A suspended calcium-magnesium fertilizer and preparation method thereof

Abstract

The present invention relates to the technical field of calcium-magnesium fertilizers, in particular to a suspended calcium-magnesium fertilizer and a preparation method thereof, wherein the suspended calcium-magnesium fertilizer comprises the following raw materials in parts by mass: 70-80 parts of nano calcium carbonate slurry, 12-18 parts of fulvic acid, 18-25 parts of nano magnesium oxide, 8-15 parts of anhydrous copper sulfate, 6-10 parts of sugar alcohol, 6-12 parts of salicylic acid, 2-5 parts of gamma-aminobutyric acid, 2-5 parts of cytokinin, 3-6 parts of antifreeze, 2-8 parts of dispersant, and 1-5 parts of defoamer. The use of nano-scale raw materials such as nano calcium carbonate and nano magnesium oxide significantly reduces the particle size of the final product, and the nano material has an extremely high specific surface area, can increase the contact area with plant leaves, more easily penetrate the cuticle on the surface of the plant leaves, enter the inside of the leaves for absorption, and improve the absorption efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of calcium-magnesium fertilizers, and in particular to a suspended calcium-magnesium fertilizer and a preparation method thereof. Background Art

[0002] Calcium and magnesium are essential nutrients for crop growth and play an irreplaceable role in the growth and development of plants. Traditional root fertilization buries fertilizer in the soil and allows the plant's roots to absorb nutrients.

[0003] However, root fertilization requires fertilizer to penetrate the soil and be absorbed by the roots, so the absorption rate is relatively slow. In alkaline soil, calcium ions easily combine with anions such as phosphate to form insoluble calcium phosphate precipitates. These precipitates will block soil pores and reduce soil permeability, thereby affecting the respiration of plant roots and nutrient absorption. Summary of the invention

[0004] In view of the defects mentioned in the background technology, the present invention provides a suspended calcium-magnesium fertilizer and a preparation method thereof, in which nano-fertilizer is used as a carrier of nutrients such as calcium and magnesium to make foliar fertilizer, so as to improve element absorption and utilization rate and improve crop quality.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows:

[0006] A suspended calcium-magnesium fertilizer comprises the following raw materials in parts by weight:

[0007] 70-80 parts of nano calcium carbonate slurry, 18-25 parts of nano magnesium oxide, 5-8 parts of antifreeze agent, 8-15 parts of anhydrous copper sulfate, 12-18 parts of fulvic acid, 6-12 parts of salicylic acid, 2-5 parts of gamma-aminobutyric acid, 2-5 parts of cytokinin, 6-10 parts of sugar alcohol, 5-10 parts of dispersant and 1-5 parts of defoaming agent.

[0008] The present invention also provides a method for preparing a suspended calcium magnesium fertilizer, comprising the following steps:

[0009] S1. Add the weighed nano calcium carbonate slurry into a reactor, stir and heat it, set the speed to 250 rpm, heat the nano calcium carbonate slurry to 50-55° C., keep warm, add weighed anhydrous copper sulfate, fulvic acid, nano magnesium oxide, γ-aminobutyric acid, cytokinin, and sugar alcohol, stir for 30-45 minutes to obtain a mixed slurry;

[0010] S2, transfer all the mixed slurry to an ultrasonic disperser, then add weighed antifreeze, dispersant, and defoamer, mix and disperse for 12 minutes to obtain calcium magnesium fertilizer slurry;

[0011] S3. The obtained calcium magnesium fertilizer slurry is filtered and then sent to a filling device for packaging to obtain a liquid suspended calcium magnesium fertilizer.

