Spherical micron phosphate fertilizer with high fertilizer efficiency and preparation method thereof

Abstract

The invention relates to a spherical micron phosphate fertilizer with high fertilizer efficiency and a preparation method thereof. The preparation method of the spherical micron phosphate fertilizer with high fertilizer efficiency comprises the following steps: reacting a crystal form control agent and monocalcium phosphate in water for at least 12 hours, and performing spray drying through a spray dryer to obtain the spherical micron phosphate fertilizer. According to the spherical micron phosphate fertilizer with high fertilizer efficiency and the preparation method thereof, the preparation method is simple, the cost is low, the reaction conditions are mild, and the prepared spherical micron phosphate fertilizer is small in size and high in fertilizer efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of fertilizers, and in particular relates to a spherical micron phosphate fertilizer with high fertilizer efficiency and a preparation method thereof. Background Art

[0002] Phosphorus is one of the three essential elements for plant growth. It plays a good role in improving plant stress resistance and can promote rapid growth and development of plants. Phosphorus deficiency can lead to stunted plant growth and development, resulting in short plants, small fruits, and purple-red spots on leaves. Therefore, fertilization is often used to meet the plant's demand for phosphorus.

[0003] However, after traditional phosphate fertilizers are applied to the soil, some of them will be absorbed and fixed on the soil surface and cannot migrate to the root system, and some will react with metal ions in the soil to be converted into ineffective phosphorus. In the end, only a small part of the phosphorus is absorbed and utilized by plants, thus greatly reducing the utilization rate of phosphate fertilizers. How to prepare a class of high-efficiency phosphate fertilizers to meet the plant's demand for phosphorus has become a technical problem that needs to be solved urgently in this field.

[0004] In view of this, the present invention prepares a spherical micron phosphate fertilizer with high fertilizer efficiency and a preparation method thereof, and the fertilizer efficiency utilization rate is high. Summary of the invention

[0005] The invention aims to provide a method for preparing spherical micron phosphate fertilizer with high fertilizer efficiency, and the preparation method is simple to operate.

[0006] In order to achieve the above purpose, the technical solution adopted is:

[0007] A method for preparing a spherical micron phosphate fertilizer with high fertilizer efficiency comprises the following steps: reacting a crystal form control agent and calcium dihydrogen phosphate in water for at least 12 hours, and then spray drying to obtain the spherical micron phosphate fertilizer.

[0008] Furthermore, the crystal form controlling agent is potassium humate, or humic acid, or carboxymethyl cellulose, or sodium lignin sulfonate.

[0009] Furthermore, the mass ratio of the crystal form controlling agent to calcium dihydrogen phosphate is 1:10-20.

[0010] Furthermore, the spray drying temperature is 180-300°C.

[0011] Furthermore, the crystal form controlling agent and calcium dihydrogen phosphate react at room temperature.

[0012] Furthermore, the crystal form controlling agent and calcium dihydrogen phosphate are reacted at room temperature for 12 hours.

[0013] Another object of the present invention is to provide a spherical micron phosphate fertilizer with high fertilizer efficiency, which is prepared by the above-mentioned preparation method and has a small size, uniform dispersion and regular morphology.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. The technical solution of the present invention has a simple preparation method, low cost and mild reaction conditions.

[0016] 2. The technical solution of the present invention uses potassium humate (HAK) / humic acid (HA) / carboxymethyl cellulose (CMC) / sodium lignin sulfonate (SLS) as a crystal form controller to prepare a spherical micron phosphate fertilizer, which has the following advantages: ① small size, good dispersibility, and no agglomeration. ② High fertilizer efficiency. ③ Micron-sized spherical phosphate fertilizer is conducive to surface coating and modification, and is conducive to migration in the soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Scanning electron microscopy (SEM) (left) and particle size statistics (right) of HAK / P prepared by selecting potassium humate as the crystal form controller and the mass ratio of potassium humate to calcium dihydrogen phosphate being 1:20.

[0018] Figure 2 Scanning electron microscopy (SEM) (left) and particle size statistics (right) of CMC / P prepared using carboxymethyl cellulose as a crystal control agent.

[0019] Figure 3 This is the XRD pattern of HAK / P prepared by selecting potassium humate as the crystal form control agent.

[0020] Figure 4 Scanning electron microscopy (SEM) of HA / P prepared using humic acid as a crystal control agent.

[0021] Figure 5 Scanning electron microscopy (SEM) of SLS / P prepared using sodium lignin sulfonate as the crystal form control agent.

[0022] Figure 6 Scanning electron microscopy (SEM) of HAK / P prepared by using potassium humate as the crystal form controller and the mass ratio of potassium humate to calcium dihydrogen phosphate being 1:10.

[0023] Figure 7 Statistics of soil column leaching experiment data.

