On-line multi-activated humic acid high-tower nitro fertilizer and preparation method thereof

Abstract

The invention belongs to an on-line multi-activated humic acid high-tower nitro fertilizer and a preparation method thereof. The nitro fertilizer is at least prepared from the following raw materials: nitric acid, ammonia water, urea peroxide, a sulfomethylation reagent, a raw material for preparing humic acid, a phosphorus element and a potassium element. Through multiple activation, the molecular weight distribution range of humic acid in the final high-tower nitro fertilizer product is wider, so that the hard water resistance is improved, more functional groups are provided, and the oxygen content is higher, so that the effects of better improving soil and stimulating crop growth are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of fertilizers, and particularly relates to an online multiple activated humic acid high-tower nitro fertilizer and a preparation method thereof. Background Art

[0002] Due to continuous cultivation and irrational use of fertilizers, the current soil problems are serious, which brings different degrees of obstacles to crop growth. Humic acid, as a very effective synergist, has a significant effect on promoting crop growth and improving soil. In the prior art, Chinese patent document CN202111096873 discloses a production method of a high-tower high-activity humic acid compound fertilizer, which is to pre-activate lignite, peat or weathered coal with potassium hydroxide or sodium hydroxide to obtain humic acid, and then perform high-tower granulation with raw materials such as urea, phosphorus, and potassium, and finally obtain a high-tower urea-based fertilizer product containing humic acid. The product has stable quality and good effect. Most of the humic acid activated by the above technical solution is a macromolecular product, which has a good effect on improving soil, but has certain deficiencies in promoting crop growth. Chinese patent document CN201910060454 discloses a nitro fertilizer containing activated mineral-source humic acid and a preparation method thereof. The method first reacts nitric acid with phosphate rock, calcium carbonate, calcium magnesium carbonate, etc. to obtain an acid solution, and then uses the acid solution to react with peat, weathered coal or lignite for activation reaction. When producing fertilizers containing phosphorus, it is necessary to remove calcium ions by freezing or mixed acid method. The fertilizer prepared by this method contains nitrofulvic acid, which has a small molecular weight and has a significant effect on promoting crop growth. However, the lack of macromolecular humic acid has certain deficiencies in improving soil. At the same time, the mixed acid method decalcifies and produces some calcium sulfate waste. Furthermore, the technical solutions recorded in the above two patents have the problem that humic acid is easily added to nitro fertilizer and the particle strength decreases. Secondly, humic acid has poor resistance to hard water and is easy to flocculate during actual use, resulting in poor product effect. Summary of the invention

[0003] The purpose of the present invention is to overcome the defects in the prior art and provide an online multiple activated humic acid high tower nitro fertilizer and a preparation method thereof.

[0004] The above technical objectives of the present invention are achieved through the following technical solutions:

[0005] An online multiple activated humic acid high tower nitro fertilizer, the nitro fertilizer comprises at least the following raw materials: nitric acid, ammonia water, urea peroxide, sulfomethylation agent, raw materials for preparing humic acid, phosphorus element and potassium element.

[0006] The beneficial effects of the present invention are as follows: a part of the raw materials for preparing humic acid is activated by nitric acid and urea peroxide, another part of the raw materials for preparing humic acid is activated by ammonia water and a sulfomethylation agent, the activated raw materials are subjected to a neutralization reaction to realize a third activation, and then the high-temperature slurry is activated for a fourth time by high-tower granulation to realize the characteristic of completely activating the humic acid. In the above process, the activation of the raw materials for humic acid by nitric acid and urea peroxide can reduce the molecular weight of humic acid while extracting humic acid, thereby realizing the characteristic of promoting crop growth. The activation of the raw materials for humic acid by ammonia water and a sulfomethylation agent can provide a high-molecular-weight humic acid product while extracting humic acid. Through the above multiple activations, the molecular weight distribution range of humic acid in the final high-tower nitro fertilizer product can be made wider, thereby improving the hard water resistance, and making the functional groups more and the oxygen content more, so as to achieve the effect of better improving soil and stimulating crop growth.

[0007] Preferably, the nitro fertilizer also includes trace elements.

[0008] Preferably, the concentration of nitric acid is 60-70%, and the concentration of ammonia water is 20-60%.

[0009] Preferably, the raw materials for preparing humic acid are weathered coal raw materials and lignite raw materials, the humic acid content in the weathered coal raw materials is 70-90%, and the humic acid content in the lignite raw materials is 60-80%.

[0010] Preferably, the sulfomethylation reagent is a mixture of sodium sulfite and paraformaldehyde, wherein the polymerization degree of paraformaldehyde is between 2 and 100, and the mass ratio of sodium sulfite to paraformaldehyde is 4:1 to 1.5.

[0011] Preferably, the phosphorus element is at least one of monoammonium phosphate, diammonium phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, superphosphate, double superphosphate, and calcium magnesium phosphate; the potassium element is at least one of potassium sulfate, potassium chloride, potassium nitrate, and potassium ammonium chloride; and the trace elements are at least one of magnesium sulfate, magnesium chloride, magnesium nitrate, calcium chloride, calcium nitrate, zinc sulfate, zinc nitrate, zinc chloride, zinc oxide, zinc carbonate, manganese sulfate, manganese nitrate, manganese chloride, manganese oxide, ferrous sulfate, ferric chloride, ferric oxide, copper sulfate, copper nitrate, boric acid, borax, and sodium octaborate tetrahydrate.

[0012] Preferably, the nitro fertilizer comprises the following raw materials in parts by weight: 40-60 parts of pure nitric acid, 10-20 parts of pure ammonia, 2-5 parts of urea peroxide, 1-3 parts of sulfomethylation agent, 1-20 parts of raw materials for preparing humic acid, 10-30 parts of phosphorus, 10-30 parts of potassium, and 2-3 parts of medium and trace elements.

