A cured polysilicic acid sol, a method for preparing the same, and an application thereof

Abstract

The application relates to the technical field of crop planting, in particular to a solidified polysilicic acid sol and a preparation method and application thereof. + The preparation method comprises the following steps: removing Na in a sodium metasilicate aqueous solution by an ion exchange method to obtain a polysilicic acid solution; concentrating the polysilicic acid solution to obtain a neutral or weakly alkaline polysilicic acid colloidal solution, the mass percentage of silicon dioxide in the polysilicic acid colloidal solution being 25-40%; and solidifying the polysilicic acid colloidal solution by microorganisms to obtain a solidified polysilicic acid colloidal solution. The solidified polysilicic acid sol obtained by solidifying the polysilicic acid colloidal solution by the microbial agent has high stability, can coexist with other pesticide or fertilizer emulsion colloidal systems, and can realize 'one spraying and multiple application'. The solidified polysilicic acid sol provided by the application can significantly improve the utilization rate of silicon elements in the field of crop planting, and has important application value.

Description

Technical Field

[0001] This invention relates to the field of crop cultivation technology, and in particular to a cured polysilicic acid sol, its preparation method, and its application. Background Technology

[0002] Supplementing crops with silicon is one of the most effective ways to improve their lodging resistance. Silicon has a high affinity for substances such as pectic acid, polyuronic acid, and glycolipids in plants, forming stable, low-soluble mono-, di-, and polysilicic acid complexes that deposit in the lignified cell walls. This makes the plant upright, enhances the mechanical strength and stability of the tissues, and improves the plant's lodging resistance and photosynthetic rate. Existing research has also shown that silicon can effectively improve the absorption efficiency of N, P, and K in crops. Therefore, in the field of crop cultivation, silicon is considered a very important fourth element, widely used in crops and vegetation, and increasingly valued by agricultural practitioners.

[0003] Existing silicon fertilizers are mainly divided into the following two categories: one is slow-release silicon fertilizer made from industrial waste residue or tailings through mechanical grinding / high-temperature calcination, which has a certain degree of citric acid solubility; the other is highly soluble and effective silicon fertilizer, which often uses sodium metasilicate pentahydrate. This type of silicon fertilizer has good water solubility and a fast dissolution rate, and has a significant effect on supplementing silicon to plants in a short period of time.

[0004] However, slow-release silicon fertilizers made from industrial waste or tailings through mechanical grinding / high-temperature calcination have poor water solubility, low available silicon content, and high energy consumption. While highly soluble sodium metasilicate pentahydrate silicon fertilizer is efficient, its strong alkalinity easily disrupts the colloidal system of other pesticides or fertilizer emulsions, making it impossible to achieve "one spray, multiple applications" during aerial fertilization. Furthermore, in the high-tower granulation process of compound fertilizer for silicon supplementation, highly available silicon fertilizers (mainly sodium metasilicate pentahydrate) also cannot be melt-blended with N, P, and K compounds due to their strong alkalinity, preventing traditional ternary fertilizers from increasing silicon content. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a cured polysilicic acid sol, its preparation method, and its application.

[0006] Existing silicon fertilizers (such as sodium metasilicate pentahydrate) suffer from strong alkalinity, making them difficult to melt-blend with N, P, and K compounds. Therefore, this invention, after extensive research, uses amorphous silica minerals as raw materials and prepares an aqueous solution of sodium metasilicate after alkaline dissolution with sodium hydroxide. Ion exchange is then used to remove impurity ions such as sodium, resulting in a polysilicic acid solution under neutral or weakly alkaline conditions (pH 6-8), which is then concentrated into a sol. While this material solves the problem of strong alkalinity, it suffers from poor stability, making it difficult to store and use for extended periods, and it is difficult to redissolve after drying. This invention further utilizes microbial solidification to process this polysilicic acid colloidal solution into a solidified polysilicic acid sol. This solid is completely redissolved in water (remaining neutral or weakly alkaline), allowing for long-term storage, which is beneficial for later use and long-distance transportation. Furthermore, the solidified polysilicic acid sol can also serve as a highly soluble additive to increase the soluble silicon content of existing mineral silicon fertilizers. The method for preparing the solidified polysilicic acid sol provided by this invention can significantly reduce production and usage costs, facilitating large-scale application.

[0007] In a first aspect, the present invention provides a method for preparing a cured polysilicate sol, comprising:

[0008] Sodium metasilicate aqueous solution was removed by ion exchange method. + Polysilicic acid solution was obtained by removing impurity ions;

[0009] The polysilicic acid solution is concentrated to obtain a polysilicic acid colloidal solution, wherein the mass percentage of silicon dioxide in the polysilicic acid colloidal solution is 25-40%.

