Efficient coal gangue aggregate modification method and device based on microbial mineralization technology

Abstract

The application relates to a high-efficiency coal gangue aggregate modification method and device based on a microbial mineralization technology, and the method comprises the following steps: selecting a mineralization microbial strain, selecting mixed bacteria of bacillus pasteurii and bacillus cohnii as the mineralization microbial strain; forming a microbial mineralization system; pretreating coal gangue; performing dynamic mineralization treatment, immersing the coal gangue aggregate into the microbial mineralization system, placing the coal gangue aggregate suspension, and ensuring that the bottom of the coal gangue aggregate is suspended; maintaining the mineralization solution in a circulating flow state, so that the mineralization solution can fully contact the aggregate surface and penetrate into internal pores, and the circulating flow state of the mineralization solution is maintained for 5-10 days; and cleaning and drying. The application realizes the continuous circulating flow of the mineralization solution on the surface and internal pores of the coal gangue aggregate through a dynamic circulation system, effectively avoids the formation of a biological membrane in a static soaking process, improves the penetration depth and deposition uniformity of the mineralization solution, and has a good industrial application prospect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of comprehensive utilization of solid waste, and particularly relates to a high-efficiency coal gangue aggregate modification method and device based on microbial mineralization technology. BACKGROUND

[0002] Coal gangue is one of the main solid wastes generated in the process of coal mining and washing. Long-term accumulation of coal gangue not only occupies a large amount of land resources, but also can cause serious pollution to the surrounding ecological environment, such as soil pollution, water pollution and air pollution. In addition, heavy metal elements in coal gangue are easily precipitated under the action of rainwater or weathering, which poses a potential threat to the ecological system and human health.

[0003] Traditional coal gangue treatment methods mainly include landfill, stockpiling and direct utilization, but these methods have significant drawbacks. Landfill and stockpiling not only occupy land resources, but also can cause soil and groundwater pollution problems; direct utilization of coal gangue as concrete aggregate is limited by its physical properties, such as low hardness, high water absorption, etc., which is difficult to meet the requirements of building materials.

[0004] With the improvement of environmental awareness and the increasing demand for sustainable development, researchers have gradually turned their attention to the resourceization and high-value utilization of coal gangue. In recent years, microbial-induced calcium carbonate precipitation technology (MICP) has gradually attracted attention as a green and environmentally friendly modification method with relatively low cost. This technology utilizes the enzyme catalytic action produced by microorganisms in the metabolic process to make calcium carbonate deposit on the surface and internal pores of coal gangue, forming a hard mineralized layer. This mineralization deposition not only effectively fixes heavy metal elements in coal gangue, reducing environmental risk, but also significantly improves the physical and mechanical properties of coal gangue, broadening its application field.

[0005] However, there are still many technical bottlenecks in the application of microbial mineralization technology to modify coal gangue. First, the mineralization ability and modification efficiency of a single strain are low, and the adaptability to environmental conditions is limited, making it difficult to better promote the mineralization deposition process and improve the modification efficiency.

[0006] Secondly, the traditional static soaking method can easily form a layer of biofilm on the surface of coal gangue. This biofilm will gradually thicken with the metabolism of microorganisms, making it difficult for subsequent mineralization solution to penetrate into the internal pores of coal gangue, significantly hindering the deep contact of bacterial solution, causing calcium carbonate deposition to concentrate on the surface layer, resulting in uneven mineralization. This limitation affects the thickness and penetration depth of the mineralized deposition layer, making it difficult to effectively improve the overall physical and mechanical properties of coal gangue aggregate.

[0007] Finally, when the coal gangue is directly placed at the bottom of the container, the contact between the aggregate bottom and the mineralization solution is poor, especially in a static environment, the solution in the bottom area is difficult to circulate fully, thereby limiting the uniform coverage of the solution on the surface of the aggregate. In addition, poor bottom contact can lead to weakened mineralization effect in this area, uneven deposition layer, and finally affect the overall consistency of the modification effect and the structural stability of the aggregate, which is difficult to meet the high performance requirements of building materials for aggregates.

[0008] In view of the above technical bottleneck, the existing modification method of coal gangue aggregate needs to be further optimized. SUMMARY

[0009] The present application provides an efficient coal gangue aggregate modification method and device based on microbial mineralization technology, aiming to solve the problems of uneven mineralization effect and low modification efficiency in the prior art.