[0013] Preferably, the nitro fertilizer comprises the following raw materials in parts by weight: 45 parts of pure nitric acid, 14 parts of pure ammonia water, 5 parts of urea peroxide, 3 parts of sulfomethylation agent, 5 parts of raw materials for preparing humic acid, 5 parts of phosphorus, 15 parts of potassium, and 2 parts of medium and trace elements; the sodium sulfite and polyformaldehyde in the sulfomethylation agent are in a weight ratio of 4:1.5; the raw materials for preparing humic acid are 3 parts of weathered coal and 2 parts of lignite; the phosphorus element is 15 parts of monoammonium phosphate; the potassium element is 15 parts of potassium sulfate raw material; the medium and trace elements are 1 part of zinc sulfate monohydrate and 1 part of borax.

[0014] The present invention also provides a method for preparing an online multiple activated humic acid high-tower nitro fertilizer, which comprises the following steps: using nitric acid and urea peroxide to activate a portion of the raw materials for preparing humic acid, using ammonia water and a sulfomethylation agent to activate another portion of the raw materials for preparing humic acid, mixing the two activated materials for neutralization reaction, further reactivating the materials using the neutralization concentration heat, finally adding phosphorus, potassium and medium and trace elements to the reactivated materials for final activation, and obtaining the high-tower nitro fertilizer in the form of high-tower granulation.

[0015] Furthermore, the present invention is a method for preparing an online multiple activated humic acid high tower nitro fertilizer, and the preparation method comprises the following steps:

[0016] Step 1: crushing the raw material for preparing humic acid; and dividing the crushed raw material for humic acid into two parts;

[0017] Step 2: Add nitric acid, urea peroxide and a portion of crushed humic acid raw materials into a reactor, and activate them at 50-60° C. for 30-60 minutes to obtain a mixed solution containing nitric acid, urea peroxide and its decomposition products and activated humic acid;

[0018] Step 3: Add ammonia water, sulfomethylation reagent and another part of crushed humic acid raw materials into a reactor, activate at 50-60° C. for 30-60 min, and obtain a mixed solution containing ammonia water, sulfomethylation reagent and its decomposition product and activated humic acid;

[0019] Step 4: placing the mixed solution containing nitric acid, urea peroxide and its decomposition products and activated humic acid in the above step 2 and the mixed solution containing ammonia water, sulfomethylation agent and its decomposition products and activated humic acid in step 3 into a tubular reactor for neutralization reaction to prepare a neutralized slurry, wherein the pH value of the neutralized slurry is 5-9;

[0020] Step 5: Add phosphorus, potassium and trace elements to the neutralized slurry in step 4, and use evaporation to concentrate the moisture to less than 1%, and then transport the slurry to the top of the granulation tower for spray granulation.

[0021] The present invention has the following advantages:

[0022] 1. The humic acid described in the present invention is activated by multiple activators and multiple activations; wherein urea peroxide is mainly used to break the CC bond in the humic acid structure and reduce the molecular weight; nitric acid is mainly used to promote the opening of the aromatic ring structure in the humic acid, increase the number of functional groups and the oxygen content, and improve the stimulating growth effect of humic acid; the above combination can achieve the characteristics of reducing the molecular weight of humic acid while increasing the number of functional groups and the oxygen content of humic acid, so as to achieve the stimulating growth effect of humic acid on crops; ammonia water mainly increases the water solubility of humic acid and provides a large molecular weight humic acid product; sulfomethylation reagent makes humic acid The number of methoxyl groups, sulfonic acid groups and other groups on the acid functional groups increases, which improves the hard water resistance of humic acid and further enhances its water solubility. Its molecular weight is close to that of the product activated by ammonia water, and is significantly higher than that of the product activated by urea peroxide and nitric acid. By using ammonia water and sulfomethylation reagent to activate humic acid, the number of methoxyl groups, sulfonic acid groups and other groups on the humic acid functional groups can be increased, thereby improving the hard water resistance of humic acid. Furthermore, after multiple activations, the molecular weight of humic acid can be within a wider distribution range, thereby improving the hard water resistance, and making the functional groups more and the oxygen content more, so as to improve the soil improvement and crop growth stimulation.

[0023] 2. The present invention uses paraformaldehyde in the sulfomethylation reagent, which has the characteristics of safety and economy, and will not volatilize during activation reaction and granulation, thereby avoiding pollution to the environment and damage to the health of operators; at the same time, it is solid and can achieve the characteristic of reducing energy consumption during subsequent evaporation and concentration; further, the formaldehyde remaining after the decomposition of the paraformaldehyde used in the present invention reacts with urea at high temperature to produce urea formaldehyde; it is well known that urea formaldehyde is a long-acting nitrogen fertilizer that can make up for the shortcoming of the lack of long-term effectiveness of nitro fertilizer itself, and the two complement each other and jointly improve the fertilizer efficiency; at the same time, urea formaldehyde also has the characteristics of significantly improving the strength of fertilizer particles and improving product quality.

[0024] 3. The present invention also uses urea peroxide during activation. Urea peroxide is relatively stable and can stably and continuously release hydrogen peroxide under high temperature conditions, which can realize continuous activation of humic acid. It not only has a long-lasting activation ability but also has the characteristics of better activation effect. Further, one of the decomposition products of urea peroxide is urea. Urea partially reacts with phosphate during the high tower granulation process to generate ammonium polyphosphate. Ammonium polyphosphate has certain chelating properties, which can chelate trace element ions in raw materials such as lignite, weathered coal and phosphorus raw materials, increase the activity of trace elements, and enhance the absorption of trace elements in fertilizers by crops. In addition, when the fertilizer is dissolved in water for use, it can chelate metal ions in irrigation water, indirectly reducing the influence of metal ions on humic acid flocculation and improving the hard water resistance of humic acid. Furthermore, as an efficient phosphate fertilizer, ammonium polyphosphate can slow down the fixation of phosphorus by soil, extend the movement distance of phosphate fertilizer in soil, and enhance the absorption capacity of crops to phosphorus, so as to achieve the effect of improving and stimulating crop growth. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] The present invention discloses an online multiple activated humic acid high tower nitro fertilizer and a preparation method thereof. The nitro fertilizer is made of at least the following raw materials: nitric acid, ammonia water, urea peroxide, sulfomethylation agent, raw materials for preparing humic acid, phosphorus and potassium. The nitro fertilizer also includes medium and trace elements. The concentration of nitric acid is 60-70%, and the concentration of ammonia water is 20-60%. The raw materials for preparing humic acid are weathered coal raw materials and lignite raw materials, the humic acid content in the weathered coal raw materials is 70-90%, and the humic acid content in the lignite raw materials is 60-80%. The sulfomethylation agent is a mixture of sodium sulfite and paraformaldehyde, wherein the polymerization degree of the paraformaldehyde is between 2 and 100, and the mass ratio of sodium sulfite to paraformaldehyde is 4:1-1.5. The phosphorus element is at least one of monoammonium phosphate, diammonium phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, superphosphate, double superphosphate, and calcium magnesium phosphate; the potassium element is at least one of potassium sulfate, potassium chloride, potassium nitrate, and potassium ammonium chloride; and the trace elements are at least one of magnesium sulfate, magnesium chloride, magnesium nitrate, calcium chloride, calcium nitrate, zinc sulfate, zinc nitrate, zinc chloride, zinc oxide, zinc carbonate, manganese sulfate, manganese nitrate, manganese chloride, manganese oxide, ferrous sulfate, ferric chloride, ferric oxide, copper sulfate, copper nitrate, boric acid, borax, and sodium octaborate tetrahydrate.