[0010] The polysilicic acid colloidal solution was cured by microorganisms to obtain cured polysilicic acid colloidal solution.

[0011] Furthermore, the sodium metasilicate aqueous solution is prepared by the following method:

[0012] Amorphous silica minerals were used as raw materials, and the mixture was dissolved in sodium hydroxide solution and then filtered.

[0013] Furthermore, the concentration includes: seed concentration and further concentration.

[0014] Furthermore, the seed crystal concentration includes: static aging; the concentration includes: atmospheric pressure and / or vacuum distillation.

[0015] Further, the microbial solidification includes:

[0016] Mix the polysilicic acid colloidal solution and the microbial agent, and stir until completely cured.

[0017] Furthermore, the microbial agent is: Bacillus mucilaginosus, and / or Bacillus subtilis.

[0018] Furthermore, the ratio of the polysilicic acid colloidal solution to the microbial agent is (300-700) mL: (0.1-1) g.

[0019] Furthermore, the ion exchange method employs an ion exchange resin.

[0020] Secondly, the present invention provides a cured polysilicic acid sol, which is prepared by the preparation method described above.

[0021] Thirdly, the present invention provides a fertilizer comprising the cured polysilicic acid sol.

[0022] Fourthly, the present invention provides the application of the cured polysilicic acid sol or the fertilizer in improving the utilization rate of silicon.

[0023] The present invention has the following beneficial effects:

[0024] This invention provides a cured polysilicic acid sol obtained by solidifying a polysilicic acid colloidal solution using microbial agents. This cured sol exhibits high stability, can be stored for extended periods, and is beneficial for later use and long-distance transportation. In practical applications, it can be directly dissolved in water before application. The cured polysilicic acid sol provided by this invention can significantly reduce production and usage costs, and is of great significance in the field of crop cultivation. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of sample A provided in Embodiment 1 of the present invention.

[0027] Figure 2 This is a schematic diagram of the cured polysilicic acid colloid provided in Embodiment 5 of the present invention.

[0028] Figure 3 This is a schematic diagram of an oven-dried sample obtained after the cured polysilicic acid colloid provided in Embodiment 6 of the present invention has undergone oven-dried treatment.

[0029] Figure 4 This is a schematic diagram of the application effects of rice in the control group and the experimental group provided in Experiment Example 1 of the present invention.

[0030] Figure 5 This is a schematic diagram of the application effect of corn in the control group and experimental group provided in Experiment Example 1 of the present invention; a is a comparison of the growth process, and b is a comparison of corn cobs. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0032] Example 1

[0033] This embodiment provides a method for preparing cured polysilicate sol, which specifically includes the following steps:

[0034] 1. Preparation of polysilicate colloidal solution

[0035] Sodium metasilicate aqueous solution is prepared by dissolving amorphous silica minerals (such as diatomaceous earth) in sodium hydroxide solution and then filtering. The sodium metasilicate aqueous solution is then passed through a cation exchange resin to remove sodium hydroxide. + Anion exchange resins for the removal of Cl - The obtained polysilicic acid solution was concentrated by seed crystals and then concentrated again to obtain a colloidal solution containing 30%–35% silica (pH = 7.5), denoted as sample A, and its morphology is as follows. Figure 1 As shown.

[0036] Sample A can be commercially available or prepared under the guidance of existing technology. In addition to amorphous silica minerals, conventional materials such as crystalline quartz sand can also be used as raw materials.

[0037] 2. Microbial agents

[0038] Inoculant B uses Bacillus mucilaginosus powder (10 billion / g, provided by Zhongwei Jufeng Technology Co., Ltd., Bacillus mucilaginosus, China Association for the Preservation and Management of Microbial Cultures, Agricultural Microbiology Center, ACCC10013), which is a strain that has been disclosed in multiple patents.

[0039] 3. Curing treatment

[0040] Weigh 500 mL of sample A and place it in a 1000 mL beaker. Add 0.75 g of bacterial agent B and stir slowly at 60 rpm for 120 min. The polysilicic acid colloidal solution will be completely cured after 18 h.

[0041] Take 20g of fully cured polysilicic acid colloid and add 20g of deionized water at a concentration of 50% and stir for 2 hours. Detect the dissolution rate and effect, and observe and evaluate the survival rate of microorganisms.

[0042] The mixed sample was then dried overnight in an oven at 80°C to obtain an oven-dried sample. 10g of the oven-dried sample was weighed and dissolved in 30g of deionized water at a concentration of approximately 35%. The dissolution rate and dissolution effect were then measured.