[0010] In order to achieve the above purpose, the technical scheme of the present application is as follows:

[0011] In a first aspect, the present application provides an efficient coal gangue aggregate modification method based on microbial mineralization technology, which comprises:

[0012] Selecting mineralization microbial strains: selecting mixed bacteria of Bacillus pasteurii and Bacillus cohnii as mineralization microbial strains;

[0013] Forming a microbial mineralization system: mixing urea, calcium source and nutrient ingredients in pure water to prepare a mineralization solution, inoculating the mineralization microbial strains into the mineralization solution, adjusting the pH value of the mineralization solution to 8.5-10, maintaining the temperature of the mineralization solution at 25-35℃, forming a microbial mineralization system suitable for microbial growth;

[0014] Pretreating coal gangue: crushing the coal gangue into particles with a particle size of 5-20mm and sieving to obtain coal gangue aggregate with uniform particle size;

[0015] Dynamic mineralization treatment: immersing the coal gangue aggregate in the microbial mineralization system, placing the coal gangue aggregate in suspension to ensure that the bottom of the coal gangue aggregate is suspended; maintaining the mineralization solution in a circulating flow state to enable the mineralization solution to fully contact the surface of the aggregate and penetrate into the internal pores, avoiding the accumulation of biofilm on the surface of the coal gangue aggregate which hinders the subsequent penetration of the mineralization solution into the interior of the aggregate; maintaining the circulating flow state of the mineralization solution for 5-10 days to form calcium carbonate precipitate on the surface of the coal gangue aggregate and in the internal pores;

[0016] Washing and drying: taking out the coal gangue particles with calcium carbonate deposition from the mineralization solution, washing them thoroughly with pure water, and then drying them to constant weight in a drying device.

[0017] Further, the nutrient components include tryptone, yeast powder, sodium chloride and glucose.

[0018] The mass ratio of the nutrient components to urea is as follows:

[0019] Tryptone: 5-15 parts

[0020] Yeast powder: 2-8 parts

[0021] Sodium chloride: 2-8 parts

[0022] Glucose: 0.5-3 parts

[0023] Urea: 10-30 parts.

[0024] Further, the calcium source includes calcium nitrate, calcium acetate or calcium chloride, and the calcium ion concentration is 0.15-0.25 mol / L.

[0025] Further, the concentration of the bacterial solution of the mineralized microorganism is 2.6×10 8 cells / ml-4.3×10 9 cells / ml.

[0026] Further, the tryptone: yeast powder: NaCl: glucose: urea = 10:5:5:1:20 by mass.

[0027] Further, the circulating flow direction of the mineralization solution is reversed every 2-5 hours.

[0028] In a second aspect, the present application provides a high-efficiency coal gangue aggregate modification device based on microbial mineralization technology, which comprises:

[0029] Container body: the container body is a rectangular structure for containing the mineralization solution and the coal gangue aggregate;

[0030] Coal gangue aggregate suspension: the coal gangue aggregate suspension is horizontally arranged in the container body, and a plurality of through holes are uniformly distributed on the coal gangue aggregate suspension, which is used to suspend the coal gangue aggregate, so that the bottom of the coal gangue aggregate is kept at a distance from the bottom of the container;

[0031] Bacterial solution dynamic circulation system: including a circulation pipeline and a circulation pump, the bacterial solution dynamic circulation system is used to drive the continuous circulation of the mineralization solution in the container;

[0032] Temperature control system: the temperature control system is arranged in the container body and includes a temperature sensor and a heating device, which is used to maintain the temperature of the mineralization solution.

[0033] Further, it further comprises:

[0034] The reverse flow control device is arranged in the circulating pump, comprising a timing controller, which drives the circulating pump to reverse within a preset time interval, changes the flow direction of the mineralized solution, and realizes the periodic forward and reverse flow of the mineralized solution in the container body.

[0035] Further, a longitudinal grid is arranged in the container body, which divides the container body into a flow guide area and a reaction area, and the coal gangue aggregate suspension is arranged in the reaction area.

[0036] Further, the distance between the coal gangue aggregate suspension and the bottom of the container body is 1 / 4 of the height of the container.