[0027] The invention provides an online multiple activated humic acid high tower nitro fertilizer. The nitro fertilizer comprises the following raw materials in parts by weight: 40 to 60 parts of pure nitric acid, 10 to 20 parts of pure ammonia, 2 to 5 parts of urea peroxide, 1 to 3 parts of sulfomethylation reagent, 1 to 20 parts of raw materials for preparing humic acid, 10 to 30 parts of phosphorus, 10 to 30 parts of potassium and 2 to 3 parts of medium and trace elements.

[0028] Furthermore, the nitro fertilizer includes the following raw materials in parts by weight: 45 parts of pure nitric acid, 14 parts of pure ammonia water, 5 parts of urea peroxide, 3 parts of sulfomethylation agent, 5 parts of raw materials for preparing humic acid, 5 parts of phosphorus, 15 parts of potassium, and 2 parts of trace elements; the sodium sulfite and polyformaldehyde in the sulfomethylation agent are in a weight ratio of 4:1.5; the raw materials for preparing humic acid are 3 parts of weathered coal and 2 parts of lignite; the phosphorus element is 15 parts of monoammonium phosphate; the potassium element is 15 parts of potassium sulfate raw material; the trace elements are 1 part of zinc sulfate monohydrate and 1 part of borax.

[0029] The present invention also provides a method for preparing an online multiple activated humic acid high-tower nitro fertilizer, which comprises the following steps: using nitric acid and urea peroxide to activate a portion of the raw materials for preparing humic acid, using ammonia water and a sulfomethylation agent to activate another portion of the raw materials for preparing humic acid, mixing the two activated materials for neutralization reaction, further reactivating the materials using the neutralization concentration heat, finally adding phosphorus, potassium and medium and trace elements to the reactivated materials for final activation, and obtaining the high-tower nitro fertilizer in the form of high-tower granulation.

[0030] Furthermore, the present invention provides a method for preparing an online multiple activated humic acid high tower nitro fertilizer, the preparation method comprising the following steps:

[0031] Step 1: crushing the raw material for preparing humic acid; and dividing the crushed raw material for humic acid into two parts;

[0032] Step 2: Add nitric acid, urea peroxide and a portion of crushed humic acid raw materials into a reactor, and activate them at 50-60° C. for 30-60 minutes to obtain a mixed solution containing nitric acid, urea peroxide and its decomposition products and activated humic acid;

[0033] Step 3: Add ammonia water, sulfomethylation reagent and another part of crushed humic acid raw materials into a reactor, activate at 50-60° C. for 30-60 min, and obtain a mixed solution containing ammonia water, sulfomethylation reagent and its decomposition product and activated humic acid;

[0034] Step 4: placing the mixed solution containing nitric acid, urea peroxide and its decomposition products and activated humic acid in the above step 2 and the mixed solution containing ammonia water, sulfomethylation agent and its decomposition products and activated humic acid in step 3 into a tubular reactor for neutralization reaction to prepare a neutralized slurry, wherein the pH value of the neutralized slurry is 5-9;

[0035] Step 5: Add phosphorus, potassium and trace elements to the neutralized slurry in step 4, and use evaporation to concentrate the moisture to less than 1%, and then transport the slurry to the top of the granulation tower for spray granulation.

[0036] The present invention is mainly aimed at the fact that humic acid activation is only carried out in one way in the prior art, and there are single situations such as humic acid molecular weight and functional groups, which cannot take into account the effects of promoting crop growth and improving soil. Further, when using the above-mentioned activated humic acid to produce nitro fertilizer, bubbles are easily generated in the slurry, resulting in a problem of reduced particle strength, and the humic acid has poor hard water resistance and is easy to flocculate when used, resulting in the defect of poor product effect; the present invention adopts two activation forms at the same time, so that the molecular weight of humic acid is in a wider distribution range and more functional groups, more oxygen content, and stronger soil improvement and crop growth stimulation. Further, by using ammonia water and sulfomethylation reagent to activate humic acid, the hard water resistance of humic acid can be improved, and urea formaldehyde can be generated to achieve the characteristics of long-term nitrogen fertilizer and improving the strength of nitro fertilizer. Further, ammonium polyphosphate can be generated to achieve the characteristics of improving hard water resistance, and its chelating performance and phosphorus fixation can promote crop growth; it should be noted that: the raw materials for preparing humic acid in step 1 of the present invention are crushed to 600-800 mesh.

[0037] In order to explain the present invention in more detail, the present invention is further described in conjunction with embodiments. Specific embodiments are as follows:

[0038] Example 1

[0039] An online multiple activated humic acid high tower nitro fertilizer, the nitro fertilizer comprises the following raw materials in parts by weight: 30 parts of pure nitric acid, 21 parts of pure ammonia, 6 parts of urea peroxide, 4 parts of sulfomethylation agent, 21 parts of raw materials for preparing humic acid, 15 parts of phosphorus, and 30 parts of potassium. The concentration of the nitric acid is 70%, and the concentration of ammonia water is 60%. The raw materials for preparing humic acid are weathered coal raw materials and lignite raw materials, the humic acid content in the weathered coal raw materials is 70-90%, and the humic acid content in the lignite raw materials is 60-80%; the weight ratio of the weathered coal raw materials to the lignite raw materials is 1:1. The sulfomethylation agent is a mixture of sodium sulfite and paraformaldehyde, wherein the polymerization degree of the paraformaldehyde is between 2 and 100, and the mass ratio of sodium sulfite to the paraformaldehyde is 4:1. The phosphorus element is a mixture of monoammonium phosphate and diammonium phosphate; the potassium element is a mixture of potassium sulfate, potassium chloride, potassium nitrate and potassium ammonium chloride.

