A method for reducing the hardness of coal gangue using microorganisms

Abstract

The application discloses a method for reducing the hardness of coal gangue by using microorganisms, and particularly, the method comprises the following steps: activating and culturing microorganisms to obtain a bacterial suspension; mixing and disposing the bacterial suspension or a culture solution obtained after separating the bacterial suspension from the coal gangue; and the microorganisms comprise Ardisia japonica leaf rod bacteria and / or floating fungi, the preservation number of the Ardisia japonica leaf rod bacteria is CGMCC No.30592, and the preservation number of the floating fungi is CGMCC No.30591. The method can significantly reduce the hardness of the coal gangue and reduce the energy consumption in subsequent crushing and utilization.

Description

Technical Field

[0001] This invention belongs to the field of industrial solid waste disposal, specifically relating to a method for reducing the hardness of coal gangue using microorganisms. Background Technology

[0002] Coal gangue is one of the main wastes generated during coal mining and processing. Its main components include dry basis ash, kaolin, hydromica, bauxite, etc. With increasing global attention to environmental protection and sustainable resource utilization, the comprehensive utilization of coal gangue has become increasingly important.

[0003] Currently, the common method for disposing of coal gangue is landfill. Under natural weathering conditions, the heavy metals in the coal gangue are released into the surrounding area, causing secondary pollution. The sustainable utilization of coal gangue is mainly reflected in road paving, building material manufacturing, fuel power generation, and handicraft production. These solutions share the characteristics of large project investments and high production costs, which seriously restricts the resource utilization of coal gangue.

[0004] Patent document 1 (A method for accelerating the conversion of waste rock into soil using coal gangue, publication number CN113441533A) discloses a method for accelerating the conversion of waste rock into soil using coal gangue. In this process, the heat generated during the combustion of coal gangue is used to heat the ore, and then water is added for quenching and crushing to achieve the purpose of accelerating the conversion of waste rock into soil, while solving the problem of ecological damage caused by coal gangue accumulation.

[0005] Patent document 2 (A strain of Penicillium oxalate decomposing coal gangue, publication number CN110951626A) discloses a method for accelerating the release of nutrients from coal gangue using microorganisms. The method isolates a strain of Penicillium oxalate from the mining area, which has strong resistance to heavy metals. Taking advantage of its small size and rapid reproduction, the mycelium obtains nutrients inside the coal gangue, promoting the degradation of the coal gangue.

[0006] Patent document 1 uses coal gangue combustion to release heat, which releases a large amount of pollutants in the process, easily causing secondary pollution.

[0007] The method in Patent Document 2 is relatively simple, but it requires crushing the coal gangue and mixing it with soil first. It cannot handle coal gangue blocks and is still constrained by high crushing energy consumption, making it difficult to promote its use.

[0008] Furthermore, technologies that utilize coal gangue as a raw material for cement production and as roadbed material all require crushing and grinding it for further processing. However, existing technologies suffer from high equipment requirements and high production costs, making coal gangue products uncompetitive in the market and easily replaceable. Therefore, there is an urgent need for a technology that can significantly reduce the hardness of coal gangue to further reduce crushing costs and improve the competitiveness of coal gangue resource products. Summary of the Invention

[0009] To address the shortcomings of existing technologies, the present invention aims to provide a method that significantly reduces the hardness of coal gangue without requiring crushing and grinding. To achieve this objective, the present invention employs the following technical solution:

[0010] In a first aspect, the present invention provides a method for reducing the hardness of coal gangue using microorganisms, comprising:

[0011] Microorganisms are activated and cultured on a large scale to obtain a bacterial suspension;

[0012] The bacterial suspension or the culture medium obtained after separating the bacterial cells from the bacterial suspension is mixed with coal gangue for disposal.

[0013] The microorganisms mentioned include *Botrytis cinerea* and / or *Planctomyces*.

[0014] The accession number for *Botrytis cinerea* is CGMCC No. 30592, and the accession number for *Planctomyces* is CGMCC No. 30591.

[0015] In a preferred embodiment, the microorganisms are Botrytis cinerea and Plankton, and more preferably, the ratio of Botrytis cinerea to Plankton is (0.5-2):1.

[0016] As a preferred embodiment, the ratio of *Botrytis cinerea* to *Plantago asiatica* is 1:1.

[0017] In one implementation, the expanded culture involves culturing the microorganisms to the logarithmic growth phase.

[0018] According to a specific embodiment of the present invention, the bacterial strain concentration in the bacterial suspension is greater than 5.0 × 10⁻⁶. 6 per mL.

[0019] In a preferred embodiment, the bacterial strain concentration in the bacterial suspension is 6.0 × 10⁻⁶. 6 per mL.