[0043] The results are as follows:

[0044] Cured polysilicate colloid: begins to dissolve after 20 minutes and completely dissolves after 60 minutes; the survival rate of microorganisms is approximately 10%.

[0045] Oven-dried sample: partial dissolution begins after 20 minutes, and 70% dissolution occurs after 120 minutes.

[0046] Example 2

[0047] The preparation methods for Sample A and Inoculum B are the same as in Example 1.

[0048] Weigh 500 mL of sample A and place it in a 1000 mL beaker. Add 0.50 g of bacterial agent B and stir slowly at 60 rpm for 100 min. The polysilicic acid colloidal solution will be completely cured after 24 h.

[0049] Take 20g of fully cured polysilicic acid colloid and add 20g of deionized water at a concentration of 50% and stir for 2 hours. Detect the dissolution rate and effect, and observe and evaluate the survival rate of microorganisms.

[0050] Weigh 10g of the completely dry sample and dissolve it in 30g of deionized water at a concentration of approximately 35%. Detect the dissolution rate and dissolution effect.

[0051] The results are as follows:

[0052] Cured polysilicate colloid: begins to dissolve after 15 minutes and completely dissolves after 50 minutes; the survival rate of microorganisms is approximately 18%.

[0053] Oven-dried sample: Partial dissolution begins after 20 minutes, and 78% dissolution occurs after 120 minutes.

[0054] Example 3

[0055] The preparation methods for Sample A and Inoculum B are the same as in Example 1.

[0056] Weigh 500 mL of sample A and place it in a 1000 mL beaker. Add 0.25 g of bacterial agent B and stir slowly at 60 rpm for 90 min. The polysilicic acid colloidal solution will be completely cured after 28 h.

[0057] Take 20g of fully cured polysilicic acid colloid and add 20g of deionized water at a concentration of 50% and stir for 2 hours. Detect the dissolution rate and effect, and observe and evaluate the survival rate of microorganisms.

[0058] Weigh 10g of the completely dry sample and dissolve it in 30g of deionized water at a concentration of approximately 35%. Detect the dissolution rate and dissolution effect.

[0059] The results are as follows:

[0060] Cured polysilicate colloid: begins to dissolve after 15 minutes and completely dissolves after 45 minutes; the survival rate of microorganisms is approximately 20%.

[0061] Oven-dried sample: Partial dissolution begins after 20 minutes, and 80% dissolution occurs after 120 minutes.

[0062] Example 4

[0063] 1. The preparation method of sample A is the same as that in Example 1.

[0064] 2. The bacterial agent C uses Bacillus subtilis powder (100 billion / g, provided by Zhongwei Jufeng Technology Co., Ltd., Bacillus subtilis, China Agricultural Microbiology Center ACCC10118). This strain is disclosed in multiple patents.

[0065] Weigh 500 mL of sample A and place it in a 1000 mL beaker. Add 0.75 g of bacterial agent C and stir slowly at 60 rpm for 120 min. The polysilicic acid colloidal solution will be completely cured after 60 h.

[0066] Take 20g of fully cured polysilicic acid colloid and add 20g of deionized water at a concentration of 50% and stir for 2 hours. Detect the dissolution rate and effect, and observe and evaluate the survival rate of microorganisms.

[0067] Weigh 10g of the completely dry sample and dissolve it in 30g of deionized water at a concentration of approximately 35%. Detect the dissolution rate and dissolution effect.

[0068] The results are as follows:

[0069] Cured polysilicate colloid: begins to dissolve after 15 minutes and completely dissolves after 50 minutes; the survival rate of microorganisms is approximately 50%.

[0070] Oven-dried sample: partial dissolution begins after 20 minutes, and 85% dissolution occurs after 120 minutes.

[0071] Example 5

[0072] The preparation methods for Sample A and Inoculum C are the same as those in Example 4.

[0073] Weigh 500 mL of sample A and place it in a 1000 mL beaker. Add 0.50 g of bacterial agent C and stir slowly at 60 rpm for 100 min. The polysilicic acid colloidal solution will be completely cured after 72 h. The fully cured polysilicic acid colloid obtained is as follows: Figure 2 As shown.

[0074] Take 20g of fully cured polysilicic acid colloid and add 20g of deionized water at a concentration of 50% and stir for 2 hours. Detect the dissolution rate and effect, and observe and evaluate the survival rate of microorganisms.

[0075] Weigh 10g of the completely dry sample and dissolve it in 30g of deionized water at a concentration of approximately 35%. Detect the dissolution rate and dissolution effect.

[0076] The results are as follows:

[0077] Cured polysilicate colloid: begins to dissolve after 15 minutes and completely dissolves after 45 minutes; the survival rate of microorganisms is approximately 60%.

