CN104291296B - A kind of production method preparing dipotassium hydrogen phosphate by-product tomato special fertilizer - Google Patents

Abstract

The present invention relates to chemical technology field, a kind of production method preparing dipotassium hydrogen phosphate by-product tomato special fertilizer, analysis by the nutrient demand to tomato, prepare in traditional handicraft in conjunction with dipotassium hydrogen phosphate, in order to avoid too much phosphorus potassium element residues in the wasting of resources resulted in solution, the mother liquor produced in dipotassium hydrogen phosphate preparation process adds other trace compounds or microelement chelate, and then improve the yield of byproduct in dipotassium hydrogen phosphate preparation technology, further improve the added value in dipotassium hydrogen phosphate product preparation process, in carrying out dipotassium hydrogen phosphate product preparation process, crystal waste is used to carry out the preparation of tomato special fertilizer, reduce the discharging of waste liquid amount in dipotassium hydrogen phosphate preparation process, there is the significant value of environmental protection and economic benefit.

Description

A kind of production method for preparing dipotassium hydrogen phosphate by-product tomato special fertilizer

technical field

The invention relates to the technical field of chemical industry, in particular to a production method for preparing dipotassium hydrogen phosphate by-product tomato special fertilizer.

Background technique

Tomato, also known as tomato, is the most important crop in the family Solanaceae, and the United States, Israel, Italy and China are its main producing countries. Tomato growth requires good soil conditions and sufficient nutrient supply. However, according to the short-board theory of wooden barrels, improper fertilization of tomatoes or other crops and insufficient nutrient mix will have adverse effects on tomato growth. If nitrogen fertilizer is too much, it will lead to an imbalance in the ratio of carbon and nitrogen, which will easily cause flower drop and fruit drop, and fruit deformity; If the potassium supply is insufficient, the tomato is prone to premature aging and the stress resistance will decrease; if the calcium is deficient, navel rot will appear, which will affect the yield and quality of the product. It needs to be researched and discussed, which provides a reference for the preparation of special fertilizer for tomato.

For example, the patent No. 201310744804.8 "A Melt Granulation Nitro Functional Tomato Special Fertilizer and Its Preparation Method" discloses a method of chelating trace elements with ammonium nitrate, monoammonium phosphate, potassium sulfate, EDTA, and compound sodium nitrophenolate. , The filler is used as the raw material to mix, granulate and cool to obtain the special fertilizer for tomato.

Another example is "A Special Fertilizer for Greenhouse Tomato Seedlings" with patent number 201310753374.6. According to the growth law of tomato, it is formulated with inorganic nutrients, organic components, synergistic components, trace elements and modifiers as raw materials, and is stirred and mixed in a stirring tank. , spray granulation, and low-temperature sieving to obtain special fertilizer for tomato.

It can be seen that, in the prior art, the preparation of special fertilizer for tomato is all based on tomato growth characteristics and habits, and according to the requirement of tomato fertilizer, the compound fertilizer that adopts existing nitrogen, phosphorus and potassium fertilizer to compound and make; But, Although this kind of compound fertilizer can be matched according to the needs of tomatoes to meet the nutrient needs of tomatoes during the growth process, but this kind of fertilizer is mixed with a variety of mixtures when it is matched. After the absorption of the compound of one element, the remaining elements of other compounds remain in the soil. After long-term residue and erosion, the soil compacts and the soil aggregate structure is seriously damaged, resulting in a significant decline in the quality of tomatoes and seriously destroying the ecological environment.

Furthermore, in the preparation process of dipotassium hydrogen phosphate, one of hot-process phosphoric acid and wet-process phosphoric acid is usually used, combined with extraction method, double decomposition method and other methods for production, often need to be purified by crystallization in the production preparation process To improve the purity of the dipotassium hydrogen phosphate product and reduce the cost of the preparation of the dipotassium hydrogen phosphate product, but in this process, a large amount of waste liquid contains other nutrients, and excessive crystallization will also reduce the purity of the dipotassium hydrogen phosphate product , the dipotassium hydrogen phosphate product needs to be purified and processed, so that the preparation cost of the dipotassium hydrogen phosphate product is relatively high, and the added value of the product is low.

For this reason, through long-term efforts and discussions, this researcher combines the preparation process of dipotassium hydrogen phosphate product and the fertilizer requirements of tomatoes, and combines the preparation process of dipotassium hydrogen phosphate with the processing technology of tomato special fertilizer, making The waste liquid in the dipotassium hydrogen phosphate preparation process is fully utilized, and a new idea is provided for preparing a compound salt compound fertilizer with a compound structure for tomato fertilizer.

