Extraction method and application of high-activity potassium fulvate

Abstract

The invention relates to an extraction method of high-activity potassium fulvate and application of the high-activity potassium fulvate in agriculture, the high-activity potassium fulvate is extracted from lignite, and the extraction method comprises the following steps: uniformly mixing lignite powder with water, then adding alkali to adjust the pH value to 9-10, stirring for 2-3 hours at the temperature of 60-80 DEG C, and carrying out solid-liquid separation to obtain a humate solution; adding strongly acidic cation exchange resin loaded with zinc phthalocyanine and dipotassium ethylene diamine tetraacetate serving as a cocatalyst, reacting for a certain time, and performing centrifugal separation; and carrying out rotary evaporation concentration on the filtrate, and drying to obtain the high-activity fulvic acid. The method is simple in production process, high in extraction rate and suitable for being popularized and used in agricultural production.

Description

Technical Field

[0001] The invention relates to the field of extracting potassium humate, and in particular to an extraction method and application of high-activity potassium humate. Background Art

[0002] In the 19th century, Bezelia discovered fulvic acid (FA) from the substance defined by Achard as humic acid, which is soluble in both alkali and acid and water. This macromolecule has a benzene ring as its basic unit and is composed of an oxygen bridge (-O 2 -), methine (-CH 2 -), ethylene (-CH 2 -CH 2 -), -NH- and -S- and other bridge bonds, and various active functional groups such as carboxyl, hydroxyl, methoxyl and so on are distributed on the benzene ring and side chain. Because of its small molecular weight, good solubility, high biological activity, more oxygen-containing functional groups, it is easily absorbed and utilized by organisms, and has greater physiological activity than general humic acid. It is one of the best core components of soil humus, and is also a plant growth regulator that can promote plant growth, play an important role in drought resistance, improve plant stress resistance, increase production and improve quality.

[0003] In the category of fulvic acid, mineral potassium fulvic acid is a product made by reacting mineral fulvic acid with potassium hydroxide or potassium carbonate. It can be used as a fertilizer alone, for foliar spraying or drip irrigation, or it can be used with various fertilizers to improve the quality and efficiency of fertilizers. Scholars have found that mineral potassium fulvic acid can promote crop rooting and germination, improve crop soil environment, increase crop nutrient absorption, and enhance stress resistance.

[0004] At present, the preparation methods of fulvic acid mainly include extraction, fermentation and electrodialysis. Among them, extraction is the most commonly used, and the simplest ones are: alkali acid precipitation, strong acid extraction, sulfuric acid acetone, ion exchange resin, catalytic oxygen hydrolysis and organic solvent extraction.

[0005] Jiao Yuangang et al. (Jiao Yuangang, Zhu Hong, Zou Jing, et al. Research on the extraction of fulvic acid from weathered coal [J]. Chemical Industry Times, 2007, (01): 30-32.) studied the hydrochloric acid-acetone method for extracting fulvic acid. Weathered coal was used as the raw material. Under room temperature conditions, the acid-coal ratio was 0.05:1, the liquid-solid ratio was 7.5:1, and the water content in the extract was 10%. The fulvic acid extraction rate could reach 41%.

[0006] However, most of the existing studies use chemical methods to directly process and extract coal. The extraction rate is low, there is a certain amount of pollution to the environment, and the filter residue after extraction is not fully utilized, resulting in the accumulation and waste of resources. Therefore, it is particularly important to explore a simple, economical and efficient method for extracting fulvic acid from numerous studies at home and abroad. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention provides a method with simple production process, high humate extraction rate and high activity.

[0008] The technical solution of the present invention is as follows: A method for extracting highly active potassium humate, characterized in that it comprises the following steps: S1: Mix brown coal powder and water evenly, then add alkali to adjust the pH to 9-10, stir at 60-80°C for 2-3h, and obtain humate solution by solid-liquid separation; S2: adding a modified strongly acidic cation exchange resin of 2-3 times the mass of the lignite powder to the humate solution obtained in S1, and adding a co-catalyst, dipotassium ethylenediaminetetraacetate, in batches while stirring at 60-70° C., and reacting for 1-2 hours; S3: After the reaction is completed, centrifuge and filter the upper filtrate under reduced pressure again; S4: collecting the solid mixture above the funnel, air-drying it at room temperature, separating the residue and the modified strongly acidic ion exchange resin through sieving, and regenerating the resin; S5: combining the filtrates, concentrating by rotary evaporation, and drying to obtain the highly active potassium humate; The modified strong acid cation exchange resin used in S2 is a strong acid cation exchange resin loaded with zinc phthalocyanine by hydrogen bonding.

