Water gushing plugging method for iron sulfide pit channel

Abstract

The invention relates to an iron sulfide mine pit water gushing plugging method which comprises the following steps: step 1, determining a water outlet point, namely a key boundary position of pollution-free water and heavy metal sewage in a pit, taking the water outlet point as a starting point, putting large-particle-size broken stones into the direction of heavy metal polluted water, and filling coarse aggregates; and secondly, vertical curtain grouting holes are drilled in the ground, on the basis that the coarse aggregate frame is built, dialysis cementation grouting plugging is conducted on the tunnel coarse aggregate frame and surrounding rock structure cracks, and a curtain blocking wall is formed. By means of the structure, pollution reduction can be achieved, water of a deep pollution source is blocked, the pollution-free water is freely led out of the tunnel and converged into surface runoff, and the water gushing problem of the mine pit is fundamentally solved.

Description

Technical Field

[0001] The invention relates to a method for blocking water gushing from a sulfide iron mine tunnel, belonging to the technical field of well water pollution control. Background Art

[0002] While mining development brings economic benefits, it also causes a series of problems to the ecological environment. The ores in the abandoned iron sulfide mine area are mainly pyrite, pyrrhotite, etc. The tunnel water is highly acidic and carries non-ferrous heavy metals, which enter the downstream farmland and irrigation water system, posing a serious threat to the soil and agricultural products of the downstream agricultural land. At present, a permeable reaction wall can be used to treat tunnel water. When the polluted water flows through the wall, the permeability of the reaction wall is used to make the pollutants flow through the reaction medium through the hydraulic gradient, and under the action of the reaction medium, it is converted into low-activity substances or non-toxic components to achieve the purpose of purifying and intercepting pollutants. However, the permeable reaction wall is expensive, and the replacement and maintenance of materials impose a heavy burden on local finances. The later investment cost is high and it cannot fundamentally control the pollution source in the mining area. Therefore, a simple and easy-to-use iron sulfide mine tunnel water blocking structure is needed to quickly cut off the connection between the water and the non-polluted water in the tunnel, effectively control the highly acidic water involving heavy metals, and fundamentally solve the water problem. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method for blocking water gushing from a sulfide iron ore tunnel, which can reduce pollution, block water from deep pollution sources, and freely lead non-polluted water out of the tunnel and merge into surface runoff, thereby fundamentally solving the problem of water gushing from the mine.

[0004] To solve the above problems, the specific technical solution of the present invention is as follows: A method for blocking water inrush in a sulfide iron mine tunnel comprises the following steps: Step 1: Determine the outlet point, which is the key position of the boundary between non-polluted water and heavy metal wastewater in the tunnel. Starting from the outlet point, place large-size crushed stones in the direction of heavy metal polluted water to fill the coarse aggregate; Step 2: Drill vertical curtain grouting holes from the ground. On the basis of the coarse aggregate frame, the coarse aggregate frame of the tunnel and the cracks in the surrounding rock structure are sealed by dialysis cementation grouting to form a curtain barrier wall.

[0005] The curtain barrier wall is obtained by injecting cement into N×M grouting holes.

[0006] Small-diameter D=60mm holes are preferred for grouting holes. Water stopping is performed after the holes pass through the water outlet point of the tunnel on the top plate of the goaf. The lower open hole is drilled to the bottom plate of the tunnel and the hole is terminated.

[0007] Among the N×M grouting holes, the middle row is set as the first-order holes, the rows on both sides of the first-order holes are the third-order holes, and the outer sides of the third-order holes are alternately arranged with the third-order holes and the second-order holes.

[0008] Before grouting, pilot holes are arranged. The pilot holes are selected from the first-order holes. The pilot holes also play an exploration role. They are drilled in sections from top to bottom to understand the geological conditions within the curtain design depth and the rock formation injection rate under the design grouting pressure.

[0009] Inspection holes are arranged in the first-order grouting holes for curtain grouting quality inspection. The number of inspection holes is 10% of the total number of grouting holes. The quality inspection is carried out through water pressure test 14 days after the completion of grouting at this location. The curtain grouting inspection holes should be subjected to water pressure test in sections from top to bottom. The water pressure test pressure is 80% of the pressure value used in grouting of this section and is not greater than 0.8MPa.

[0010] The spacing between grouting holes should ensure that an intersecting curtain is formed after grouting of each hole; the curtain grouting should adopt the principle of sequential encryption, first grouting the first-sequence hole, then the second-sequence hole, and finally the third-sequence hole. The length of the grouting hole is determined according to the buried depth of the tunnel. When the length of the grouting hole is less than 6m, the full-hole one-time grouting method can be adopted. When it is greater than 6m, the top-down or bottom-up segmented grouting method can be adopted.

