MICP and MISP synergistic spraying dust suppressant for mining and preparation method and application of MICP and MISP synergistic spraying dust suppressant
By adding phosphate and magnesium ions to the MIP dust suppressant, a magnesium ammonium phosphate crystalline compound is generated, which solves the problem of ammonia nitrogen pollution in the process of urea hydrolysis by the MIP dust suppressant, and achieves efficient dust suppression and resource utilization.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-19
- Publication Date
- 2026-04-07
AI Technical Summary
Existing MIP dust suppressants generate ammonia nitrogen pollution during the hydrolysis of urea, posing an environmental pollution risk, and their dust suppression effect is poor.
The MIP (Micro-Mine Spray) dust suppressant is used in conjunction with MISP (Micro-Mine Spray) to provide phosphate ions by adding anhydrous dipotassium hydrogen phosphate during the preparation process and adding magnesium chloride to the cementing solution. The MISP reaction is then used to generate magnesium ammonium phosphate crystals, which neutralize ammonium ions and form environmentally friendly magnesium ammonium phosphate crystals, thus reducing ammonia nitrogen residue.
It effectively reduces ammonia nitrogen pollution, creates a highly efficient dust suppression effect, and generates reusable slow-release fertilizer, reducing environmental pollution and improving the utilization rate of dust suppressants.
Smart Images
Figure CN121801543A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of mining spray dust suppressants, specifically relating to a MICP synergistic MISP mining spray dust suppressant. Background Technology
[0002] Currently, dust control and suppression technologies for coal mining mainly encompass physical, chemical, and microbial dust suppressant solidification methods. Physical methods are convenient to operate, but suffer from drawbacks such as low dust suppression efficiency, short duration of effect, and high water consumption. Traditional chemical dust suppressants, while capable of forming crusts, face numerous problems including difficulty in material degradation, potential alteration of soil properties, and the risk of secondary pollution. Microbial dust suppressants represent a revolutionary green solution. They utilize the life activities of microorganisms to induce the formation of natural minerals, thereby tightly binding dust particles in situ. The dense crust structure formed through biomineralization possesses strong resistance to wind erosion and rainwater runoff, enabling long-lasting dust suppression.
[0003] Among the current mainstream microbial dust suppression methods, the MIP (Microbial Concentration-Based Powder) method utilizes bacteria to produce urease, which hydrolyzes urea to generate carbonate ions. These carbonate ions combine with an added cementing solution containing calcium ions to form calcium carbonate crystals, thus cementing coal dust and preventing it from being lifted into the air. However, ammonia nitrogen pollution is also generated during the hydrolysis of urea. During bacterial metabolism, each unit of urea hydrolyzed produces twice the amount of ammonia. Part of this ammonia is released directly in gaseous form, while the other part remains in the solution as ammonia nitrogen, thus posing a risk of secondary pollution. The bio-cementing waste liquid, rich in ammonium ions, can decompose to produce ammonia gas under certain conditions, posing a pollution threat to the environment. During prolonged dust settling processes, large amounts of ammonia gas and ammonia-nitrogen-containing liquids are generated, polluting air and water sources and further affecting the health of workers. Summary of the Invention
[0004] This invention aims to provide a MIP synergistic with MISP mining spray dust suppressant to reduce ammonia nitrogen pollution, achieve efficient dust suppression, and solve the problem of high concentration of ammonia nitrogen byproducts and environmental pollution generated during the dust suppression process of current single-phase MIP dust suppressants.
[0005] Therefore, the technical solution adopted in this invention is: a method for preparing a MIP synergistic MISP mining spray dust suppressant, comprising the following steps:
[0006] Step S1: Inoculate and culture Bacillus pasteurellii bacterial solution and keep it at a constant temperature. Then add anhydrous dipotassium hydrogen phosphate and stir evenly to obtain bacterial solution, which is used as the first spray of dust suppressant for mining.
[0007] Step S2: Add urea, anhydrous calcium chloride, magnesium chloride and surfactant to pure water and mix evenly to obtain a cementing solution, which is used as the second spray of the dust suppressant for mining.
[0008] As a preferred embodiment of the above scheme, in step S1, before inoculating with Bacillus pasteurellii culture, the prepared solid and liquid culture media, petri dishes, conical flasks and inoculation instruments are placed in a high-temperature sterilizer for 20 minutes and sterilized at 121°C. Then, they are placed in a clean bench and sterilized with ultraviolet lamps. The sterilization is thorough and meets the requirements.