Contents of the invention

In order to solve the above-mentioned technical problems existing in the prior art, the present invention provides a kind of production method of preparing dipotassium hydrogen phosphate by-product tomato special fertilizer, has the preparation that tomato compound fertilizer can be carried out according to the demand of nutrient element in the fertilizer of tomato, and The compound fertilizer uses crystallization waste liquid produced during the preparation of dipotassium hydrogen phosphate as a raw material, and adds other trace element compounds and trace element chelates to ensure that when tomato is used as fertilizer, the product of dipotassium hydrogen phosphate In the preparation process, deep crystallization is not necessary to increase yield, reduce production cost, and further ensure that the purity of the dipotassium hydrogen phosphate product can reach more than 97%.

Specifically, it is achieved through the following technical solutions:

A production method for preparing dipotassium hydrogen phosphate by-product special tomato fertilizer, using phosphoric acid and carbonamide in a molar ratio of (1.5-2.1): 1 to mix, stirring and reacting at a temperature of 100-130°C for 3-5 hours to obtain intermediate Body slurry; then use the intermediate slurry to mix with 1.3-1.7mol alkaline potassium salt, and control the reaction temperature at 65°C-75°C, stir for 40-60min, and when the pH value is 8-9.5, the reaction ends , to obtain a slurry containing nitrogen, phosphorus, and potassium, and place the slurry containing nitrogen, phosphorus, and potassium in a cooling crystallizer for cooling crystallization and filtration, make the filtrate circulate and crystallize in the cooling crystallizer, and detect and analyze the filtrate , when the mass ratio of nitrogen, phosphorus pentoxide, potassium oxide is (0.9-1.1): (2.9-3.1): (1.4-1.6), stop crystallization and filter, and the filter cake that obtains is dipotassium hydrogen phosphate product, Add medium and trace element compounds to the filtrate to adjust to the primary product of compound fertilizer; put the primary product in a dryer, use a heating rate of 3°C/min to raise the temperature to 40-60°C, dry for 1-2h, adjust When the water content is 1-2%, special fertilizer for tomato can be prepared.

The reaction of phosphoric acid and carbonamide is the reaction of phosphoric acid solution and carbonamide solid.

The reaction of phosphoric acid and carbonamide is the reaction of phosphoric acid solution and carbonamide liquid.

The reaction of phosphoric acid and carbonamide is the reaction of phosphoric acid solid and carbonamide liquid.

The basic potassium salt is one of potassium hydroxide, potassium sulfate, potassium carbonate and potassium oxalate.

Described medium and trace element compound is the mixture of calcium sulfate, lime water, iron ion EDTA chelate, zinc sulfate, selenium EDTA chelate; Wherein, the molar content of calcium ion is 1-1.5mol; The molar content of iron ion 0.005-0.006mol; the added amount of zinc sulfate is 0.003-0.007% of the weight of the filtrate, and the added amount of the selenium EDTA chelate is 0.002-0.006% of the weight of the filtrate.

The special fertilizer for spinach is a chemical compound fertilizer, and its active ingredients are One or more mixtures of them.

Through the reaction of phosphoric acid and urea, and controlled by temperature, molar ratio and other process parameters, the structural formula of urea phosphate undergoes a complex polymerization reaction to form The intermediate ion has strong stability, and there is also a coordination bond between the carbon and oxygen atoms, and the solution in which the ion exists contains a large amount of dihydrogen phosphate. Therefore, when the intermediate When potassium ions are added to the solution of ions, the potassium ions gradually react with the dihydrogen phosphate in the solution to form potassium dihydrogen phosphate. As the amount of potassium ions added gradually increases and the pH value is adjusted, potassium dihydrogen phosphate gradually Converted into dipotassium hydrogen phosphate, and appropriate excess potassium ions, the intermediate ions react with potassium ions, replacing part of the ammonium ions, so that the intermediate ions are chelated into The intermediate ion has a positive charge, and when the solution participates in other negatively charged ions or compounds, it will form a double salt compound with the ion, further enriching the nutritional content of the product.

If potassium sulfate is added to the solution to adjust the content of potassium element in the solution, sulfur-based double salt compound fertilizer will be produced.

If potassium nitrate is added to the solution to adjust the content of potassium element and nitrogen element in the solution, then nitrate compound salt compound fertilizer will be generated.

At the same time, when the solution contains a large amount of elements that affect fertilizer impurities, it is not easy to form colloids, so that the properties of the fertilizer will not be affected:

For example, in the process of wet-process phosphoric acid production of dipotassium hydrogen phosphate products, a large amount of iron, magnesium, aluminum and other elements will produce colloids in the solution, which will affect the process simplicity of the dipotassium hydrogen phosphate product preparation process, making dipotassium hydrogen phosphate In the preparation process of potassium products, the cost of impurity removal is relatively high; iron ions, magnesium ions, and aluminum ions are all positively charged ions, which will not interfere with the intermediate ions. Instead, the solution and the intermediate ions form a Another easy-to-decompose intermediate ion of elements such as aluminum makes it fully absorbed by crops.