[0040] The preparation method comprises the following steps: using nitric acid and urea peroxide to activate a part of the raw materials for preparing humic acid, using ammonia water and a sulfomethylation agent to activate another part of the raw materials for preparing humic acid, mixing the two activated materials for neutralization reaction, further reactivating the materials by using the heat of neutralization concentration, finally adding phosphorus, potassium and medium and trace elements to the reactivated materials for final activation, and obtaining high-tower nitro fertilizer by adopting the form of high-tower granulation.

[0041] Example 2

[0042] The invention discloses an online multiple activated humic acid high tower nitro fertilizer, which comprises the following raw materials in parts by weight: 40 parts of pure nitric acid, 10 parts of pure ammonia, 2 parts of urea peroxide, 1 part of sulfomethylation agent, 1 part of raw material for preparing humic acid, 10 parts of phosphorus element, 10 parts of potassium element and 2 parts of medium and trace elements.

[0043] The nitro fertilizer also includes medium and trace elements; the medium and trace elements are a mixture of magnesium sulfate, magnesium chloride, magnesium nitrate, calcium chloride, calcium nitrate, zinc sulfate, zinc nitrate, zinc chloride, zinc oxide, zinc carbonate, manganese sulfate, manganese nitrate, manganese chloride, manganese oxide, ferrous sulfate, ferric chloride, ferric oxide, copper sulfate, copper nitrate, boric acid, borax and sodium octaborate tetrahydrate. The concentration of nitric acid is 60%, and the concentration of ammonia water is 60%. The raw material for preparing humic acid is weathered coal raw material, and the humic acid content in the weathered coal raw material is 70-90%. The sulfomethylation agent is a mixture of sodium sulfite and paraformaldehyde, wherein the degree of polymerization of paraformaldehyde is between 2 and 100, and the mass ratio of sodium sulfite to paraformaldehyde is 4:1.5. The phosphorus element is a mixture of monoammonium phosphate, diammonium phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, superphosphate, double superphosphate, and calcium magnesium phosphate; the potassium element is a mixture of potassium sulfate, potassium chloride, potassium nitrate, and potassium ammonium chloride.

[0044] A method for preparing an online multiple activated humic acid high tower nitro fertilizer, the preparation method comprising the following steps:

[0045] Step 1: crushing the raw material for preparing humic acid; and dividing the crushed raw material for humic acid into two parts;

[0046] Step 2: Add nitric acid, urea peroxide and a portion of the crushed humic acid raw materials into a reactor, and activate them at 50° C. for 30 minutes to obtain a mixed solution containing nitric acid, urea peroxide and its decomposition products and activated humic acid;

[0047] Step 3: Add ammonia water, sulfomethylation reagent and another part of crushed humic acid raw materials into a reactor, activate at 60° C. for 60 minutes, and obtain a mixed solution containing ammonia water, sulfomethylation reagent and its decomposition products and activated humic acid;

[0048] Step 4: placing the mixed solution containing nitric acid, urea peroxide and its decomposition products and activated humic acid in the above step 2 and the mixed solution containing ammonia water, sulfomethylation agent and its decomposition products and activated humic acid in step 3 into a tubular reactor for neutralization reaction to prepare a neutralized slurry, wherein the pH value of the neutralized slurry is 5-9;

[0049] Step 5: Add phosphorus, potassium and trace elements to the neutralized slurry in step 4, and use evaporation to concentrate the moisture to less than 1%, and then transport the slurry to the top of the granulation tower for spray granulation.

[0050] Example 3

[0051] The invention discloses an online multiple activated humic acid high tower nitro fertilizer, which comprises the following raw materials in parts by weight: 60 parts of pure nitric acid, 20 parts of pure ammonia, 5 parts of urea peroxide, 3 parts of sulfomethylation agent, 20 parts of raw materials for preparing humic acid, 30 parts of phosphorus element, 30 parts of potassium element and 3 parts of medium and trace elements.

[0052] The nitro fertilizer also includes trace elements, and the trace element is zinc chloride. The concentration of nitric acid is 70%, and the concentration of ammonia water is 20%. The raw materials for preparing humic acid are weathered coal raw materials and lignite raw materials, the humic acid content in the weathered coal raw materials is 70-90%, the humic acid content in the lignite raw materials is 60-80%, and the weight ratio of the weathered coal raw materials to the lignite raw materials is 1:2. The sulfomethylation reagent is a mixture of sodium sulfite and paraformaldehyde, wherein the degree of polymerization of paraformaldehyde is between 2 and 100, and the mass ratio of sodium sulfite to paraformaldehyde is 4:1.2. The phosphorus element is a mixture of dipotassium hydrogen phosphate and superphosphate; the potassium element is potassium nitrate.

[0053] A method for preparing an online multiple activated humic acid high tower nitro fertilizer, the preparation method comprising the following steps:

[0054] Step 1: crushing the raw material for preparing humic acid; and dividing the crushed raw material for humic acid into two parts;

[0055] Step 2: Add nitric acid, urea peroxide and a portion of crushed humic acid raw materials into a reactor, and activate them at 60° C. for 60 minutes to obtain a mixed solution containing nitric acid, urea peroxide and its decomposition products and activated humic acid;

[0056] Step 3: Add ammonia water, sulfomethylation reagent and another part of crushed humic acid raw materials into a reactor, activate at 50° C. for 30 minutes, and obtain a mixed solution containing ammonia water, sulfomethylation reagent and its decomposition products and activated humic acid;

[0057] Step 4: placing the mixed solution containing nitric acid, urea peroxide and its decomposition products and activated humic acid in the above step 2 and the mixed solution containing ammonia water, sulfomethylation agent and its decomposition products and activated humic acid in step 3 into a tubular reactor for neutralization reaction to prepare a neutralized slurry, wherein the pH value of the neutralized slurry is 5-9;

[0058] Step 5: Add phosphorus, potassium and trace elements to the neutralized slurry in step 4, and use evaporation to concentrate the moisture to less than 1%, and then transport the slurry to the top of the granulation tower for spray granulation.

