Microbial in-situ long-acting oxygen scavenger based on controllable sulfur circulation as well as preparation method and application of microbial in-situ long-acting oxygen scavenger
By preparing microbial in-situ long-acting oxygen dehydrating agent based on controllable sulfur cycle, using cobalt oxide catalysis and sulfur reduction bacteria reaction, the problems of easy increase in oxygen concentration in coal mines and attenuation of the effect of the inhibitor are solved, and long-acting coal spontaneous combustion prevention and control are achieved.
Patent Information
- Application Number
- CN202510642300.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-19
- Publication Date
- 2025-08-19
- Estimated Expiration
- 2045-05-19
AI Technical Summary
Among the existing coal self-ignition prevention and control technologies for coal underground coal mines, nitrogen injection inertification and spraying inhibitors have problems such as the oxygen concentration easily increases and the resistance effect continues to decrease, making it difficult to achieve long-term prevention and control.
A microbial in-situ long-acting oxygen dehydrator based on controlled sulfur cycle is prepared, and continuous oxygen dehydration is achieved by enriching oxygen and using cobalt oxide catalyzing and sulfur reducing bacteria reduction reaction.
It achieves long-term reduction of oxygen in coal mines, avoids the increase in oxygen concentration again and the attenuation of the inhibitor effect. It is suitable for complex environments and is cheap.
Smart Images
Figure CN120502222A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of underground coal mine fire prevention and extinguishing, and in particular to a microbial in-situ long-acting oxygen scavenger based on a controllable sulfur cycle, and a preparation method and application thereof. Background Art
[0002] Coal mine fires are one of the major hazards encountered during underground mining. As mining depths increase, spontaneous combustion of coal caused by excessive oxygen concentrations from air leaks becomes more frequent. This not only severely impacts normal mining operations but also threatens the lives of underground workers. Coal-oxygen barrier fire prevention and extinguishing technology is a key method for suppressing spontaneous combustion of coal underground. This technology reduces oxygen concentration to below the coal-oxygen combustion limit or alters the physical and chemical properties of coal, thereby reducing its tendency to spontaneous combustion and achieving effective fire prevention and extinguishing effects.
[0003] Currently, coal mines primarily utilize methods such as nitrogen injection for inerting and spraying of inhibitors for oxygen-blocking fire prevention and extinguishing. Nitrogen injection involves directly injecting nitrogen into underground goafs, displacing the oxygen surrounding the coal, creating an inert environment and effectively preventing spontaneous combustion. Inhibitor spraying reduces coal's oxidative activity by enhancing its thermal stability and moisture absorption and heat dissipation capacity or by catalytically decomposing coal oxidation intermediates, thereby inhibiting the oxidation reaction and reducing its spontaneous combustion tendency. However, these methods also have limitations in practical application. For example, after nitrogen injection for inerting, the gas easily escapes through air leaks due to diffusion, leading to a re-increase in oxygen concentration in the goaf. Furthermore, the effectiveness of coal spontaneous combustion inhibitors decreases over time, leading to re-ignition of coal in the goaf, making long-term retardation difficult. Therefore, there is an urgent need to develop a long-term, environmentally friendly coal-oxygen-blocking fire prevention and extinguishing technology for underground coal mines to address these issues and enable the safe application of oxygen-elimination fire prevention and extinguishing technology underground. Summary of the Invention
[0004] The purpose of the present invention is to provide a microbial in-situ long-acting oxygen scavenger based on a controllable sulfur cycle, and a preparation method and application thereof. The preparation method is simple and convenient, and the material cost is low. The prepared microbial in-situ long-acting oxygen scavenger based on a controllable sulfur cycle can continuously reduce and eliminate oxygen in coal mines, thereby achieving long-term prevention and control of coal spontaneous combustion disasters.