Compared with the prior art, the technical effect of the technical solution of the present invention is reflected in:

1. Through the analysis of the nutrient requirements of tomatoes, combined with the traditional process of dipotassium hydrogen phosphate preparation, in order to avoid the waste of resources caused by too much phosphorus and potassium remaining in the solution, the dipotassium hydrogen phosphate produced in the preparation process Add other trace element compounds or trace element chelates to the mother liquor, thereby increasing the yield of by-products in the preparation process of dipotassium hydrogen phosphate, further increasing the added value in the preparation process of dipotassium hydrogen phosphate products, and preparing dipotassium hydrogen phosphate products In the process, the crystallization waste liquid is used to prepare tomato special fertilizer, which reduces the discharge of waste liquid in the preparation process of dipotassium hydrogen phosphate, and has significant environmental protection value and economic benefits.

2. By combining the preparation process of tomato special fertilizer and dipotassium hydrogen phosphate product, it avoids the guarantee of the output of dipotassium hydrogen phosphate product in the traditional process, and avoids the waste of phosphorus and potassium element resources, excessive crystallization, resulting in phosphoric acid The technical problem that the purity of dipotassium hydrogen phosphate product is lower appears, for this reason, through the combination of above two kinds of techniques, make in the process of preparing dipotassium hydrogen phosphate product, have prepared the special compound state compound fertilizer that is suitable for tomato application, simultaneously The purity of the dipotassium hydrogen phosphate product is also improved to more than 97%, the added value of the product is improved, and the cost is reduced by 85%.

3. According to the demand of tomato for special fertilizer, the mother liquor in the preparation process of dipotassium hydrogen phosphate is used to prepare tomato special fertilizer, so that the special fertilizer forms a compound fertilizer in a chemical state, improves the absorption and utilization rate of tomatoes, and ensures the absorption and utilization process Among them, the absorption of each compound fertilizer can be absorbed in a balanced ratio, so that the nutrients remaining in the soil exist in the form of compound salts, and will not react with other mineral elements in the soil alone, avoiding the short board of the barrel The emergence of the theory ensures the normal growth needs of tomatoes without causing changes in the soil structure layer, that is, avoiding soil compaction, ensuring soil quality, and avoiding environmental pollution caused by crop fertilization.

4. Through the control of the technical parameters in the compound fertilizer production process, that is, the temperature, raw material concentration and ratio, after the reaction of phosphoric acid and urea, a urea phosphate product is produced. The urea phosphate product itself has strong acidity, and phosphoric acid and urea Urea is a compounded double salt formed by coordinating bonds, which is also used as a fertilizer for crops in traditional technology, and the absorption rate of the compounded double salt by crops is higher than that of urea, ammonium carbonate, and ammonium nitrate. It is a compound fertilizer with excellent absorption rate of mono- and binary fertilizers. However, in the presence of phosphoric acid, complex decomposition and polymerization reactions will occur at a temperature of 80-250°C. , so that urea phosphate forms (H ₂ PO ₄ ) ^- and (H ₂ NCONH ₃ ) ⁺ two ions, (H ₂ NCONH ₃ ) ⁺ ions are close to phosphoric acid, and form at a temperature of 80-160°C The intermediate ion and dihydrogen phosphate form a coordination bond between C and O. This intermediate ion can chelate with the middle element compound to form a multi-element intermediate ion, which can then continue to interact with other negatively charged compounds or ions Form a chelate, increase the content of elements in the double salt, and then adjust the nutrient content in the double salt where the ion exists. At the same time, the chelate can be hydrolyzed and absorbed by the crops, thereby effectively providing fertilizer for the crops for a long time. At the same time, combined with the determination of the element content in the solution in which the ion exists, the content of each element when the double salt is formed is adjusted, and the compound fertilizer containing the compound double salt structure is obtained by drying, which improves the quality of the tomato special fertilizer.

detailed description

The technical solutions of the present invention will be further limited below in conjunction with specific embodiments, but the scope of protection is not limited to the descriptions made.