[0059] Example 4

[0060] An online multiple activated humic acid high tower nitro fertilizer, the nitro fertilizer comprises the following raw materials in parts by weight: 50 parts of pure nitric acid, 15 parts of pure ammonia, 3.5 parts of urea peroxide, 2 parts of sulfomethylation reagent, 9.5 parts of raw materials for preparing humic acid, 20 parts of phosphorus, 20 parts of potassium, and 2.5 parts of medium and trace elements. The medium and trace elements are a mixture of calcium chloride, ferric chloride and ferric oxide. The concentration of nitric acid is 65%, and the concentration of ammonia water is 40%. The raw materials for preparing humic acid are weathered coal raw materials and lignite raw materials, the humic acid content in the weathered coal raw materials is 70-90%, the humic acid content in the lignite raw materials is 60-80%, and the weight ratio of the weathered coal raw materials to the lignite raw materials is 2:1. The sulfomethylation reagent is a mixture of sodium sulfite and paraformaldehyde, wherein the polymerization degree of the paraformaldehyde is between 2 and 100, and the mass ratio of sodium sulfite to paraformaldehyde is 4:1.3. The phosphorus element is calcium magnesium phosphate; the potassium element is a mixture of potassium chloride and potassium ammonium chloride.

[0061] A method for preparing an online multiple activated humic acid high tower nitro fertilizer, the preparation method comprising the following steps:

[0062] Step 1: crushing the raw material for preparing humic acid; and dividing the crushed raw material for humic acid into two parts;

[0063] Step 2: Add nitric acid, urea peroxide and a portion of the crushed humic acid raw materials into a reactor, and activate them at 55° C. for 45 minutes to obtain a mixed solution containing nitric acid, urea peroxide and its decomposition products and activated humic acid;

[0064] Step 3: Add ammonia water, sulfomethylation reagent and another part of crushed humic acid raw materials into a reactor, activate at 55° C. for 45 minutes, and obtain a mixed solution containing ammonia water, sulfomethylation reagent and its decomposition products and activated humic acid;

[0065] Step 4: placing the mixed solution containing nitric acid, urea peroxide and its decomposition products and activated humic acid in the above step 2 and the mixed solution containing ammonia water, sulfomethylation agent and its decomposition products and activated humic acid in step 3 into a tubular reactor for neutralization reaction to prepare a neutralized slurry, wherein the pH value of the neutralized slurry is 5-9;

[0066] Step 5: Add phosphorus, potassium and trace elements to the neutralized slurry in step 4, and use evaporation to concentrate the moisture to less than 1%, and then transport the slurry to the top of the granulation tower for spray granulation.

[0067] Example 5

[0068] An online multiple activated humic acid high tower nitro fertilizer, the nitro fertilizer comprises the following raw materials in parts by weight: 45 parts of pure nitric acid, 14 parts of pure ammonia water, 5 parts of urea peroxide, 3 parts of sulfomethylation agent, 5 parts of raw materials for preparing humic acid, 5 parts of phosphorus element, 15 parts of potassium element, and 2 parts of medium and trace elements;

[0069] The sulfomethylation reagent is a mixture of sodium sulfite and paraformaldehyde, wherein the polymerization degree of paraformaldehyde is between 2 and 100, and the weight ratio of sodium sulfite to paraformaldehyde is 4:1.5; the raw materials for preparing humic acid include 3 parts of weathered coal and 2 parts of lignite, the humic acid content in the weathered coal raw material is 70-90%, and the humic acid content in the lignite raw material is 60-80%; the phosphorus element is 15 parts of monoammonium phosphate; the potassium element is 15 parts of potassium sulfate raw material; the trace elements are 1 part of zinc sulfate monohydrate and 1 part of borax.

[0070] A method for preparing an online multiple activated humic acid high tower nitro fertilizer, the preparation method comprising the following steps:

[0071] Step 1: crushing the raw material for preparing humic acid; and dividing the crushed raw material for humic acid into two parts;

[0072] Step 2: Add nitric acid, urea peroxide and a portion of crushed humic acid raw materials into a reactor, and activate them at 60° C. for 60 minutes to obtain a mixed solution containing nitric acid, urea peroxide and its decomposition products and activated humic acid;

[0073] Step 3: Add ammonia water, sulfomethylation reagent and another part of crushed humic acid raw materials into a reactor, activate at 50° C. for 30 minutes, and obtain a mixed solution containing ammonia water, sulfomethylation reagent and its decomposition products and activated humic acid;

[0074] Step 4: placing the mixed solution containing nitric acid, urea peroxide and its decomposition products and activated humic acid in the above step 2 and the mixed solution containing ammonia water, sulfomethylation agent and its decomposition products and activated humic acid in step 3 into a tubular reactor for neutralization reaction to prepare a neutralized slurry, wherein the pH value of the neutralized slurry is 5-9;

[0075] Step 5: Add phosphorus, potassium and trace elements to the neutralized slurry in step 4, and use evaporation to concentrate the moisture to less than 1%, and then transport the slurry to the top of the granulation tower for spray granulation.

[0076] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0077] Comparative Example 1

[0078] An online multiple activated humic acid high tower nitro fertilizer, the fertilizer is made of the following raw materials by weight: 45 parts of pure nitric acid, 14 parts of pure ammonia water, 5 parts of unactivated humic acid, 15 parts of monoammonium phosphate, 15 parts of potassium sulfate raw material, 1 part of zinc sulfate monohydrate, and 1 part of borax. The preparation method is as follows: step 1: mixing nitric acid and ammonia water in a tubular reactor for neutralization and concentration, and controlling the pH of the neutralized slurry at 5.5; step 2: adding unactivated humic acid, monoammonium phosphate, potassium sulfate, zinc sulfate monohydrate, evaporating the water content of borax to less than 1%, and then conveying the slurry to the top of the granulation tower for spray granulation.

