Preparation process of saline-alkali soil conditioner capable of preventing salt and alkali return

Abstract

The invention relates to the technical field of saline-alkali land improvement, and particularly discloses a saline-alkali land soil conditioner preparation process capable of preventing salt and alkali return, which comprises the following steps: (1) uniformly mixing vinegar residue powder, zeolite powder and molasses aqueous solution, granulating, adding wood flour into the obtained particles for coating, separating out the particles after coating, and drying to obtain dried particles; and obtaining the core for later use. (2) uniformly mixing the calcium silicate or pseudo-wollastonite powder, zeolite powder and desulfurized gypsum powder, adding water, and uniformly stirring to form slurry; and coating the surface of the inner core with the slurry, and drying to obtain the modifier. The modifier prepared by the process disclosed by the invention not only can reduce the alkali content in the saline alkali soil and improve the microbial environment of the soil, but also can prevent the absorbed salt from returning to the soil to cause alkali and salt return, so that the improvement effect is more lasting.

Description

Technical Field

[0001] The invention relates to the technical field of saline-alkali land improvement, and in particular to a preparation process of a saline-alkali land soil conditioner capable of preventing salt and alkali return. Background Art

[0002] Saline-alkali land generally has high salt content or alkalinity, poor soil structure, easy compaction, low organic matter content and poor nutrients. It is a degraded soil with poor properties and low fertility, which seriously affects crop growth. Saline-alkali land is mostly formed in arid climate, high groundwater level, low-lying terrain and coastal areas. Saline-alkali land is widely present in Northwest, Northeast and North China of my country. These areas are in arid or semi-arid state all year round, with low rainfall and high evaporation, resulting in a large accumulation of salt in the soil and causing salinization. The comprehensive transformation and utilization of saline-alkali land is an important aspect of natural resource protection and improvement. It is an important strategic reserve resource for improving the quality and expanding the capacity of my country's cultivated land, and it is a "potential granary" for increasing my country's grain production.

[0003] Chemical improvement technology is currently one of the important methods for improving saline-alkali land. It usually uses chemical substances such as desulfurized gypsum and phosphogypsum to neutralize the soil alkalinity and reduce the soil salinity. However, the effect of this method is not long-lasting, and it is easy to return to salt and alkali. The above-mentioned chemical substances need to be added regularly to maintain the improvement effect. However, with the continuous accumulation of the amount of application, the excessive amount of these chemical substances can easily destroy the ecological balance of the soil, affect the living environment of soil microorganisms, and produce adverse effects instead. Summary of the invention

[0004] The present invention provides a preparation process of a saline-alkali soil conditioner for preventing salt and alkali return, which can not only reduce the alkali content in saline-alkali soil and improve the microbial environment of the soil, but also prevent the absorbed salt from returning to the soil to cause salt and alkali return, thereby making the improvement effect more durable. The technical solution of the present invention is as follows.

[0005] A preparation process of a saline-alkali soil conditioner for preventing salt and alkali return comprises the following steps: (1) Mix vinegar residue powder, zeolite powder and molasses aqueous solution evenly and then granulate them. Then add wood powder to the obtained granules for coating. After the granules are separated and dried, the core is obtained and set aside.

[0006] (2) Mix wollastonite or pseudowollastonite powder, zeolite powder and desulfurized gypsum powder evenly, add water and mix well to form slurry. Then wrap the slurry on the surface of the core, and after drying, the improver can be obtained.

[0007] Furthermore, in step (1), the ratio of the vinegar residue powder, the zeolite powder and the molasses aqueous solution is 60-80 parts by weight: 30-45 parts by weight: 15-22 parts by weight.

[0008] Further, in step (1), the volume ratio of molasses to water in the molasses aqueous solution is 1:1.3 - 1.7.

[0009] Further, in step (1), the fineness of the zeolite powder is 10 - 30 mesh.

[0010] Further, in step (1), the mass ratio of the particulate matter to the wood powder is 1:0.15 - 0.25. Optionally, the fineness of the wood powder is 30 - 50 mesh.

[0011] Further, in step (1), the drying temperature is 60 - 80 °C and the time is 1 - 1.5 hours.

[0012] Further, in step (1), the particle size of the core is 0.5 - 2 cm, and particulate matter with any other suitable particle size can also be selected according to needs.

[0013] Further, in step (2), the ratio of the wollastonite or pseudowollastonite powder, zeolite powder, and desulfurized gypsum powder is 100 - 130 parts by weight: 40 - 58 parts by weight: 30 - 41 parts by weight. Optionally, the fineness of the powders is all 80 - 120 mesh.