Principle description:

The present invention studies and discusses the mechanism of the reaction between phosphoric acid and carbonamide, and combines the prior art literature to understand that phosphoric acid and carbonamide react to form urea phosphate, and its molecular formula is: CO(NH ₂ ) ₂ .H ₃ PO ₄ , In a higher temperature environment, the chemical bond between H and O in phosphoric acid will be broken, and hydrogen ions will combine with urea to form an ion state with a positive charge, making urea phosphate form an ion double salt that attracts positive and negative charges. , the mechanism and structural reaction is as follows: CO(NH ₂ ) ₂ .H ₃ PO ₄ →(H ₂ PO ₄ ) ^- .(H ₂ NCONH ₃ ) ⁺

Furthermore, in the presence of phosphoric acid in the presence of phosphoric acid, the (H ₂ NCONH ₃ ) ⁺ positive ion in the double salt of urea phosphate ion is close to phosphoric acid to form the intermediate ion of the C→O coordination bond, which is (CO ₅ PN ₂ H ₈ ) ⁺ , so that the urea phosphate intermediate contains a large amount of (H ₂ PO ₄ ) ^- and (CO ₅ PN ₂ H ₈ ) ⁺ ions. Potassium dihydrogen phosphate crystals are precipitated, and there is a dynamic equilibrium between potassium dihydrogen phosphate and dipotassium hydrogen phosphate. By controlling the pH environment of the solution, dipotassium hydrogen phosphate can be generated, and excess potassium ions and (CO ₅ PN ₂ H ₈ ) ⁺ ions react, and replace part of NH ₄ ⁺ , so that the solution contains (CO ₅ PNH ₄ K) ⁺ double salt ions, and through detection, analysis and control of the content of N, P, and K elements in the solution, it can be obtained after heating and drying. The combined state double salt compound fertilizer containing N, P and K elements can be obtained.

Its specific reaction principle will be further explained by the following reaction structural formula and reaction mechanism:

Reaction formula one:

CO(NH ₂ ) ₂ +H ₃ PO ₄ →CO(NH ₂ ) ₂ .H ₃ PO ₄

Reaction two:

Reaction three:

Wherein, the dotted line between the carbon atom and the oxygen atom indicates that there is a coordination bond between the C atom and the O atom.

Reaction four:

Wherein, the dotted line between the carbon atom and the oxygen atom indicates that there is a coordination bond between the C atom and the O atom.

Reaction five:

Obtain potassium ammonium hydrogen phosphate double salt, potassium ions in potassium ammonium hydrogen phosphate react with potassium dihydrogen phosphate to generate dipotassium hydrogen phosphate and ammonium hydrogen phosphate ion, and ammonium hydrogen phosphate ion is then combined with The intermediate ionization synthesizes the combined nitrogen, phosphorus and potassium compound salt structure, and then can adjust the nitrogen, phosphorus and potassium compound fertilizer suitable for spinach.

Noun description:

Urea phosphate (UP), CAS No. 4861-19-2, molecular formula CH ₇ N ₂ O ₅ P, can be expressed as CO(NH ₂ ) ₂ ·H ₃ PO ₄ :

It is a fine chemical product widely used in animal husbandry, industry, agriculture and other fields. Its solid is white crystal or crystalline powder, soluble in water and alcohol, insoluble in ether, toluene and carbon tetrachloride, and its aqueous solution is It is acidic and starts to decompose when melting to release carbon dioxide and ammonia.

Embodiment: The present invention will be further elaborated below with specific operation examples.

Example 1

A production method for preparing dipotassium hydrogen phosphate by-product tomato special fertilizer, comprising the following steps:

(1) Preparation and mixing of raw materials: Phosphoric acid and carbonamide are placed in a stirred reactor at a molar ratio of 2.1:1, at a temperature of 130°C, and the stirring speed of the stirred tank is controlled at 200r/min to stir and mix for 5 hours to obtain an intermediate slurry;

(2) Preparation of K ₂ HPO ₄ : Add 1.7 mol of basic potassium salt into the reaction kettle containing the intermediate slurry prepared in step 1) at a constant speed for 3 hours, the reaction temperature is 75°C, stir for 60 minutes, and check the pH value When being 9.5, reaction finishes, obtains the slurry containing nitrogen, phosphorus, potassium;

(3) Cyclic crystallization filtration: place the slurry containing nitrogen, phosphorus, and potassium obtained in step 2) in a cooling crystallizer to cool down to a temperature of 5°C within 10 seconds, cool down to cyclic crystallization filtration, and detect and analyze the nutrient content in the filtrate, When the mass ratio of nitrogen component, phosphorus pentoxide component, and potassium oxide component is 1.1:3.1:1.6, stop crystallization and filter to obtain filter cake as dipotassium hydrogen phosphate, add trace element compounds to the filtrate to adjust the fertilizer structure to become a compound The initial product of state compound fertilizer;

(4) Filtrate drying: the first product of compound fertilizer obtained in step 3) is placed in a dryer, and the temperature is raised to 60° C. at a heating rate of 3° C./min. After drying for 2 hours, the moisture content is adjusted to 2%. The special fertilizer for tomato can be obtained.

The reaction of phosphoric acid and carbonamide is the reaction of phosphoric acid solution and carbonamide solid.

Described alkaline potassium salt is potassium hydroxide, and its concentration is 30%.