[0079] Comparative Example 2

[0080] An online multiple activated humic acid high tower nitro fertilizer, the fertilizer is made of the following raw materials by weight: 45 parts of pure nitric acid, 14 parts of pure ammonia water, 3 parts of weathered coal, 2 parts of lignite, 15 parts of monoammonium phosphate, 15 parts of potassium sulfate raw material, 1 part of zinc sulfate monohydrate, and 1 part of borax. The humic acid content in the weathered coal raw material is 70-90%, and the humic acid content in the lignite raw material is 60-80%. The preparation method is as follows: step 1: crush the lignite or weathered coal to 600-800 mesh; step 2: mix nitric acid with weathered coal and lignite in proportion and add them to a reactor, activate them at 50°C for 60 minutes, and obtain a mixed solution containing nitric acid and activated humic acid. Step 3: mix the above solution and ammonia water, neutralize and concentrate them in a tubular reactor, and control the pH of the neutralized slurry to 5.5. Step 4: Add monoammonium phosphate, potassium sulfate, zinc sulfate monohydrate, and evaporate the water content of borax to below 1%, and then transport the slurry to the top of the granulation tower for spray granulation.

[0081] Comparative Example 3

[0082] An online multiple activated humic acid high tower nitro fertilizer, the fertilizer is made of the following raw materials by weight: 45 parts of pure nitric acid, 5 parts of urea peroxide, 14 parts of pure ammonia water, 3 parts of weathered coal, 2 parts of lignite, 15 parts of monoammonium phosphate, 15 parts of potassium sulfate raw material, 1 part of zinc sulfate monohydrate, and 1 part of borax. The humic acid content in the weathered coal raw material is 70-90%, and the humic acid content in the lignite raw material is 60-80%. The preparation method is as follows: step 1: crush the lignite or weathered coal to 600-800 mesh; step 2: mix nitric acid, urea peroxide, weathered coal, and lignite in proportion and add them to a reactor, activate them at 50°C for 60 minutes, and obtain a mixed solution containing nitric acid and activated humic acid. Step 3: mix the above solution and ammonia water, neutralize and concentrate them in a tubular reactor, and control the pH of the neutralized slurry to 5.5. Step 4: Add monoammonium phosphate, potassium sulfate, zinc sulfate monohydrate, and evaporate the water content of borax to below 1%, and then transport the slurry to the top of the granulation tower for spray granulation.

[0083] Comparative Example 4

[0084] An online multiple activated humic acid high tower nitro fertilizer, the fertilizer is made of the following raw materials by weight: 45 parts of pure nitric acid, 14 parts of pure ammonia water, 3 parts of weathered coal, 2 parts of lignite, 15 parts of monoammonium phosphate, 15 parts of potassium sulfate raw material, 1 part of zinc sulfate monohydrate, and 1 part of borax. The humic acid content in the weathered coal raw material is 70-90%, and the humic acid content in the lignite raw material is 60-80%. The preparation method is as follows: step 1: crush the lignite or weathered coal to 600-800 mesh; step 2: mix ammonia water with weathered coal and lignite in proportion and add them to a reactor, activate them at 50°C for 60 minutes, and obtain a mixed solution containing ammonia water and activated humic acid. Step 3: mix the above solution and nitric acid, neutralize and concentrate them in a tubular reactor, and control the pH of the neutralized slurry to 5.5. Step 4: Add monoammonium phosphate, potassium sulfate, zinc sulfate monohydrate, and evaporate the water content of borax to below 1%, and then transport the slurry to the top of the granulation tower for spray granulation.

[0085] Comparative Example 5

[0086] An online multiple activated humic acid high tower nitro fertilizer, the fertilizer is made of the following raw materials by weight: 45 parts of pure nitric acid, 14 parts of pure ammonia water, 3 parts of sulfomethylation agent, 3 parts of weathered coal, 2 parts of lignite, 15 parts of monoammonium phosphate, 15 parts of potassium sulfate raw material, 1 part of zinc sulfate monohydrate, and 1 part of borax. The humic acid content in the weathered coal raw material is 70-90%, and the humic acid content in the lignite raw material is 60-80%. The preparation method is as follows: step 1: crushing lignite or weathered coal to 600-800 mesh; step 2: mixing ammonia water, sulfomethylation agent, weathered coal, and lignite in proportion and adding them into a reactor, activating them at 50°C for 60 minutes, and obtaining a mixed solution containing ammonia water and activated humic acid. Step 3: mixing the above solution and nitric acid, neutralizing and concentrating them in a tubular reactor, and controlling the pH of the neutralized slurry to 5.5. Step 4: Add monoammonium phosphate, potassium sulfate, zinc sulfate monohydrate, and evaporate the water content of borax to below 1%, and then transport the slurry to the top of the granulation tower for spray granulation.

[0087] Comparative Example 6

[0088] Take the solution activated in step 2 and step 3 of Example 5, neutralize it at room temperature to pH 5.5, and then dry it at 40-50° C. to a moisture content of less than 1%.

[0089] Comparative Example 7

[0090] Take the slurry after the tubular reactor in step 4 of Example 5, and then dry it at 40-50° C. to a moisture content of less than 1%.

[0091] Test example:

[0092] Comparative Examples 1-7 and Example 5 were subjected to fertilizer property detection and agronomic tests. The tests were conducted in the Xinlianxin R&D Laboratory and greenhouse in Xinxiang County, Xinxiang City, Henan Province from November 2023 to February 2024. The agronomic tests used cucumbers as experimental materials. The same field management was adopted to measure the cucumber yield and soil bulk density at a dosage of 30 kg per mu of base fertilizer. The results are shown in Table 1:

[0093] Table 1: Different fertilizer properties and their effects on cucumber yield and soil bulk density

[0094]