[0009] Then, take out the activated bacterial culture, use a pipette sterilized with ultraviolet light to pick up a small amount of the bacterial culture and put it into the sterilized culture medium for inoculation; to ensure the success rate of preparation.
[0010] The *Pasteurella multocida* culture was continuously shaken and cultured at 110 RPM and 31°C for 48 hours, and then stored at a constant temperature of 4°C. The parameters were set reasonably to ensure the survival rate of the *Pasteurella multocida* culture.
[0011] More preferably, in step S1, the solid culture medium used to culture Bacillus pasteurellii is LB medium, and the liquid culture medium used to culture Bacillus pasteurellii consists of urea, yeast, and sodium chloride, wherein the concentration of yeast and urea is 10 g / L and the concentration of sodium chloride is 1 g / L, to ensure the survival rate of Bacillus pasteurellii.
[0012] More preferably, in step S1, the concentration of anhydrous dipotassium hydrogen phosphate is 2 mol / L to 2.5 mol / L, which is a reasonable range. This provides sufficient hydrogen phosphate and magnesium ions to mineralize with ammonium ions to form magnesium phosphate crystals, thereby reducing the concentration of ammonia nitrogen byproducts.
[0013] More preferably, in step S2, the molar ratio of anhydrous calcium chloride, urea, and magnesium chloride is 0.75–1:1:1.5–2 to ensure sufficient magnesium ions for the reaction.
[0014] More preferably, in step S2, the surfactant is sodium dodecylbenzenesulfonate, and the amount of surfactant added is 0.5% of the mass of the cementitious liquid. Sodium dodecylbenzenesulfonate is an excellent surfactant.
[0015] This solution also employs a MICP-MISP synergistic mining spray dust suppressant, which is prepared using the aforementioned method for preparing a MICP-MISP synergistic mining spray dust suppressant.
[0016] This scheme also adopts the above-mentioned application of MIP in conjunction with MISP mining spray dust suppressant as a spray dust suppressant in coal mines. First, a cementing liquid is sprayed on the coal dust, and then Bacillus pasteurellium liquid is sprayed.
[0017] The beneficial effects of this invention are:
[0018] (1) Compared with the MISP dust suppression method, which generates ammonia nitrogen pollution during urea hydrolysis, this scheme adds phosphate and magnesium ions during the MISP process. In particular, anhydrous dipotassium hydrogen phosphate is added during the preparation of the bacterial solution to provide sufficient phosphate ions, and magnesium chloride is added during the preparation of the cementing solution to provide sufficient magnesium ions. Thus, the precipitate of magnesium ammonium phosphate is generated by the MISP reaction to neutralize the ammonium ions generated by MISP, thereby reducing ammonia nitrogen residue pollution. On the one hand, it can reduce the concentration of ammonium ions and avoid ammonia nitrogen pollution in the environment as much as possible; on the other hand, the MISP reaction process produces environmentally friendly magnesium ammonium phosphate crystalline compounds, which meet environmental protection requirements.
[0019] (2) The final magnesium ammonium phosphate crystal compound is rich in nitrogen, phosphorus and other key nutrients. It is a high-quality slow-release fertilizer that can be applied to agriculture in a resource-based manner to achieve reuse, ensuring excellent dust reduction and dust suppression effects while reducing ammonia nitrogen pollution.
[0020] (3) Due to the strong hydrophobicity of coal dust, it is necessary to spray a cementing liquid on the coal dust first, and use the surfactant in the cementing liquid to wet the coal dust and increase the adhesion of the coal dust. Finally, spray the Bacillus pasteurellium solution to ensure that it reacts fully on the coal dust and increase the utilization rate of the dust suppressant.
[0021] In summary, the present invention has the advantages of excellent dust reduction and suppression effect, environmental friendliness, low cost, and high utilization rate of dust suppressant. Attached Figure Description
[0022] Figure 1 The image shows the XRD pattern of the dust suppressant prepared in Example 4 applied to coal dust.