Described middle trace element compound is the mixture of calcium sulfate, lime water, iron ion EDTA chelate, zinc sulfate, selenium EDTA chelate; Wherein, the molar content of calcium ion is 1mol; The molar content of iron ion is 0.005mol The addition of zinc sulfate is 0.003% of the weight of the filtrate, and the addition of the selenium EDTA chelate is 0.002% of the weight of the filtrate.

Example 2

A production method for preparing dipotassium hydrogen phosphate by-product tomato special fertilizer, comprising the following steps:

(1) Preparation and mixing of raw materials: Phosphoric acid and carbonamide are placed in a stirred reactor at a molar ratio of 1.5:1, at a temperature of 100°C, and the stirring speed of the stirred tank is controlled at 180r/min to stir and mix for 3 hours to obtain an intermediate slurry;

(2) Preparation of K ₂ HPO ₄ : Add 1.3 mol of basic potassium salt into the reaction kettle containing the intermediate slurry prepared in step 1) at a constant speed for 2 hours, the reaction temperature is 65°C, stir for 40 minutes, and check the pH value When being 8, reaction finishes, obtains the slurry containing nitrogen, phosphorus, potassium;

(3) Cyclic crystallization filtration: place the slurry containing nitrogen, phosphorus, and potassium obtained in step 2) in a cooling crystallizer to cool down to a temperature of 4° C. within 10 seconds, cool down to cyclic crystallization filtration, and detect and analyze the nutrient content in the filtrate. When the mass ratio of nitrogen component, phosphorus pentoxide component and potassium oxide component is 0.9:2.9:1.4, stop crystallization and filter, obtain filter cake as dipotassium hydrogen phosphate, add trace element compound to the filtrate to adjust fertilizer structure to become compound The initial product of state compound fertilizer;

(4) Filtrate drying: the first finished product of the combined compound fertilizer obtained in step 3) is placed in a dryer, and the temperature is raised to 40° C. at a heating rate of 3° C./min. After drying for 1 hour, the moisture content is adjusted to be 1%, that is, Special fertilizer for tomato can be obtained.

The reaction of phosphoric acid and carbonamide is the reaction of phosphoric acid solution and carbonamide liquid.

Described basic potassium salt is potassium sulfate, and concentration is 20%.

Described middle trace element compound is the mixture of calcium sulfate, lime water, iron ion EDTA chelate, zinc sulfate, selenium EDTA chelate; Wherein, the molar content of calcium ion is 1.5mol; The molar content of iron ion is 0.006 mol; the addition of zinc sulfate is 0.007% of the weight of the filtrate, and the addition of the selenium EDTA chelate is 0.006% of the weight of the filtrate.

Example 3

A production method for preparing dipotassium hydrogen phosphate by-product tomato special fertilizer, comprising the following steps:

(1) Preparation and mixing of raw materials: Phosphoric acid and carbonamide are placed in a stirred reactor at a molar ratio of 1.8:1, at a temperature of 115°C, and the stirring speed of the stirred tank is controlled at 190r/min to stir and mix for 4 hours to obtain an intermediate slurry;

(2) Preparation of K ₂ HPO ₄ : Add 1.5 mol of basic potassium salt into the reaction kettle containing the intermediate slurry prepared in step 1) at a constant speed for 2.5 hours, the reaction temperature is 70°C, stir for 50 minutes, and check the pH When the value was 8.5, the reaction ended, and the slurry containing nitrogen, phosphorus and potassium was obtained;

(3) Cyclic crystallization filtration: place the slurry containing nitrogen, phosphorus, and potassium obtained in step 2) in a cooling crystallizer to cool down to a temperature of 3°C within 10 seconds, cool down to cyclic crystallization filtration, and detect and analyze the nutrient content in the filtrate, When the mass ratio of nitrogen component, phosphorus pentoxide component and potassium oxide component is 1:3:1.5, stop crystallization and filter to obtain filter cake as dipotassium hydrogen phosphate, add trace element compound to the filtrate to adjust the fertilizer structure to become a compound The initial product of state compound fertilizer;

(4) Filtrate drying: place the primary product of compound fertilizer obtained in step 3) in a dryer, and use a heating rate of 3° C./min to raise the temperature to 50° C. After drying for 1.5 hours, adjust the moisture content to 1.5%. , can make special fertilizer for tomato.

The reaction of phosphoric acid and carbonamide is the reaction of phosphoric acid solid and carbonamide liquid.

Described basic potassium salt is potassium carbonate, and concentration is 25%.

Described middle trace element compound is the mixture of calcium sulfate, lime water, iron ion EDTA chelate, zinc sulfate, selenium EDTA chelate; Wherein, the molar content of calcium ion is 1.3mol; The molar content of iron ion is 0.0055 mol; the addition of zinc sulfate is 0.005% of the weight of the filtrate, and the addition of the selenium EDTA chelate is 0.004% of the weight of the filtrate.