[0009] In some embodiments of the present invention, the preparation method of the strongly acidic cation exchange resin loaded with zinc phthalocyanine described in S2 comprises the following steps: placing a solution of zinc phthalocyanine containing an acidic group in a beaker, then weighing a strongly acidic cation exchange resin and placing it therein, soaking it at 50-70°C for 2-5h, taking it out and filtering it, washing and drying it to obtain the modified strongly acidic cation exchange resin.

[0010] Furthermore, the zinc phthalocyanine is at least one of β-monocarboxyl zinc phthalocyanine, tetracarboxyl zinc phthalocyanine, and sulfonyl zinc phthalocyanine.

[0011] Furthermore, the strong acid cation exchange resin is at least one of 732 strong acid cation exchange resin, NKC-9 strong acid cation exchange resin, D001, D002, CD350, CD450, CD550, and CD650 strong acid cation exchange resin.

[0012] Furthermore, the mass fraction of the solution of zinc phthalocyanine containing an acidic group is 1-5%.

[0013] Furthermore, the mass ratio of the acidic group-containing zinc phthalocyanine to the strongly acidic cation exchange resin is 27-32:100.

[0014] In some embodiments of the present invention, in S1, the mass ratio of lignite powder to water is 1:3 - 5.

[0015] In some embodiments of the present invention, in S1, the alkali is sodium hydroxide or potassium hydroxide.

[0016] In some embodiments of the present invention, the addition batches of the cocatalyst dipotassium ethylenediaminetetraacetate are not less than 3 times.

[0017] The present invention also provides the application of the above-mentioned highly active potassium fulvate in the agricultural field. It can be used as a drip irrigation fertilizer, a flushing fertilizer, a foliar fertilizer or a pesticide additive and promoter. It can be compounded with various macronutrient fertilizers to form a multifunctional high-efficiency compound fertilizer, and can also be mixed with acidic macronutrient fertilizers, fungicides and some pesticides to improve the utilization rate.

[0018] When used as a foliar spray, the dosage per mu is 50 - 100 g, diluted 500 - 1000 times, and sprayed evenly. It can be used alone or mixed with other water-soluble macronutrient chemical fertilizers, pesticides, fungicides, herbicides, etc., and can play the role of a synergist.

[0019] When used as a drip irrigation fertilizer, the recommended dosage per mu is 3 - 5 kg. It can stimulate the rooting of crops, promote growth, resist lodging, and improve the yield and quality of crops. It is preferably used in combination with water-soluble macronutrient chemical fertilizers, and can play the role of a synergist. Note that it cannot be mixed with divalent or higher-valent metal ions.

[0020] Beneficial effects: Compared with the prior art, the present invention creatively uses a strongly acidic cation exchange resin loaded with zinc phthalocyanine containing acidic groups as a catalyst, and cooperates with dipotassium ethylenediaminetetraacetate as a cocatalyst, which can efficiently oxidize macromolecular humic acid into small-molecular fulvic acid, effectively improving the activation rate of humic acid in lignite; combined with the change of the addition method - adding in batches, the decomposition of the modified strongly acidic cation exchange resin on small-molecular potassium fulvate can be reduced, thereby improving the activity of the obtained fulvate salt. Specific embodiments

[0021] The following further elaborates on the above content of the present invention through specific examples, but this should not be construed as limiting the content of the present invention to the following examples.

[0022] The following exemplarily illustrates the preparation process of the modified strongly acidic cation exchange resin used in the examples: Modified strongly acidic cation exchange resin #1 2700 parts of a 1% aqueous solution of β-monocarboxyphthalocyanine zinc was prepared and placed in a beaker, and then 100 parts of 732 strong acid cation exchange resin were weighed and placed in the beaker. After soaking at 50° C. for 2 hours, the mixture was taken out, filtered, washed, and dried to obtain the modified strong acid cation exchange resin #1.

[0023] Modified Strong Acid Cation Exchange Resin #2 1000 parts of a 3% aqueous solution of tetracarboxyl phthalocyanine zinc were placed in a beaker, and then 100 parts of NKC-9 strong acid cation exchange resin were weighed and placed therein. After soaking at 60° C. for 3 hours, the mixture was taken out, filtered, washed, and dried to obtain the modified strong acid cation exchange resin #2.