[0037] Compared with the prior art, the beneficial effects of the present application are as follows:

[0038] The present application adopts a mixed bacterial solution system of Bacillus pasteurii and Bacillus cohnii, which plays a synergistic role in mineralization efficiency, environmental adaptability and heavy metal fixation capacity of the two strains, significantly improves the efficiency and uniformity of calcium carbonate deposition; through the dynamic circulation system, the mineralized solution is continuously circulated on the surface and internal pores of the coal gangue aggregate, effectively avoiding the formation of biofilm in the static soaking process, improving the penetration depth and deposition uniformity of the mineralized solution; the design of suspension placement separates the coal gangue aggregate from the bottom of the container, ensuring that the mineralized solution can cover the surface of the aggregate at multiple angles and penetrate into the internal pores, solving the problem of poor bottom contact; combined with the temperature control system and the reverse flow control device, the temperature and pH value of the mineralization environment are further stabilized, the uniformity and controllability of the solution flow are enhanced, and finally the physical and mechanical properties of the mineralized coal gangue aggregate are significantly improved, the water absorption and porosity thereof are reduced, and the heavy metal elements therein are effectively fixed, which has good industrial application prospect.

[0039] Of course, implementing each technical solution of the present application does not necessarily need to achieve all the advantages described above. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings of embodiments according to these drawings without creative labor.

[0041] Figure 1 is a method flowchart of the embodiments of the present application.

[0042] Figure 2 is a schematic diagram of the power bacterial solution circulating device of the embodiments of the present application.

[0043] In the figure, 1 - container body, 101 - longitudinal grid, 2 - coal gangue aggregate suspension, 301 - circulating pump, 302 - circulating pipeline, 303 - shunt nozzle device, 4 - coal gangue aggregate. DETAILED DESCRIPTION

[0044] The application will be described in further detail below with reference to the drawings. Like elements in different embodiments are denoted by like reference numerals. In the following description, numerous specific details are described to provide a thorough understanding of the application. However, those of ordinary skill in the art will recognize that the application can be practiced without one or more of the specific details. In other instances, well-known structures have not been described in order to avoid obscuring the application. Furthermore, the description of the application is not intended to limit the scope of the application, as claimed below, but rather to provide a description of the various embodiments of the application.

[0045] In addition, features, operations or characteristics described in the specification can be combined in any suitable manner to form various embodiments. Also, the steps or acts in the method description can be performed in any suitable order, as is apparent to those skilled in the art. Therefore, the order of the description in the specification and the drawings is merely for clarity, and does not mean that the order is necessary.

[0046] Example 1:

[0047] A high-efficiency coal gangue coarse aggregate modification method based on microbial mineralization technology, the steps are as follows:

[0048] Step 1: Select mineralization microbial strains

[0049] The mixed bacteria of Bacillus pasteurii and Bacillus cohnii are selected as mineralization microbial strains. Urease produced in the metabolic process of the mixed bacteria catalyzes the decomposition of urea to generate ammonia and carbon dioxide, which further reacts with calcium ions to form calcium carbonate deposits.

[0050] In this embodiment, the mixed bacteria of Bacillus pasteurii and Bacillus cohnii have significant synergistic advantages in the microbial mineralization process; Bacillus pasteurii is known for its high urease activity, which can quickly catalyze the decomposition of urea to generate carbonate ions, providing sufficient carbonate sources for calcium carbonate deposition; Bacillus cohnii has excellent adaptability in high-salinity and high-alkalinity environments, and can maintain stable activity when the conditions of the mineralization solution fluctuate; In addition, Bacillus cohnii has good adsorption and fixation ability for heavy metal ions, and its metabolic products can form stable mineral precipitates with heavy metal ions, further improving the environmental friendliness and safety of the coal gangue modification process; The use of two strains can simultaneously exert the high mineralization efficiency of Bacillus pasteurii and the environmental tolerance and heavy metal fixation ability of Bacillus cohnii, thereby forming a synergistic effect and significantly optimizing the uniformity, density and mechanical properties of the mineralization deposition layer.

[0051] Step 2: Forming a microbial mineralization system

[0052] Dissolve urea, tryptone, yeast powder, sodium chloride and glucose in pure water according to the mass fraction of 30 parts, 15 parts, 8 parts, 8 parts and 3 parts respectively, add 0.25 mol / L calcium acetate, and prepare a mineralization solution; inoculate the mixed bacteria into the mineralization solution, and the concentration of the bacterial solution is 2.6×10 8 cells / ml. Adjust the pH value of the mineralization solution to 10 and control the temperature at 35℃.

