Process for treating acidic mineral salt water by using high-water material for gob-side entry retaining

Abstract

The invention discloses a technology for treating acid ore salt water through a high-water-content material for gob-side entry retaining and relates to the technical field of mine environment protection and green mining. The technology specifically comprises the following steps of S1, modified high-water-content material preparation, S2, ore water treatment, S3, material regeneration and modification treatment and S4, gob-side entry retaining filling. According to the technology for treating the acid mineral salt water through the high-water-content material for gob-side entry retaining, metal is efficiently removed, specifically, a bentonite / chitosan / nano Fe3O4 ternary composite material is adopted, the adsorption capacity on heavy metal ions such as Cu < 2 + >, Zn < 2 + > and Fe < 3 + > reaches 80-100 mg / g, the heavy metal concentration of treated effluent is smaller than or equal to 0.5 mg / L and is far lower than the limit value of the Integrated Wastewater Discharge Standard (GB 8978-1996), and the treatment effect is good. And through a hydrochloric acid desorption-modification regeneration process, the material can be repeatedly used for more than or equal to 8 times (the traditional adsorption material is less than or equal to 3 times), the adsorption capacity retention rate after regeneration is more than 90%, the filling body has excellent performance, the compressive strength reaches 8-10 MPa (the traditional filling material is 5-6 MPa) within 28 days, and the coal mine tunnel supporting requirement is met.

Description

Technical Field

[0001] The present invention relates to the technical field of mine environmental protection and green mining, and particularly to a process for treating acidic mine salt water with high-water materials for gob-side entry retaining. Background Art

[0002] Pain points in the treatment of existing coal acidic mine water:

[0003] A large amount of heavy metal sludge is generated by the traditional neutralization method (accounting for 30%-50% of the treatment cost);

[0004] Adsorption materials (such as activated carbon) cannot be recycled, and there is no subsequent resource utilization approach.

[0005] Technical bottlenecks in existing gob-side entry retaining technology:

[0006] The current cost of concrete filling is high (300-500 yuan / m 3 ), and the setting time is long (>12 hours);

[0007] The roof contact rate of the filling body is insufficient (<80%), resulting in an excessive roadway deformation.

[0008] Defects in the existing technology:

[0009] Other patents use ordinary bentonite to treat wastewater, but do not solve the problems of material regeneration and secondary utilization;

[0010] The literature "Research on Mining Filling Materials" proposed backfilling of waste residues, but did not relate to the wastewater treatment link. Summary of the Invention

[0011] (I) Technical problems to be solved

[0012] In view of the deficiencies of the existing technology, the present invention provides a process for treating acidic mine salt water with high-water materials for gob-side entry retaining, which solves the problems of non-renewable materials and difficult sludge disposal in the treatment of acidic mine water; breaks through the bottlenecks of high cost and insufficient performance of gob-side entry retaining filling materials; and realizes the problem of "treating waste with waste" for the whole process of green mining in mines.

[0013] (II) Technical solutions

[0014] To achieve the above objectives, the present invention is realized through the following technical solutions: A process for treating acidic mine salt water with high-water materials for gob-side entry retaining specifically includes the following steps:

[0015] S1. Preparation of modified high-water materials: Activate bentonite with 10% hydrochloric acid for 2 hours, wash and dry it, then dissolve chitosan in a 2wt% acetic acid solution, mix it with the activated bentonite in a mass ratio of 3:1, and then add 0.5% glutaraldehyde cross-linking agent and cure it at 60°C to form a shape;

[0016] S2. Mine water treatment: Input the wastewater, adjust the pH to 5.0 - 7.0, add 1 - 5 g / L of ternary composite material, stir at a speed of 300 rpm, react for 20 - 60 minutes, and after plate and frame pressure filtration, the effluent Cu 2+ is less than 0.2 mg / L, and the material adsorption capacity reaches 82 mg / g;

[0017] S3. Material regeneration and modification treatment: Carry out desorption treatment by spraying 0.1 - 0.5 mol / L hydrochloric acid for 10 - 30 minutes, the heavy metal desorption rate is 92%, then add 5% sodium silicate, 25% coal gangue powder and retarder, stir until the slump is 18 - 20 cm, and the slurry density is 1.85 g / cm 3 , and the initial setting time is 55 minutes;

[0018] S4. Gob-side entry retaining filling: Pump the modified high-water material prepared in step S1 into the gob-side entry retaining under high pressure, the pumping pressure is 0.3 - 0.5 MPa, and at the same time, carry out solidification treatment by spraying calcium chloride solution. The 3-day compressive strength of the filling body is 4.8 MPa, the 28-day expansion rate is 208%, the roof contact rate is 94%, and the heavy metal leaching concentration: Cu 2+ is 0.18 mg / L.