[0012] Preferably, the mass concentration of the nano calcium carbonate slurry is 100-200 g / L, and the preparation method thereof comprises the following steps:

[0013] A1. Passing oxygen-enriched air into the lime kiln to calcine limestone at high temperature to obtain quicklime;

[0014] A2, a certain amount of quicklime and water are mixed for digestion reaction to obtain a calcium hydroxide slurry with a mass concentration of 75-95g / L;

[0015] A3, after the digestion reaction is completed, the calcium hydroxide slurry is sieved to remove coarse particles, the calcium hydroxide slurry is sequentially passed through 100 mesh, 200 mesh, and 300 mesh vibrating screens, the sieved calcium hydroxide slurry is sent to a carbonization reactor for stirring and heating, the temperature of the calcium hydroxide slurry is controlled at 20-35 ° C, a crystal form control agent is added, the speed is set to 250 rpm, CO2 is continuously introduced into the carbonization reactor for carbonization reaction, when the pH monitoring system measures the pH of the slurry ≤ 10.5, a surface treatment agent is added, and when the pH monitoring system measures the pH of the slurry ≤ 7.5, CO2 is stopped to obtain a nano calcium carbonate slurry;

[0016] A4. Reset the speed to 380 rpm, add weighed chelating agent, polyethylene glycol and silicone oil to the calcium carbonate slurry in sequence, stir for 25 to 30 minutes, and obtain the modified nano calcium carbonate slurry.

[0017] Preferably, the surface treatment agent is fumed silica.

[0018] Preferably, the crystal shape controlling agent is one or more of monosaccharides, disaccharides, polysaccharides, and sugar derivatives.

[0019] Preferably, the chelating agent is EDTA or DTPA.

[0020] Preferably, the antifreeze agent is prepared by mixing ethylene glycol, propylene glycol and pure water in a weight ratio of 3:3:4.

[0021] Preferably, the dispersant is polymerized from acrylic acid, sodium methacrylic acid sulfonate and maleic anhydride in a weight ratio of 10:3:3.

[0022] Preferably, the defoaming agent is dimethyl silicone oil.

[0023] After adopting the above technical solution, the beneficial effects of the present invention are:

[0024] The use of nano-scale raw materials such as nano-calcium carbonate and nano-magnesium oxide significantly reduces the particle size of the final product. Nanomaterials have an extremely high specific surface area, which can increase the contact area with plant leaves, allowing them to more easily penetrate the cuticle on the surface of plant leaves and enter the interior of the leaves for absorption, thereby improving absorption efficiency. DETAILED DESCRIPTION

[0025] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present invention and are not configured to limit the present invention. For those skilled in the art, the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention.

[0026] Example 1

[0027] A method for preparing a suspended calcium-magnesium fertilizer comprises the following steps:

[0028] Step 1: Preparation of mixed slurry

[0029] First, add 70 parts (by mass fraction) of nano calcium carbonate slurry with a mass concentration of 100-200 g / L into the reactor, and then stir it, setting the stirring speed to 250 rpm. While stirring, heat the nano calcium carbonate slurry to 50-55 ° C through a steam coil. After the temperature rises, add weighed anhydrous copper sulfate 8 parts, fulvic acid 12 parts, nano magnesium oxide 18 parts, salicylic acid 6 parts, γ-aminobutyric acid 2 parts, cytokinin 2 parts, and sugar alcohol 6 parts, continue stirring for 30-45 minutes, stop heating, and form a uniform mixed slurry.

[0030] Magnesium is an important component of chlorophyll. Nano-magnesium oxide, as an important source of magnesium, can increase the photosynthetic rate and enable plants to use light energy more effectively for material production, thereby improving crop yield and quality.

[0031] Calcium is one of the important components of the cell wall. It participates in the formation of the intercellular and intracellular structures of the cell wall by combining with polysaccharides such as pectin. It can also improve the resistance of crops to adverse environments such as heavy metals, pests and diseases, and drought. As an important source of calcium, nano calcium carbonate in the slurry plays a vital role in the growth, development, yield and quality of crops.

[0032] Copper is one of the trace elements necessary for plant growth and is involved in many plant physiological processes such as chlorophyll synthesis, photosynthesis, and electron transfer. Anhydrous copper sulfate is rich in copper, which can promote plant photosynthesis, improve light energy utilization efficiency, and thus promote plant growth and development.

[0033] Fulvic acid can increase the chlorophyll content of crop leaves, improve the efficiency of photosynthesis, enable crops to synthesize more organic matter, and promote the growth and development of crops. Fulvic acid can also reduce the opening strength of plant leaf stomata, reduce the leaf transpiration rate, thereby reducing crop water consumption, improving the water status in the plant body, allowing crops to grow and develop normally under drought conditions, and enhancing drought resistance.