[0053] Determine the optimal ratio of mixed bacteria by measuring the mass of deposited calcium carbonate and analyzing the microstructure. In this embodiment, the ratio of Bacillus pasteurii and Bacillus cohnii is 1:1, inoculate two strains in the mineralization solution, and the concentration of the two strains is 1.3×10 8 cells / ml.

[0054] Step 3: Pretreatment of coal gangue

[0055] Use a crusher to crush the coal gangue to particles with a particle size range of 20mm, and screen the coal gangue aggregate with uniform particle size.

[0056] Step 4: Dynamic mineralization treatment

[0057] Suspension of aggregate: suspend the coal gangue aggregate on the aggregate rack, maintaining a distance of 1 / 4 container height from the bottom of the container.

[0058] Dynamic circulation system: maintain the continuous flow of mineralization solution on the surface and pores of the aggregate through the circulation pipeline and circulation pump, and adjust the flow direction every 2 hours.

[0059] Temperature control system: the temperature of the mineralization solution is maintained at 35℃, and the mineralization time is 5 days.

[0060] Step 5: Cleaning and drying

[0061] After the mineralization process is completed, the coal gangue aggregate is taken out of the mineralization solution, washed with pure water to remove the surface residual solution and bacterial solution, and then dried in a drying device to a constant weight to obtain the modified coal gangue.

[0062] Example 2:

[0063] A high-efficiency coal gangue coarse aggregate modification method based on microbial mineralization technology, the steps are as follows:

[0064] Step 1: Selecting mineralization microbial strains

[0065] The mixed bacteria of Bacillus pasteurii and Bacillus cohnii are selected as the mineralization microbial strains. Bacillus pasteurii produces urease in the metabolic process, which can catalyze the decomposition of urea to generate ammonia and carbon dioxide, and the carbon dioxide further reacts with calcium ions to form calcium carbonate precipitate.

[0066] Step 2: Forming a microbial mineralization system

[0067] Urea, tryptone, yeast powder, sodium chloride and glucose are dissolved in pure water according to the mass fraction of 20 parts, 10 parts, 5 parts, 5 parts and 1 part respectively, 0.20 mol / L calcium nitrate (calcium source) is added to prepare a mineralization solution; the mixed bacteria are inoculated into the mineralization solution, and the bacterial concentration is controlled at 3.2×10 7 cells / m. The pH value of the mineralization solution is adjusted to 9.5, and the temperature is controlled at 30℃ to form an environment suitable for microbial growth and mineralization deposition.

[0068] The optimal ratio of mixed bacteria is determined by measuring the mass of calcium carbonate deposition and microscopic structure analysis. In this embodiment, the ratio of Bacillus pasteurii and Bacillus cohnii is 3:1, and the mixed bacteria inoculated in the mineralization solution has a concentration of 2.4×10 8 cells / ml for Bacillus pasteurii and 0.8×10 8 cells / ml for Bacillus cohnii.

[0069] Step 3: Pretreatment of coal gangue

[0070] Coal gangue from Ordos City, Inner Mongolia is selected, and the coal gangue is crushed to particles with a particle size of 10mm using a jaw crusher, and then sieved to obtain coal gangue aggregate with uniform particle size.

[0071] Step 4: Dynamic mineralization treatment

[0072] The pretreated coal gangue aggregate is placed in a dynamic bacterial solution circulating device, which includes a coal gangue aggregate rack placed in the air, a bacterial solution dynamic circulation system and a temperature control system.

[0073] Aggregate suspension placement: horizontally suspend the coal gangue aggregate on the aggregate frame, keeping a distance between the bottom of the aggregate and the bottom of the container to avoid direct contact with the bottom.

[0074] Power circulation system: continuously circulate the mineralized solution on the surface and internal pores of the coal gangue aggregate through the circulation pipeline and circulation pump to avoid the formation of biofilm during static soaking, while promoting uniform coverage of the bacterial solution on each surface of the aggregate and penetration into the internal pores; the flow direction of the mineralized solution is reversed every 3 hours.

[0075] Temperature control system: maintain the temperature of the mineralized solution at 30°C through the temperature control device. The mineralization treatment time is 7 days.