[0019] Preferably, in step S1, the performance optimization of the high-water material: The water-cement ratio adjustment range is 1.4:1 - 1.6:1, the stone formation rate is 100%, the expansion rate is 3% - 5%, and the compressive strength is inversely proportional to the water-cement ratio. The strength of 30 - 50 MPa can be achieved by adjusting the water-cement ratio of 0.5:1 - 0.75:1.

[0020] Preferably, in step S2, the pH of the input wastewater is 2.3, Cu 2+ is 180 mg / L, Zn 2+ is 95 mg / L, and the flow rate is 5 m 3 / h.

[0021] Preferably, in step S2, lime milk is used to adjust the pH, and the dosage is 1.2 kg / m 3 .

[0022] Preferably, in step S2, the mine water treatment is carried out by using a pH adjustment tank, a high-water material reaction tank and a solid-liquid separator respectively;

[0023] A lime milk dosing pump and a stirrer are arranged in the pH adjustment tank to adjust the pH of the wastewater to 6.0;

[0024] The high-water material reaction tank is used to mix and react the added modified bentonite and chitosan composite gel material (3 g / L), and the reaction time is 45 minutes;

[0025] The bottom of the solid-liquid separator is provided with a heavy metal-enriched sludge outlet, and the top is connected to an effluent detection device.

[0026] Preferably, in step S3, material regeneration and modification treatments are respectively carried out using a desorption tank, a cleaning tank, and a modification mixer;

[0027] Through the desorption tank, a 0.3 mol / L hydrochloric acid spraying system is used, and the desorption time is 20 minutes;

[0028] The cleaning tank is controlled by a pH sensor to recycle the cleaning water to neutral;

[0029] By adding sodium silicate solution, coal gangue powder, and a setting retarder to the modification mixer, the material regeneration performance is optimized.

[0030] Preferably, in step S4, gob-side entry retaining filling is respectively carried out using a slurry preparation tank, a high-pressure pumping system, and a roadway solidification module;

[0031] Based on the characteristics of the high-water material, the water-solid ratio is set to 1.2:1 - 1.5:1 through the slurry preparation tank to ensure the fluidity of the slurry;

[0032] The high-pressure pumping system uses a wear-resistant ceramic coating conduit, and the pumping pressure is 0.4 MPa;

[0033] Through the roadway solidification module, 2 - 5 L / m of calcium chloride solution is sprayed 2 , combined with the rapid setting characteristic of the high-water material, the initial setting time ≤ 60 minutes, significantly improving the filling efficiency.

[0034] Preferably, the thickness of the wear-resistant ceramic coating conduit is 1.5 - 2.0 mm.

[0035] (III) Beneficial effects

[0036] The present invention provides a process for treating acidic mine water with a high-water material for gob-side entry retaining. Compared with the prior art, it has the following beneficial effects:

[0037] (1), In the process for treating acidic mine water with a high-water material for gob-side entry retaining, heavy metals are efficiently removed: Using a bentonite / chitosan / nano-Fe3O4 ternary composite material, the adsorption capacity for heavy metal ions such as Cu 2+ , Zn 2+ , Fe 3+ etc. reaches 80 - 100 mg / g, and the heavy metal concentration in the effluent after treatment ≤ 0.5 mg / L, far lower than the limit value of the Comprehensive Wastewater Discharge Standard (GB 8978 - 1996).

[0038] (2) The process of using high-water materials to treat acidic mine brine in gob-side entry retaining features high material recycling efficiency: Through the hydrochloric acid desorption-modification regeneration process, the materials can be reused ≥8 times (traditional adsorption materials ≤3 times), and the adsorption capacity retention rate after regeneration is >90%.

[0039] (3) The process of using high-water materials to treat acidic mine brine in gob-side entry retaining features excellent filling body performance: Compressive strength: The strength at 28 days reaches 8-10 MPa (traditional filling materials 5-6 MPa), meeting the requirements for coal mine roadway support.