[0005] To achieve the above object, the present invention is implemented by the following technical solution: a method for preparing a microbial in-situ long-acting oxygen scavenger based on a controllable sulfur cycle, the preparation method comprising the following steps:
[0006] S1: NaOH and blast furnace slag-fly ash powder are uniformly mixed, calcined at high temperature and melted, then heated in an ultrasonic water bath, vacuum dried and acid washed, and finally washed and dried to obtain zeolite-phase porous inorganic particles;
[0007] S2: placing the zeolite-phase porous inorganic particles prepared in step S1 into a cobalt chloride ethanol solution, adding 3% 3-aminopropyltriethoxysilane by weight of the cobalt chloride ethanol solution, stirring to fully disperse the precursor, controlling the temperature at 75° C. to 85° C. during stirring, and then calcining to obtain zeolite-phase porous inorganic particles modified with nano-cobalt oxide;
[0008] S3: immersing the zeolite-phase porous inorganic particles modified with nano-cobalt oxide obtained in step S2 into an ethanol solution of short-chain sodium alkyl sulfonate, placing the particles into a reaction kettle, adding phenyltriethoxysilane at a concentration of 5‰ by mass of the ethanol solution of short-chain sodium alkyl sulfonate, and heating the particles in an oven for hydrothermal reaction. After the reaction is completed, the particles are cooled, washed, and dried, and finally ground and passed through a 5-20 mesh sieve to obtain zeolite-phase porous inorganic particles modified with nano-cobalt oxide and short-chain sodium alkyl sulfonate;
[0009] S4: Polylysine and calcium chloride are sequentially added to a sulfur-reducing bacteria liquid at the late exponential growth stage with an OD600 of about 0.8 to 1.2, and the liquid is stirred and cross-linked at room temperature to make the surface of the sulfur-reducing bacteria positively charged. The positively cross-linked sulfur-reducing bacteria are separated by centrifuge and deionized water is added to prepare a positively charged sulfur-reducing bacteria liquid.
[0010] S5: Immersing the zeolite-phase porous inorganic microparticles modified with nano-cobalt oxide and short-chain sodium alkyl sulfonate obtained in step S3 into the positively charged sulfur-reducing bacteria solution prepared in step S4, allowing it to stand for adsorption, and then washing and drying to obtain a microbial in-situ long-acting oxygen scavenger based on controllable sulfur circulation.
[0011] Preferably, in step S1, the calcination melting temperature is 800°C and the calcination time is 2 hours; the ultrasonic water bath temperature is 45°C and the heating is 30 minutes; vacuum drying is performed for 4 hours; acid washing is performed using a mixed acid consisting of 1% acetic acid and 0.5% hydrochloric acid; the drying temperature is 70°C and the drying time is 12 hours.
[0012] Preferably, in step S2, the mass ratio of the zeolite phase porous inorganic particles to cobalt chloride is (5-20):1; stirring is carried out at a rate of 100 rpm for 6 hours; the calcination temperature is 400° C., and the calcination time is 5 hours; the concentration of the cobalt chloride ethanol solution is 15-60 mg / mL.
[0013] Preferably, in step S3, the mass ratio between the zeolite-phase porous inorganic particles modified with nano-cobalt oxide and the short-chain alkyl sodium sulfonate is (7-150):1; the hydrothermal reaction temperature is 150° C., and the hydrothermal reaction time is 2 h; and the concentration of the short-chain alkyl sodium sulfonate ethanol solution is 6.7-11.1 mg / mL.
[0014] Preferably, in step S4, the sulfur-reducing bacteria liquid is a mixed bacterial liquid, including at least two of the following: Desulfurizing Bacteria propionic acid, Desulfococcus polyphagous, Desulfurizing Enterobacteriaceae, Desulfobacterium, Desulfovibrio, and Thermosulfurizing Bacteria.
[0015] Preferably, in step S5, the mass ratio of calcium chloride to polylysine is (1-4):1; and the cross-linking is carried out by stirring at a rate of 150 rpm for 30 minutes.
[0016] To achieve the above object, the present invention also provides a microbial in-situ long-acting oxygen scavenger based on controllable sulfur cycle prepared by the above preparation method.
[0017] To achieve the above objectives, the present invention also provides the use of the microbial in-situ long-acting oxygen scavenger based on controllable sulfur cycle prepared by the above preparation method in the preparation of long-acting oxygen-removing and retardant materials for fire prevention and extinguishing in coal mines. The specific application process is: the microbial in-situ long-acting oxygen scavenger is added to nitrogen foam at a ratio of 5% of the total mass to prepare a microbial in-situ long-acting oxygen-removing nitrogen foam material.
