Preparation process and application of multifunctional slow-release saline-alkali soil conditioner

Abstract

The invention relates to the technical field of saline-alkali soil improvement, and particularly discloses a preparation process and application of a multifunctional slow-release saline-alkali soil conditioner. The preparation process comprises the following steps: (1) uniformly mixing alginic acid powder, ardealite powder, carbon powder and water to form a wet material, then putting the wet material into a closed container, and carrying out heating and heat preservation treatment to obtain a precursor; and (2) standing the precursor at normal temperature, and then crushing the precursor to obtain the soil conditioner. The soil conditioner prepared by the process disclosed by the invention not only can more efficiently and quickly fix sodium, potassium, calcium and magnesium ions in soil, but also can reduce the content of carbonate ions, so that the salt content of the soil is reduced, and the alkalinity of the soil is reduced. In addition, the soil conditioner disclosed by the invention is also beneficial to relieving the alkali and salt returning phenomenon of the soil, and the use amount of the conditioner in the subsequent continuous soil improvement process is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of saline-alkali soil improvement, and in particular to a preparation process and application of a multifunctional slow-release saline-alkali soil conditioner. Background Art

[0002] Saline-alkali land refers to a type of land that contains too much salt and alkaline substances in the soil, resulting in a decline in land productivity and deterioration of the ecological environment. According to incomplete statistics, the area of ​​saline-alkali land in the world exceeds 900 million hectares, of which my country accounts for more than 10%. These large saline-alkali lands are widely distributed in Northeast my country, North China, Northwest China and other regions. Since most crops usually have difficulty surviving in saline-alkali land, even if they can survive, they will have a large reduction in production, which seriously affects agricultural production and the ecological environment. Therefore, the improvement of saline-alkali land soil is crucial. The reason why saline-alkali land is characterized by high salt and high alkalinity is mainly because saline-alkali land contains a large amount of sodium, potassium, calcium, magnesium and carbonates, sulfates, and chlorides formed. For example, neutral salts such as sodium sulfate, potassium sulfate, and calcium chloride make the soil highly saline, and alkaline salts such as sodium carbonate and potassium carbonate make the soil highly alkaline. Since sodium and potassium ions are difficult to fix from the soil, a large amount of water washing is required to de-alkali the soil, which not only consumes a large amount of water and produces a large amount of wastewater, but also requires a huge amount of engineering. The method of improving saline-alkali land through plants or microorganisms has a long cycle and slow results. Therefore, there is an urgent need to explore efficient and long-term saline-alkali land soil improvement technology. Summary of the invention

[0003] In view of the above problems, the present invention provides a preparation process and application of a multifunctional slow-release saline-alkali soil conditioner, which can not only more efficiently and quickly fix sodium, potassium, calcium and magnesium ions in the soil, but also reduce the content of carbonate ions, thereby reducing both the salt content of the soil and the alkalinity of the soil. Specifically, the technical solution of the present invention is as follows.

[0004] First, the present invention discloses a preparation process of a multifunctional slow-release saline-alkali soil conditioner, comprising the following steps: (1) Alginate powder, phosphogypsum powder, carbon powder and water are uniformly mixed to form a wet material, and then the wet material is placed in a sealed container for heating and heat preservation treatment, and a precursor is obtained after completion.

[0005] (2) The precursor is allowed to stand at room temperature, and then crushed to obtain the soil conditioner.

[0006] Furthermore, in step (1), the mass ratio of the alginate powder, the phosphogypsum powder and the carbon powder is 1-2.5 g: 4-7 g: 2-3 g.

[0007] Furthermore, in step (1), the material-liquid ratio of the alginate powder, phosphogypsum powder, carbon powder and water is 1 g: 3-4.2 g. Optionally, the fineness of the carbon powder is 20-40 mesh.

[0008] Furthermore, in step (1), the heating and heat preservation temperature is 150-220° C., and the time is 1-3 hours.

[0009] Furthermore, in step (1), the pressure in the sealed container is 0.35-0.6 MPa.