Example 4

A production method for preparing dipotassium hydrogen phosphate by-product tomato special fertilizer, comprising the following steps:

(1) Preparation and mixing of raw materials: Put phosphoric acid and carbonamide at a molar ratio of 1.7:1 in a stirred reactor at a temperature of 110°C and control the stirring speed of the stirred tank at 185r/min to stir and mix for 3.5 hours to obtain intermediate body slurry;

(2) Preparation of K ₂ HPO ₄ : Add 1.4 mol of basic potassium salt into the reaction kettle containing the intermediate slurry prepared in step 1) at a constant speed for 2.3 hours, the reaction temperature is 68°C, stir for 45 minutes, and check the pH When the value is 9, the reaction ends, and the slurry containing nitrogen, phosphorus and potassium is obtained;

(3) Cyclic crystallization filtration: place the slurry containing nitrogen, phosphorus, and potassium obtained in step 2) in a cooling crystallizer to cool down to a temperature of 5°C within 10 seconds, cool down to cyclic crystallization filtration, and detect and analyze the nutrient content in the filtrate, When the mass ratio of nitrogen component, phosphorus pentoxide component and potassium oxide component is 0.9:3.1:1.4, stop crystallization and filter to obtain filter cake as dipotassium hydrogen phosphate, add trace element compound to the filtrate to adjust the fertilizer structure to become a compound The initial product of state compound fertilizer;

(4) Filtrate drying: place the primary product of compound fertilizer obtained in step 3) in a dryer, and heat up to 45°C at a heating rate of 3°C/min. After drying for 1.3h, adjust the moisture content to 1.3%. , can make special fertilizer for tomato.

The reaction of phosphoric acid and carbonamide is the reaction of phosphoric acid solution and carbonamide liquid.

The basic potassium salt is potassium oxalate with a concentration of 30%.

Described middle trace element compound is the mixture of calcium sulfate, lime water, iron ion EDTA chelate, zinc sulfate, selenium EDTA chelate; Wherein, the molar content of calcium ion is 1.2mol; The molar content of iron ion is 0.0053 mol; the addition of zinc sulfate is 0.004% of the weight of the filtrate, and the addition of the selenium EDTA chelate is 0.003% of the weight of the filtrate.

Example 5

A production method for preparing dipotassium hydrogen phosphate by-product tomato special fertilizer, comprising the following steps:

(1) Preparation and mixing of raw materials: Put phosphoric acid and carbonamide at a molar ratio of 1.9:1 in a stirred reactor at a temperature of 120°C and control the stirring speed of the stirred tank at 195r/min to stir and mix for 4.5 hours to obtain intermediate body slurry;

(2) Preparation of K ₂ HPO ₄ : Add 1.6 mol of basic potassium salt into the reaction kettle containing the intermediate slurry prepared in step 1) at a constant speed for 2.8 hours, the reaction temperature is 70°C, stir for 55 minutes, and check the pH When the value was 8.8, the reaction ended, and the slurry containing nitrogen, phosphorus and potassium was obtained;

(3) Cyclic crystallization filtration: place the slurry containing nitrogen, phosphorus, and potassium obtained in step 2) in a cooling crystallizer to cool down to a temperature of 4° C. within 10 seconds, cool down to cyclic crystallization filtration, and detect and analyze the nutrient content in the filtrate. When the mass ratio of nitrogen component, phosphorus pentoxide component and potassium oxide component is 1.1:2.9:1.6, stop crystallization and filter to obtain filter cake as dipotassium hydrogen phosphate, add trace element compound to the filtrate to adjust the fertilizer structure to become a compound The initial product of state compound fertilizer;

(4) Filtrate drying: place the primary product of compound fertilizer obtained in step 3) in a dryer, and heat up to 55°C at a heating rate of 3°C/min. After drying for 1.8h, adjust the moisture content to 1.8%. , can make special fertilizer for tomato.

The reaction of phosphoric acid and carbonamide is the reaction of phosphoric acid solid and carbonamide liquid.

Described alkaline potassium salt is potassium hydroxide, concentration 30%.

Described middle trace element compound is the mixture of calcium sulfate, lime water, iron ion EDTA chelate, zinc sulfate, selenium EDTA chelate; Wherein, the molar content of calcium ion is 1.4mol; The molar content of iron ion is 0.0058 mol; the addition of zinc sulfate is 0.006% of the weight of the filtrate, and the addition of the selenium EDTA chelate is 0.005% of the weight of the filtrate.

Experimental example: the technical effect and product characteristics of the technical solution of the present invention will be further described in conjunction with specific examples below.