[0018] The repair mechanism of the present invention is as follows: the microbial in-situ long-lasting oxygen scavenger based on controllable sulfur cycle prepared by the present invention is transported to the target location through a water-rich carrier material, and the free oxygen in the target area is enriched by zeolite-phase porous inorganic particles. The loaded short-chain sodium alkyl sulfonate reacts with oxygen under the catalysis of nano-cobalt oxide to initially reduce the oxygen concentration. At the same time, the generated sulfate ions are reduced to hydrogen sulfide under the action of composite sulfur-reducing bacteria and participate in the oxidation reaction again, thereby continuously reducing oxygen in the coal mine and achieving long-term oxygen removal in the target area.
[0019] Compared with the prior art, the present invention has the following beneficial effects:
[0020] 1. The present invention utilizes the multivalent redox reaction of sulfur, uses cobalt oxide to catalyze the oxidation reaction of short-chain sodium alkyl sulfonate and the anaerobic metabolism of sulfur-reducing bacteria to reduce sulfate ions, to achieve long-term prevention and control of coal spontaneous combustion in coal mines based on controllable sulfur cycle and oxygen reduction, and solves the problem that methods such as spraying inhibitors and nitrogen injection have short prevention time and are prone to re-ignition of coal.
[0021] 2. The present invention reduces oxygen in the goaf of coal mines through a physicochemical and biological coordinated controllable sulfur cycle process such as physical adsorption-catalytic oxidation-bacterial reduction. The high-concentration oxygen reduction has a good coal-oxygen barrier effect on coals with different spontaneous combustion tendencies, avoiding the problem of poor universality of traditional inhibitors for coals and easy secondary pollution.
[0022] 3. The microbial in-situ long-lasting oxygen scavenger based on controllable sulfur cycle prepared by the present invention is applied to the prevention and control of coal spontaneous combustion in coal mines. The operation process is simple and convenient, and the material cost is low; the oxygen-consuming sulfur cycle has strong stability and is suitable for the complex and harsh environment of the goaf area in coal mines. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 Zeta potential images of the sulfur-reducing bacteria surface after positive cross-linking treatment with different concentrations of calcium chloride in Examples 1-6;
[0024] Figure 2 This is a graph showing the change in oxygen concentration over time for the oxygen reduction and elimination effect test of the microbial in-situ long-acting oxygen scavenger prepared in Examples 7-9. DETAILED DESCRIPTION
[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0026] Example 1
[0027] A microbial in-situ long-acting oxygen scavenger based on a controllable sulfur cycle comprises the following steps:
[0028] S1: 10 g of NaOH was mixed with 12 g of blast furnace slag-fly ash powder and calcined at 800°C for 2 h. The mixture was then heated at 45°C for 30 min in an ultrasonic water bath. After vacuum drying for 4 h, the mixture was pickled with a mixed acid of 1% acetic acid and 0.5% hydrochloric acid. The mixture was then washed and dried at 70°C for 12 h to obtain zeolite-phase porous inorganic particles.
[0029] S2: 10 g of zeolite-phase porous inorganic particles were placed in 100 ml of a 15 mg / mL cobalt chloride ethanol solution, 3% by weight of the cobalt chloride ethanol solution of 3-aminopropyltriethoxysilane was added as a stabilizer, and the mixture was stirred at 100 rpm for 6 h to ensure that the precursor was fully dispersed. The temperature was kept at around 80°C during the stirring process, and then calcined at 400°C for 5 h to obtain zeolite-phase porous inorganic particles modified with nano-cobalt oxide;
[0030] S3: immersing 10 g of the zeolite-phase porous inorganic particles modified with nano-cobalt oxide obtained in step S2 into a reaction kettle containing 100 ml of a 6.7 mg / mL short-chain alkyl sodium sulfonate ethanol solution, adding phenyltriethoxysilane at a mass of 5‰ of the short-chain alkyl sodium sulfonate ethanol solution, and placing the particles in an oven and heating them to 150° C. for hydrothermal reaction for 8 h. After the reaction is completed, cooling, washing, and drying, the particles are ground and passed through a 5-20 mesh sieve to obtain zeolite-phase porous inorganic particles modified with nano-cobalt oxide and short-chain alkyl sodium sulfonate;
[0031] S4: 0.625 g of polylysine and 2.5 g of calcium chloride were added sequentially to a 1000 ml sulfur-reducing bacteria culture at the late exponential growth stage with an OD600 of 0.8 to 1.2. The culture was stirred at 150 rpm for 30 min at room temperature to cross-link the surface of the sulfur-reducing bacteria so that the surface of the sulfur-reducing bacteria became positively charged. The positively cross-linked sulfur-reducing bacteria were separated by centrifuge and deionized water was added to prepare a positively charged sulfur-reducing bacteria culture.
