Coal gangue soil conditioner and production method thereof

Abstract

The invention discloses a coal gangue soil conditioner and a production method thereof in the field of coal gangue soil conditioners. According to the method, deep development and efficient utilization of the coal gangue are achieved through the steps of fine grinding, leaching, mixing, granulation, calcination and the like, the dolomite powder and the magnesite powder are added into the filtrate, the produced coal gangue soil conditioner has remarkable citric acid solubility, effective components in the conditioner can be effectively absorbed by plant roots, and the soil conditioner has the advantages that the soil conditioner can be used for improving the soil quality of plants. Compared with a traditional soil conditioner, the coal gangue soil conditioner has the advantages that the biological utilization rate is higher, the soil environment can be more directly and effectively improved, the yield of crops is increased, the quality of the crops is improved, the coal gangue soil conditioner further has the characteristic of alkalescence, acidic substances in soil can be neutralized, and the soil conditioner can be used for improving the soil quality of the crops. The pH value of the soil can be adjusted to be neutral or alkalescent, so that the structure and texture of the soil can be improved, the water and fertilizer retention capacity of the soil can be improved, and the problem of crop growth limitation caused by soil acidification can be effectively relieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal gangue soil conditioner, and particularly relates to a coal gangue soil conditioner and a production method thereof. Background Art

[0002] Soil problems are important issues that cannot be ignored in agricultural production. With the rapid development of modern agriculture, the soil faces many challenges, such as soil degradation, nutrient imbalance, increasing pollution, etc. These have seriously affected the growth and quality of crops and even threatened the sustainable development of the agricultural ecosystem. A soil conditioner is a substance that can improve soil structure, adjust soil pH, supplement soil nutrients, and increase soil fertility. It is usually composed of various beneficial organic matters, minerals, and nutrient elements and is processed through scientific proportioning. Coal gangue is a solid waste generated during the coal mining process and coal washing process. It is a black-gray rock with a lower carbon content and harder than coal that is associated with coal seams during the coal formation process. Its chemical composition is mainly aluminum oxide and silicon dioxide, and the content can usually reach 50% - 80%. In addition, it also contains varying amounts of iron oxide, calcium oxide, magnesium oxide, sodium oxide, potassium oxide, phosphorus pentoxide, sulfur trioxide, etc. These components endow coal gangue with certain utilization value. As a solid waste, if coal gangue can be reasonably processed and utilized to be transformed into valuable raw materials for soil conditioner, it can achieve the recycling of resources and the sustainable development of agriculture. Therefore, it is necessary to propose a coal gangue soil conditioner and a production method thereof. Summary of the Invention

[0003] In view of the above situation, to overcome the defects of the prior art, the present invention provides a solution to the problem of the unreasonable utilization of coal gangue. The present invention proposes to prepare a coal gangue soil conditioner through steps such as fine grinding, leaching, mixing, granulation, and calcination, realizing the in-depth development and efficient utilization of coal gangue.

[0004] To achieve the above object, the following technical solutions are adopted: The present invention provides a coal gangue soil conditioner and a production method thereof, including the following steps:

[0005] S1. Add coal gangue to a ball mill for grinding, and pass through a 150-mesh sieve to obtain the first coal gangue powder;

[0006] S2. Leach the first coal gangue powder with an alkali solution, then pass through a 150-mesh sieve again, and dry it to obtain the second coal gangue powder;

[0007] S3. Leach the second coal gangue powder with a sodium citrate solution, filter to obtain a filtrate and a filter residue, add dolomite powder and magnesite powder to the filtrate, and stir and react at 50°C for 1 h. After the reaction ends, obtain a conditioner intermediate;

[0008] S4. Mix the conditioner intermediate with filter residue, boron-magnesium mud, humus, and tannic acid, dry, granulate, and calcine to obtain the coal gangue soil conditioner.

[0009] Further, the coal gangue soil conditioner comprises the following components in parts by weight: 60 - 80 parts of conditioner intermediate, 15 - 20 parts of filter residue, 20 - 30 parts of boron-magnesium mud, 15 - 40 parts of humus, and 5 - 12 parts of tannic acid.

[0010] Further, the alkaline solution is a solution of one of sodium hydroxide, potassium hydroxide, cesium hydroxide, sodium carbonate, potassium carbonate, and cesium carbonate.

[0011] Further, the alkaline solution is a solution with a mass fraction of 10 - 20%.

[0012] Further, the sodium citrate solution is a solution with a mass fraction of 8 - 15%.

[0013] Further, the conditioner intermediate comprises the following components in parts by weight: 50 - 80 parts of filtrate, 40 - 60 parts of dolomite powder, and 25 - 45 parts of magnesite powder.

[0014] Further, the fineness of the dolomite powder is 50 - 150 mesh, and the fineness of the magnesite powder is 100 - 200 mesh.

[0015] Further, the temperature of ball mill grinding is 55 - 75 °C, and the time of ball mill grinding is 10 - 20 min.