[0040] (4) The process of using high-water materials to treat acidic mine brine in gob-side entry retaining features controllable swelling rate: The swelling rate in 72 hours is 180-250%, effectively filling the cracks in the goaf, and the roof contact rate >90%.

[0041] (5) The process of using high-water materials to treat acidic mine brine in gob-side entry retaining features optimized setting time: Initial setting time ≤60 minutes (traditional concrete >12 hours), significantly shortening the mining cycle.

[0042] Significant cost savings: The cost of filling materials is reduced by 40-50% (the cost in Example 2 is reduced from 320 yuan / m 3 to 175 yuan / m 3 ); The consumption of wastewater treatment chemicals is reduced by more than 30% (the lime dosage is only 1 / 3 of that in the traditional neutralization method);

[0043] Resource recovery benefits: Heavy metals are recovered. Each ton of recycled materials can enrich 5-8 kg of metals such as Cu 2+ ; Comprehensive utilization of coal gangue. 30% of the aggregate is coal mine waste residue, reducing the cost of solid waste disposal. Brief Description of the Drawings

[0044] Figure 1 It is the process system flow chart of the present invention. Detailed Embodiments

[0045] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the 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 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.

[0046] Please refer to Figure 1 , the embodiments of the present invention provide four technical solutions: A process of using high-water materials to treat acidic mine brine in gob-side entry retaining, specifically including the following embodiments:

[0047] Example 1: Full-process test of the collaborative process:

[0048] 1. Mineral water treatment stage:

[0049] Input wastewater: pH = 2.3, Cu 2+ 180 mg / L, Zn 2+ 95 mg / L, flow rate 5 m 3 / h;

[0050] Adjust the pH to 6.0 (lime milk dosage 1.2 kg / m 3 );

[0051] Add 3 g / L of ternary composite material, stirring speed 300 rpm, reaction time 45 minutes;

[0052] The effluent after plate and frame pressure filtration has Cu 2+ <0.2 mg / L, and the material adsorption capacity reaches 82 mg / g.

[0053] 2. Material regeneration and modification:

[0054] Desorption: Spray with 0.3 mol / L hydrochloric acid for 20 minutes, and the heavy metal desorption rate is 92%;

[0055] Modification: Add 5% sodium silicate + 25% coal gangue powder, stir until the slump is 18 - 20 cm;

[0056] The slurry density is 1.85 g / cm 3 , and the initial setting time is 55 minutes.

[0057] 3. Filling application effect:

[0058] The pumping pressure is 0.4 MPa, and the 3-day compressive strength of the filling body is 4.8 MPa;

[0059] The 28-day expansion rate is 208%, and the roof contact rate is 94%;

[0060] Heavy metal leaching concentration: Cu 2+ 0.18 mg / L (lower than the GB 5085.3 limit value of 0.5 mg / L).

[0061] Example 2: The performance comparison of key components is shown in the following table:

[0062]

[0063] Example 3: A process for treating acidic mine brine with high-water materials for gob-side entry retaining, specifically including the following steps:

[0064] S1. Preparation of modified high-water material: Bentonite is activated with 10% hydrochloric acid for 2 hours, washed and dried. Then chitosan is dissolved in a 2wt% acetic acid solution, mixed with the activated bentonite in a mass ratio of 3:1, and then 0.5% glutaraldehyde cross-linking agent is added. It is cured and formed at 60°C. Optimization of high-water material properties: The water-cement ratio can be adjusted in the range of 2:1, the stone formation rate is 100%, the expansion rate is 3%-5%, and the compressive strength is inversely proportional to the water-cement ratio. The strength of 40 MPa can be achieved by adjusting the water-cement ratio to 0.6:1 (the traditional filling material is only 5-6 MPa).

[0065] S2. Mine water treatment: Input the wastewater, adjust the pH to 5.0, add 3 g / L of ternary composite material, stir at a speed of 300 rpm, react for 40 minutes, and after plate and frame filtration, the effluent Cu 2+ is <0.2 mg / L, the material adsorption capacity reaches 82 mg / g, the pH of the input wastewater is 2.3, and the Cu 2+ is 180 mg / L, Zn 2+ is 95 mg / L, the flow rate is 5 m 3 / h, lime milk is used to adjust the pH, and the dosage is 1.2 kg / m 3 . The mine water treatment is carried out respectively using a pH adjustment tank, a high-water material reaction tank and a solid-liquid separator.