[0020] As one implementation method, the method includes: activating and expanding the culture of the microorganisms to obtain a bacterial suspension, separating the bacterial cells in the bacterial suspension, and mixing the obtained culture solution with coal gangue.

[0021] As one implementation method, the method includes: activating and expanding the culture of the microorganisms to obtain a bacterial suspension; inoculating the bacterial strains obtained after separating the bacterial suspension into coal gangue; and then adding liquid culture medium for treatment.

[0022] In one implementation method, when inoculating the bacterial strain obtained after separating the bacterial suspension into coal gangue, 0.1% to 10% of the bacterial strain relative to the mass of the coal gangue is added.

[0023] In one embodiment, the liquid-solid mass ratio of the bacterial suspension to the coal gangue is 1:1 to 5:1.

[0024] In one embodiment, the liquid-to-solid mass ratio of the bacterial suspension to the coal gangue is 5:1.

[0025] In this invention, the culture medium used for expanding the cultivation of the microorganisms is a liquid culture medium. According to a specific embodiment of the invention, the liquid culture medium comprises one or more of the following: peptone, beef extract, yeast extract, glucose, sodium chloride, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, magnesium sulfate, and ferrous sulfate.

[0026] As one implementation method, the process parameters for treatment include: treatment temperature of 18–35°C, pH of 4–8, dissolved oxygen concentration of 0–0.6 mmol / L, and treatment time of not less than 10 days.

[0027] As one implementation method, the treatment process parameters include: treatment temperature of 18-35°C, pH of 4-8, and treatment time of not less than 30 days.

[0028] As a preferred embodiment, the treatment process parameters are: treatment temperature of 30°C, pH of 6.8, dissolved oxygen concentration of 0.3 mmol / L, and treatment time of 45 days.

[0029] In this invention, the volume equivalent particle size of the coal gangue is not less than 20 mm.

[0030] Secondly, the present invention provides a microbial inoculant comprising Botrytis cinerea and / or Planktonic mold, wherein the Botrytis cinerea has the accession number CGMCC No. 30592 and the Planktonic mold has the accession number CGMCC No. 30591.

[0031] In a preferred embodiment, the microbial agent comprises Botrytis cinerea and Plankton.

[0032] According to a specific embodiment of the present invention, the ratio of *Botrytis cinerea* and *Planctomyces* is (0.5-2):1.

[0033] As a preferred embodiment, the ratio of *Botrytis cinerea* to *Plantago asiatica* is 1:1.

[0034] Thirdly, the present invention provides the application of the microbial agent described in the second aspect of the present invention in reducing the hardness of coal gangue.

[0035] Beneficial effects:

[0036] This invention provides a method for reducing the hardness of coal gangue using microorganisms. The microorganisms used in this invention are environmentally friendly, safe, and widely available. The method significantly reduces the hardness of coal gangue, thereby reducing energy consumption in its subsequent crushing and utilization. This method also has a certain complexing effect on heavy metals in coal gangue, reducing their activity and minimizing secondary pollution. This method can also be used for the disposal of slag from other types of mines, such as manganese ore slag. The method is flexible, allowing for the selection of the most suitable method based on local conditions. Attached Figure Description

[0037] Figure 1 The effect of treatment with Botrytis cinerea and / or Plankton on the hardness of coal gangue.

[0038] Microbial preservation for patented procedures:

[0039] 1. The *Botrytis cinerea* of this invention

[0040] Deposit date: May 10, 2024;

[0041] Preservation Institution: China General Microbiological Culture Collection Center (CGMCC);

[0042] Accession number: CGMCC No. 30592;

[0043] Classification and nomenclature: Phyllobacterium myrsinacearum;

[0044] Address of the depository: No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing.

[0045] 2. The planktonic fungus of the present invention

[0046] Deposit date: May 10, 2024;

[0047] Preservation Institution: China General Microbiological Culture Collection Center (CGMCC);

[0048] Accession number: CGMCC No. 30591;

[0049] Classification and nomenclature: Planctomyces sp.;

[0050] Address of the depository: No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing. Detailed Implementation

[0051] Before further describing specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terminology used in the embodiments of the present invention is for describing specific embodiments and not for limiting the scope of protection of the present invention.

[0052] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. In addition to the specific methods, apparatus, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description of this invention, any prior art methods, apparatus, and materials similar to or equivalent to those described, apparatus, and materials in the embodiments of this invention may be used to implement the present invention.

[0053] Unless otherwise stated, the experimental methods, detection methods and preparation methods disclosed in this invention all adopt conventional techniques in this technical field.

[0054] In this specification, the range of values ​​referred to as "value A to value B" refers to the range including the endpoint values ​​A and B.

[0055] All unit names used in this manual are international standard unit names, and unless otherwise stated, "%" refers to volume percentage content.