[0034] GABA participates in the photosynthesis process in plants, which helps improve the photosynthesis efficiency of plants and thus increase energy metabolism. It can also significantly promote the absorption of trace elements by plants, such as potassium ions, calcium ions, and magnesium ions, which helps balance and accumulate nutrients in plants and improve crop yield and quality.

[0035] Cytokinins can promote the division of plant cells and regulate their differentiation. They activate a series of signal transduction events by binding to cell surface receptors. These receptors usually have kinase activity, can undergo autophosphorylation, and transfer phosphate groups to downstream signaling molecules such as histidine phosphotransfer proteins (AHPs) and response regulators (RRs). This process ultimately leads to the activation of B-type ARR transcription factors (B-ARRs), which in turn regulate the expression of specific genes, affecting cell division and differentiation. Cytokinins are also involved in regulating the synthesis of cell walls and cell growth. Cytokinins can promote the relaxation of cell walls, thereby promoting cell elongation. In addition, cytokinins can also regulate cell growth and differentiation by affecting the expression of cell wall-related genes.

[0036] Salicylic acid can induce plants to produce salt-resistant traits, maintain water balance in the body by improving the plant's osmotic regulation and antioxidant capacity, and reduce the damage of salt stress to crops.

[0037] As a natural nutrient osmotic agent, sugar alcohol can improve the permeability of cell membranes, promote the rapid conduction and distribution of trace elements such as magnesium, calcium, and copper in plants, and ensure that all parts of crops can obtain sufficient nutrient support. Sugar alcohol can also enhance the resistance of plants to stress, such as drought resistance and cold resistance, and improve the overall growth of plants.

[0038] Step 2: Ultrasonic dispersion

[0039] The mixed slurry is then transferred to an ultrasonic disperser, which uses the energy generated by high-frequency ultrasonic vibration to disperse and refine the particles in the slurry. During the dispersion process, 3 parts of antifreeze, 2 parts of dispersant and 1 part of dimethyl silicone oil are added and mixed and dispersed for 12 minutes to ensure that the raw materials are fully mixed and the particles are evenly dispersed, thereby obtaining a fine and stable calcium magnesium fertilizer slurry.

[0040] The antifreeze is made of ethylene glycol, propylene glycol and pure water in a weight ratio of 3:3:4, and is used to prevent the finished suspended calcium magnesium fertilizer from freezing during use in winter or low-temperature transportation.

[0041] The dispersant is made of three monomers, acrylic acid, sodium methacrylate sulfonate and maleic anhydride, polymerized in a weight ratio of 10:3:3. It can help the solid particles in the calcium magnesium fertilizer slurry to be better dispersed in the liquid, prevent the particles from agglomerating and settling, and reduce the interaction between the particles, so that the particles can be stably suspended in the liquid. At the same time, the dispersant can also improve the fluidity and permeability of the fertilizer, making it easier for crops to absorb and utilize it.

[0042] When preparing liquid suspended calcium magnesium fertilizer, a large amount of foam will be generated due to the mixing of raw materials and ultrasonic dispersion. If these foams are not eliminated in time, they will affect the filling and packaging efficiency of the fertilizer, and may even cause the filling equipment to be blocked or the fertilizer to overflow. Dimethyl silicone oil is used as a defoaming agent. During the dispersion process, dimethyl silicone oil will quickly disperse in the slurry, which can destroy the surface tension of the foam, causing the foam to burst quickly and prevent the generation of new foam.

[0043] Step 3: Filtration and filling

[0044] After ultrasonic dispersion, the calcium magnesium fertilizer slurry needs to be filtered to remove large impurities or incompletely dispersed particles in the slurry to ensure the purity and uniformity of the fertilizer. The filtered calcium magnesium fertilizer slurry is then sent to the filling equipment for packaging, and finally a liquid suspended calcium magnesium fertilizer is obtained.

[0045] Example 2

[0046] The difference from Example 1 is that:

[0047] 76 parts of nano calcium carbonate slurry, 22 parts of nano magnesium oxide, 5 parts of antifreeze, 14.5 parts of anhydrous copper sulfate, 15.5 parts of fulvic acid, 11.5 parts of salicylic acid, 3 parts of gamma-aminobutyric acid, 2.5 parts of cytokinin, 8.5 parts of sugar alcohol, 7 parts of dispersant and 4 parts of dimethyl silicone oil.