[0095] In terms of the first hard water resistance, the unactivated humic acid used in Comparative Example 1 has extremely low hard water resistance, and flocculation occurs under 1D0 hard water, which basically does not meet the application conditions. After single or mixed activation with nitric acid, ammonia, urea peroxide, and sulfomethylation reagent, the hard water resistance is significantly enhanced. Comparing Comparative Examples 1 and 3 with Comparative Examples 4 and 5, it can be found that the hard water resistance of nitric acid or urea peroxide activation is higher than that of ammonia or sulfomethylation reagent activation. The main reason is that the humic acid activated by nitric acid or urea peroxide has a small molecular weight and strong hard water resistance, while the humic acid activated by ammonia or sulfomethylation reagent has a large molecular weight and weak hard water resistance. Comparing Comparative Example 3 with Comparative Example 2 and Comparative Example 5 with Comparative Example 4, it can be found that after using two activators, the hard water resistance is better than that of a single activator. The main reason is that the number of functional groups increases and the molecular weight decreases slightly after using multiple activators, which helps to improve the hard water resistance. Comparing Example 5 with Comparative Examples 6 and 7, it can be found that the hard water resistance is gradually enhanced. The main reason is that Example 5 has undergone two additional activation processes of neutralization and high-temperature granulation, with more functional groups, higher ammonium polyphosphate content, and smaller molecular weight. Finally, various effects synergistically enhance the hard water resistance.

[0096] Second, in terms of particle strength, by comparing Example 5 with Comparative Examples 1-7, it can be found that the particle strength of Comparative Examples 1-6 is about 30N, while that of Example 5 reaches 48N, the hardness is significantly improved, and the product quality is enhanced. The main reason is that additional urea formaldehyde is produced during the multiple activation process of humic acid, and urea formaldehyde has the effect of enhancing the hardness of fertilizer particles. Comparative Examples 1-6 do not have substances that produce urea formaldehyde, so the strength is relatively low. Comparative Example 7 has undergone a neutralization process, producing a small amount of urea formaldehyde, and the hardness is also improved to a certain extent.

[0097] Third, in terms of urea formaldehyde content, by comparing Example 5 with Comparative Examples 1-7, it can be found that the urea formaldehyde content in Example 5 reaches 2.1%. Urea formaldehyde, as a long-acting nitrogen fertilizer, can make up for the shortcomings of nitro fertilizer itself, which has strong quick-acting but insufficient long-acting properties. The two synergize and enhance the fertilizer effect by combining quick and slow effects. Comparative Examples 1-6 do not have substances that produce urea formaldehyde, so there is no urea formaldehyde. Comparative Example 7 has undergone a neutralization process and also produces a small amount of urea formaldehyde, with a content of 0.4%.

[0098] Fourth, in terms of the ammonium polyphosphate content, by comparing Example 5 with Comparative Examples 1-7, it can be found that the ammonium polyphosphate content in Example 5 reaches 3.6%. Ammonium polyphosphate has certain chelating properties, which can chelate trace element ions in raw materials such as lignite, weathered coal and phosphorus raw materials, increase the activity of trace elements, and enhance the absorption of trace elements in fertilizers by crops. In addition, when the fertilizer is dissolved in water for use, it can chelate metal ions in irrigation water, indirectly reducing the effect of metal ions on humic acid flocculation and improving the hard water resistance of humic acid. Third, ammonium polyphosphate, as an efficient phosphate fertilizer, can slow down the fixation of phosphorus by the soil, extend the movement distance of phosphate fertilizer in the soil, and enhance the absorption of phosphorus by crops. Comparative Examples 1-6 do not have the conditions for producing ammonium polyphosphate, so there is no ammonium polyphosphate. Comparative Example 7 has undergone a neutralization process and also produced a small amount of ammonium polyphosphate, with a content of 0.9%.

[0099] In terms of the fifth molecular weight, comparative example 1 has the largest molecular weight due to the lack of activation. After single or mixed activation with nitric acid, ammonia, carbamide peroxide, or sulfomethylating agent, the molecular weight tends to decrease. Comparing comparative examples 1 and 3 with comparative examples 4 and 5, it can be found that the humic acid activated by nitric acid or carbamide peroxide has a small molecular weight and strong hard water resistance, while the humic acid activated by ammonia or sulfomethylating agent has a large molecular weight. Comparing comparative example 3 with comparative example 2 and comparative example 5 with comparative example 4, it can be found that after using two activators, the molecular weight is less than that of a single activator. Comparing embodiment 5 with comparative examples 2-5, it can be found that the molecular weight distribution of embodiment 5 is more balanced, mainly because humic acid is activated by multiple activators. Comparing embodiment 5 with comparative examples 6 and 7, it can be found that as the activation process increases, the molecular weight tends to gradually decrease, mainly because embodiment 5 undergoes two additional activation processes of neutralization and high temperature granulation, at which time the activation reaction continues to occur, and the molecular weight gradually decreases, ultimately achieving a relatively uniform distribution of large, medium, and micro molecular weights, a wider molecular weight distribution range, and a more balanced effect of improving soil and stimulating crop growth.

[0100] In terms of the sixth functional group, since comparative example 1 has not been activated, the number of functional groups is small. After single or mixed activation with nitric acid, ammonia, carbamide peroxide, or sulfomethylation reagent, the functional groups tend to increase. Comparing comparative example 3 with comparative example 2, and comparing comparative example 5 with comparative example 4, it can be found that after using two activators, the number of functional groups is higher than that of a single activator. Comparing example 5 with comparative examples 2-5, it can be found that the number of functional groups in example 5 is the largest, mainly because humic acid is activated by multiple activators. Comparing example 5 with comparative examples 6 and 7, it can be found that with the increase of the activation process, the functional groups tend to gradually increase, mainly because example 5 undergoes two additional activation processes of neutralization and high-temperature granulation, and the activation reaction continues to occur at this time.

[0101] Seventh, in terms of soil improvement, the soil bulk density of Comparative Example 1 is the largest, because the unactivated humic acid does not have the function of improving the soil, the soil has poor air permeability and high density. The bulk density of Comparative Example 4 activated by ammonia water is the smallest, because the molecular weight of humic acid activated by ammonia water is large, and its effect on soil improvement is the most obvious. The rest also have a certain soil improvement effect, and the bulk density has decreased to varying degrees.