[0024] Figure 8 This is a potted experiment to study the effects of root fertilizer on various plant traits. Figure 8 a is the growth of soybean 30 days after fertilization. Figure 8b is the statistics of net photosynthetic rate of soybean 30 days after fertilization. Figure 8 c is the dry weight statistics of soybean 30 days after fertilization. Figure 8 d is the fresh weight statistics of soybean 30 days after fertilization.

[0025] Fig. 9 Scanning electron microscopy (SEM) of P fertilizer prepared without adding crystal control agent. DETAILED DESCRIPTION

[0026] In order to further explain the spherical micron phosphate fertilizer with high fertilizer efficiency and its preparation method of the present invention and achieve the expected purpose of the invention, the following is a detailed description of the spherical micron phosphate fertilizer with high fertilizer efficiency and its preparation method according to the present invention, its specific implementation method, structure, characteristics and efficacy in combination with the preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0027] Before describing in detail the spherical micron phosphate fertilizer with high fertilizer efficiency and the preparation method thereof of the present invention, it is necessary to further explain the related materials mentioned in the present invention to achieve better effects.

[0028] Potassium humate (HAK) is a high molecular weight, non-uniform aromatic hydroxycarboxylate with the appearance of black granules or powdered solids. It is the product of lignite fine selection and extraction with KOH liquid reaction. It is soluble in water, alkaline, and contains active groups such as carboxyl and phenolic hydroxyl groups. Potassium humate is also a highly efficient organic potassium fertilizer because the humic acid in it is a biologically active agent that can increase the available potassium content in the soil, reduce the loss and fixation of potassium, increase the absorption and utilization rate of potassium by crops, and also has the functions of improving soil, promoting crop growth, improving crop resistance, improving crop quality, and protecting the agricultural ecological environment.

[0029] Humic acid (HA) is a type of organic matter that is accumulated from the remains of plants and animals, mainly plants, after decomposition and transformation by microorganisms, as well as a series of complex geochemical reactions. It is a high-molecular organic acid composed of aromatics and their various functional groups, with good physiological activity and absorption, complexation, exchange and other functions. It is widely used in agriculture, forestry, animal husbandry, petroleum, chemical industry, building materials, medicine and health, environmental protection and other fields.

[0030] Carboxymethyl cellulose (CMC) is a non-toxic and tasteless white flocculent powder with stable performance and is easily soluble in water. Its aqueous solution is a neutral or alkaline transparent viscous liquid. It is soluble in other water-soluble glues and resins, but insoluble in organic solvents such as ethanol. Carboxymethyl cellulose is the most widely distributed and most abundant polysaccharide in nature. It has a very rich source and can be used as an adhesive, thickener, suspending agent, emulsifier, dispersant, stabilizer, sizing agent, etc.

[0031] Sodium lignin sulfonate (SLS) is a type of lignin sulfonate. Lignin is a natural high molecular polymer second only to cellulose and chitin in nature. As a filling and bonding material, it can strengthen the interaction between plant cellulose and is also a component that must be removed when people extract and utilize plant cellulose on a large scale.

[0032] After understanding the relevant materials mentioned in the present invention, the following will further introduce in detail a spherical micron phosphate fertilizer with high fertilizer efficiency and a preparation method thereof in combination with specific embodiments:

[0033] In order to prepare a high-efficiency phosphate fertilizer, a high-efficiency spherical micron phosphate fertilizer and a preparation method thereof are proposed in the present invention. The technical solution of the present invention is as follows:

[0034] A method for preparing a spherical micron phosphate fertilizer with high fertilizer efficiency comprises the following steps: reacting a crystal form control agent and calcium dihydrogen phosphate in water for at least 12 hours, and then spray drying to obtain the spherical micron phosphate fertilizer.

[0035] Preferably, the crystal form controlling agent is potassium humate, or humic acid, or carboxymethyl cellulose, or sodium lignin sulfonate.

[0036] In the above technical scheme, the present invention prepares spherical micron phosphate fertilizer by adopting unconventional crystal form control agent, which can improve the fertilizer efficiency as a fertilizer while controlling the morphology, thereby playing the role of regulating the morphology of micron phosphate fertilizer and improving the fertilizer efficiency.

[0037] Preferably, the mass ratio of the crystal form controlling agent to calcium dihydrogen phosphate is 1:10-20.

[0038] Preferably, the spray drying temperature is 180-300°C.

[0039] Preferably, the crystal form controlling agent and calcium dihydrogen phosphate react at room temperature.

[0040] Preferably, the crystal form controlling agent and calcium dihydrogen phosphate are reacted at room temperature for 12 hours.

[0041] Example 1.

