that the second-order grout, the unreacted first-order carbon dioxide, and the second-order carbon dioxide react fully to form a second-order stone body layer, wherein the amount of second-order carbon dioxide injected is less than the amount of first-order carbon dioxide injected;

[0010] Repeat steps S1-S2 to form multiple continuous stone layers in the grouting hole and the fissure, and then seal the grouting hole with grout to complete the grouting process.

[0011] In the layered grouting method for preventing mine water inrush of the present invention, before injecting grout into the grouting hole, the parameters of the grout and the rock mass layer are tested, and the construction parameters are obtained according to the relationship between the grout parameters, the rock mass layer parameters, the mine water inrush prevention parameters and the construction parameters. The construction parameters include the injection pump volume, grout injection time, carbon dioxide injection time, interval time and number of carbon dioxide injections.

[0012] In the layered grouting method for preventing mine water inrush of the present invention, after the grouting hole is sealed, the grouting effect is evaluated. The evaluation includes the permeability parameters, strength parameters, durability parameters, and carbon dioxide absorption parameters of the stone body layer.

[0013] In the layered grouting method for preventing mine water inrush of the present invention, when injecting carbon dioxide into the grouting hole, a gradient pressure control method of first low and then high is adopted.

[0014] In the layered grouting method for preventing mine water inrush of the present invention, when carbon dioxide is injected into the grouting hole, the pressure inside the grouting hole is monitored. When the pressure value is higher than the set value, the injection of carbon dioxide is paused, and the injection of carbon dioxide continues after a preset time.

[0015] In the layered grouting method for preventing mine water inrush of the present invention, the first-order carbon dioxide and the second-order carbon dioxide are the same, both being industrial waste gas and / or supercritical carbon dioxide.

[0016] In the layered grouting method for preventing mine water inrush of the present invention, the first grout and the second grout are the same, both including magnesium oxide, cement, blast furnace slag, nano silica and polycarboxylate superplasticizer.

[0017] In the layered grouting method for preventing mine water inrush of the present invention, the preset time is 1 minute.

[0018] In the layered grouting method for preventing mine water inrush of the present invention, a cement-based sealing material is used when sealing the grouting hole.

[0019] Compared with the prior art, the present invention has the following advantages and technical effects:

[0020] In this invention, a multi-layered stone body is formed by layered grouting, thereby improving the impermeability of the stone body. At the same time, the grout reacts with carbon dioxide to form a stone body, thus achieving the sealing of carbon dioxide. Furthermore, the alternating injection of carbon dioxide and grout creates a "carbonization front advancement effect," resulting in more complete carbon dioxide absorption and a more thorough reaction, effectively alleviating the problem of inconsistent reaction rates among different materials. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a flow chart of the grouting process of the present invention;

[0023] Figure 2 This is a schematic diagram of the grouting equipment of the present invention;

[0024] Figure 3 This is a schematic diagram of the first-order grouting principle of the present invention;

[0025] Figure 4 This is a schematic diagram of the first carbon injection principle of the present invention;

[0026] Figure 5 This is a schematic diagram of the second-order grouting principle of the present invention;

[0027] Figure 6 This is a schematic diagram of the second carbon injection principle of the present invention;

[0028] Among them, 1. Carbon delivery pipe; 2. Grout delivery pipe; 3. Carbon injection pump; 4. Grouting pump; 5. Carbon injection pipe; 6. Grouting pipe; 7. Grouting hole; 8. Control valve; 9. Rock; 10. Fissure; 11. First-order grout; 12. First-order carbon dioxide; 13. First-order stone layer; 14. Second-order grout; 15. Second-order stone layer; 16. Second-order carbon dioxide. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Reference Figures 1 to 6 This invention discloses a layered negative carbon grouting method for preventing mine water inrush, the steps of which are as follows:

[0032] S1. First-order grout 11 is injected into grouting hole 7. First-order grout 11 fills the cracks 10 between rocks 9 to form first-order grouting area. First-order carbon dioxide 12 is injected into grouting hole 7 so that the first-order carbon dioxide 12 displaces the first-order grout 11 in the first-order grouting area and forms first-order carbon dioxide injection area. The first-order carbon dioxide 12 can react with the first-order grout 11 to form first-order stone body layer 13.