[0076] Step 5: washing and drying

[0077] After the mineralization treatment is completed, the coal gangue aggregate is taken out of the mineralized solution, washed with pure water to remove the residual solution and bacterial solution on the surface, and then dried in a drying device to a constant weight to obtain the modified coal gangue.

[0078] Example 3:

[0079] A high-efficiency coal gangue coarse aggregate modification method based on microbial mineralization technology, the steps are as follows:

[0080] Step 1: Selecting mineralization microbial strains

[0081] Selecting mixed bacteria of Bacillus pasteurii and Bacillus cohnii as mineralization microbial strains, which produce urease during metabolism to catalyze the decomposition of urea, generating ammonia and carbon dioxide, which further combine with calcium ions to form calcium carbonate deposits.

[0082] Step 2: Forming a microbial mineralization system

[0083] Dissolve urea, tryptone, yeast powder, sodium chloride, and glucose in pure water according to the mass fraction of 10 parts, 5 parts, 2 parts, 2 parts, and 0.5 parts, respectively, and add 0.15 mol / L of calcium chloride to prepare a mineralized solution; inoculate the mixed bacteria into the mineralized solution, with a bacterial solution concentration of 4.3×10 9 cells / ml. The pH value of the mineralized solution is adjusted to 8.5, and the temperature is controlled at 25°C.

[0084] Determine the optimal ratio of mixed bacteria through calcium carbonate deposition mass measurement and microstructure analysis. In this embodiment, the ratio of Bacillus pasteurii and Bacillus cohnii is 3:2, and the mixed bacteria inoculated in the mineralized solution have a Bacillus pasteurii concentration of 2.58×10 8 cells / ml and a Bacillus cohnii concentration of 1.72×10 8 cells / ml. Step 3: Pretreatment of coal gangue

[0085] The coal gangue is crushed to a particle size range of 5 mm using a crusher, and after screening, coal gangue aggregates with uniform particle size are obtained.

[0086] Step 4: Dynamic mineralization treatment

[0087] Aggregates suspension placement: The coal gangue aggregates are suspended on the aggregate frame, maintaining a distance of 1 / 4 container height from the bottom of the container.

[0088] Power circulation system: The continuous flow of the mineralization solution on the surface and pores of the aggregates is maintained through the circulation pipeline and circulation pump, and the flow direction is reversed every 5 hours.

[0089] Temperature control system: The temperature of the mineralization solution is maintained at 25°C, and the mineralization time is 10 days.

[0090] Step 5: Washing and drying

[0091] After the mineralization treatment is completed, the coal gangue aggregates are removed from the mineralization solution, washed with pure water to remove the residual solution and bacterial solution on the surface, and then dried in a drying device to a constant weight to obtain modified coal gangue.

[0092] The surface of the mineralized coal gangue aggregates forms a uniform calcium carbonate deposition layer, the porosity is significantly reduced, the water absorption is reduced, and the mechanical properties are significantly improved. At the same time, the heavy metal elements in the coal gangue are effectively fixed, and the modified aggregates have good physical properties and environmental friendliness, and can be used as high-performance building materials.

[0093] Test example:

[0094] The unmodified coal gangue aggregates in Example 1 are used as the control group.

[0095] Table 1 is the test results of the water absorption, crushing index, apparent density and heavy metal element fixation rate of the example and the control group.

[0096] Table 1 Water absorption, crushing index, apparent density and heavy metal element fixation rate of the example and the control group

[0097]

[0098]

[0099] According to the test results in Table 1, the apparent density and heavy metal element fixation rate of the coal gangue can be significantly improved, and the water absorption and crushing index can be reduced after modification according to the scheme of the present application.

[0100] Example 4:

[0101] Reference Figure 2The embodiment discloses a high-efficiency coal gangue aggregate modification device based on a microbial mineralization technology, referred to as a dynamic bacteria liquid circulation device; the device mainly comprises a container main body 1, a coal gangue aggregate suspension 2 and a bacteria liquid dynamic circulation system.