[0066] A lime milk dosing pump and a stirrer are set in the pH adjustment tank to adjust the pH of the wastewater to 5.0.

[0067] The high-water material reaction tank is used to mix and react the added modified bentonite and chitosan composite gel material, and the reaction time is 45 minutes.

[0068] The bottom of the solid-liquid separator is provided with a heavy metal enriched sludge outlet, and the top is connected to an effluent detection device.

[0069] S3. Material regeneration and modification treatment: Desorption treatment is carried out by spraying with 0.3 mol / L hydrochloric acid for 20 minutes, and the heavy metal desorption rate is 92%. Then 5% sodium silicate, 25% coal gangue powder and a retarder are added, and stirred until the slump is 19 cm and the slurry density is 1.85 g / cm 3 . The material regeneration and modification treatment are carried out respectively using a desorption tank, a cleaning tank and a modification mixer.

[0070] The desorption tank uses a hydrochloric acid spraying system.

[0071] The cleaning tank controls the cleaning water circulation to neutral through a pH sensor.

[0072] The regeneration performance of the material is optimized by adding sodium silicate solution, coal gangue powder and a retarder to the modification mixer.

[0073] S4. Gob-side entry retaining filling: The modified high-water material prepared in step S1 is pumped into the gob-side entry retaining under high pressure, with a pumping pressure of 0.4 MPa. At the same time, solidification treatment is carried out by spraying calcium chloride solution. The 3-day compressive strength of the filling body is 4.8 MPa, the 28-day expansion rate is 208%, the roof contact rate is 94%, and the heavy metal leaching concentration: Cu 2+ is 0.18 mg / L (lower than the limit value of 0.5 mg / L in GB 5085.3). The gob-side entry retaining filling is processed by a slurry preparation tank, a high-pressure pumping system, and a roadway solidification module respectively;

[0074] Based on the characteristics of the high-water material, the water-solid ratio is set to 1.3:1 by the slurry preparation tank to ensure the fluidity of the slurry;

[0075] The high-pressure pumping system uses a wear-resistant ceramic coating conduit with a thickness of 1.7 mm and a pumping pressure of 0.4 MPa;

[0076] Spray 3 L / m of calcium chloride solution through the roadway solidification module 2 , combined with the rapid setting characteristics of the high-water material, the initial setting time ≤ 60 minutes, significantly improving the filling efficiency.

[0077] Example 4: A process for treating acidic mine brine with a high-water material for gob-side entry retaining, specifically including the following steps:

[0078] S1. Preparation of modified high-water material: Bentonite is activated by 10% hydrochloric acid for 2 hours, washed and dried. Then chitosan is dissolved in a 2 wt% acetic acid solution, mixed with the activated bentonite at a mass ratio of 3:1, and then 0.5% glutaraldehyde cross-linking agent is added and cured at 60 °C. Optimization of the performance of the high-water material: The water-cement ratio adjustment range is 3:1, the stone formation rate is 100%, the expansion rate is 5%, and the compressive strength is inversely proportional to the water-cement ratio. The strength of 50 MPa can be achieved by adjusting the water-cement ratio to 0.75:1 (the traditional filling material is only 5 - 6 MPa);

[0079] S2. Mine water treatment: Input the wastewater, adjust the pH to 7.0, add 5 g / L of ternary composite material, stir at a speed of 300 rpm, react for 60 minutes, and the Cu in the effluent after plate and frame filtration 2+ <0.2 mg / L, the material adsorption capacity reaches 82 mg / g, the pH of the input wastewater is 2.3, and the Cu 2+ is 180 mg / L, the Zn 2+ is 95 mg / L, the flow rate is 5 m 3 / h, lime milk is used to adjust the pH, and the dosage is 1.2 kg / m 3 , and the mine water treatment is processed by a pH adjustment tank, a high-water material reaction tank, and a solid-liquid separator respectively;

[0080] A lime milk dosing pump and a stirrer are installed in the pH adjustment tank to adjust the pH of the wastewater to 7.0;

[0081] The high-water material reaction tank is used to mix and react the added modified bentonite and chitosan composite gel material, and the reaction time is 45 minutes;

[0082] The bottom of the solid-liquid separator is provided with a heavy metal enriched sludge outlet, and the top is connected to an effluent detection device;