[0024] Modified Strong Acid Cation Exchange Resin #3 640 parts of a 5% aqueous solution of sulfonylphthalocyanine zinc were placed in a beaker, and then 100 parts of D001 strong acid cation exchange resin were weighed and placed therein. After soaking at 70° C. for 5 hours, the modified strong acid cation exchange resin #3 was obtained by filtering, washing and drying.

[0025] Meanwhile, the experimental methods described in the following examples are all conventional methods unless otherwise specified; the reagents and materials described are all commercially available unless otherwise specified.

[0026] In the embodiment, the lignite is available from Jinan Beihai Chemical Co., Ltd., wherein the total amount of humic acid is 53.7% of the mass of the lignite.

[0027] Example 1 S1: 100 parts of lignite powder and 300 parts of water were mixed evenly, and then sodium hydroxide was added to adjust the pH to 9, and stirred at 60°C for 3 hours, and a humate solution was obtained by solid-liquid separation; S2: Add 300 parts of modified strong acid cation exchange resin #1 to the humate solution obtained in S1, and add 200 parts of co-catalyst dipotassium ethylenediaminetetraacetate in three batches while stirring at 60°C, and react for 1 hour; S3: After the reaction is completed, centrifuge and filter the upper filtrate under reduced pressure again; S4: collecting the solid mixture above the funnel, air-drying it at room temperature, separating the residue and the modified strongly acidic ion exchange resin #1 through sieving, and regenerating the resin; S5: combining the filtrates, concentrating by rotary evaporation, and drying to obtain the highly active potassium humate.

[0028] Example 2 S1: 100 parts of lignite powder and 400 parts of water were mixed evenly, and then potassium hydroxide was added to adjust the pH to 10, and the mixture was stirred at 70°C for 2.5 hours, and a humate solution was obtained by solid-liquid separation; S2: Add 250 parts of modified strong acid cation exchange resin #2 to the humate solution obtained in S1, and add 140 parts of co-catalyst dipotassium ethylenediaminetetraacetate in 4 batches while stirring at 65°C, and react for 1.5 hours; S3: After the reaction is completed, centrifuge and filter the upper filtrate under reduced pressure again; S4: collecting the solid mixture above the funnel, air-drying at room temperature, separating the residue and the modified strongly acidic ion exchange resin #2 through sieving, and regenerating the resin; S5: combining the filtrates, concentrating by rotary evaporation, and drying to obtain the highly active potassium humate.

[0029] Example 3 S1: 100 parts of lignite powder and 500 parts of water were mixed evenly, and then potassium hydroxide was added to adjust the pH to 10, and the mixture was stirred at 80°C for 2 hours, and a humate solution was obtained by solid-liquid separation; S2: Add 200 parts of modified strong acid cation exchange resin #3 to the humate solution obtained in S1, and add 100 parts of co-catalyst dipotassium ethylenediaminetetraacetate in 5 batches while stirring at 70°C, and react for 2 hours; S3: After the reaction is completed, centrifuge and filter the upper filtrate under reduced pressure again; S4: collecting the solid mixture above the funnel, air-drying at room temperature, separating the residue and the modified strongly acidic ion exchange resin #3 through sieving, and regenerating the resin; S5: combining the filtrates, concentrating by rotary evaporation, and drying to obtain the highly active potassium humate.

[0030] Example 4 The same as Example 3, except that the co-catalyst dipotassium ethylenediaminetetraacetate in S2 is added once.

[0031] Comparative Example 1 Same as Example 3, except that the modified strongly acidic cation exchange resin #3 is replaced by D001 strongly acidic cation exchange resin.

[0032] Comparative Example 2 Same as Example 3, except that the modified strongly acidic cation exchange resin #3 is replaced by sulfonyl phthalocyanine zinc.

[0033] Comparative Example 3 Same as Example 3, except that the co-catalyst dipotassium ethylenediaminetetraacetate is not added.