[0056] Example 1

[0057] A mixture of *Phyllobacterium myrsinacearum* (CGMCC No. 30592) and *Planctomyces sp.* (CGMCC No. 30591) was used, with a 1:1 ratio of *Phyllobacterium myrsinacearum* to *Planctomyces sp.*. After activation, the strains were cultured in liquid medium (10g peptone, 5g yeast extract, 1g glucose, 1g magnesium sulfate, 1L distilled water, pH adjusted to 6.8 with HCl and NaOH) for 40 hours until the initial strain concentration was approximately 6 × 10⁻⁶. 6 The bacterial suspension was obtained by dividing the bacterial count by 100 cells / mL.

[0058] The bacterial suspension was mixed with sterilized coal gangue at a mass ratio of 5:1, and the temperature was maintained at 30°C with a dissolved oxygen concentration of 0.3 mmol / L for 45 days. The Mohs hardness of the coal gangue decreased from 6 to 4.2.

[0059] In this invention, the method for testing the hardness of coal gangue is as follows: using a Mohs hardness pen, lines are drawn on a flat area of ​​the coal gangue with the Mohs hardness increasing from small to large. The scratches are observed. When no scratches are left or the scratches are not obvious, the hardness of the coal gangue is less than the corresponding reading of the hardness pen. When obvious scratches are left, the hardness is the hardness of the coal gangue at that time.

[0060] Example 2

[0061] Phyllobacterium myrsinacearum (CGMCC No. 30592) was used for treatment. After activation, the strain was cultured in liquid medium (10g peptone, 5g yeast extract, 1g glucose, 1g magnesium sulfate, 1L distilled water, pH adjusted to 6.8 with HCl and NaOH) for 40 hours until the initial strain concentration was approximately 6 × 10⁻⁶. 6 The bacterial suspension was obtained by dividing the bacterial count by 100 cells / mL.

[0062] The bacterial suspension was mixed with sterilized coal gangue at a mass ratio of 5:1, and the temperature was maintained at 30°C with a dissolved oxygen concentration of 0.3 mmol / L for 45 days. The Mohs hardness of the coal gangue decreased from 6 to 4.9.

[0063] Example 3

[0064] The strain was treated with *Planctomyces sp.* (CGMCC No. 30591). After activation, the strain was cultured in liquid medium (10g peptone, 5g yeast extract, 1g glucose, 1g magnesium sulfate, 1L distilled water, pH adjusted to 6.8 with HCl and NaOH) for 40 hours until the initial strain concentration was approximately 6 × 10⁻⁶. 6 The bacterial suspension was obtained by dividing the bacterial count by 100 cells / mL.

[0065] The bacterial suspension was mixed with sterilized coal gangue at a mass ratio of 5:1, and the temperature was maintained at 30°C with a dissolved oxygen concentration of 0.3 mmol / L for 45 days. The Mohs hardness of the coal gangue decreased from 6 to 5.2.

[0066] The results of the effects of *Botrytis cinerea* and / or *Plancium chinense* treatment on the hardness of coal gangue are shown in [the table below]. Figure 1 .

[0067] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for reducing the hardness of coal gangue using microorganisms, comprising: Microorganisms are activated and cultured on a large scale to obtain a bacterial suspension; The bacterial suspension or the culture medium obtained after separating the bacterial cells from the bacterial suspension is mixed with coal gangue for disposal. The microorganisms mentioned include Botrytis cinerea and Plankton. The preservation number of Botrytis cinerea is CGMCC No. 30592, and the preservation number of Planktonic mold is CGMCC No. 30591; The ratio of *Botrytis cinerea* to *Planctomyces* was (0.5-2):

1.

2. The method according to claim 1, wherein, The bacterial suspension contains a bacterial strain concentration greater than 5.0 × 10⁻⁶. 6 per mL.

3. The method according to claim 2, wherein, The bacterial strain concentration in the bacterial suspension was 6.0 × 10⁻⁶. 6 per mL.

4. The method according to claim 1, wherein, The liquid-solid mass ratio of the bacterial suspension to the coal gangue is 1:1 to 5:

1.

5. The method according to claim 4, wherein, The liquid-to-solid mass ratio of the bacterial suspension to the coal gangue is 5:

1.

6. The method according to any one of claims 1-5, wherein, The process parameters for treatment include: treatment temperature of 18~35℃, pH of 4~8, dissolved oxygen concentration of 0~0.6mmol / L, and treatment time of not less than 10 days.

7. A microbial inoculant comprising *Botrytis cinerea* and *Plantago asiatica*, wherein, The preservation number of *Botrytis cinerea* is CGMCC No. 30592, and the preservation number of *Plasmodium* is CGMCC No. 30591. The ratio of *Botrytis cinerea* to *Plasmodium* is (0.5-2):

1.

8. The application of the microbial agent according to claim 7 in reducing the hardness of coal gangue.

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