[0014] Further, in step (2), the solid content of the slurry is 50 - 60 wt.%.

[0015] Further, in step (2), according to the mass ratio of the slurry to the core of 0.35 - 0.5:1, apply the slurry to the core and tumble evenly, then separate the particulate matter, and after drying, the modified agent can be obtained.

[0016] Further, in step (2), the drying temperature is 50 - 60 °C and the time is 1 - 1.5 hours.

[0017] Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects: The saline-alkali soil conditioner of the present invention uses a mixture of vinegar residue, zeolite powder, and molasses as the core, and is coated with a shell formed by wollastonite or pseudowollastonite, zeolite powder, and desulfurized gypsum powder on its surface. After adding the conditioner with such a structure and component characteristics of the present invention to the saline-alkali soil, on the one hand, the vinegar residue and molasses in the core release acidic substances to neutralize the alkalinity of the soil, which can quickly reduce the soil alkalinity. At the same time, the molasses can provide a large amount of organic matter lacking in saline-alkali soil for the reproduction of microorganisms in the soil, increase soil fertility, reduce soil compaction, and improve soil structure. On the other hand, the core uses its adsorption effect to absorb and concentrate the salts in the soil, so as to achieve the purpose of quickly reducing the salt content in the soil. On the other hand, wollastonite or pseudowollastonite in the shell undergoes a carbonization reaction with carbonate radicals in the soil in the presence of moisture to form calcium carbonate and nano-silica, so that wollastonite or pseudowollastonite solidifies the carbonate radicals in the form of insoluble calcium carbonate, reducing the main alkaline source carbonate ions in the soil, because the carbonate ions hydrolyze to produce hydroxide ions, resulting in the alkalinity of the soil. In addition, after the wollastonite or pseudowollastonite is consumed, the nano-silica and calcium ions released by calcium sulfate formed gradually react with calcium hydroxide formed by hydroxide ions in the soil to form hydrated calcium silicate gel components, which can effectively prevent the salts adsorbed in the core from re-entering the soil and causing the phenomenon of salt return and alkali return after sealing the shell. In addition, the conditioner can also be separated from the soil by screening, so as to completely avoid the salts in the core from re-entering the soil and causing salt return and alkali return. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings forming a part of this specification are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention. Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings, in which: Figure 1 It is a sample diagram of the saline-alkali soil conditioner prepared for Example 1 below.

[0019] Figure 2 It is a sample diagram of the saline-alkali soil conditioner prepared for Example 2 below. DETAILED DESCRIPTION OF THE INVENTION

[0020] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. The experimental methods without specific conditions noted in the following embodiments are generally carried out under conventional conditions or according to the conditions recommended by the manufacturer.

[0021] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to persons skilled in the art. The reagents or raw materials used in the present invention can all be obtained by conventional means of purchase. Unless otherwise specified, the reagents or raw materials used in the present invention are used in accordance with the conventional methods in the art or in accordance with the product instructions.

[0022] In addition, any methods and materials similar or equivalent to the described content can be applied to the method of the present invention. The present invention will be further described below in conjunction with the accompanying drawings of the specification and specific embodiments. The preferred implementation methods and materials described in the present invention are only for demonstration purposes.

[0023] Example 1: A preparation process of a saline-alkali soil conditioner for preventing salt and alkali return, comprising the following steps: (1) Mix molasses and water according to a volume ratio of 1:1.3 and stir evenly to obtain a molasses aqueous solution. Mix the vinegar residue powder with a fineness of 20 mesh, the zeolite powder with a fineness of 20 mesh, and the molasses aqueous solution in a ratio of 70 parts by weight: 40 parts by weight: 16 parts by weight, stir evenly, and then granulate. Then add wood powder with a mesh size of 50 to the obtained particulate matter, and the mass ratio of the two is 1:0.18. Roll to evenly coat the surface of the particulate matter with wood powder, and then separate the particulate matter, and dry it at 60 °C for 1.5 hours to obtain a core with a particle size distribution between 1 and 1.5 cm for standby.

[0024] (2) Mix wollastonite powder, zeolite powder, and desulfurized gypsum powder with a fineness of 100 mesh in a ratio of 110 parts by weight: 48 parts by weight: 36 parts by weight, stir evenly, and then add water and stir evenly to obtain a slurry with a solid content of 55 wt.%. Then, according to a mass ratio of the slurry to the core of 0.42:1, apply the slurry to the rolling core and continue to roll to form a uniform coating layer on the surface of the core. Then dry the obtained particulate matter at 60 °C for 1.5 hours to obtain the saline-alkali soil conditioner (as Figure 1 shown).