[0010] Furthermore, in step (1), the wet material further contains sugar cane molasses. Optionally, the sugar cane molasses accounts for 10-14% of the total mass of the alginate powder, phosphogypsum powder and carbon powder.

[0011] Furthermore, in step (2), the crushing is performed after standing for 5 to 7 days to obtain a soil conditioner.

[0012] Furthermore, in step (2), the particle size of the soil conditioner is 1-5 mm.

[0013] Secondly, the present invention discloses the application of the multifunctional slow-release saline-alkali soil conditioner: the conditioner is applied to saline-alkali soil and stirred evenly, and then water is sprinkled to moisten the soil and the soil is allowed to stand.

[0014] Furthermore, the application amount of the improver is 230~350kg / mu.

[0015] Furthermore, the standing time after watering and wetting is 7 to 10 days. Optionally, watering and wetting is performed every 2 to 3 days.

[0016] Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects: The soil conditioner of the present invention uses alginic acid powder, phosphogypsum powder, carbon powder and molasses as raw materials, and the above raw materials are mixed and pretreated at high temperature and high pressure. In this process, the carbon powder is activated by the acidic environment provided by the phosphogypsum, and the adsorption performance of the carbon powder is improved, thereby helping to improve the desalination ability of the conditioner to the soil. Further, the present invention also uses the hydration and gelling characteristics of the phosphogypsum to cement the components together to form a conditioner that can desalinate and dealkalize the soil. When this conditioner enters the soil, on the one hand, carbonate, bicarbonate, sodium, potassium, calcium and magnesium ions in the soil enter the conditioner under the adsorption action of the carbon powder, and the phosphoric acid contained in the phosphogypsum is acidic. After reacting with the carbonate and bicarbonate, it is converted into carbon dioxide and water to be removed, thereby quickly reducing the alkalinity of the soil. At the same time, phosphorus is provided to the soil, which helps to improve the nutrition of the soil. On the other hand, the alginic acid reacts with carbonate and bicarbonate in the alkaline environment of the soil to form sodium alginate and potassium alginate, and the carbonate and bicarbonate are converted into carbon dioxide and water. The sodium alginate and potassium alginate are cross-linked to form a gel-like substance under the action of calcium and magnesium ions. Since this substance is insoluble in water, the simultaneous solidification of sodium, potassium, calcium and magnesium ions is achieved. After the above-mentioned action, the salt content in the soil can be quickly reduced, and since carbonate, bicarbonate and sodium and potassium form water-soluble salts, which are the main sources of high alkalinity in the soil, the removal and solidification of these ions also effectively reduce the alkalinity of the soil. On the other hand, as the alkalinity of the soil decreases after desalination and de-alkali, the reaction of the alginic acid gradually stops, and the gelling material forms a slow-release structure in the void channel inside the modifier, thereby avoiding excessive consumption of the modifier. When the soil returns to alkali again, the reaction of the alginic acid starts to start, which helps to alleviate the phenomenon of soil alkali and salt return, and reduces the amount of modifier used in the subsequent process of continuing to improve the soil. In addition, the sugarcane molasses can not only reduce the alkalinity of the soil, but also provide nutrients for microorganisms in the soil, promote the reproduction of microorganisms in the soil, reduce soil compaction, and improve soil fertility. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein: Figure 1 This is a wet sample image prepared in Example 1 below.

[0018] Figure 2 This is a sample picture of the slow-release saline-alkali soil conditioner prepared in the following Example 1. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples without specifying specific conditions are usually carried out under conventional conditions or under conditions recommended by the manufacturer.

[0020] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. The reagents or raw materials used in the present invention can be purchased through conventional channels. Unless otherwise specified, the reagents or raw materials used in the present invention are used in a conventional manner in the art or in accordance with the product instructions.

[0021] In addition, any method and material similar or equivalent to the content described above can be applied to the method of the present invention. The present invention is further described in conjunction with the accompanying drawings and specific implementation methods. The preferred implementation methods and materials described in the present invention are only for demonstration purposes.