[0016] Further, in step S4, the drying temperature is 150 - 180 °C, the granulation particle size in step S4 is 1.5 - 5 mm, and the calcination temperature in step S4 is 350 - 400 °C.

[0017] The beneficial effects of the present invention are as follows: Through steps such as fine grinding, leaching, mixing, granulation, and calcination, the present invention realizes the deep development and efficient utilization of coal gangue. By adding dolomite powder and magnesite powder to the filtrate, the produced coal gangue soil conditioner has significant citrate solubility, and the active ingredients in the conditioner can be effectively absorbed by plant roots, thereby promoting the growth and development of plants. Compared with traditional soil conditioners, the product of the present invention has a higher biological utilization rate, can more directly and effectively improve the soil environment, increase the yield and quality of crops. The coal gangue soil conditioner produced by the present invention also has the property of weak alkalinity, can neutralize acidic substances in the soil, adjust the pH value of the soil to be neutral or slightly alkaline, which is not only beneficial to improving the structure and texture of the soil, enhancing the water and fertilizer retention capacity of the soil, but also can effectively alleviate the problem of crop growth limitation caused by soil acidification. Description of the Drawings

[0018] Figure 1 Soil pH values after 15, 30, and 45 days of application of the coal gangue soil conditioner prepared in each example and comparative example of the present invention.

[0019] The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. Detailed implementation manners

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0021] Unless otherwise defined, all professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to the described content can be applied to the present invention. The preferred implementation methods and materials described herein are only for illustrative purposes and do not limit the content of this application.

[0022] The experimental methods in the following embodiments are all conventional methods unless otherwise specified. The test materials used in the following embodiments are all obtained from commercial channels unless otherwise specified.

[0023] Example 1

[0024] A coal gangue soil conditioner and its production method

[0025] The production method includes the following steps:

[0026] S1. Add coal gangue to a ball mill for grinding, and pass through a 150-mesh sieve to obtain the first coal gangue powder;

[0027] S2. Leach the first coal gangue powder with an alkali solution, then pass through a 150-mesh sieve again, and dry it to obtain the second coal gangue powder;

[0028] S3. Leach the second coal gangue powder with a sodium citrate solution, filter to obtain a filtrate and a filter residue. Add dolomite powder and magnesite powder to the filtrate, and stir and react at 50 °C for 1 h. After the reaction, obtain a conditioner intermediate;

[0029] S4. Mix the conditioner intermediate with the filter residue, boron-magnesium mud, humus, and tannic acid, dry, granulate, and calcine to obtain the coal gangue soil conditioner.

[0030] The coal gangue soil conditioner comprises the following components in parts by weight: 60 parts of conditioner intermediate, 15 parts of filter residue, 20 parts of boron-magnesium mud, 15 parts of humus, and 5 parts of tannic acid.

[0031] The alkali solution is a sodium hydroxide solution with a mass fraction of 10%.

[0032] The sodium citrate solution is a solution with a mass fraction of 8%.

[0033] The conditioner intermediate comprises the following components in parts by weight: 50 parts of filtrate, 40 parts of dolomite powder, and 25 parts of magnesite powder.

[0034] The fineness of the dolomite powder is 50 - 150 mesh, and the fineness of the magnesite powder is 100 - 200 mesh.

[0035] The temperature of ball mill grinding is 55 °C, and the time of ball mill grinding is 10 min.

[0036] In step S4, the drying temperature is 150 °C, the granulation particle size is 1.5 mm, and the calcination temperature in step S4 is 350 °C.

[0037] Example 2

[0038] A coal gangue soil conditioner and its production method

[0039] The production method comprises the same steps as those in Example 1.

[0040] The coal gangue soil conditioner comprises the following components in parts by weight: 80 parts of conditioner intermediate, 20 parts of filter residue, 30 parts of boron-magnesium mud, 40 parts of humus, and 12 parts of tannic acid.

[0041] The alkali solution is a potassium hydroxide solution with a mass fraction of 20%.

[0042] The sodium citrate solution is a solution with a mass fraction of 15%.

[0043] The conditioner intermediate comprises the following components in parts by weight: 80 parts of filtrate, 60 parts of dolomite powder, and 45 parts of magnesite powder.

[0044] The fineness of the dolomite powder is 50 - 150 mesh, and the fineness of the magnesite powder is 100 - 200 mesh.

[0045] The temperature of ball mill grinding is 75 °C, and the time of ball mill grinding is 20 min.

[0046] In step S4, the drying temperature is 180 °C, the granulation particle size is 5 mm, and the calcination temperature in step S4 is 400 °C.

[0047] Example 3

[0048] A coal gangue soil conditioner and its production method

[0049] The steps included in the production method are the same as those in Example 1.

[0050] The coal gangue soil conditioner includes the following components by weight: 70 parts of conditioner intermediate, 18 parts of filter residue, 25 parts of boromagnesite mud, 25 parts of humus, and 8 parts of tannic acid.