[0042] The specific steps are as follows:

[0043] Weigh 1 g of potassium humate (HAK) and 20 g of calcium dihydrogen phosphate, add them into 500 mL of water, stir and react at room temperature for 12 h, and then use a spray dryer to spray granulate at a drying temperature of 180°C to obtain spherical micron phosphate fertilizer (HAK / P).

[0044] The scanning electron microscopy (SEM) (left) and particle size statistics (right) of HAK / P prepared in this example are as follows Figure 1 As shown, the XRD pattern is Figure 3 As shown. Figure 1 , 3 It can be seen that the present embodiment successfully prepared spherical micron phosphate fertilizer.

[0045] Example 2.

[0046] The specific steps are as follows:

[0047] Weigh 1 g of carboxymethyl cellulose (CMC) and 20 g of calcium dihydrogen phosphate, add them into 500 mL of water, stir and react at room temperature for 12 h, and then use a spray dryer to spray granulate at a drying temperature of 180°C to obtain spherical micron phosphate fertilizer (CMC / P).

[0048] The scanning electron microscopy (SEM) (left) and particle size statistics (right) of CMC / P prepared in this example are as follows Figure 2 As shown by Figure 2 It can be seen that the present embodiment successfully prepared spherical micron phosphate fertilizer.

[0049] Example 3.

[0050] The specific steps are as follows:

[0051] Weigh 1 g of humic acid (HA) and 15 g of calcium dihydrogen phosphate, add them into 500 mL of water, stir and react at room temperature for 18 h, and then use a spray dryer to spray granulate at a drying temperature of 200° C. to obtain spherical micron phosphate fertilizer (HA / P).

[0052] The scanning electron microscopy of HA / P prepared in this example is as follows Figure 4 As shown by Figure 4 It can be seen that the present embodiment successfully prepared spherical micron phosphate fertilizer.

[0053] Example 4.

[0054] The specific steps are as follows:

[0055] Weigh 1 g of sodium lignin sulfonate (SLS) and 20 g of calcium dihydrogen phosphate, add them into 500 mL of water, stir and react at room temperature for 24 h, and then use a spray dryer to spray granulate at a drying temperature of 250°C to obtain spherical micron phosphate fertilizer (SLS / P).

[0056] The scanning electron microscopy of the SLS / P prepared in this example is as follows: Figure 5 As shown by Figure 5 It can be seen that the present embodiment successfully prepared spherical micron phosphate fertilizer.

[0057] Example 5.

[0058] The specific steps are as follows:

[0059] Weigh 1 g of potassium humate (HAK) and 10 g of calcium dihydrogen phosphate, add them into 500 mL of water, stir and react at room temperature for 12 h, and then use a spray dryer to spray granulate at a drying temperature of 300°C to obtain spherical micron phosphate fertilizer (HAK / P).

[0060] The scanning electron microscopy of HAK / P prepared in this example is as follows Figure 6 As shown by Figure 6 It can be seen that the present embodiment successfully prepared spherical micron phosphate fertilizer.

[0061] Example 6: Determination of available phosphorus content

[0062] Weigh 0.7882g HAK / P (prepared in Example 1), place it in a 250mL beaker, add 150mL disodium ethylenediaminetetraacetic acid solution, plug the bottle cap, shake the volumetric flask to disperse the sample in the solution, and then place it in a constant temperature water bath oscillator at 60°C for 1h. Then take out the volumetric flask, cool to room temperature, dilute with water to the scale, and mix well. Dry filter, discard the first few milliliters of filtrate, and test. Use a pipette to transfer 25mL of sample solution, place it in a 400mL beaker, add 10mL of nitric acid solution, dilute with water to 100mL, and heat to boiling. Remove it, add 35mL of quinoline molybdate solution, and keep it warm in a near-boiling water bath until the precipitation is stratified. Take out the beaker and cool to room temperature. Filter with a glass crucible filter that has been dried to constant weight at 180°C in advance, first filter the upper clear liquid, and then wash the precipitate 1 to 2 times by pouring method, each time with 25mL of water. Move the precipitate into the filter and wash it with water. Then place the precipitate and the filter in an electric constant temperature drying oven at 180°C. After the temperature reaches 180°C, dry for 45 minutes. Take it out, move it into a dryer, cool it to room temperature, and weigh it. At the same time, set up a blank experiment. Except for not adding the sample solution, follow the test sample steps. Finally, after data processing, the effective phosphorus content was measured to be 40.06%.

[0063] Example 7: Soil column leaching experiment

[0064] Method: Take a PVC tube with a height of 28 cm and a diameter of 7 cm, select one end to fill two layers of phosphorus-free filter paper, and wrap the outermost layer with nylon mesh as a filtration system for standby use. Weigh 1200g of screened air-dried soil, put it into the prepared PVC tube, and compact it. Then put the weighed fertilizer in, and put 2cm of quartz sand on top. Add 200mL of deionized water on the 1st, 4th, 7th, 11th, and 16th day, and test the total phosphorus content in the leaching solution respectively.