[0022] Embodiment 1: A preparation process of a multifunctional slow-release saline-alkali soil conditioner comprises the following steps: (1) Mix alginate powder, phosphogypsum powder and 40-mesh carbon powder in a mass ratio of 2g:5g:2.5g and stir evenly to form a mixed powder. Then add 4 times the mass of the mixed powder and stir quickly to form a wet material (such as Figure 1 As shown), the wet material is then placed in a reaction container, sealed and heated to 180° C. for 1.5 hours, wherein the pressure is set to 0.6 MPa, and a precursor is obtained after completion.

[0023] (2) After the precursor is taken out of the reaction container, it is allowed to stand at room temperature for 7 days, and then crushed to screen out particles with a particle size of 1 to 3 mm. The soil conditioner, such as Figure 2 shown.

[0024] The soil conditioner prepared in this embodiment was added to a test saline-alkali soil with a pH of 8.74 at an addition rate of 300 kg / mu, stirred evenly and sprinkled with water to moisten it. Then it was left to stand for 7 days, during which it was sprinkled with water every 2 days. The pH-a of the improved soil and the salt content (CO3 2- 、HCO3 - , K + 、Na + , Ca 2+ Mg 2+ ), calculate the reduction of salt content / desalination rate a. In addition, the pH-b and salt content of the improved soil were measured again after an interval of 60 days, and the desalination rate b was calculated. The results are shown in the following table: .

[0025] Embodiment 2: A preparation process of a multifunctional slow-release saline-alkali soil conditioner comprises the following steps: (1) Alginate powder, phosphogypsum powder and 20-mesh carbon powder are mixed in a mass ratio of 1g:4g:2g and stirred evenly to form a mixed powder. Then, 10% of the mass of the mixed powder and 3 times the mass of the mixed powder are added with clean water and stirred evenly to form a wet material. The wet material is then placed in a reaction container, sealed and heated to 150°C for 3 hours, wherein the pressure is set to 0.5 MPa, and a precursor is obtained after completion.

[0026] (2) After the precursor is taken out from the reaction container, it is allowed to stand at room temperature for 6 days, and then crushed to screen out particles with a particle size of 3 to 5 mm, the soil conditioner.

[0027] The soil conditioner prepared in this example was added to a test saline-alkali soil with a pH of 8.74 (the same as in Example 1) at an addition amount of 350 kg / mu, stirred evenly, and then sprinkled with water to moisten it. Then it was left to stand for 10 days, during which it was sprinkled with water every 3 days. The pH-a of the improved soil and the salt content (CO3 2- 、HCO3 - , K + 、Na + , Ca 2+ Mg 2+ ), calculate the reduction of salt content / desalination rate a. In addition, the pH-b and salt content of the improved soil were measured again after an interval of 60 days, and the desalination rate b was calculated. The results are shown in the following table: .

[0028] Embodiment 3: A preparation process of a multifunctional slow-release saline-alkali soil conditioner comprises the following steps: (1) Alginate powder, phosphogypsum powder and 20-mesh carbon powder were mixed in a mass ratio of 2.5 g:7 g:3 g and stirred evenly to form a mixed powder. Then, 14% of the mass of the mixed powder and 4.2 times the mass of the mixed powder were added with clean water and stirred evenly to form a wet material. The wet material was then placed in a reaction container, sealed and heated to 220° C. for 1 hour, with the pressure set to 0.35 MPa. After completion, a precursor was obtained.

[0029] (2) After the precursor is taken out from the reaction container, it is allowed to stand at room temperature for 5 days, and then crushed to screen out particles with a particle size of 1 to 4 mm, the soil conditioner.

[0030] The soil conditioner prepared in this example was added to a test saline-alkali soil with a pH of 8.74 (the same as in Example 1) at an addition amount of 230 kg / mu, stirred evenly, and then sprinkled with water to moisten it. Then it was left to stand for 8 days, during which it was sprinkled with water every 3 days. The pH-a of the improved soil and the salt content (CO3 2- 、HCO3 - , K + 、Na + , Ca 2+ Mg 2+ ), calculate the reduction of salt content / desalination rate a. In addition, the pH-b and salt content of the improved soil were measured again after an interval of 60 days, and the desalination rate b was calculated. The results are shown in the following table: .