[0025] Performance test: (1) Add the conditioner prepared in this example to saline-alkali soil with a total salt content (including sodium chloride, potassium chloride, sodium sulfate, and sodium carbonate) of 10.27 g per kilogram of soil and a pH of 8.59. The addition amount is 25% of the soil mass. After stirring evenly, sprinkle water into the soil according to a moisture content of 20%. Then, test the total salt content and pH value in the soil after 15 days and 45 days (while maintaining the above moisture content during the process) (while maintaining the above moisture content during the process), and calculate the salt removal rate. The results are shown in the following table. It can be seen that after the improvement, the salt content and alkalinity of the soil have decreased significantly, and the phenomenon of salt and alkali return caused by the re-entry of the salt absorbed in the conditioner into the soil has been effectively overcome.

[0026]

[0027] Example 2: A preparation process of a saline-alkali soil conditioner for preventing salt and alkali return, comprising the following steps: (1) Mix molasses and water in a volume ratio of 1:1.5 and stir evenly to obtain a molasses aqueous solution. Mix vinasse powder with a fineness of 30 mesh, zeolite powder with a fineness of 20 mesh, and the molasses aqueous solution in a ratio of 80 parts by weight: 45 parts by weight: 22 parts by weight, stir evenly, and then granulate. Then add wood powder with a mesh size of 30 to the obtained particulate matter, with a mass ratio of the two being 1:0.25, and roll to evenly coat the surface of the particulate matter with wood powder. Then separate the particulate matter and dry it at 70 °C for 1.0 hour to obtain a core with a particle size distribution between 1.5 and 2 cm for standby.

[0028] (2) Mix wollastonite powder, zeolite powder, and desulfurized gypsum powder, all with a fineness of 120 mesh, in a ratio of 100 parts by weight: 40 parts by weight: 30 parts by weight, stir evenly, and then add water and stir evenly to obtain a slurry with a solid content of 60 wt.%. Then, according to a mass ratio of the slurry to the core of 0.35:1, apply the slurry to the rolling core and continue to roll to form a uniform coating layer on the surface of the core. Then dry the obtained particulate matter at 60 °C for 1.0 hour to obtain the saline-alkali soil conditioner (as Figure 2 shown).

[0029] Performance test: (1) Add the conditioner prepared in this example to saline-alkali soil with a total salt content (including sodium chloride, potassium chloride, sodium sulfate, and sodium carbonate) of 10.27 g per kilogram of soil and a pH of 8.59. The addition amount is 25% of the soil mass. After stirring evenly, sprinkle water into the soil according to a water content ratio of 20%. Then, test the total salt content and pH value in the soil after 15 days and 45 days (while maintaining the above water content during the process), and calculate the salt removal rate. The results are shown in the following table. It can be seen that after improvement, the salt content and alkalinity of the soil have decreased significantly, and the phenomenon of salt and alkali return caused by the salt absorbed in the conditioner re-entering the soil has been effectively overcome.

[0030]

[0031] Example 3: A preparation process of a saline-alkali soil conditioner for preventing salt and alkali return, comprising the following steps: (1) Mix molasses and water in a volume ratio of 1:1.7 and stir evenly to obtain a molasses aqueous solution. Mix vinasse powder with a fineness of 10 mesh, zeolite powder with a fineness of 10 mesh, and the molasses aqueous solution in a ratio of 60 parts by weight: 30 parts by weight: 15 parts by weight, stir evenly, and then granulate. Then add wood powder with a fineness of 40 mesh to the obtained particulate matter, with a mass ratio of the two being 1:0.15, roll to uniformly coat the surface of the particulate matter with wood powder, then separate the particulate matter, and dry it at 80 °C for 1.0 hour to obtain a core with a particle size distribution between 0.5 and 1.0 cm for standby.

[0032] (2) Mix wollastonite powder, zeolite powder, and desulfurized gypsum powder, all with a fineness of 80 mesh, in a ratio of 130 parts by weight: 58 parts by weight: 41 parts by weight, stir evenly, then add water and stir evenly to obtain a slurry with a solid content of 50 wt.%. Then, according to a mass ratio of the slurry to the core of 0.5:1, apply the slurry to the rolling core and continue to roll to form a uniform coating layer on the surface of the core. Then dry the obtained particulate matter at 50 °C for 1.5 hours to obtain a saline-alkali soil conditioner.