[0011] In order to ensure the fluidity of slurry injection, the slurry injection pressure needs to be controlled in the range of 0.5~1.0MPa, and the slurry injection speed needs to be controlled in the range of 1.5~2.0m / s to ensure that the slurry does not produce coagulation, precipitation and other conditions; the concentration of the grouting slurry should follow the principle of changing step by step from dilute to concentrated.

[0012] The cement used for grouting is ordinary Portland cement, the strength grade of the cement is 42.5, and the fineness is that the residue passing through the 80μm square hole sieve is not more than 5%.

[0013] The particle size of the large crushed stone is 40 to 80 mm.

[0014] The advantages and beneficial effects of the present invention using the above technology are: The invention is suitable for blocking water gushing from sulfide iron mine tunnels, cutting off the connection between gushing water and non-polluted water in the tunnels, and effectively preventing strong acidic gushing water containing heavy metals from flowing into nearby water bodies and downstream farmland, reducing the risk of irrigation water pollution, improving regional irrigation water quality, preventing further pollution of farmland soil, and effectively protecting the safety of downstream agricultural land. It is of great significance to ensure the safety of irrigation water for agricultural land. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a cross-sectional view of the iron sulfide mine tunnel blocking structure of the present invention.

[0016] Figure 2 Schematic diagram of grouting hole drilling layout. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] Taking the actual situation of "a tunnel water inrush blocking and treatment project of a sulfide iron mine in Benxi City" as an example, Figure 1 As shown, the main shaft of the tunnel (mining tunnel) is a tunnel diagonally down the vein, with a width of nearly 3m, an inclination of about 28°, and a length of more than 500m. Water leakage occurred at 80m down the incline, with a small amount of water and normal water quality. According to the test, the arsenic content of the deep groundwater in the tunnel exceeded the standard, the copper content slightly exceeded the standard, the pH value was 1.75, and the water flow was 0.218L / s.

[0019] The method for blocking water inrush from the above-mentioned iron sulfide mine tunnel of the present invention comprises the following steps: Step 1: Determine the water outlet point, which is the key position of the boundary between non-polluted water and heavy metal sewage in the tunnel. The water from the wellhead to the water outlet point is non-polluted water. Therefore, starting from the water outlet point, large-size crushed stones with a particle size of 40-80mm are placed in the direction of heavy metal polluted water, and coarse aggregate is filled to a depth of 30m to build an aggregate frame; Step 2: Drill 6×3 grouting holes from the ground with a drilling spacing of 6m and a hole diameter of 60mm.

[0020] like Figure 2 As shown, the grouting order is set in the six columns of grouting holes. The third column from the left in the middle is set as the first-order hole, the second column from the left and the fourth column from the left on both sides of the first-order hole are the third-order holes, and the outside of the third-order holes are the second-order holes and the third-order holes are arranged alternately, that is, the first column from the left is the second-order hole, the fifth column from the left is the second-order hole, and the sixth column from the left is the third-order hole.

[0021] Before grouting, pilot holes are arranged in the grouting holes. The pilot holes are selected from the first-order holes. The pilot holes also play the role of exploration. They are drilled in sections from top to bottom to understand the geological conditions within the curtain design depth range and the rock formation injection rate under the design grouting pressure. Inspection holes are arranged in the first-order grouting holes for curtain grouting quality inspection. The number is 10% of the total number of grouting holes. The quality inspection is carried out through water pressure test 14 days after the grouting of this part is completed. The curtain grouting inspection holes should be subjected to water pressure test in sections from top to bottom. The water pressure test pressure is 80% of the pressure value used in the grouting of this section and is not greater than 0.8MPa.

[0022] The spacing between grouting holes should ensure that an intersecting curtain is formed after grouting of each hole; the curtain grouting should adopt the principle of sequence encryption, first grouting the first-sequence holes, then the second-sequence holes, and finally the third-sequence holes. The length of the grouting holes is determined according to the buried depth of the tunnel. When the length of the grouting holes is less than 6m, the full-hole one-time grouting method can be adopted. When it is greater than 6m, the top-down or bottom-up segmented grouting method can be adopted to seal the structural fissures and cracks with seepage cementation grouting.

[0023] On the basis of the coarse aggregate frame, the coarse aggregate frame of the tunnel and the cracks of the surrounding rock structure are sealed by dialysis cementation grouting to form a curtain barrier wall. The cement used for grouting is ordinary silicate cement, the strength grade of cement is 42.5, and the fineness is that the residue passing through the 80μm square hole sieve is not more than 5%. The grouting hole is preferably a small-diameter D=60mm drill hole. After the hole passes the water outlet point of the tunnel on the top plate of the goaf, water is stopped. The lower open hole is drilled to the tunnel floor position and the hole is terminated.