[0051] The alkali solution is a sodium carbonate solution with a mass fraction of 15%.

[0052] The sodium citrate solution is a solution with a mass fraction of 12%.

[0053] The conditioner intermediate includes the following components by weight: 60 parts of filtrate, 50 parts of dolomite powder, and 30 parts of magnesite powder.

[0054] The fineness of the dolomite powder is 50 - 150 mesh, and the fineness of the magnesite powder is 100 - 200 mesh.

[0055] The temperature of ball mill grinding is 80°C, and the time of ball mill grinding is 15 min.

[0056] In step S4, the drying temperature is 170°C, the granulation particle size is 2 mm, and the calcination temperature in step S4 is 380°C.

[0057] Comparative Example 1

[0058] The difference between this comparative example and Example 1 is that an equal amount of dolomite powder is used to replace the magnesite powder, and the other components, component contents, and steps included in the preparation process are the same as those in Example 1.

[0059] Comparative Example 2

[0060] The difference between this comparative example and Example 1 is that an equal amount of magnesite powder is used to replace the dolomite powder, and the other components, component contents, and steps included in the preparation process are the same as those in Example 1.

[0061] Result analysis

[0062] According to the application amount of 100 kg per mu, after applying the coal gangue soil conditioners prepared in each example and comparative example and then ploughing, mix them evenly with the 20 - cm plough layer soil, and detect the soil pH value after 15, 30, and 45 days respectively. The results are shown in Figure 1 .

[0063] From Figure 1It can be seen that the coal gangue soil conditioner prepared by the present invention has the characteristic of weak alkalinity, which can neutralize the acidic substances in the soil, adjust the pH value of the soil, and make it tend to be neutral or slightly alkaline. This not only helps to improve the structure and texture of the soil, enhance the water and fertilizer retention capacity of the soil, but also effectively alleviates the problem of crop growth limitation caused by soil acidification.

[0064] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

[0065] The above description of the present invention and its implementation manners is not restrictive. What is shown in the drawings is only one of the implementation manners of the present invention, and the actual application is not limited thereto. Generally speaking, if those of ordinary skill in the art are inspired by it and design similar ways and embodiments to this technical solution without creative efforts without departing from the purpose of the present invention, they shall fall within the protection scope of the present invention.

Claims

1. A coal gangue soil conditioner and a production method thereof, characterized in that: The steps include: S1, adding coal gangue into a ball mill for grinding, passing through a 150-mesh sieve, and obtaining a first coal gangue powder; S2, leaching the first gangue powder with an alkaline solution, passing it through a 150-mesh sieve again, and drying it to obtain a second gangue powder; S3, leaching the second coal gangue powder with a sodium citrate solution, filtering to obtain a filtrate and a filter residue, adding dolomite powder and magnesite powder to the filtrate, stirring at 50° C. for 1 h, and obtaining a conditioning agent intermediate after the reaction is completed; S4, mixing the conditioning agent intermediate with filter residue, boron magnesium mud, humus, and tannic acid, drying, granulating, and calcining to obtain the coal gangue soil conditioning agent.

2. The method for producing a coal gangue soil conditioner according to claim 1, characterized in that: The coal gangue soil conditioner comprises the following components in parts by weight: 60-80 parts of a conditioner intermediate, 15-20 parts of filter residue, 20-30 parts of boron magnesium mud, 15-40 parts of humus, and 5-12 parts of tannic acid.

3. The method for producing a coal gangue soil conditioner according to claim 2, characterized in that: The alkaline solution is a solution of one of sodium hydroxide, potassium hydroxide, cesium hydroxide, sodium carbonate, potassium carbonate and cesium carbonate.

4. The method for producing a coal gangue soil conditioner according to claim 3, characterized in that: The alkaline solution is a solution with a mass fraction of 10-20%.

5. The method for producing a coal gangue soil conditioner according to claim 4, characterized in that: The sodium citrate solution is a solution with a mass fraction of 8-15%.

6. The method for producing a coal gangue soil conditioner according to claim 5, characterized in that: The conditioning agent intermediate comprises the following components in parts by weight: 50-80 parts of filtrate, 40-60 parts of dolomite powder, and 25-45 parts of magnesite powder.

7. The method for producing a coal gangue soil conditioner according to claim 6, characterized in that: The fineness of the dolomite powder is 50-150 meshes, and the fineness of the magnesite powder is 100-200 meshes.

8. The method for producing a coal gangue soil conditioner according to claim 7, characterized in that: The grinding temperature of the ball mill is 55-75° C., and the grinding time of the ball mill is 10-20 min.

9. The method for producing a coal gangue soil conditioner according to claim 8, characterized in that: The drying temperature in step S4 is 150-180°C, the granulation particle size in step S4 is 1.5-5mm, and the calcination temperature in step S4 is 350-400°C.

10. A coal gangue soil conditioner, characterized in that: Produced according to the production method according to any one of claims 1 to 9.

Images