[0033] Performance test: (1) Add the conditioner prepared in this example to saline-alkali soil with a total salt content (including sodium chloride, potassium chloride, sodium sulfate, and sodium carbonate) of 10.27 g per kilogram of soil and a pH of 8.59. The addition amount is 25% of the soil mass. After stirring evenly, sprinkle water into the soil according to a water content ratio of 20%. Then, test the total salt content and pH value in the soil after 15 days and 45 days (while maintaining the above water content during the process), and calculate the salt removal rate. The results are shown in the following table. It can be seen that after improvement, the salt content and alkalinity of the soil have decreased significantly, and the phenomenon of salt and alkali returning due to the re-entry of the salt absorbed in the conditioner into the soil has been effectively overcome.

[0034]

[0035] Example 4: A preparation process for a saline-alkali soil conditioner that prevents salt and alkali return, comprising the following steps: (1) Mix molasses and water in a volume ratio of 1:1.3 and stir evenly to obtain a molasses aqueous solution. Mix zeolite powder with a fineness of 20 mesh and the molasses aqueous solution in a ratio of 110 parts by weight: 16 parts by weight, stir evenly, and then granulate. Then add wood powder with a fineness of 50 mesh to the obtained particulate matter, with a mass ratio of the two being 1:0.18, roll to uniformly coat the surface of the particulate matter with wood powder, then separate the particulate matter, and dry it at 60 °C for 1.5 hours to obtain a core with a particle size distribution between 1 and 1.5 cm for standby.

[0036] (2) Mix wollastonite powder, zeolite powder, and desulfurized gypsum powder, all with a fineness of 100 mesh, in a ratio of 110 parts by weight: 48 parts by weight: 36 parts by weight, and stir evenly. Then add water and stir evenly to obtain a slurry with a solid content of 55 wt.%. Then, according to the mass ratio of the slurry to the core of 0.42:1, apply the slurry to the rolling core and continue rolling to form a uniform coating layer on the surface of the core. Then dry the obtained particulate matter at 60°C for 1.5 hours to obtain the saline-alkali soil conditioner.

[0037] Performance test: (1) Add the conditioner prepared in this example to saline-alkali soil with a total salt content (including sodium chloride, potassium chloride, sodium sulfate, and sodium carbonate) of 10.27 g per kilogram of soil and a pH of 8.59. The addition amount is 25% of the soil mass. After stirring evenly, sprinkle water on the soil according to a moisture content of 20%. Then, test the total salt content and pH value in the soil after 15 days and 45 days (while maintaining the above moisture content during the process), and calculate the salt removal rate. The results are shown in the following table. It can be seen that although the effect of the conditioner prepared in this example on salt removal and alkalinity reduction in the soil has decreased, it shows good performance in preventing the salt in the conditioner from re-entering the soil and causing the problem of salt and alkali return.

[0038]

[0039] Example 5: A preparation process for a saline-alkali soil conditioner that prevents salt and alkali return, comprising the following steps: (1) Mix molasses and water in a volume ratio of 1:1.5 and stir evenly to obtain a molasses aqueous solution. Mix vinegar residue powder with a fineness of 30 mesh, zeolite powder with a fineness of 20 mesh, and the molasses aqueous solution in a ratio of 80 parts by weight: 45 parts by weight: 22 parts by weight, and stir evenly. Then granulate. Then add wood powder with a fineness of 30 mesh to the obtained particulate matter, and the mass ratio of the two is 1:0.25. Roll to evenly coat the surface of the particulate matter with wood powder, and then separate the particulate matter. Dry it at 70°C for 1.0 hour to obtain a core with a particle size distribution between 1.5 and 2 cm for standby.

[0040] (2) Mix zeolite powder and desulfurized gypsum powder, both with a fineness of 120 mesh, in a ratio of 140 parts by weight: 30 parts by weight, and stir evenly. Then add water and stir evenly to obtain a slurry with a solid content of 60 wt.%. Then, according to the mass ratio of the slurry to the core of 0.35:1, apply the slurry to the rolling core and continue rolling to form a uniform coating layer on the surface of the core. Then dry the obtained particulate matter at 60°C for 1.0 hour to obtain the saline-alkali soil conditioner.

[0041] Performance test: (1) Add the modifier prepared in this embodiment to saline-alkali soil with a total salt content (including sodium chloride, potassium chloride, sodium sulfate, and sodium carbonate) of 10.27 g per kilogram of soil and a pH of 8.59. The addition amount is 25% of the soil mass. After stirring evenly, sprinkle water into the soil at a water content ratio of 20%. Then, test the total salt content and pH value in the soil after 15 days and 45 days (while maintaining the above water content during the process), and calculate the salt removal rate. The results are shown in the following table. It can be seen that the modifier prepared in this embodiment has a significantly decreased effect on salt removal and alkalinity reduction in the soil, and moreover, it fails to effectively prevent the salt absorbed in the modifier from re-entering the soil, resulting in the phenomenon of salt and alkali return.