[0102] Eighth, in terms of yield, Example 5 has the highest yield, mainly due to the following reasons: First, humic acid has undergone multiple activations, a wider molecular weight distribution range, stronger resistance to hard water, more functional groups, more oxygen content, and stronger soil improvement and crop growth stimulation. Secondly, urea formaldehyde is generated. Urea formaldehyde, as a long-acting nitrogen fertilizer, can make up for the shortcomings of nitro fertilizer itself, which has strong quick-acting but insufficient long-acting properties. The two synergize and enhance the effect of fertilizers, combining fast and slow, and jointly improve the effect of fertilizers. Finally, ammonium polyphosphate is generated, which has certain chelating properties and can chelate trace element ions in raw materials such as lignite, weathered coal and phosphorus raw materials, increase the activity of trace elements, and enhance the absorption of trace elements in fertilizers by crops. When the fertilizer is dissolved in water and used, ammonium polyphosphate can chelate metal ions in irrigation water, indirectly reducing the influence of metal ions on humic acid flocculation and improving the resistance to hard water of humic acid. As an efficient phosphate fertilizer, ammonium polyphosphate can slow down the fixation of phosphorus by soil, extend the movement distance of phosphate fertilizer in soil, and enhance the absorption of phosphorus by crops.

[0103] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An online multiple activated humic acid high tower nitro fertilizer, characterized by: The nitro fertilizer is made of at least the following raw materials: nitric acid, ammonia water, urea peroxide, sulfomethylation agent, raw materials for preparing humic acid, phosphorus element and potassium element.

2. The online multiple activated humic acid high tower nitro fertilizer according to claim 1, characterized in that: The nitro fertilizer also includes trace elements.

3. The online multiple activated humic acid high tower nitro fertilizer according to claim 1, characterized in that: The concentration of the nitric acid is 60-70%, and the concentration of the ammonia water is 20-60%.

4. The online multiple activated humic acid high tower nitro fertilizer according to claim 1, characterized in that: The raw materials for preparing humic acid are weathered coal raw materials and lignite raw materials. The humic acid content in the weathered coal raw materials is 70-90%, and the humic acid content in the lignite raw materials is 60-80%.

5. The online multiple activated humic acid high tower nitro fertilizer according to claim 1, characterized in that: The sulfomethylation reagent is a mixture of sodium sulfite and paraformaldehyde, wherein the polymerization degree of the paraformaldehyde is between 2 and 100, and the mass ratio of sodium sulfite to paraformaldehyde is 4:1 to 1.

5.

6. The online multiple activated humic acid high tower nitro fertilizer according to claim 2, characterized in that: The phosphorus element is at least one of monoammonium phosphate, diammonium phosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, superphosphate, triple superphosphate, and calcium magnesium phosphate; The potassium element is at least one of potassium sulfate, potassium chloride, potassium nitrate and potassium ammonium chloride; The trace elements are at least one of magnesium sulfate, magnesium chloride, magnesium nitrate, calcium chloride, calcium nitrate, zinc sulfate, zinc nitrate, zinc chloride, zinc oxide, zinc carbonate, manganese sulfate, manganese nitrate, manganese chloride, manganese oxide, ferrous sulfate, ferric chloride, ferric oxide, copper sulfate, copper nitrate, boric acid, borax, and sodium octaborate tetrahydrate.

7. An online multiple activated humic acid high tower nitro fertilizer according to any one of claims 1 to 6, characterized in that: The nitro fertilizer comprises the following raw materials in parts by weight: 40-60 parts of pure nitric acid, 10-20 parts of pure ammonia, 2-5 parts of urea peroxide, 1-3 parts of sulfomethylation reagent, 1-20 parts of raw materials for preparing humic acid, 10-30 parts of phosphorus, 10-30 parts of potassium, and 2-3 parts of medium and trace elements.

8. The online multiple activated humic acid high tower nitro fertilizer according to claim 7, characterized in that: The nitro fertilizer comprises the following raw materials in parts by weight: 45 parts of pure nitric acid, 14 parts of pure ammonia water, 5 parts of urea peroxide, 3 parts of sulfomethylation reagent, 5 parts of raw materials for preparing humic acid, 5 parts of phosphorus, 15 parts of potassium, and 2 parts of medium and trace elements; The weight ratio of sodium sulfite to paraformaldehyde in the sulfomethylation reagent is 4:1.5; The raw materials for preparing humic acid are 3 parts of weathered coal and 2 parts of lignite; The phosphorus element is 15 parts of monoammonium phosphate; The potassium element is 15 parts of potassium sulfate raw material; The trace elements are 1 part of zinc sulfate monohydrate and 1 part of borax.

9. A method for preparing an online multiple activated humic acid high tower nitro fertilizer, characterized in that: The preparation method comprises the following steps: using nitric acid and urea peroxide to activate a part of the raw materials for preparing humic acid, using ammonia water and a sulfomethylation agent to activate another part of the raw materials for preparing humic acid, mixing the two activated materials for neutralization reaction, further reactivating the materials by using the heat of neutralization concentration, finally adding phosphorus, potassium and medium and trace elements to the reactivated materials for final activation, and obtaining high-tower nitro fertilizer by adopting the form of high-tower granulation.

10. The method for preparing an online multiple activated humic acid high tower nitro fertilizer according to claim 9, characterized in that: The preparation method thereof comprises the following steps: Step 1: crushing the raw material for preparing humic acid; and dividing the crushed raw material for humic acid into two parts; Step 2: Add nitric acid, urea peroxide and a portion of crushed humic acid raw materials into a reactor, and activate them at 50-60° C. for 30-60 minutes to obtain a mixed solution containing nitric acid, urea peroxide and its decomposition products and activated humic acid; Step 3: Add ammonia water, sulfomethylation reagent and another part of crushed humic acid raw materials into a reactor, activate at 50-60° C. for 30-60 min, and obtain a mixed solution containing ammonia water, sulfomethylation reagent and its decomposition product and activated humic acid; Step 4: placing the mixed solution containing nitric acid, urea peroxide and its decomposition products and activated humic acid in the above step 2 and the mixed solution containing ammonia water, sulfomethylation agent and its decomposition products and activated humic acid in step 3 into a tubular reactor for neutralization reaction to prepare a neutralized slurry, wherein the pH value of the neutralized slurry is 5-9; Step 5: Add phosphorus, potassium and trace elements to the neutralized slurry in step 4, and use evaporation to concentrate the moisture to less than 1%, and then transport the slurry to the top of the granulation tower for spray granulation.

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