[0102] The container main body 1 adopts a rectangular structure and is used for containing a mineralization solution and coal gangue aggregates 4; the container is made of a corrosion-resistant material and is suitable for a reaction environment of a microbial mineralization process; a flow guide area and a reaction area are arranged in the container main body 1 and are separated by a longitudinal grid 101; in the embodiment, the longitudinal grid 101 is located at 1 / 3 of the length direction of the container main body; the flow guide area and the reaction area are in communication through the gap of the longitudinal grid 101, so that the mineralization solution can flow freely in the circulation process. In the embodiment, the total length of the container main body 1 is 450 unit lengths, the total width is 150 unit lengths, and the total height is 200 unit lengths; the length of the flow guide area is 150 unit lengths, and the length of the reaction area is 300 unit lengths.

[0103] The coal gangue aggregate suspension 2 is horizontally arranged in the reaction area of the container main body and is used for placing the coal gangue aggregates 4; the coal gangue aggregate suspension 2 is made of a corrosion-resistant material and uniformly has a plurality of through holes; the coal gangue aggregate suspension 2 is arranged in the reaction area and is spaced apart from the bottom of the container main body by 50 unit lengths, so that the mineralization solution can cover the coal gangue aggregates 4 from all angles, including the bottom area of the coal gangue aggregates 4, and the problem of poor contact caused by static placement is avoided.

[0104] The bacteria liquid dynamic circulation system comprises a circulation pump 301, a circulation pipeline 302 and a shunt nozzle device 303; the circulation pump 301 is located at the bottom of the flow guide area, the mineralization solution is pumped from the bottom of the container to the top through the circulation pipeline 302, and the solution is uniformly distributed around the coal gangue aggregates 4 in the reaction area through the shunt nozzle device 303; the circulation pipeline 302 connects the flow guide area and the reaction area and is connected with the shunt nozzle device 303 through a top outlet, so that the mineralization solution is efficiently transported and uniformly distributed; the shunt nozzle device 303 is located above the aggregate rack and ensures that the mineralization solution can continuously flow on the surface and in the internal pores of the coal gangue aggregates 4, fully covers the coal gangue aggregates 4 and forms a dynamic circulating flow environment, so that the uniformity and efficiency of mineralization deposition are significantly improved; the entire bacteria liquid dynamic circulation system is completely immersed in the mineralization solution and is driven by the circulation pump to realize closed circulation flow of the solution between the flow guide area and the reaction area, so that the problem of biological membrane accumulation under static conditions is avoided.

[0105] The shunt nozzle device 303 adopts a multi-hole shunt design, which is composed of a plurality of uniformly distributed nozzles to achieve uniform distribution of the mineralized solution; the aperture and number of the nozzles are optimized according to the particle size and laying area of the coal gangue aggregate 4, to ensure that the sprayed solution can cover the surface of the coal gangue aggregate and penetrate into the internal pores; in order to enhance the flow performance, the material of the shunt nozzle device 303 is selected to be corrosion-resistant and low-friction, and the inner wall is designed to be smooth to reduce the flow resistance of the solution, effectively preventing the deposition of microorganisms or particle blockage of the nozzles in the mineralized solution, and ensuring the long-term stable operation of the nozzle.

[0106] Temperature control system: The temperature control system is arranged in the container body and includes a temperature sensor and a heating device, and is used to maintain the temperature of the mineralized solution.

[0107] Through the above structural design and the function of the bacteria liquid power circulation system, the device of the embodiment can significantly improve the mineralization efficiency and deposition uniformity of the coal gangue aggregate, and is suitable for large-scale coal gangue aggregate modification treatment scenarios.

[0108] Example 5:

[0109] The embodiment discloses an efficient coal gangue aggregate modification device based on microbial mineralization technology, referred to as a power bacteria liquid circulation device; the device mainly includes a container body, a coal gangue aggregate suspension, a bacteria liquid power circulation system, a temperature control system, and a reverse flow control device.

[0110] Container body: The container body adopts a rectangular structure and is used to contain the mineralized solution and the coal gangue aggregate. The container is made of corrosion-resistant material and is suitable for the reaction environment of the microbial mineralization process. The container is provided with a flow guide area and a reaction area, which are separated by a longitudinal grid. The flow guide area and the reaction area are communicated through the grid gap to ensure that the mineralized solution can flow freely during the circulation.