[0032] S5: Immerse 10 g of the zeolite-phase porous inorganic microparticles modified with nano-cobalt oxide and short-chain sodium alkyl sulfonate obtained in step S3 into the positively charged sulfur-reducing bacteria solution prepared in step S4, allow to stand and adsorb for 24 hours, then wash and dry to obtain a microbial in-situ long-acting oxygen scavenger based on controllable sulfur circulation.
[0033] Example 2
[0034] The preparation method of this embodiment is the same as that of Example 1, except that the masses of polylysine and calcium chloride in step S4 of this embodiment are 0.5 g and 2 g, respectively.
[0035] Example 3
[0036] The preparation method of this embodiment is the same as that of Example 1, except that the masses of polylysine and calcium chloride in step S4 of this embodiment are 0.375 g and 1.5 g, respectively.
[0037] Example 4
[0038] The preparation method of this embodiment is the same as that of Example 1, except that the masses of polylysine and calcium chloride in step S4 of this embodiment are 0.25 g and 1 g, respectively.
[0039] Example 5
[0040] The preparation method of this embodiment is the same as that of Example 1, except that the masses of polylysine and calcium chloride in step S4 of this embodiment are 0.125 g and 0.5 g, respectively.
[0041] Comparative Example
[0042] The preparation method of this comparative example is the same as that of Example 1, except that polylysine and calcium chloride are not added in step S4 of this example.
[0043] Example 6
[0044] The preparation method of this embodiment is the same as that of Example 1, except that in step S4 of this embodiment, "0.2 g of polylysine and 0.8 g of calcium chloride are added in sequence."
[0045] 10L of nitrogen was introduced into 500ml of foam liquid through a vertical air blower foamer to prepare nitrogen foam for preventing and controlling coal spontaneous combustion in coal mines. The microbial in-situ long-acting oxygen scavenger based on controllable sulfur cycle prepared in this example was added to the nitrogen foam at a ratio of 5% of the total mass to prepare a microbial in-situ long-acting oxygen-scavenging nitrogen foam material.
[0046] Example 7
[0047] The preparation method of this embodiment is the same as that of Example 6, except that the concentrations of the cobalt chloride ethanol solution and the short-chain alkyl sulfonate sodium ethanol solution in step S2 and step S3 in this embodiment are 30 mg / mL and 8.3 mg / mL, respectively.
[0048] 10L of nitrogen was introduced into 500ml of foam liquid through a vertical air blower foamer to prepare nitrogen foam for preventing and controlling coal spontaneous combustion in coal mines. The microbial in-situ long-acting oxygen scavenger based on controllable sulfur cycle prepared in this example was added to the nitrogen foam at a ratio of 5% of the total mass to prepare a microbial in-situ long-acting oxygen-scavenging nitrogen foam material.
[0049] Example 8
[0050] The preparation method of this embodiment is the same as that of Example 6, except that in this embodiment, the concentrations of the cobalt chloride ethanol solution and the short-chain alkyl sulfonate sodium ethanol solution in steps S2 and S3 are 60 mg / mL and 11.1 mg / mL, respectively.
[0051] 10L of nitrogen was introduced into 500ml of foam liquid through a vertical air blower foamer to prepare nitrogen foam for preventing and controlling coal spontaneous combustion in coal mines. The microbial in-situ long-acting oxygen scavenger based on controllable sulfur cycle prepared in this example was added to the nitrogen foam at a ratio of 5% of the total mass to prepare a microbial in-situ long-acting oxygen-scavenging nitrogen foam material.