[0033] Specifically, during the first grouting sequence, the control valve 8 is first opened to open the grouting channel and the carbon injection channel is closed. The grout is then delivered to the grouting pump 4 via the grout delivery pipe 2. The grouting pump 4 injects the grout into the grouting hole 7 through the grouting pipe 6 according to the preset grouting pump volume. At this time, the grout enters the fissures 10 between the rocks 9, forming the grouting area. This grout is the first-sequence grout 11, completing the first grouting sequence. The grouting pump 4 is then closed, and the control valve 8 is closed to shut off the grouting channel. During the first carbon injection sequence, the control valve 8 is opened to open the carbon injection channel. Carbon dioxide enters the carbon injection pump 3 through the carbon delivery pipe 1, and then the carbon injection pump 3 provides power to enter the grouting hole 7 through the carbon injection pipe 5. The carbon dioxide enters the fissure 10 between the rocks 9 and forms the first-order carbon injection area under pressure. At this time, the carbon dioxide is the first-order carbon dioxide 12. The first-order carbon dioxide 12 located outside the first-order carbon injection area reacts with the first-order grout 11 to form the first-order stone body layer 13, completing the first-order carbon injection. The carbon injection pump 3 is turned off, and the control valve 8 closes the carbon injection channel.

[0034] S2. Inject the second-order grout 14 into the grouting hole 7 so that the second-order grout 14 displaces the first-order carbon dioxide 12 that was not consumed by the reaction in the first-order carbon injection area and forms the second-order grouting area; inject the second-order carbon dioxide 16 into the grouting hole 7 so that the second-order grout 14, the first-order carbon dioxide 12 that was not consumed by the reaction and the second-order carbon dioxide 16 react fully to form the second-order stone body layer 15, wherein the amount of second-order carbon dioxide 16 injected is less than the amount of first-order carbon dioxide 12 injected;

[0035] Specifically, during the second grouting sequence, the control valve 8 opens the grouting channel, and the grout is delivered to the grouting pump 4 via the grouting pipe 2. The grouting pump 4 injects the grout into the grouting hole 7 through the grouting pipe 6 according to the preset grouting pump volume. At this time, the grout enters the first carbon injection area and forms the second grouting area. The grout at this time is the second grout 14. The second grout 14 displaces the unreacted first grout 12. The second grout 14 fully reacts with the unreacted portion of the first grout 12 and completes the carbon dioxide sealing. The second grouting sequence ends, the grouting pump 4 is turned off, and the control valve 8 opens the grouting channel. The grouting pump 4 is then closed. Control valve 8 closes the grouting channel; when performing the second carbon injection, control valve 8 opens the carbon injection channel, carbon dioxide enters the carbon injection pump 3 through carbon delivery pipe 1, and then the carbon injection pump 3 provides power to enter the grouting hole 7 through carbon injection pipe 5. The carbon dioxide enters the fissure 10 between the rocks 9 and forms the second carbon injection area under pressure. At this time, the carbon dioxide is the second carbon dioxide 16. The second carbon dioxide 16, the first carbon dioxide 12 and the second grout 14 react fully to form the second stone body layer 15. Then, the carbon injection pump 3 is closed and control valve 8 closes the carbon injection channel.

[0036] Repeat steps S1-S2 to form multiple continuous stone layers within the grouting hole 7 and the fissure 10, and then seal the grouting hole 7 with grout to complete the grouting process.

[0037] In one alternative approach, before injecting grout into the grouting hole 7, the parameters of the grout and the rock layer are tested, and the construction parameters are obtained based on the relationship between the grout parameters, the rock layer parameters, the parameters for preventing mine water inrush, and the construction parameters. The construction parameters include the injection pump volume, grout injection time, carbon dioxide injection time, interval time, and number of carbon dioxide injections.

[0038] In one alternative approach, after sealing the grouting hole 7, the grouting effect is evaluated. The evaluation includes parameters such as permeability, strength, durability, and carbon dioxide absorption of the stone layer.

[0039] In one alternative approach, when injecting carbon dioxide into the grouting hole 7, a gradient pressure control method of first low and then high is adopted.

[0040] In one alternative approach, when injecting carbon dioxide into the grouting hole 7, the pressure inside the grouting hole 7 is monitored. When the pressure value is higher than the set value, the injection of carbon dioxide is paused, and the injection of carbon dioxide continues after a preset time.

[0041] In one of the optional options, the preset time is 1 minute.

[0042] This setting can effectively prevent the crack 10 from expanding excessively.

[0043] In one alternative scheme, the first sequence carbon dioxide 12 and the second sequence carbon dioxide 16 are the same, both being industrial waste gas and / or supercritical carbon dioxide.

[0044] Using industrial waste gas can effectively control construction costs, while using supercritical carbon dioxide can improve carbon sealing efficiency.

[0045] The pressure conditions for storing liquid supercritical carbon dioxide, i.e., above 7.0 MPa, can be met under the high pressure and high stress environment of deep mines; the temperature conditions for storing liquid supercritical carbon dioxide, i.e., above 31℃, can be met under the high temperature environment of deep mines.