Test example 1 dipotassium hydrogen phosphate product purity detection

Example 1, Example 2, Example 3, Example 4, and Example 5 were sampled 5g respectively, placed in a 50ml beaker, dissolved in distilled water and stirred evenly, and then titrated with 30% hydrochloric acid, and recorded The consumption V1 of hydrochloric acid; Adopt the concentration again that the sodium hydroxide solution titration concentration of 30% is the hydrochloric acid V1 of 30%, record the consumption of hydrochloric acid; Carry out the calculation of dipotassium hydrogen phosphate content according to equivalent replacement formula again, and then calculate embodiment 1, the purity of the dipotassium hydrogen phosphate product that embodiment 2, embodiment 3, embodiment 4, embodiment 5 make are shown in table 1 respectively:

Table 1:

Example 1 Example 2 Example 3 Example 4 Example 5 Dipotassium phosphate(%) 97.1 97.6 98.8 98.3 99.1

As can be seen from the table, the dipotassium hydrogen phosphate directly produced by the technical scheme of the present invention can make the purity of the dipotassium hydrogen phosphate product reach more than 97% without the need for the treatment of the impurity removal step, which is a significant improvement.

Experimental example 2 Effect experiment of special fertilizer for tomato on the growth of tomato cultivation process

2.1 Experimental processing and methods

Experimental group: The tomato special fertilizer+livestock manure obtained in Example 1, Example 2, Example 3, Example 4, and Example 5 were used to cultivate tomatoes in the experimental group, and other cultivation steps were the same as the traditional cultivation scheme.

Control group 1: Traditional compound fertilizers were used to prepare nitrogen, phosphorus and potassium fertilizers + livestock manure to cultivate tomatoes, and other cultivation steps were the same as traditional cultivation steps.

Control group 2: Tomatoes were cultivated with livestock manure, and other steps were the same as the traditional cultivation steps.

Dosage: The amount of fertilizer is 5kg.

500 plants were planted in each experiment.

2.2 Experimental results

Observe the tomato fruit cultivated by the above several groups of test groups and the control group, the premature senescence of the tomato and the flower drop of the tomato flowering process, the results are shown in Table 2:

Table 2:

Fruit deformity rate (%) Fruit navel disease rate (%) Premature aging rate (%) Flower drop rate (%) Example 1 11.6 3.5 10.1 30 Example 2 11.7 4.8 9.8 twenty three Example 3 11.3 5.1 10.2 25 Example 4 12.1 3.4 8.9 28 Example 5 11.4 4.1 8.5 twenty one Control group 1 22.3 25.2 27.6 43 Control group 2 45.3 51.2 50.6 64

As can be seen from the results shown in the data in Table 2 above, the special fertilizer for tomato of the present invention has a relieving effect on tomato fruit, tomato premature senescence and flower drop in the flowering process, and the relieving effect is more obvious, and has a better effect on promoting tomato production. progressive.

Test Example 3 Contrast test of elemental detection of tomato special fertilizer remaining in the soil after being absorbed by tomato

3.1 Test treatment

Experimental group: use the special compound fertilizer for tomato produced by the production methods of Example 1, Example 2, Example 3, Example 4, and Example 5 of the present invention to carry out nutrient solution soilless cultivation of tomato.

Control group: The traditional tomato compound fertilizer formulated according to the requirements of tomato nitrogen, phosphorus and potassium nutrients was used for nutrient solution soilless cultivation.

Method: After the tomato was cultivated for one month, the contents of nitrogen, phosphorus and potassium nutrients in the experimental group and the control group were determined.

Fertilizer dosage: both the experimental group and the control group used 0.5 kg of fertilizer.

3.2 Test results

table 3:

As can be seen from the data in the above table, the special tomato fertilizer of the present invention can be absorbed by tomatoes in a large amount, and the content of nitrogen, phosphorus and potassium elements in the nutrient solution of the control group has a large range of improvement compared with before cultivation. It can be seen that the present invention The special tomato fertilizer can be better absorbed and utilized by tomatoes, thereby maintaining the nutrients in the original soil, ensuring the quality of the soil, and will not cause excessive nitrogen, phosphorus, and potassium elements in the soil to cause compaction, which is different from traditional complex fertilizers. Compared with compound fertilizer, it has a significant effect.

At the same time, the amount of nitrogen, phosphorus, and potassium elements remaining in the nutrient solution is integrated, and it can be seen that the nitrogen, phosphorus, and potassium elements remaining in the nutrient solution can meet the element matching in the chemical structure of the active ingredients, and then the overall residual In the nutrient solution, the technical problems of decomposing the fertilizer into a single element and causing waste of the element and polluting the environment after application of the fertilizer are avoided.

It must be pointed out here that the above examples and test examples are limited to further elaboration and understanding of the technical solution of the present invention, and cannot be interpreted as further limiting the technical solution of the present invention. Those skilled in the art made on this basis Inventions and creations with non-prominent substantive features and significant progress still belong to the protection category of the present invention.