[0052] Examples 6-8 use an air leakage oxygen consumption simulation test device to test the oxygen reduction effect of a microbial in-situ long-term oxygen scavenger using nitrogen foam as a carrier. The device mainly consists of a micro airflow pump, an oxygen concentration sensor, a barometer, and a closed tank body with a diameter of 300mm and a height of 400mm. 150mm of engineering stones are piled up inside the tank body in advance; a micro airflow pump is used to pump gas into the tank body. If the air pressure display at the top of the device is consistent with the pressure of the airflow pump pressure valve, it indicates that the device is airtight and the test can begin. During the test, nitrogen foam mixed with a microbial in-situ long-term oxygen scavenger is injected into the pipe. After the engineering stone pile is completely covered, the injection is stopped. A 14% concentration of oxygen-nitrogen mixed gas is continuously injected into the tank body using a micro airflow pump. After the oxygen concentration sensor inserted into the tank body shows a stable reading, the initial oxygen concentration C0 is recorded. The oxygen concentration data Ct is recorded after 1, 3, 5, 7, and 9 days respectively, and the oxygen concentration change rate is calculated according to the following formula:
[0053] η=(C0-C t ) / C0×100%
[0054] Wherein, η is the oxygen concentration reduction rate, %; C0 is the initial oxygen concentration, %; C t is the oxygen concentration after time t, %.
[0055] The Zeta potential images of the sulfur-reducing bacteria surface after the positive cross-linking treatment with different concentrations of CaCl2 in step S4 of the microbial in-situ long-acting oxygen scavengers prepared in Examples 1-5 and Comparative Examples are as follows: Figure 1 As shown in the figure, with the increase of calcium chloride concentration, the surface Zeta potential of sulfur-reducing bacteria turns positive and slowly increases, which helps sulfur-reducing bacteria to better adhere to the surface of negatively charged short-chain alkyl sulfonate sodium modified zeolite phase porous inorganic particles through electrostatic adsorption.
[0056] The oxygen consumption effect of the microbial in-situ long-term oxygen and nitrogen removal foam material prepared in Example 6-8 is as follows: Figure 2 As shown, as the concentrations of the cobalt chloride ethanol solution and the short-chain alkyl sulfonate sodium ethanol solution increase, the oxygen consumption rate attenuation of the microbial in-situ long-term oxygen and nitrogen scavenging foam material gradually decreases. The oxygen concentration curve corresponding to Example 8 shows that the overall oxygen consumption rate of the microbial in-situ long-term oxygen scavenger prepared from this material component shows almost no attenuation over time within 9 days. This is because the increased loading of nano-cobalt oxide and short-chain alkyl sulfonate sodium reduces the oxygen concentration to a lower level, which is conducive to the increased activity of sulfur-reducing bacteria, resulting in an increase in sulfate reduction and maintaining the continuous oxygen consumption capacity of the controllable sulfur cycle. This shows that the microbial in-situ long-term oxygen scavenger based on the controllable sulfur cycle can effectively reduce the free oxygen in the coal mine, reduce the oxygen concentration in the target area, and effectively prevent and control coal spontaneous combustion disasters.