[0046] In one alternative, the first grout 11 and the second grout 14 are identical, both comprising magnesium oxide, cement, blast furnace slag, nano-silica, and polycarboxylate superplasticizer.

[0047] The composition of the components is as follows: magnesium oxide (10%~35%), cement (40%~60%), blast furnace slag (10%~30%), nano-silica (1%~5%), and polycarboxylate superplasticizer (0.5%~2%).

[0048] Magnesium oxide reacts with carbon dioxide to form magnesium carbonate, which has better chemical stability than calcium carbonate, thus improving the corrosion resistance of the stone layer. Magnesium carbonate also has a stronger ability to bind carbon dioxide, enhancing the carbon storage capacity of the stone layer. Magnesium carbonate crystals form Mg-O-Si bonds with the rock surface, improving the adhesion of the stone layer. Magnesium carbonate crystals have higher strength than CSH gel, and nano-silica fills pores and promotes secondary hydration, forming a high-strength framework, thus increasing the strength of the stone layer. The volume expansion of magnesium oxide during carbonization offsets its self-shrinkage and fills microcracks, while nano-silica optimizes particle size distribution and blocks micropores. Slag hydration generates low-porosity CASH gel, improving the impermeability of the stone layer. Injected carbon dioxide increases the carbonization efficiency of the stone layer, further promoting performance improvement.

[0049] In one alternative, the amount of magnesium oxide added to the slurry is less than 35%.

[0050] Adding less than 35% magnesium oxide can effectively prevent excessive expansion of the slurry after solidification.

[0051] In one alternative, a cement-based sealing material is used when sealing the grouting hole 7.

[0052] Detailed grouting steps:

[0053] Geological exploration was conducted. Based on the results of the geological exploration and the actual engineering requirements, boreholes were designed and constructed, and grouting holes 7 were drilled at the locations to be grouted. Geological exploration data should include information such as rock strata type, fracture distribution, rock permeability, aquifer characteristics, and groundwater flow direction and velocity. For example, when the grouting area has high permeability (>10... -4 When the grouting area is a fractured zone with well-developed fissures (m / s), the distance between the grouting holes 7 needs to be reduced and the length of the grouting holes 7 increased to ensure that the grout can uniformly fill the fissures. When the grouting area is a high-permeability aquifer (aquifer water pressure > 5 MPa), the grouting pressure needs to be increased and the angle of the grouting holes 7 needs to be set against the direction of water flow to more effectively block the water flow. At the same time, the grout is prepared and tested to obtain the main parameters of the grout (such as rheology, setting time, etc.) and the parameters of the stone body formed after the grout reacts with carbon dioxide (such as stone body strength, permeability, etc.). Generally speaking, the grout should ensure reasonable flow properties (< 0.5 Pa·s) and setting time (within a few hours of initial setting), and the permeability coefficient of the stone body needs to be less than 10. -5 The requirement can be met by a speed of cm / s.

[0054] Based on the properties of the original rock, grout parameters, parameters of the rock mass layer, the requirements for preventing mine water inrush, and the relationship between construction parameters, the construction parameters are determined. Construction parameters include, but are not limited to, injection pump volume, grout injection time, carbon dioxide injection time, interval time, and number of carbon dioxide injections. For example, in injection areas with high original rock permeability and a permeability unit of 1 Lvrong value or higher, the grout water-cement ratio needs to be increased (0.5~1.0), and the grouting time extended.

[0055] Construction is carried out according to the obtained construction parameters. The construction process is as follows: the first grouting is carried out. The control valve 8 is opened to open the grouting channel and the carbon injection channel is closed. The grout is sent to the grouting pump 4 through the grouting pipe 2. The grouting pump 4 injects the grout into the grouting hole 7 through the grouting pipe 6 according to the preset grouting pump volume. At this time, the grout enters the crack 10 between the rocks 9 to form the grouting area. At this time, the grout is the first grout 11. The first grouting is completed. The grouting pump 4 is closed and the control valve 8 is closed to close the grouting channel.

[0056] First-order carbon injection: Control valve 8 opens the carbon injection channel, carbon dioxide enters the carbon injection pump 3 through carbon delivery pipe 1, and then the carbon injection pump 3 provides power to enter the grouting hole 7 through carbon injection pipe 5. The carbon dioxide enters the fissures 10 between rocks 9 and forms the first-order carbon injection area under pressure. At this time, the carbon dioxide is the first-order carbon dioxide 12. The first-order carbon dioxide 12 located outside the first-order carbon injection area reacts with the first-order grout 11 to form the first-order stone body layer 13, completing the first-order carbon injection. The carbon injection pump 3 is closed, and the control valve 8 closes the carbon injection channel.