[0031] Embodiment 4: A preparation process of a multifunctional slow-release saline-alkali soil conditioner comprises the following steps: (1) Phosphogypsum powder and 40-mesh carbon powder were mixed in a mass ratio of 5 g:2.5 g and stirred to form a mixed powder. Then, clean water 4 times the mass of the mixed powder was added and quickly stirred to form a wet material. The wet material was then placed in a reaction container, sealed and heated to 180° C. for 1.5 hours, wherein the pressure was set to 0.6 MPa, and a precursor was obtained after completion.

[0032] (2) After taking the precursor out of the reaction container, leaving it to stand at room temperature for 7 days, and then crushing it to screen out particles with a particle size of 1 to 3 mm, the soil conditioner.

[0033] The soil conditioner prepared in this example was added to the same saline-alkali soil as in Example 1 at an addition rate of 300 kg / mu, stirred evenly and then sprinkled with water to moisten. Then it was left to stand for 7 days, during which it was sprinkled with water every 2 days. Then the pH-a of the improved soil and the salt content (CO3 2- 、HCO3 - , K + 、Na + , Ca 2+ Mg 2+ ), calculate the reduction of salt content / desalination rate a. In addition, the pH-b and salt content of the improved soil were measured again after an interval of 60 days, and the desalination rate b was calculated. The results are shown in the following table: .

[0034] Embodiment 5: A preparation process of a multifunctional slow-release saline-alkali soil conditioner comprises the following steps: (1) Alginate powder and phosphogypsum powder were mixed in a mass ratio of 2.5 g:7 g and stirred evenly to form a mixed powder. Then, 14% of the mass of the mixed powder and 4.2 times the mass of the mixed powder were added with clean water and stirred evenly to form a wet material. The wet material was then placed in a reaction container, sealed and heated to 220° C. for 1 hour, with the pressure set to 0.35 MPa. After completion, a precursor was obtained.

[0035] (2) After the precursor is taken out from the reaction container, it is allowed to stand at room temperature for 5 days, and then crushed to screen out particles with a particle size of 1 to 4 mm, the soil conditioner.

[0036] The soil conditioner prepared in this example was added to the same saline-alkali soil as in Example 1 at an addition rate of 300 kg / mu, stirred evenly and then sprinkled with water to moisten. The soil was then left to stand for 8 days, during which it was sprinkled with water every 3 days. The pH-a of the improved soil and the salt content (CO3 2- 、HCO3 - , K + 、Na + , Ca 2+ Mg 2+ ), calculate the reduction of salt content / desalination rate a. In addition, the pH-b and salt content of the improved soil were measured again after an interval of 60 days, and the desalination rate b was calculated. The results are shown in the following table: .

[0037] Embodiment 6: A preparation process of a multifunctional slow-release saline-alkali soil conditioner comprises the following steps: (1) Alginate powder, phosphogypsum powder and 20-mesh carbon powder are mixed in a mass ratio of 1g:4g:2g and stirred evenly to form a mixed powder. Then, 10% of the mass of the mixed powder and 3 times the mass of the mixed powder are added with clean water and stirred evenly to form a wet material.

[0038] (2) The wet material is allowed to stand at room temperature for 6 days, and then crushed to separate particles with a particle size of 3 to 5 mm, which is the soil conditioner.

[0039] The soil conditioner prepared in this example was added to the same saline-alkali soil as in Example 1 at an addition rate of 300 kg / mu, stirred evenly and then sprinkled with water to moisten. Then it was left to stand for 10 days, during which it was sprinkled with water every 3 days. Then the pH-a of the improved soil and the salt content (CO3 2- 、HCO3 - , K + 、Na +, Ca 2+ Mg 2+ ), calculate the reduction of salt content / desalination rate a. In addition, the pH-b and salt content of the improved soil were measured again after an interval of 60 days, and the desalination rate b was calculated. The results are shown in the following table: .