Claims
1. A method for preparing a microbial in-situ long-acting oxygen scavenger based on a controllable sulfur cycle, characterized in that: The following steps are involved: S1: NaOH and blast furnace slag-fly ash powder are uniformly mixed, calcined at high temperature and melted, then heated in an ultrasonic water bath, vacuum dried and acid washed, and finally washed and dried to obtain zeolite-phase porous inorganic particles; S2: placing the zeolite-phase porous inorganic particles prepared in step S1 into a cobalt chloride ethanol solution, adding 3% 3-aminopropyltriethoxysilane by weight of the cobalt chloride ethanol solution, stirring to fully disperse the precursor, controlling the temperature at 75° C. to 85° C. during stirring, and then calcining to obtain zeolite-phase porous inorganic particles modified with nano-cobalt oxide; S3: immersing the zeolite-phase porous inorganic particles modified with nano-cobalt oxide obtained in step S2 into an ethanol solution of short-chain sodium alkyl sulfonate, placing the particles into a reaction kettle, adding phenyltriethoxysilane at a concentration of 5‰ by mass of the ethanol solution of short-chain sodium alkyl sulfonate, and heating the particles in an oven for hydrothermal reaction. After the reaction is completed, the particles are cooled, washed, and dried, and finally ground and passed through a 5-20 mesh sieve to obtain zeolite-phase porous inorganic particles modified with nano-cobalt oxide and short-chain sodium alkyl sulfonate; S4: Polylysine and calcium chloride are sequentially added to a sulfur-reducing bacteria liquid at the late exponential growth stage with an OD600 of about 0.8 to 1.2, and the liquid is stirred and cross-linked at room temperature to make the surface of the sulfur-reducing bacteria positively charged. The positively cross-linked sulfur-reducing bacteria are separated by centrifuge and deionized water is added to prepare a positively charged sulfur-reducing bacteria liquid. S5: Immersing the zeolite-phase porous inorganic microparticles modified with nano-cobalt oxide and short-chain sodium alkyl sulfonate obtained in step S3 into the positively charged sulfur-reducing bacteria solution prepared in step S4, allowing it to stand for adsorption, and then washing and drying to obtain a microbial in-situ long-acting oxygen scavenger based on controllable sulfur circulation.
2. The method for preparing a microbial in-situ long-acting oxygen scavenger based on a controllable sulfur cycle according to claim 1 or 2, characterized in that: In step S1, the calcination melting temperature is 800°C and the calcination time is 2 hours; the ultrasonic water bath temperature is 45°C and the heating is performed for 30 minutes; vacuum drying is performed for 4 hours; acid washing is performed using a mixed acid consisting of 1% acetic acid and 0.5% hydrochloric acid; the drying temperature is 70°C and the drying time is 12 hours.
3. The method for preparing a microbial in-situ long-acting oxygen scavenger based on a controllable sulfur cycle according to claim 1 or 2, characterized in that: In step S2, the mass ratio of the zeolite-phase porous inorganic particles to the cobalt chloride is (5-20):1; the mixture is stirred at 100 rpm for 6 hours; the calcination temperature is 400° C., and the calcination time is 5 hours; and the concentration of the cobalt chloride ethanol solution is 15 to 60 mg / mL.
4. The method for preparing a microbial in-situ long-acting oxygen scavenger based on a controllable sulfur cycle according to claim 1 or 2, characterized in that: In step S3, the mass ratio of the zeolite-phase porous inorganic particles modified with nano-cobalt oxide to the short-chain alkyl sodium sulfonate is (7-150):1; the hydrothermal reaction temperature is 150° C., and the hydrothermal reaction time is 2 hours; and the concentration of the short-chain alkyl sodium sulfonate ethanol solution is 6.7 to 11.1 mg / mL.
5. The method for preparing a microbial in-situ long-acting oxygen scavenger based on a controllable sulfur cycle according to claim 1 or 2, characterized in that: In step S4, the sulfur-reducing bacteria liquid is a mixed bacterial liquid, including at least two of propionic acid desulfurizing bacteria, multivorous desulfurizing cocci, rumen desulfurizing enterobacteria, Desulfobacterium, Desulfovibrio, and common thermodesulfobacterium.
6. The method for preparing a microbial in-situ long-acting oxygen scavenger based on a controllable sulfur cycle according to claim 1 or 2, characterized in that: In step S4, the mass ratio of calcium chloride to polylysine is (1-4):1; and the cross-linking is carried out by stirring at a rate of 150 rpm for 30 minutes.
7. A microbial in-situ long-acting oxygen scavenger based on controllable sulfur cycle prepared by the preparation method according to any one of claims 1 to 6.
8. Use of the microbial in-situ long-acting oxygen scavenger based on controllable sulfur cycle as claimed in claim 7 in the preparation of a long-acting oxygen-scavenging and flame-retardant material for fire prevention and extinguishing in coal mines, the specific application process being: adding the microbial in-situ long-acting oxygen scavenger to nitrogen foam at a ratio of 5% of the total mass to prepare a microbial in-situ long-acting oxygen-scavenging and nitrogen foam material.