CN-122010612-A - Hard water resistant compound fertilizer and preparation method and application thereof

Abstract

The invention belongs to the technical field of fertilizers and preparation thereof, and in particular relates to a hard water resistant compound fertilizer, a preparation method and application thereof. The hard water resistant compound fertilizer disclosed by the invention has excellent dissolution stability in a hard water environment, can be completely dissolved in a 30-50 DEG high-hardness water environment and has no flocculation or precipitation, and meanwhile, the compound fertilizer has the advantages of being suitable for high-tower production, high in nutrient content, capable of improving the organic matter level in soil, the nitrogen fertilizer utilization rate and the like, and has a wide application prospect.

Inventors

• GUO FENGLEI
• LIU XIAOBO
• JIAO WEIPING
• QU BAOLONG
• REN XIANSHUN
• LIANG AIXIN
• LI TONGHUA
• BAO JUNPING

Assignees

• 中化化肥有限公司临沂农业研发中心
• 中化农业（临沂）研发中心有限公司

Dates

Publication Date

20260512

Application Date

20251229

Claims (10)

1. 1. The hard water resistant compound fertilizer is characterized by comprising the following components: Urea; Monoammonium phosphate; Humic acid with molecular weight less than 5000 dalton; An anti-hard water auxiliary agent.
2. 2. The hard water resistant composite fertilizer according to claim 1, further comprising an auxiliary material comprising a medium trace element and/or an inhibitor; optionally, the medium trace elements include medium elements and/or trace elements; optionally, the secondary elements include one or more of calcium, magnesium, and sulfur; optionally, the trace elements include one or more of iron, manganese, zinc, copper, and boron; Optionally, the inhibitor is a nitrification inhibitor; Optionally, the nitrification inhibitor is DMPSA and/or DMPP.
3. 3. The hard water resistant compound fertilizer of claim 1, wherein the humic acid with molecular weight <5000 daltons is prepared by an electrodialysis process; Optionally, the humic acid is of mineral origin; Optionally, the hard water resistant aid comprises one or more of disodium lauryl sulfosuccinate monoester, disodium fatty alcohol polyoxyethylene ether sulfosuccinate monoester, disodium acid monoethanolamide sulfosuccinate monoester, potassium monolauryl phosphate, potassium lauryl ether phosphate, ammonium fatty alcohol polyoxyethylene ether sulfate and disodium lauriminodiacetate.
4. 4. The hard water resistant compound fertilizer according to any one of claims 1 to 3, wherein the mass ratio of the urea, the monoammonium phosphate, the humic acid with molecular weight less than 5000 daltons and the hard water resistant auxiliary agent is (35 to 70): 8 to 30): 7 to 20): 0.1 to 0.5; optionally, in the hard water resistant compound fertilizer, the mass ratio of the auxiliary materials is 0.5-1.5%; Optionally, in the auxiliary materials, the mass ratio of the medium trace elements to the inhibitor is (6-8) (2-4).
5. 5. The hard water resistant composite fertilizer according to any one of claims 1 to 4, wherein the hard water resistant composite fertilizer further comprises a potassium source; optionally, the potassium source comprises potassium chloride and/or potassium sulfate; Preferably, the mass ratio of the urea to the potassium chloride to the potassium sulfate to the monoammonium phosphate to the humic acid with the molecular weight less than 5000 daltons to the hard water resistant auxiliary agent is (35-70): (1-5): (10-40): (8-30): (7-20): (0.1-0.5).
6. 6. A method for preparing the hard water resistant compound fertilizer according to any one of claims 1 to 5, which comprises the following steps: s1, heating and melting urea to obtain a melt; s2, adding monoammonium phosphate, humic acid with molecular weight less than 5000 daltons and anti-hard water auxiliary agent into the melt, and carrying out mixing treatment to obtain mixed feed liquid; and S3, carrying out curing forming treatment and post-treatment on the mixed feed liquid to obtain the hard water resistant compound fertilizer.
7. 7. The method according to claim 6, wherein in step S2, auxiliary materials including medium trace elements and/or inhibitors are further added; Optionally, in step S1, a potassium source may also be added; optionally, the potassium source comprises potassium chloride and/or potassium sulfate; optionally, the residence time of the monoammonium phosphate in the melt is less than or equal to 10 min; optionally, the temperature of the mixing treatment is 100-115 ℃.
8. 8. The method according to claim 6, wherein the temperature of the heat-melting treatment is 100-125 ℃; Optionally, the anti-caking agent used for the coating in the post-treatment is a fully water-soluble anti-caking agent.
9. 9. The method according to claim 6, characterized in that in step S2, the humic acid with molecular weight <5000 dalton is obtained by means of electrodialysis device preparation; Preferably, the electrodialysis device uses a double dialysis membrane consisting of an anion membrane and a dialysis membrane.
10. 10. The use of the hard water resistant compound fertilizer of any one of claims 1-5 in hard water fertigation.