[0083] S3. Material regeneration and modification treatment: Desorption treatment is carried out by spraying 0.5 mol / L hydrochloric acid for 30 minutes, and the heavy metal desorption rate is 92%. Then, 5% sodium silicate, 25% coal gangue powder and a retarder are added, and stirred until the slump is 20 cm and the slurry density is 1.85 g / cm 3 , the initial setting time is 55 minutes. The material regeneration and modification treatment are respectively carried out by a desorption tank, a cleaning pool and a modification mixer;

[0084] The desorption tank adopts a hydrochloric acid spraying system;

[0085] The cleaning pool is controlled by a pH sensor to recycle the cleaning water to neutral;

[0086] By adding sodium silicate solution, coal gangue powder and a retarder to the modification mixer, the material regeneration performance is optimized;

[0087] S4. Gob-side entry retaining filling: The modified high-water material prepared in step S1 is pumped to the gob-side entry retaining under high pressure, and the pumping pressure is 0.5 MPa. At the same time, solidification treatment is carried out by spraying calcium chloride solution. The 3-day compressive strength of the filling body is 4.8 MPa, the 28-day expansion rate is 208%, and the roof contact rate is 94%. The heavy metal leaching concentration: Cu 2+ is 0.18 mg / L (lower than the GB 5085.3 limit value of 0.5 mg / L). The gob-side entry retaining filling is respectively carried out by a slurry preparation tank, a high-pressure pumping system and a roadway solidification module;

[0088] Based on the characteristics of the high-water material, the water-solid ratio is set to 1.5:1 by the slurry preparation tank to ensure the fluidity of the slurry;

[0089] The high-pressure pumping system adopts a wear-resistant ceramic coating conduit, and the thickness of the wear-resistant ceramic coating conduit is 2.0 mm, and the pumping pressure is 0.4 MPa;

[0090] 5 L / m of calcium chloride solution is sprayed through the roadway solidification module 2 , combined with the fast setting characteristics of the high-water material, the initial setting time ≤ 60 minutes, significantly improving the filling efficiency.

[0091] In summary, for the efficient removal of heavy metals in the present invention: The bentonite / chitosan / nano-Fe3O4 ternary composite material is used for Cu 2+, Zn 2+ , Fe 3+ The adsorption capacity for heavy metal ions such as reaches 80 - 100 mg / g. After treatment, the heavy metal concentration in the effluent is ≤ 0.5 mg / L, far lower than the limit of the Comprehensive Wastewater Discharge Standard (GB 8978 - 1996). The material has a high recycling rate: Through the hydrochloric acid desorption - modification and regeneration process, the material can be reused ≥ 8 times (the traditional adsorption material ≤ 3 times), and the retention rate of the adsorption capacity after regeneration is > 90%. The filling body has excellent performance: Compressive strength: The 28 - day strength reaches 8 - 10 MPa (the traditional filling material is 5 - 6 MPa), meeting the requirements for coal mine roadway support. The expansion rate is controllable: The 72 - hour expansion rate is 180 - 250%, effectively filling the cracks in the goaf, and the roof - contacting rate is > 90%. The setting time is optimized: The initial setting time is ≤ 60 minutes (the traditional concrete > 12 hours), significantly shortening the mining cycle. The cost savings are remarkable: The cost of the filling material is reduced by 40 - 50% (in Example 2, the cost is reduced from 320 yuan / m 3 to 175 yuan / m 3 ); The consumption of wastewater treatment agents is reduced by more than 30% (the lime dosage is only 1 / 3 of that of the traditional neutralization method); Resource recovery benefits: Heavy metals are recovered. Each ton of the regenerated material can enrich 5 - 8 kg of metals such as Cu2+, having the potential for resource recovery; The comprehensive utilization of coal gangue, 30% of the aggregate is coal mine waste residue, reducing the cost of solid waste disposal.

[0092] Meanwhile, the content not detailedly described in this specification belongs to the prior art well - known to those skilled in the art.