[0023] Figure 2 The image shows a schematic diagram of the microstructure of the mineralized product of coal dust obtained by the dust suppressant prepared in Example 4. The left image is a microstructure diagram, and the right image is a scanning electron microscope-energy dispersive spectroscopy (SEM) diagram. Detailed Implementation
[0024] The present invention will be further described below with reference to the embodiments and accompanying drawings:
[0025] Combination Figure 1 — Figure 2 As shown, a method for preparing a MICP-MISP synergistic mining spray dust suppressant is presented.
[0026] The reaction formulas involved are as follows.
[0027] Urease-producing bacteria hydrolyze urea: CO(NH2)2+H2O→NH2COOH+NH3; NH2COOH+H2O→NH3+H2CO3;
[0028] Ammonia nitrogen is produced: NH3 + H2O → NH + +OH - ;
[0029] Magnesium ammonium phosphate mineralization: Mg 2+ +NH + +HPO4 2- +6H₂O→MgNH₄PO₄·6H₂O↓+H + ;
[0030] Step S1: Inoculate with and culture Bacillus pasteurellium culture solution and keep at a constant temperature. Then add anhydrous dipotassium hydrogen phosphate and stir evenly to obtain bacterial solution, which is used as the first spray of dust suppressant for mining.
[0031] Before inoculating with *Bacillus pasteurellii* culture, the prepared solid and liquid culture media, petri dishes, Erlenmeyer flasks, and inoculation instruments were placed in a high-temperature sterilizer for 20 minutes and sterilized at 121°C. Then, they were placed in a clean bench and sterilized with ultraviolet light. After that, the activated bacterial culture was taken out, and a small amount of bacterial culture was taken with a pipette sterilized by ultraviolet light and placed into the sterilized culture medium for inoculation. The *Bacillus pasteurellii* culture was continuously shaken and cultured at 110 RPM and 31°C for 48 hours and stored at a constant temperature of 4°C.
[0032] In step S1, the solid culture medium used to culture Bacillus pasteurellis is LB medium, and the liquid culture medium used to culture Bacillus pasteurellis consists of urea, yeast and sodium chloride, wherein the concentration of yeast and urea is 10 g / L and the concentration of sodium chloride is 1 g / L.
[0033] In step S1, the concentration of anhydrous dipotassium hydrogen phosphate is 2 mol / L to 2.5 mol / L.
[0034] Step S2: Add urea, anhydrous calcium chloride, magnesium chloride and surfactant to pure water and mix evenly to obtain a cementing solution, which is used as the second spray of the dust suppressant for mining.
[0035] In step S2, the preferred molar ratio of anhydrous calcium chloride, urea, and magnesium chloride is 0.75–1:1:1.5–2.
[0036] In step S2, sodium dodecylbenzenesulfonate is preferably used as the surfactant, and the amount of surfactant added is 0.5% of the mass of the binder.
[0037] Example 1
[0038] Add 17.418 g of anhydrous dipotassium hydrogen phosphate to 50 ml of Bacillus pasteurellium bacterial culture and stir well to obtain bacterial culture. The concentration of anhydrous dipotassium hydrogen phosphate is 2 mol / L.
[0039] Add 6 g of urea, 8.325 g of anhydrous calcium chloride, 14.282 g of magnesium chloride, and 0.5% sodium dodecylbenzenesulfonate to 50 ml of pure water and mix thoroughly to obtain a cemented solution. The concentration of urea is 2 mol / L, the concentration of anhydrous calcium chloride is 1.5 mol / L, and the concentration of magnesium chloride is 3 mol / L.
[0040] Example 2
[0041] Add 21.773 g of anhydrous dipotassium hydrogen phosphate to 50 ml of Bacillus pasteurellium bacterial culture and stir well to obtain bacterial culture. The concentration of anhydrous dipotassium hydrogen phosphate is 2.5 mol / L.
[0042] Add 3 g of urea, 5.55 g of anhydrous calcium chloride, 9.521 g of magnesium chloride, and 0.5% sodium dodecylbenzenesulfonate to 50 ml of pure water and mix well to obtain a cementing solution. The concentration of urea is 1 mol / L, the concentration of anhydrous calcium chloride is 1 mol / L, and the concentration of magnesium chloride is 2 mol / L.
[0043] Example 3
[0044] Add 21.773 g of anhydrous dipotassium hydrogen phosphate to 50 ml of Bacillus pasteurellium bacterial culture and stir well to obtain bacterial culture. The concentration of anhydrous dipotassium hydrogen phosphate is 2.5 mol / L.