[0078] Oven-dried sample: partial dissolution begins after 20 minutes, and 95% dissolution occurs after 120 minutes.

[0079] Example 6

[0080] The preparation methods for Sample A and Inoculum B are the same as in Example 1.

[0081] Weigh 500 mL of sample A and place it in a 1000 mL beaker. Add 0.25 g of bacterial agent B and stir slowly at 60 rpm for 90 min. The polysilicic acid colloidal solution will be completely cured after 78 h.

[0082] Take 20g of fully cured polysilicic acid colloid and add 20g of deionized water at a concentration of 50% and stir for 2 hours. Detect the dissolution rate and effect, and observe and evaluate the survival rate of microorganisms.

[0083] Weigh 10g of the completely dry sample and dissolve it in 30g of deionized water at a concentration of approximately 35%. Detect the dissolution rate and dissolution effect.

[0084] The results are as follows:

[0085] Cured polysilicate colloid: begins to dissolve after 15 minutes and completely dissolves after 40 minutes; the survival rate of microorganisms is approximately 65%.

[0086] Oven-dried sample: Partial dissolution begins after 20 minutes, 98% dissolution occurs after 120 minutes, and the morphology is as follows. Figure 3 As shown.

[0087] Experimental Example 1

[0088] This experimental example uses the cured polysilicic acid colloid and oven-dried samples prepared in the above examples for field trials, specifically including the following procedures:

[0089] 1. For rice in the tillering stage, control and experimental groups were set up, with each group having an experimental area of ​​5m×5m;

[0090] The control group received no treatment;

[0091] The experimental group applied the cured polysilicic acid colloid sample of Example 5 (dissolved in deionized water at a mass-volume percentage of 35%) at a rate of 30 g / mu. The application method was to spray the sample after dissolving and diluting it with water, with an interval of 15 days between sprays, for a total of 3 times.

[0092] To test the effects of lodging resistance and yield increase.

[0093] The results are as follows Figure 4 As shown, the rice in the experimental group exhibited high uniformity, with wide leaves, wide stem diameter, and good resilience. The rice yield of the control group was 607 kg / mu, while the rice yield of the experimental group was 657 kg / mu, representing an increase of 50 kg / mu compared to the control group.

[0094] 2. During the fertilization stage after planting corn, a control group and an experimental group were set up, with each group using a 5m×5m experimental area;

[0095] The control group was given conventional NPK compound fertilizer (available commercially), at a rate of 23 kg / mu, applied by broadcasting.

[0096] The experimental group was given nitrogen, phosphorus and potassium compound fertilizer (the same as the control group) + the oven-dried sample from Example 6 (mass ratio of 5%), with an application rate of 23 kg / mu and an application method of broadcasting.

[0097] The study examined the formation status of aerial roots during the growing season, the maturity of the three leaves on the stem, the early maturity of the living stem, and the yield-increasing effect.

[0098] The results are as follows Figure 5 As shown:

[0099] The corn cobs in the control group showed a pointed tip and the yield was 849 kg / mu, while the corn cobs in the experimental group did not show a pointed tip and the yield was 884 kg / mu.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a cured polysilicate sol, characterized in that, include: Sodium metasilicate aqueous solution was removed by ion exchange method. + Polysilicic acid solution was obtained by removing impurity ions; The polysilicic acid solution is concentrated to obtain a polysilicic acid colloidal solution, wherein the mass percentage of silicon dioxide in the polysilicic acid colloidal solution is 25-40%. Mix the polysilicic acid colloidal solution and the microbial agent, and stir until completely cured to obtain cured polysilicic acid colloidal solution; The microbial agent is: Bacillus candelillaris, and / or Bacillus subtilis.

2. The preparation method according to claim 1, characterized in that, The sodium metasilicate aqueous solution was prepared by the following method: Amorphous silica minerals were used as raw materials, and the mixture was dissolved in sodium hydroxide solution and then filtered.

3. The preparation method according to claim 1, characterized in that, The concentration includes: seed concentration and further concentration.

4. The preparation method according to claim 3, characterized in that, The seed crystal concentration includes: static aging; the re-concentration includes: atmospheric and / or vacuum distillation.

5. The preparation method according to claim 1, characterized in that, The ratio of the polysilicic acid colloidal solution to the microbial agent is (300~700) mL: (0.1~1) g.

6. The cured polysilicate sol is prepared by the preparation method according to any one of claims 1-5.

7. A fertilizer, characterized in that, The fertilizer includes the cured polysilicic acid sol as described in claim 6.

8. The application of the cured polysilicic acid sol according to claim 6 or the fertilizer according to claim 7 in improving the utilization rate of silicon.

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