[0057] Second-stage grouting: Control valve 8 opens the grouting channel, and the grout is sent to the grouting pump 4 through the grouting pipe 2. The grouting pump 4 injects the grout into the grouting hole 7 through the grouting pipe 6 according to the preset grouting pump volume. At this time, the grout enters the first-stage carbon dioxide injection area and forms the second-stage carbon dioxide injection area. At this time, the grout is the second-stage grout 14. The second-stage grout 14 displaces the unreacted first-stage carbon dioxide 12. The second-stage grout 14 fully reacts with the unreacted part of the first-stage carbon dioxide 12 and completes carbon dioxide sealing. The second-stage grouting ends, the grouting pump 4 is turned off, and the control valve 8 is turned off to close the grouting channel.

[0058] Second-order carbon injection: Control valve 8 opens the carbon injection channel, carbon dioxide enters the carbon injection pump 3 through carbon delivery pipe 1, and then the carbon injection pump 3 provides power to enter the grouting hole 7 through carbon injection pipe 5. The carbon dioxide enters the fissures 10 between rocks 9 and forms the second-order carbon injection area under pressure. At this time, the carbon dioxide is the second-order carbon dioxide 16. The second-order carbon dioxide 16, the first-order carbon dioxide 12 and the second-order grout 14 react fully to form the second-order stone body layer 15. Then, the carbon injection pump 3 is closed and the control valve 8 closes the carbon injection channel.

[0059] Repeat the construction process until the construction parameters are met. Grouting is the final step before sealing the grouting hole 7. After the final step is completed, shut down the grouting pump 4, control the regulating valve 8 to close the grouting channel and dismantle the equipment. Use cement-based ventilation control material to seal the grouting hole 7.

[0060] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0061] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A layered negative carbon grouting method for preventing mine water inrush, characterized in that, The steps are as follows: S1. Inject first-order grout (11) into the grouting hole (7), the first-order grout (11) fills the cracks (10) between the rocks (9) to form a first-order grouting area; inject first-order carbon dioxide (12) into the grouting hole (7) so that the first-order carbon dioxide (12) displaces the first-order grout (11) in the first-order grouting area and forms a first-order carbon dioxide injection area, and the first-order carbon dioxide (12) can react with the first-order grout (11) to form a first-order stone body layer (13). S2. Inject a second-order grout (14) into the grouting hole (7) so that the second-order grout (14) displaces the first-order carbon dioxide (12) that was not consumed by the reaction in the first-order carbon injection area and forms a second-order grouting area; inject a second-order carbon dioxide (16) into the grouting hole (7) so that the second-order grout (14), the first-order carbon dioxide (12) that was not consumed by the reaction and the second-order carbon dioxide (16) react fully to form a second-order stone body layer (15), wherein the amount of second-order carbon dioxide (16) injected is less than the amount of first-order carbon dioxide (12) injected; Repeat steps S1-S2 to form multiple continuous stone layers in the grouting hole (7) and the fissure (10). After the construction parameters are met, the grouting hole (7) is sealed by grouting to complete the grouting process. Before injecting grout into the grouting hole (7), test the parameters of the grout and the stone layer, and obtain the construction parameters based on the relationship between the grout parameters, the stone layer parameters, the parameters for preventing mine water inrush and the construction parameters. The construction parameters include the injection pump volume, grout injection time, carbon dioxide injection time, interval time, and number of carbon dioxide injections. When injecting carbon dioxide into the grouting hole (7), a gradient pressure control method of first low and then high is adopted; The first grout (11) and the second grout (14) are the same, both including magnesium oxide, cement, blast furnace slag, nano silica and polycarboxylate superplasticizer.

2. The layered negative carbon grouting method for preventing mine water inrush according to claim 1, characterized in that, After sealing the grouting hole (7), the grouting effect is evaluated. The evaluation includes the permeability parameters, strength parameters, durability parameters, and carbon dioxide absorption parameters of the stone body layer.

3. A layered negative carbon grouting method for preventing mine water inrush according to claim 1, characterized in that, When injecting carbon dioxide into the grouting hole (7), the pressure inside the grouting hole (7) is monitored. When the pressure value is higher than the set value, the injection of carbon dioxide is paused and the injection of carbon dioxide continues after a preset time.

4. A layered negative carbon grouting method for preventing mine water inrush according to claim 1, characterized in that, The first-order carbon dioxide (12) and the second-order carbon dioxide (16) are the same, both being industrial waste gas and / or supercritical carbon dioxide.

5. A layered negative carbon grouting method for preventing mine water inrush according to claim 3, characterized in that, The preset time is 1 minute.

6. A layered negative carbon grouting method for preventing mine water inrush according to claim 1, characterized in that, When sealing the grouting hole (7), a cement-based sealing material is used.

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