[0045] Add 1.5 g of urea, 2.775 g of anhydrous calcium chloride, 4.761 g of magnesium chloride, and 0.5% sodium dodecylbenzenesulfonate to 50 ml of pure water and mix thoroughly to obtain a cemented solution. The concentration of urea is 0.5 mol / L, the concentration of anhydrous calcium chloride is 0.5 mol / L, and the concentration of magnesium chloride is 1 mol / L.
[0046] Example 4
[0047] Add 21.773 g of anhydrous dipotassium hydrogen phosphate to 50 ml of Bacillus pasteurellium bacterial culture and stir well to obtain bacterial culture. The concentration of anhydrous dipotassium hydrogen phosphate is 2.5 mol / L.
[0048] Add 6 g of urea, 8.325 g of anhydrous calcium chloride, 14.282 g of magnesium chloride, and 0.5% sodium dodecylbenzenesulfonate to 50 ml of pure water and mix thoroughly to obtain a cemented solution. The concentration of urea is 2 mol / L, the concentration of anhydrous calcium chloride is 1.5 mol / L, and the concentration of magnesium chloride is 3 mol / L.
[0049] A MIP synergistic MISP mining spray dust suppressant, characterized in that it is prepared by the above-mentioned method for preparing a MIP synergistic MISP mining spray dust suppressant.
[0050] The application of a MICP synergistic with MISP mining spray dust suppressant in coal mines involves first spraying a cementing liquid onto the coal dust, followed by spraying a Bacillus pasteurellium bacterial solution.
[0051] Because coal dust is highly hydrophobic, a cementing solution needs to be sprayed onto the coal dust first. The surfactants in the cementing solution wet the coal dust, increasing its adhesion. Finally, a Bacillus pasteurellium solution is sprayed to ensure a full reaction on the coal dust. Phosphate and magnesium ions are added during the MISP process. The precipitate of magnesium ammonium phosphate is generated by the MISP reaction to neutralize the ammonium ions produced by MISP, thus reducing ammonia nitrogen residue pollution.
[0052] The hardness and mass of coal dust solidified material prepared in Examples 1-4 were determined. The solidification hardness of the coal dust samples from Examples 1-4 was tested using a D2479-01-1EA digital Shore hardness tester. The mass of the solidified coal dust samples from Examples 1-4 was weighed using an electronic balance and compared with water. The results are shown in Table 1.
[0053]
[0054] The dust suppressants prepared in Examples 1-4 were subjected to wind resistance tests on coal dust solidification.
[0055] Experiments were conducted using a small wind tunnel testing platform. Wind was blown at wind speeds of 5 m / s, 7 m / s, and 10 m / s at a distance of 150 mm from the coal dust solidification samples, with the wind direction at a 30° angle to the samples. The samples were continuously exposed to the wind for 15 minutes. Subsequently, the wind erosion resistance of the coal dust samples under different treatment methods was evaluated by measuring the mass loss after coal dust solidification. The wind erosion rate of the samples was calculated using the following formula.
[0056] ;
[0057] in, Wind erosion rate (g / m 2 / min); m1 is the mass (g) of the petri dish, coal dust, and dust suppressant before the experiment; m2 is the mass (g) of the petri dish, coal dust, and dust suppressant after the experiment; A is the sample area (m²). 2 T represents the wind erosion time (minutes).
[0058] The results were compared with those of clean water, and are shown in Table 2:
[0059]
[0060] As can be seen from Tables 1 and 2, when the dust suppressants prepared in Examples 1-4 are applied to coal dust, the quality of coal dust agglomerates, average hardness, and wind resistance are all significantly improved.
[0061] For the dust suppressant prepared in Implementation Example 4, which showed the best performance in all aspects in the table above, XRD tests were conducted on the mineralized products of coal dust, and the minerals solidified on the coal dust were tested.
[0062] The collected minerals were pulverized using a mortar and pestle and placed in a sample container. Powder XRD was performed using a Rigaku Miniflex 600 XRD system (Japan) at a scanning speed of 10° / min and a 2θ range of 10–80°. The raw data obtained was analyzed using the MDI Jade 6.0 program to determine the phase composition of the product.
[0063] XRD results showed that the mineralized Example 4 produced both calcium carbonate and magnesium phosphate crystalline compounds.