Claims (7)

1. the production method preparing dipotassium hydrogen phosphate by-product tomato special fertilizer, it is characterised in that use phosphoric acid and phosphoamide It is (1.5-2.1) according to mol ratio: 1 mixing, is 100-130 DEG C in temperature, stirring reaction 3-5h, obtain intermediate slip；Again Use this intermediate slip to mix with 1.3-1.7mol alkaline potassium salt, and to control reaction temperature be 65 DEG C-75 DEG C, stirring reaction 40-60min, when detection pH value is 8-9.5, reaction terminates, it is thus achieved that nitrogenous, the slip of phosphorus, potassium, and by nitrogenous, phosphorus, the slip of potassium It is placed in cooler crystallizer and carries out decrease temperature crystalline filtration treatment, make filtrate circulation crystallization in cooler crystallizer process, and detect Analyze filtrate, when nitrogen, phosphorus pentoxide, the mass ratio of potassium oxide are (0.9-1.1): (2.9-3.1): time (1.4-1.6), stop Crystallize and filter, it is thus achieved that filter cake be dipotassium hydrogen phosphate product, in filtrate add in trace compound mixture adjust Whole for compound state composite fertilizer just finished product；And first finished product is placed in baker, using programming rate is that 3 DEG C/min is warming up to 40- 60 DEG C, after being dried 1-2h, adjustment moisture is 1-2%, can be prepared by tomato special fertilizer；Described middle trace compound Mixture be calcium sulfate, limewash, iron ion EDTA chelate, zinc sulfate, the mixture of selenium EDTA chelate.

Prepare the production method of dipotassium hydrogen phosphate by-product tomato special fertilizer the most as claimed in claim 1, it is characterised in that include Following steps:

(1) raw material preparation mixing: be (1.5-2.1) according to mol ratio by phosphoric acid and phosphoamide: 1 in stirring-type reactor, Temperature is 100-130 DEG C, and the mixing speed controlling stirred tank is that 180-200r/min stirs hybrid reaction 3-5h, obtains intermediate Slip；

(2) K is prepared₂HPO₄: again the alkaline potassium salt 2-3h of 1.3-1.7mol is at the uniform velocity added containing in steps 1) the intermediate material for preparing In the reactor of slurry, reaction temperature is 65 DEG C-75 DEG C, stirring reaction 40-60min, and when detection pH value is 8-9.5, reaction terminates, Obtain nitrogenous, the slip of phosphorus, potassium；

(3) circulation crystallization filters: by step 2) obtain slip nitrogenous, phosphorus, potassium and be placed in cooler crystallizer and in 10s, be cooled to temperature Spend≤5 DEG C, down cycles crystallization filtration treatment, and detect the nutrient content analyzed in filtrate, treat that nitrogen component, phosphorus pentoxide become Divide, the mass ratio of potassium oxide composition is (0.9-1.1): (2.9-3.1): time (1.4-1.6), stops crystallization and also filters, it is thus achieved that filter Cake is dipotassium hydrogen phosphate, and in adding in filtrate, trace compound adjusts fertilizer structure becomes to become at the beginning of compound state composite fertilizer Product；

(4) filtrate dries: by step 3) the compound state composite fertilizer that obtains just finished product is placed in baker, and using programming rate is 3 DEG C/min is warming up to 40-60 DEG C, after being dried 1-2h, adjustment moisture is 1-2%, can be prepared by tomato special fertilizer.

Prepare the production method of dipotassium hydrogen phosphate by-product tomato special fertilizer the most as claimed in claim 1 or 2, it is characterised in that Described phosphoric acid reacts with phosphoamide, for phosphoric acid solution and phosphoamide solid reaction.

Prepare the production method of dipotassium hydrogen phosphate by-product tomato special fertilizer the most as claimed in claim 1 or 2, it is characterised in that Described phosphoric acid reacts with phosphoamide, for phosphoric acid solution and phosphoamide liquid reactions.

Prepare the production method of dipotassium hydrogen phosphate by-product tomato special fertilizer the most as claimed in claim 1 or 2, it is characterised in that Described phosphoric acid reacts with phosphoamide, for phosphoric acid solid and phosphoamide liquid reactions.

Prepare the production method of dipotassium hydrogen phosphate by-product tomato special fertilizer the most as claimed in claim 1 or 2, it is characterised in that Described alkaline potassium salt is a kind of in potassium carbonate, potassium oxalate.

Prepare the production method of dipotassium hydrogen phosphate by-product tomato special fertilizer the most as claimed in claim 1 or 2, it is characterised in that described tomato Special fertilizer is compound state composite fertilizer, and its active ingredient has In one or more mixtures, above-mentioned active ingredient In structural formula, carbon oxygen dotted line is coordinate bond.