[0065] The experiment was designed with three treatments, and the fertilizers were: 4 g P (monocalcium phosphate), 4.2 g HAK / P prepared in Example 1, and a mixed fertilizer of 4 g P (monocalcium phosphate) and 0.2 g HAK (potassium humate).

[0066] Results: The experimental results are as follows Figure 7 As shown, it was demonstrated that HAK / P mobility was improved.

[0067] Example 8: Potted plant test

[0068] Methods: The total duration of the experiment was 35 days after the water-primed soybeans were potted. The soybean pot experiment was conducted in an artificial climate-controlled greenhouse. Each pot (15.5 cm in diameter and 17 cm in height) was filled with 1 kg of soil (vermiculite: perlite: straw carbon: soil = 1:1:2:2). Before fertilization, the seedlings were thinned out, leaving 4 uniform seedlings in each pot.

[0069] Four treatments were designed in the experiment, namely CK (blank control), P (monocalcium phosphate), HAK+P (mixed application of monocalcium phosphate and potassium humate), and HAK / P prepared in the example, and each treatment had 5 parallel experiments.

[0070] After thinning, phosphate fertilizer was applied at a standard of 0.20 g P / kg soil, and no fertilizer was added to the CK treatment. On the 30th day after fertilization, various traits of soybean plants were tested and statistically analyzed, such as net photosynthetic rate, dry weight, and fresh weight.

[0071] Results: Figure 8 As shown in the figure, 30 days after soybean fertilization, the growth (a), net photosynthetic rate (b), dry weight (c) and fresh weight (d) of the soybean plants were significantly improved in the growth, net photosynthetic rate, dry weight and fresh weight of the HAK / P group, and they were all significantly the best, proving that HAK / P fertilizer efficiency is higher.

[0072] Comparative Example 1.

[0073] The specific steps are as follows:

[0074] Weigh 20 g of calcium dihydrogen phosphate, add it to 500 mL of water, stir it at room temperature for 12 hours, and then use a spray dryer to spray granulate at a drying temperature of 180° C. to obtain phosphate fertilizer.

[0075] The scanning electron microscope image of the phosphate fertilizer prepared in this embodiment is as follows: Fig. 9 As shown by Fig. 9 It can be seen that this embodiment failed to successfully prepare spherical micron phosphate fertilizer.

[0076] Compared with Examples 1-4, it can be seen that carboxymethyl cellulose, sodium lignin, humic acid and potassium humate play an important role in controlling the crystal form in the preparation of spherical micron phosphate fertilizer.

[0077] Comparative Example 2.

[0078] The operating steps of Comparative Example 2 are the same as those of Example 1, except that the mass ratio of the crystal form controlling agent to monocalcium phosphate is as shown in Table 1.

[0079] Table 1

[0080]

[0081]

[0082] It can be seen from Table 1 that when the mass ratio of the crystal form controller to monocalcium phosphate is 1:10-20, a phosphate fertilizer with good morphology can be obtained, but when the mass ratio of the crystal form controller to monocalcium phosphate is not within the range of 1:10-20, a regular sphere cannot be prepared.

[0083] The above is only a preferred embodiment of the embodiment of the present invention, and does not impose any form of limitation on the embodiment of the present invention. Any simple modification, equivalent changes and modifications made to the above embodiment based on the technical essence of the embodiment of the present invention are still within the scope of the technical solution of the embodiment of the present invention.

Claims

1. A method for preparing a spherical micron phosphate fertilizer with high fertilizer efficiency, characterized in that: The preparation method comprises the following steps: reacting a crystal form control agent and calcium dihydrogen phosphate in water for at least 12 hours, and then spray drying to obtain a spherical micron phosphate fertilizer.

2. The preparation method according to claim 1, characterized in that: The crystal form control agent is potassium humate, or humic acid, or carboxymethyl cellulose, or sodium lignin sulfonate.

3. The preparation method according to claim 1, characterized in that: The mass ratio of the crystal form control agent to calcium dihydrogen phosphate is 1:10-20.

4. The preparation method according to claim 1, characterized in that: The spray drying temperature is 180-300°C.

5. The preparation method according to claim 1, characterized in that: The crystal form controlling agent and calcium dihydrogen phosphate react at room temperature.

6. The preparation method according to claim 1, characterized in that: The crystal form controlling agent and calcium dihydrogen phosphate are reacted at room temperature for 12 hours.

7. A spherical micron phosphate fertilizer with high fertilizer efficiency, characterized in that: The preparation method is described in any one of claims 1 to 6.

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