[0024] In order to ensure the fluidity of slurry injection, the slurry injection pressure should be controlled in the range of 0.5~1.0MPa, and the slurry injection speed should be controlled in the range of 1.5~2.0m / s to ensure that the slurry does not produce coagulation, precipitation and other conditions; the concentration of the grouting slurry should follow the principle of step-by-step change from thin to thick. The concentration of the grouting slurry should follow the principle of step-by-step change from thin to thick. During the grouting process, slurries with water-cement ratios of 5, 3, 2, 1, 0.8, and 0.6 (or 0.5) are used. According to the pilot hole water pressure test and the simple water pressure test before grouting, the permeability is tested. If the permeability before filling is greater than 5Lu, the water-cement ratio can be 3 for opening filling. If the permeability before filling is less than 5Lu, the water-cement ratio can be a thinner 5 for opening filling. If the permeability before filling is greater than 10Lu, the water-cement ratio before opening filling can be a thicker 2 or thicker slurry, which can be adjusted according to actual conditions during implementation.

Claims

1. A method for blocking water inrush in a sulfide iron mine tunnel, characterized in that The following steps are involved: Step 1: Determine the outlet point, which is the key position of the boundary between non-polluted water and heavy metal wastewater in the tunnel. Starting from the outlet point, place large-size crushed stones in the direction of heavy metal polluted water to fill the coarse aggregate; Step 2: Drill vertical curtain grouting holes from the ground. On the basis of the coarse aggregate frame, the coarse aggregate frame of the tunnel and the cracks in the surrounding rock structure are sealed by dialysis cementation grouting to form a curtain barrier wall.

2. The method for blocking water inrush in a sulfide mine tunnel according to claim 1, characterized in that: The curtain barrier wall is obtained by injecting cement into N×M grouting holes.

3. The method for blocking water inrush in a sulfide mine tunnel according to claim 2, characterized in that: Small-diameter D=60mm holes are preferred for grouting holes. Water stopping is performed after the holes pass through the water outlet point of the tunnel on the top plate of the goaf. The lower open hole is drilled to the bottom plate of the tunnel and the hole is terminated.

4. The method for blocking water inrush in a sulfide mine tunnel according to claim 2, characterized in that: Among the N×M grouting holes, the middle row is set as the first-order holes, the rows on both sides of the first-order holes are the third-order holes, and the outer sides of the third-order holes are alternately arranged with the third-order holes and the second-order holes.

5. The method for blocking water inrush in a sulfide mine tunnel according to claim 4, characterized in that: Before grouting, pilot holes are arranged. The pilot holes are selected from the first-order holes. The pilot holes also play an exploration role. They are drilled in sections from top to bottom to understand the geological conditions within the curtain design depth and the rock formation injection rate under the design grouting pressure.

6. The method for blocking water inrush in a sulfide mine tunnel according to claim 5, characterized in that: Inspection holes are arranged in the first-order grouting holes for curtain grouting quality inspection. The number of inspection holes is 10% of the total number of grouting holes. The quality inspection is carried out through water pressure test 14 days after the completion of grouting at this location. The curtain grouting inspection holes should be subjected to water pressure test in sections from top to bottom. The water pressure test pressure is 80% of the pressure value used in grouting of this section and is not greater than 0.8MPa.

7. The method for blocking water inrush in a sulfide mine tunnel according to claim 4, characterized in that: The spacing between grouting holes should ensure that an intersecting curtain is formed after grouting of each hole; the curtain grouting should adopt the principle of sequential encryption, first grouting the first-sequence hole, then the second-sequence hole, and finally the third-sequence hole. The length of the grouting hole is determined according to the buried depth of the tunnel. When the length of the grouting hole is less than 6m, the full-hole one-time grouting method can be adopted. When it is greater than 6m, the top-down or bottom-up segmented grouting method can be adopted.

8. The method for blocking water inrush in a sulfide mine tunnel according to claim 7, characterized in that: In order to ensure the fluidity of slurry injection, the slurry injection pressure needs to be controlled in the range of 0.5~1.0MPa, and the slurry injection speed needs to be controlled in the range of 1.5~2.0m / s to ensure that the slurry does not produce coagulation, precipitation and other conditions; the concentration of the grouting slurry should follow the principle of changing step by step from dilute to concentrated.

9. The method for blocking water inrush in a sulfide mine tunnel according to claim 2, characterized in that: The cement used for grouting is ordinary Portland cement, the strength grade of the cement is 42.5, and the fineness is that the residue passing through the 80μm square hole sieve is not more than 5%.

10. The method for blocking water inrush in a sulfide mine tunnel according to claim 1, characterized in that: The particle size of the large crushed stone is 40 to 80 mm.

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