[0042]

[0043] Example 6: A preparation process for a saline-alkali soil modifier to prevent salt and alkali return, including the following steps: Mix molasses and water in a volume ratio of 1:1.7 and stir evenly to obtain a molasses aqueous solution. Mix vinegar residue powder with a fineness of 10 meshes, zeolite powder with a fineness of 10 meshes, and the molasses aqueous solution in a ratio of 60 parts by weight: 30 parts by weight: 15 parts by weight, stir evenly, and then granulate. Then, add wood powder with a fineness of 40 meshes to the obtained particulate matter, with a mass ratio of 1:0.15 between the two. Roll to evenly coat the surface of the particulate matter with wood powder, and then separate the particulate matter. Dry it at 80 °C for 1.0 hour to obtain a saline-alkali soil modifier with a particle size distribution between 0.5 and 1.0 cm.

[0044] Performance test: (1) Add the modifier prepared in this embodiment to saline-alkali soil with a total salt content (including sodium chloride, potassium chloride, sodium sulfate, and sodium carbonate) of 10.27 g per kilogram of soil and a pH of 8.59. The addition amount is 25% of the soil mass. After stirring evenly, sprinkle water into the soil at a water content ratio of 20%. Then, test the total salt content and pH value in the soil after 15 days and 45 days (while maintaining the above water content during the process), and calculate the salt removal rate. The results are shown in the following table. It can be seen that the modifier prepared in this embodiment has a significantly decreased effect on salt removal and alkalinity reduction in the soil, and moreover, an obvious phenomenon of salt and alkali return occurs.

[0045]

[0046] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation process of a saline-alkali soil conditioner for preventing salt and alkali return, characterized in that: The steps include: (1) mixing vinegar residue powder, zeolite powder and molasses aqueous solution uniformly and granulating the mixture, then adding wood powder to the obtained granules for coating, separating the granules and drying them to obtain the core for later use; (2) Mix wollastonite or pseudowollastonite powder, zeolite powder and desulfurized gypsum powder evenly, then add water and mix well to form a slurry; then wrap the slurry on the surface of the core, and after drying, the improver can be obtained.

2. The preparation process of the saline-alkali soil conditioner for preventing salt and alkali return according to claim 1, characterized in that: In step (1), the ratio of the vinegar residue powder, zeolite powder and molasses aqueous solution is 60-80 parts by weight: 30-45 parts by weight: 15-22 parts by weight; optionally, in step (1), the fineness of the zeolite powder is 10-30 mesh.

3. The preparation process of the saline-alkali soil conditioner for preventing salt and alkali return according to claim 1, characterized in that: In step (1), the volume ratio of molasses to water in the molasses aqueous solution is 1:1.3-1.

7.

4. The preparation process of the saline-alkali soil conditioner for preventing salt and alkali return according to claim 1, characterized in that: In step (1), the mass ratio of the particulate matter to the wood powder is 1:0.15-0.25; optionally, the fineness of the wood powder is 30-50 mesh.

5. The preparation process of the saline-alkali soil conditioner for preventing salt and alkali return according to claim 1, characterized in that: In step (1), the drying temperature is 60-80° C. and the drying time is 1-1.5 hours.

6. The preparation process of the saline-alkali soil conditioner for preventing salt and alkali return according to claim 1, characterized in that: In step (1), the particle size of the inner core is 0.5-2 cm.

7. The preparation process of the saline-alkali soil conditioner for preventing salt and alkali return according to claim 1, characterized in that: In step (2), the ratio of the wollastonite or pseudowollastonite powder, zeolite powder and desulfurized gypsum powder is 100-130 parts by weight: 40-58 parts by weight: 30-41 parts by weight; optionally, the fineness of the powder is 80-120 mesh.

8. The preparation process of the saline-alkali soil conditioner for preventing salt and alkali return according to claim 1, characterized in that: In step (2), the solid content of the slurry is 50-60 wt.%.

9. The process for preparing the saline-alkali soil conditioner for preventing salt and alkali return according to claim 1, characterized in that: In step (2), the slurry is applied to the inner core in a mass ratio of 0.35 to 0.5:1, and the slurry is rolled evenly, and then the particles are separated and dried to obtain the improver.

10. The process for preparing the saline-alkali soil conditioner for preventing salt and alkali return according to any one of claims 1 to 9, characterized in that: In step (2), the drying temperature is 50-60° C. and the drying time is 1-1.5 hours.

Images