Description

Hard water resistant compound fertilizer and preparation method and application thereof Technical Field The invention belongs to the technical field of fertilizer and preparation thereof, and in particular relates to a hard water resistant compound fertilizer and a preparation method and application thereof. Background At present, in order to realize rapid nutrient supply, a high-tower melt granulation process is generally adopted to produce a full-water-soluble compound fertilizer, and organic matters such as mineral source humic acid and the like are added to improve soil fertility. However, in the application process of water-soluble fertilizers, especially fully water-soluble organic and inorganic fertilizers, it is found that because the groundwater dissolving the fertilizers is generally higher in hardness, calcium (Ca 2+) and magnesium (Mg 2+) ions in the hard water are easily combined with organic matters such as phosphate radical (PO 43-/HPO42-) and macromolecular humic acid in the fertilizers to generate insoluble precipitates (such as calcium phosphate and calcium sulfate) or floccules, so that the dissolution rate of the fertilizers is obviously slowed down, even layering or flocculation precipitation occurs, and the phenomena such as blocking of spray heads, drip tapes or filters are caused by flocculation precipitation, so that the fertilization efficiency is influenced, and meanwhile, nutrients in the precipitates cannot be absorbed by crops, so that the fertilizer efficiency is reduced. The humic acid with good water solubility is usually prepared by reacting alkaline substances such as potassium hydroxide/sodium and the like with humic acid, however, the molecular weight of the humic acid obtained by the process is large, the humic acid contains a large amount of macromolecular humic acid with poor water solubility, the humic acid promotes the soil aggregate structure to form through the slightly acidic characteristic and the cation exchange capability, and monovalent salts of the humic acid are soluble, divalent and trivalent salts are insoluble, specifically, after the humic acid with the mineral source sold in the market is dissolved in water, the humic acid anions (R-COO -) and potassium (K +) or sodium (Na +) ions are ionized, and when the fertilizer containing the humic acid is dissolved in hard water such as underground water, calcium ions (Ca 2+) and magnesium ions (Mg 2+) in water can have strong combination effect with the humic acid anions to replace potassium ions and sodium ions which are combined originally, so that macromolecular complexes such as calcium phytate and magnesium phytate with poor water solubility are formed, and the like are flocculated or precipitated. Therefore, development of a hard water resistant compound fertilizer which can well solve the problem of hard water flocculation, and has the advantages of being suitable for high-tower production, keeping full water solubility, high in nutrient content, capable of improving the organic matter level in soil, the nitrogen fertilizer utilization rate and the like is needed. Disclosure of Invention The invention aims to solve at least one of the technical problems existing in the prior art to a certain extent, and particularly solves the problem that the hard water-soluble compound fertilizer is flocculated or precipitated. Therefore, the invention provides the hard water resistant compound fertilizer, and the preparation method and the application thereof. The hard water resistant compound fertilizer disclosed by the invention has excellent dissolution stability in a hard water environment, can be completely dissolved in a 30-50 DEG high-hardness water environment and has no flocculation or precipitation, and meanwhile, the compound fertilizer has the advantages of being suitable for high-tower production, high in nutrient content, capable of improving the organic matter level in soil, the nitrogen fertilizer utilization rate and the like, and has a wide application prospect. In a first aspect of the invention, the invention provides an anti-hard water compound fertilizer. According to the embodiment of the invention, the hard water resistant compound fertilizer comprises urea, monoammonium phosphate, humic acid with molecular weight of less than 5000 daltons and hard water resistant auxiliary agents. According to the hard water resistant compound fertilizer disclosed by the embodiment of the invention, under the hard water condition of up to 30-50 degrees, the quick and complete dissolution can be realized, the clarity and transparency can be kept for a long time, and no flocculation or precipitation is generated, so that the key problem that the traditional humic acid-containing fertilizer is easy to flocculate or precipitate in the hard water application is thoroughly solved. According to the embodiment of the invention, the hard water resistant compound fertilizer can also have at least one of the following ad