[0034] Performance Testing Potassium fulvic acid content: refer to the method in Appendix B of GB / T 5045-5046-2016 standard to test the fulvic acid content; Potassium humate activity: According to the growth requirements of Pseudoperonospora cubana, a glucose culture dish was prepared, and the potassium humate obtained in Examples 1-4 and Comparative Examples 1-3 was added thereto. A blank control group (without potassium humate) was set to ensure that the content of potassium humate in each group of tests was consistent. After 7 days of incubator culture, the activity of potassium humate was reflected according to the ratio of the growth amount of the mold in each group of tests to the growth amount of the blank control group, with the blank group as 100%. Humic acid activation rate: calculated by the final amount of potassium fulvic acid / the total amount of humic acid in lignite.

[0035] Table 1 Examples 1-4 and Comparative Examples 1-3 As shown in Table 1, by using the modified strongly acidic cation exchange resin prepared in the present invention to treat humic acid, the activation rate of humic acid in lignite can reach more than 43%, and the inhibitory activity of the obtained potassium humate against the pathogenic bacteria of Pseudoperonospora cubaniensis can reach up to 91.6% (Example 3). From the comparison between Example 3 and Example 4, it can be seen that the batch addition method of the co-catalyst is better than the one-time addition method, which is more conducive to improving the activity of potassium humate; from the comparison between Comparative Examples 1-2 and Example 3, it can be seen that in the modified strongly acidic cation exchange resin, the phthalocyanine zinc containing an acidic group has a synergistic effect with the strongly acidic cation exchange resin; the result of Comparative Example 3 reflects the importance of the co-catalyst dipotassium ethylenediaminetetraacetic acid in the extraction method provided by the present invention.

Claims

1. A method for extracting highly active potassium humate, characterized in that: The following steps are involved: S1: Mix brown coal powder and water evenly, then add alkali to adjust the pH to 9-10, stir at 60-80°C for 2-3h, and obtain humate solution by solid-liquid separation; S2: adding a modified strongly acidic cation exchange resin of 2-3 times the mass of the lignite powder to the humate solution obtained in S1, and adding a co-catalyst, dipotassium ethylenediaminetetraacetate, in batches while stirring at 60-70° C., and reacting for 1-2 hours; S3: After the reaction is completed, centrifuge and filter the upper filtrate under reduced pressure again; S4: collecting the solid mixture above the funnel, air-drying at room temperature, separating the residue and the strong acid ion exchange resin through sieving, and regenerating the resin; S5: combining the filtrates, concentrating by rotary evaporation, and drying to obtain the highly active potassium humate; The modified strong acid cation exchange resin used in S2 is a strong acid cation exchange resin loaded with zinc phthalocyanine by hydrogen bonding.

2. The method for extracting highly active potassium humate according to claim 1, characterized in that: The preparation method of the strongly acidic cation exchange resin loaded with zinc phthalocyanine described in S2 comprises the following steps: placing a solution of zinc phthalocyanine containing an acidic group in a beaker, then weighing a strongly acidic cation exchange resin and placing it therein, soaking it at 50-70°C for 2-5h, taking it out and filtering it, washing and drying it to obtain the modified strongly acidic cation exchange resin.

3. The method for extracting highly active potassium humate according to claim 2, characterized in that: The zinc phthalocyanine is at least one of β-monocarboxyl zinc phthalocyanine, tetracarboxyl zinc phthalocyanine and sulfonyl zinc phthalocyanine.

4. The method for extracting highly active potassium humate according to claim 2, characterized in that: The strong acid cation exchange resin is at least one of 732 strong acid cation exchange resin, NKC-9 strong acid cation exchange resin, D001, D002, CD350, CD450, CD550, and CD650 strong acid cation exchange resin.

5. The method for extracting highly active potassium humate according to claim 2, characterized in that: The mass fraction of the solution prepared by the zinc phthalocyanine containing an acidic group is 1-5%.

6. The method for extracting highly active potassium humate according to claim 2, characterized in that: The mass ratio of the acidic group-containing zinc phthalocyanine to the strongly acidic cation exchange resin is 27-32:

100.

7. The method for extracting highly active potassium humate according to claim 1, characterized in that: In the S1, the mass ratio of lignite powder to water is 1:3-5.

8. The method for extracting highly active potassium humate according to claim 1, characterized in that: The alkali in S1 is sodium hydroxide or potassium hydroxide.

9. The method for extracting highly active potassium humate according to claim 2, characterized in that: In S2, the dipotassium ethylenediaminetetraacetate is added in batches of no less than 3 times.

10. Use of the highly active potassium humate according to any one of claims 1 to 9 in the agricultural field.

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