[0040] Embodiment 7: A preparation process of a multifunctional slow-release saline-alkali soil conditioner comprises the following steps: (1) Alginate powder, chemically pure gypsum powder (component: CaSO4·2H2O) and 40-mesh carbon powder were mixed in a mass ratio of 2g:5g:2.5g and stirred to form a mixed powder. Then, clean water 4 times the mass of the mixed powder was added and quickly stirred to form a wet material. The wet material was then placed in a reaction container, sealed and heated to 180°C for 1.5 hours, wherein the pressure was set to 0.6 MPa, and a precursor was obtained after completion.

[0041] (2) After taking the precursor out of the reaction container, leaving it to stand at room temperature for 7 days, and then crushing it to screen out particles with a particle size of 1 to 3 mm, the soil conditioner.

[0042] The soil conditioner prepared in this example was added to the same saline-alkali soil as in Example 1 at an addition rate of 300 kg / mu, stirred evenly and then sprinkled with water to moisten. Then it was left to stand for 7 days, during which it was sprinkled with water every 2 days. Then the pH-a of the improved soil and the salt content (CO3 2- 、HCO3 - , K + 、Na + , Ca 2+ Mg 2+ ), calculate the reduction of salt content / desalination rate a. In addition, the pH-b and salt content of the improved soil were measured again after an interval of 60 days, and the desalination rate b was calculated. The results are shown in the following table: .

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A preparation process of a multifunctional slow-release saline-alkali soil conditioner, characterized in that: The steps include: (1) mixing alginate powder, phosphogypsum powder, carbon powder and water to form a wet material, and then placing the wet material in a sealed container for heating and heat preservation treatment to obtain a precursor; (2) The precursor is allowed to stand at room temperature, and then crushed to obtain the soil conditioner.

2. The preparation process of the multifunctional slow-release saline-alkali soil conditioner according to claim 1, characterized in that: In step (1), the mass ratio of the alginate powder, the phosphogypsum powder and the carbon powder is 1-2.5 g: 4-7 g: 2-3 g.

3. The preparation process of the multifunctional slow-release saline-alkali soil conditioner according to claim 1, characterized in that: In step (1), the material-liquid ratio of the alginate powder, phosphogypsum powder, carbon powder and water is 1g:3-4.2g; optionally, in step (1), the fineness of the carbon powder is 20-40 mesh.

4. The preparation process of the multifunctional slow-release saline-alkali soil conditioner according to claim 1, characterized in that: In step (1), the heating and heat preservation temperature is 150-220° C., and the time is 1-3 hours.

5. The preparation process of the multifunctional slow-release saline-alkali soil conditioner according to claim 1, characterized in that: In step (1), the pressure in the sealed container is 0.35-0.6 MPa.

6. The preparation process of the multifunctional slow-release saline-alkali soil conditioner according to claim 1, characterized in that: In step (1), the wet material further contains sugar cane molasses; optionally, the sugar cane molasses accounts for 10-14% of the total mass of the alginate powder, phosphogypsum powder and carbon powder.

7. The preparation process of the multifunctional slow-release saline-alkali soil conditioner according to claim 1, characterized in that: In step (2), the crushing is performed after standing for 5 to 7 days to obtain the soil conditioner.

8. The preparation process of the multifunctional slow-release saline-alkali soil conditioner according to any one of claims 1 to 7, characterized in that: In step (2), the particle size of the soil conditioner is 1-5 mm.

9. Application of the multifunctional slow-release saline-alkali soil conditioner obtained by the preparation process according to any one of claims 1 to 8, characterized in that: The improver is applied to the saline-alkali soil and stirred evenly, and then water is sprinkled to moisten the soil and the soil is allowed to stand.

10. The use according to claim 9, characterized in that: The application amount of the improver is 230-350 kg / mu; optionally, the standing time after watering is 7-10 days; optionally, watering is performed every 2-3 days.

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