[0111] Coal gangue aggregate suspension: The coal gangue aggregate suspension is horizontally arranged in the reaction area of the container body and is used to place the coal gangue aggregate. The suspension is made of corrosion-resistant material and uniformly distributed with a plurality of through holes. The bottom of the suspension and the bottom of the container body are spaced apart by 1 / 4 of the height of the container to ensure that the mineralized solution can cover the coal gangue aggregate from all angles and avoid the problem of poor contact caused by static placement.

[0112] Bacteria liquid power circulation system: The bacteria liquid power circulation system includes a circulation pipeline and a circulation pump. One end of the circulation pipeline is connected to the water inlet of the flow guide area of the container body, and the other end is connected to the water outlet of the reaction area, forming a closed circulation loop. The circulation pump is arranged in the middle of the pipeline to drive the continuous circulation of the mineralized solution in the container. By adjusting the flow rate of the circulation pump, the mineralized solution can flow fully in the surface and internal pores of the coal gangue aggregate, preventing the formation of a biological membrane and improving the uniformity and depth of mineralization deposition.

[0113] Temperature control system: The temperature control system includes a temperature sensor and a heating device, which are arranged inside the container body; the temperature sensor detects the temperature of the mineralization solution in real time, and the heating device controls heating according to the feedback of the temperature sensor, so as to ensure that the temperature of the mineralization solution is always maintained within the range of 25-35℃, thereby providing a stable environment for the microbial mineralization process.

[0114] Reverse flow control device: The reverse flow control device is arranged in the bacteria liquid power circulation system and includes a timing controller and a circulating pump; the timing controller is connected with the circulating pump and can drive the circulating pump to reverse at regular time intervals, so that the flow direction of the mineralization solution is automatically changed every 2-5 hours, thereby realizing periodic forward and reverse flow in the container and further improving the uniformity of the coverage of the mineralization solution on the surface and internal pores of the aggregate.

[0115] The device realizes the sufficient coverage and flow of the mineralization solution on the surface and pores of the coal gangue aggregate through the synergistic effect of the partition design in the container, the aggregate suspension structure and the power circulation system; the temperature control system provides a suitable mineralization environment, and the reverse flow control device further enhances the uniform distribution of the solution, so that the mineralization deposition is more uniform and efficient; the device is suitable for large-scale modification treatment of coal gangue aggregate and has remarkable environmental protection and economic benefits.

[0116] Example 6:

[0117] The embodiment discloses an efficient coal gangue aggregate modification device based on the microbial mineralization technology, which further optimizes the bacteria liquid power circulation system on the basis of the embodiment 4 or the embodiment 5, and the bacteria liquid power circulation system adopts a layered circulation design, thereby significantly enhancing the dynamic regulation and control capability of the mineralization solution; the basic structures and functions of other parts of the embodiment, including the container body, the coal gangue aggregate suspension, the temperature control system and the reverse flow control device, are consistent with those of the embodiment 5, and only the different parts are described below.

[0118] The bacteria liquid power circulation system of the embodiment adopts a layered circulation design, divides the reaction zone into a surface area of aggregate, a middle layer pore area and a bottom layer flow area, and drives the flow of the mineralization solution in each layer area through independent pipelines and circulating pumps; the flow rate is set according to the mineralization requirement, the flow rate of the surface area of aggregate is 1L per minute, the flow rate of the middle layer pore area is 0.5L per minute, and the flow rate of the bottom layer flow area is 2L per minute, so as to ensure that the mineralization solution can uniformly cover the surface of the aggregate and penetrate into the internal pores; at the same time, the flow direction of the mineralization solution is switched every 3 hours by using the reverse flow control device, thereby further enhancing the coverage capability of the solution in the aggregate and avoiding insufficient local deposition.

[0119] Through the combination of hierarchical circulation and dynamic regulation, the embodiment realizes the accurate control of the mineralized solution in different circulation areas, significantly optimizes the uniformity and depth of the deposition layer, effectively improves the efficiency and effect of the coal gangue aggregate modification, and is suitable for large-scale processing scenarios with high requirements.

[0120] The above application of specific examples to illustrate the application, is used to help understand the application, and does not limit the application. For those skilled in the art to which the application belongs, according to the idea of the application, a number of simple deductions, deformations or substitutions can be made.