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

[0094] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process for treating acidic mine brine with high-water materials in gob-side entry retaining, characterized in that: Specifically, it includes the following steps: S1. Preparation of modified high-water material: Activate bentonite with 10% hydrochloric acid for 2 hours, wash and dry it. Then dissolve chitosan in 2wt% acetic acid solution, mix it with the activated bentonite at a mass ratio of 3:1, and then add 0.5% glutaraldehyde cross-linking agent and cure it at 60°C to form a shape. S2. Mine water treatment: Input the wastewater, adjust the pH to 5.0 - 7.0, add 1 - 5 g / L of the ternary composite material, stir at a speed of 300 rpm, react for 20 - 60 minutes, and the effluent water after plate and frame pressure filtration has Cu 2+ < 0.2 mg / L, and the material adsorption capacity reaches 82 mg / g; S3. Material regeneration and modification treatment: Desorption treatment is carried out by spraying 0.1 - 0.5 mol / L hydrochloric acid for 10 - 30 minutes, and the heavy metal desorption rate is 92%. Then 5% sodium silicate, 25% coal gangue powder and a retarder are added, and stirred until the slump is 18 - 20 cm and the slurry density is 1.85 g / cm 3 , and the initial setting time is 55 minutes; S4. Gob-side entry retaining filling: The modified high-water material prepared in step S1 is pumped into the gob-side entry retaining under high pressure, with the pumping pressure of 0.3 - 0.5 MPa. Meanwhile, solidification treatment is carried out by spraying calcium chloride solution. The 3-day compressive strength of the filling body is 4.8 MPa, the 28-day expansion rate is 208%, the roof contact rate is 94%, and the heavy metal leaching concentration: Cu 2+ is 0.18 mg / L.

2. The process for treating acidic mine brine with high water material for gob-side entry retaining according to claim 1, characterized in that: Performance optimization of the high-water material in step S1: The water-cement ratio adjustment range is 1.4:1 - 1.6:1, the stone formation rate is 100%, the expansion rate is 3% - 5%, and the compressive strength is inversely proportional to the water-cement ratio. The strength of 30 - 50 MPa is achieved by adjusting the water-cement ratio to 0.5:1 - 0.75:

1.

3. A process for treating acidic mine salt water with high-water materials for gob-side entry retaining according to claim 1, characterized in that: In the step S2, the pH of the input wastewater is 2.3, and the concentration of Cu 2+ is 180 mg / L, the concentration of Zn 2+ is 95 mg / L, and the flow rate is 5 m 3 / h.

4. A process for treating acidic mine brine with high-water materials for gob-side entry retaining according to claim 1, characterized in that: In the step S2, lime milk is used to adjust the pH, and the dosage is 1.2 kg / m 3 .

5. A process for treating acidic mine brine with high water material in gob-side entry retaining according to claim 1, characterized in that: In step S2, the mine water treatment is carried out using a pH adjustment tank, a high-water material reaction tank, and a solid-liquid separator respectively. A lime milk dosing pump and a stirrer are arranged in the pH adjustment tank to adjust the pH of the wastewater to 6.

0. The high-water material reaction tank is used to mix and react the added modified bentonite and chitosan composite gel material, and the reaction time is 45 minutes. The bottom of the solid-liquid separator is provided with a heavy metal-enriched sludge outlet, and the top is connected to an effluent detection device.

6. A process for treating acidic mine brine with high water material for gob-side entry retaining according to claim 1, characterized in that: In step S3, the material regeneration and modification treatment are carried out using a desorption tank, a cleaning tank, and a modification mixer respectively. In the desorption tank, a 0.3mol / L hydrochloric acid spraying system is used, and the desorption time is 20 minutes. The cleaning tank controls the cleaning water circulation to neutral through a pH sensor. By adding sodium silicate solution, coal gangue powder, and a retarder to the modification mixer, the material regeneration performance is optimized.

7. A process for treating acidic mine brine with high-water materials for gob-side entry retaining according to claim 1, characterized in that: In step S4, the gob-side entry retaining filling is carried out using a slurry preparation tank, a high-pressure pumping system, and a roadway curing module respectively. Based on the characteristics of the high-water material, the water-solid ratio is set to 1.2:1 - 1.5:1 in the slurry preparation tank to ensure the fluidity of the slurry. The high-pressure pumping system uses a wear-resistant ceramic coating conduit, and the pumping pressure is 0.4 MPa. Spray 2 - 5 L / m of calcium chloride solution through the roadway solidification module 2 , combined with the rapid setting characteristics of the high - water material, the initial setting time ≤ 60 minutes, significantly improving the filling efficiency.

8. A process for treating acidic mine brine with high-water materials in gob-side entry retaining according to claim 7, characterized in that: The thickness of the wear-resistant ceramic coating conduit is 1.5 - 2.0 mm.

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