[0064] like Figure 1 As shown, magnesium phosphate crystals appeared in the minerals at 2θ = 15.998°, 20.991°, 21.558°, 27.27°, 30.599°, 32.15°, and 33.36°. (020) (111) (021) (130) (211) (040) (022) Crystal plane characteristic diffraction peaks appeared at 21.596°, 29.729°, 46.41° and 57.418°, respectively. CaCO3(011) (-112) (113)(122) Crystal plane characteristic diffraction peaks also appeared.
[0065] Therefore, it can be inferred that MICP and MISP have synergistic mineralization characteristics, and that phosphate ions and magnesium ions can mediate the reaction, converting the ammonium ions generated during the MICP process into magnesium phosphate crystal compounds, effectively reducing the concentration of ammonium ions in the cemented waste liquid.
[0066] The microstructure of the mineralized products of the dust suppressant prepared in Example 4 was analyzed using scanning electron microscopy based on the microstructural characteristics of coal dust.
[0067] like Figure 2 As shown, the surface of coal dust is uniformly covered by fine minerals, which adhere tightly to the surface of the coal powder particles, forming a continuous and stable covering layer.
[0068] As clearly seen in the image, the coal powder surface exhibits a relatively thin but tightly structured lamellar texture. This is likely because, during microbial-induced mineralization, magnesium phosphate crystals and calcium carbonate may simultaneously nucleate and grow. Due to the differences in lattice parameters and growth habits between the two minerals, their growth process inevitably involves competition for metal ions in the solution and for growth space. This competitive inhibition effect may prevent calcium carbonate crystals from developing into complete cubic or spherical structures according to their inherent habits, forcing them to expand horizontally and ultimately present as lamellar structures. Furthermore, organic acids or extracellular polymers produced by Bacillus pasteurellis metabolism may adsorb onto the crystal surface, further inhibiting vertical growth and promoting the formation of lamellar structures.
Claims
1. A method for preparing a MIP synergistic MISP mining spray dust suppressant, characterized in that, Includes the following steps: Step S1: Inoculate and culture Bacillus pasteurellii bacterial solution and keep it at a constant temperature. Then add anhydrous dipotassium hydrogen phosphate and stir evenly to obtain bacterial solution, which is used as the first spray of dust suppressant for mining. Step S2: Add urea, anhydrous calcium chloride, magnesium chloride and surfactant to pure water and mix evenly to obtain a cementing solution, which is used as the second spray of the dust suppressant for mining.
2. The method for preparing a MIP synergistic MISP mining spray dust suppressant according to claim 1, characterized in that: In step S1, the Bacillus pasteurellium culture was continuously shaken and cultured at 110 RPM and 31°C for 48 hours, and then stored at a constant temperature of 4°C.
3. The method for preparing a MIP synergistic MISP mining spray dust suppressant according to claim 1, characterized in that: In step S1, the solid culture medium used to culture Bacillus pasteurellis is LB medium, and the liquid culture medium used to culture Bacillus pasteurellis consists of urea, yeast and sodium chloride, wherein the concentration of yeast and urea is 10 g / L and the concentration of sodium chloride is 1 g / L.
4. The method for preparing a MIP synergistic MISP mining spray dust suppressant according to claim 1, characterized in that: In step S1, the concentration of anhydrous dipotassium hydrogen phosphate is 2 mol / L to 2.5 mol / L.
5. The method for preparing a MIP synergistic MISP mining spray dust suppressant according to claim 1, characterized in that: In step S2, the molar ratio of anhydrous calcium chloride, urea, and magnesium chloride is 0.75–1:1:1.5–2.
6. The method for preparing a MIP synergistic MISP mining spray dust suppressant according to claim 1, characterized in that: In step S2, the surfactant is sodium dodecylbenzenesulfonate, and the amount of surfactant added is 0.5% of the mass of the binder.
7. A MICP synergistic MISP mining spray dust suppressant, characterized in that: It is prepared using any one of the methods for preparing MIP-co-MISP mining spray dust suppressant according to claims 1-6.
8. The application of the MIP synergistic MISP mining spray dust suppressant as described in claim 7 as a spray dust suppressant in coal mines, characterized in that: First, spray the cementing liquid onto the coal dust, then spray the Bacillus pasteurellium solution.