Claims

1. A high-efficiency coal gangue aggregate modification device based on microbial mineralization technology, characterized in that, include: Container body: The container body is a rectangular structure used to hold the mineralization solution and coal gangue aggregate; Coal gangue aggregate suspension: The coal gangue aggregate suspension is horizontally set inside the container body. Multiple through holes are evenly distributed on the coal gangue aggregate suspension. The coal gangue aggregate suspension is used to suspend the coal gangue aggregate in the air, so that the bottom of the coal gangue aggregate is kept at a distance from the bottom of the container. Bacterial liquid dynamic circulation system: including circulation pipelines and circulation pumps, the bacterial liquid dynamic circulation system is used to drive the continuous circulation of mineralization solution in the container; Temperature control system: The temperature control system is installed inside the container body and includes a temperature sensor and a heating device. The temperature control system is used to maintain the temperature of the mineralization solution. Reverse flow control device: The reverse flow control device is installed in the circulation pump and includes a timer controller. The timer controller drives the circulation pump to reverse within a preset time interval to change the flow direction of the mineralization solution and realize the periodic forward and reverse flow of the mineralization solution in the container body. The container body is provided with a longitudinal grid, which divides the container body into a flow guiding zone and a reaction zone. The coal gangue aggregate suspension is located in the reaction zone. The reaction zone is divided into an aggregate surface area, a middle pore area, and a bottom flow area. The mineralization solution in each layer is driven to flow through independent pipes and circulating pumps. The flow rate in the aggregate surface area is 1 L / min, the flow rate in the middle pore area is 0.5 L / min, and the flow rate in the bottom layer is 2 L / min.

2. A highly efficient method for modifying coal gangue aggregate based on microbial mineralization technology, characterized in that, Based on the device of claim 1, it includes: Selection of mineralizing microbial strains: A mixture of Bacillus pasteurellii and Bacillus coccidioides was selected as the mineralizing microbial strains; Forming a microbial mineralization system: Urea, calcium source and nutrients are thoroughly mixed in pure water to prepare a mineralization solution. The mineralization microbial strains are inoculated into the mineralization solution, the pH value of the mineralization solution is adjusted to 8.5-10, and the temperature of the mineralization solution is maintained at 25-35℃ to form a microbial mineralization system suitable for microbial growth. Pre-treatment of coal gangue: The coal gangue is crushed into particles with a diameter of 5-20mm and screened to obtain coal gangue aggregate with uniform particle size. Dynamic mineralization treatment: The coal gangue aggregate is immersed in the microbial mineralization system, with the coal gangue aggregate suspended to ensure that the bottom of the coal gangue aggregate is suspended; the mineralization solution is maintained in a circulating state, so that the mineralization solution can fully contact the surface of the aggregate and penetrate into the internal pores, avoiding the formation of biofilm accumulation on the surface of the coal gangue aggregate, which would hinder the subsequent penetration of the mineralization solution into the interior of the aggregate; the circulating state of the mineralization solution is maintained for 5-10 days, forming calcium carbonate precipitate on the surface and in the internal pores of the coal gangue aggregate; Cleaning and drying: Remove the coal gangue particles with calcium carbonate deposits from the mineralization solution, rinse them with pure water, and then dry them to constant weight in a drying equipment; The direction of circulation of the mineralization solution is reversed every 2-5 hours; The distance between the coal gangue aggregate suspension and the bottom of the container body is 1 / 4 of the container height.

3. The efficient coal gangue aggregate modification method based on microbial mineralization technology according to claim 2, characterized in that, The nutrients include tryptone, yeast powder, sodium chloride, and glucose; The mass ratio range of the nutrients to urea is as follows: Tryptone: 5-15 parts Yeast powder: 2-8 parts Sodium chloride: 2-8 parts Glucose: 0.5-3 parts Urea: 10-30 parts.

4. The efficient coal gangue aggregate modification method based on microbial mineralization technology according to claim 2, characterized in that, The calcium source includes calcium nitrate, calcium acetate, or calcium chloride, with a calcium ion concentration of 0.15-0.25 mol / L.

5. The efficient coal gangue aggregate modification method based on microbial mineralization technology according to claim 2, characterized in that, The concentration of the mineralizing microbial strain in the culture was 2.6 × 10⁻⁶. 8 cells / ml - 4.3 × 10 9 cells / ml.

6. The efficient coal gangue aggregate modification method based on microbial mineralization technology according to claim 3, characterized in that, The ratio of tryptone: yeast extract: NaCl: glucose: urea is 10:5:5:1:20 by weight.

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