[0048] Example 3

[0049] The difference from Example 1 is that:

[0050] 78 parts of nano calcium carbonate slurry, 23 parts of nano magnesium oxide, 5.5 parts of antifreeze, 12 parts of anhydrous copper sulfate, 16 parts of fulvic acid, 10 parts of salicylic acid, 4 parts of gamma-aminobutyric acid, 4 parts of cytokinin, 9 parts of sugar alcohol, 7.5 parts of dispersant and 4.5 parts of dimethyl silicone oil.

[0051] Example 4

[0052] The difference from Example 1 is that:

[0053] 80 parts of nano calcium carbonate slurry, 25 parts of nano magnesium oxide, 6 parts of antifreeze, 15 parts of anhydrous copper sulfate, 18 parts of fulvic acid, 5 parts of gamma-aminobutyric acid, 5 parts of cytokinin, 12 parts of salicylic acid, 10 parts of sugar alcohol, 8 parts of dispersant and 5 parts of dimethyl silicone oil.

[0054] In Examples 1-4, the preparation method of nano calcium carbonate slurry comprises the following steps:

[0055] Step 1: Preparation of quicklime

[0056] Oxygen-rich air is introduced into the lime kiln to calcine limestone or calcite (mainly calcium carbonate) at high temperature, decomposing the limestone or calcite into quicklime and carbon dioxide.

[0057] Step 2: Preparation of calcium hydroxide slurry

[0058] The quicklime obtained by calcination is quantitatively fed into a rotary digester through a vibrating feeder. Water is measured by a flow meter and pumped into the rotary digester to react with the quicklime to finally obtain a calcium hydroxide slurry with a mass concentration of 95 to 125 g / L.

[0059] Step 3: Preparation of Nano-Calcium Carbonate Slurry

[0060] After the digestion reaction is completed, the calcium hydroxide slurry is sieved to remove coarse particles. The calcium hydroxide slurry is passed through 100 mesh, 200 mesh, and 300 mesh vibrating screens in turn, and the sieved calcium hydroxide slurry is sent to the carbonization reactor for stirring and heating. The temperature of the calcium hydroxide slurry is controlled at 20-35°C, and a crystal shape control agent is added to adjust the crystal morphology and particle size distribution of calcium carbonate. The speed is set to 250rpm to ensure uniform reaction, and CO2 is continuously introduced into the reactor for carbonization reaction. When the pH monitoring system measures that the pH of the slurry is ≤10.5, a surface treatment agent is added. When the pH monitoring system measures that the pH of the slurry is ≤7.5, the introduction of CO2 is stopped. At this time, the carbonization reaction is basically completed, and a nano-calcium carbonate slurry with a cubic crystal shape and a carbonization rate of 95% (the carbonization rate is the degree of carbonization reaction, generally expressed by the ratio of the amount of calcium hydroxide that has reacted in the suspension to the amount of calcium hydroxide in the original slurry, and the content of calcium hydroxide and calcium carbonate is detected during the carbonization process) or above and a mass concentration of 100-200g / L is obtained.

[0061] Step 4: Modification of Nano-Calcium Carbonate Slurry

[0062] Maintain the above temperature and reset the speed to 380rpm to improve the stirring efficiency and ensure that the additives added later can be evenly dispersed in the nano-calcium carbonate slurry. Add weighed chelating agent, polyethylene glycol, and silicone oil in turn to improve the dispersibility and stability of nano-calcium carbonate. Stir for 25 to 30 minutes to fully mix the additives with the calcium carbonate slurry to complete the modification of the nano-calcium carbonate slurry.

[0063] The crystal shape control agent is one or more of monosaccharides (such as glucose, fructose, ribose, deoxyribose), disaccharides (such as sucrose, maltose, lactose), polysaccharides (such as starch, glycogen, chitosan), sugar derivatives (such as sugar alcohol, xylitol, trehalose, D-xylose, sugar acid, erythritol, glycosamine, glycoside), and the dosage is 0.8% of the weight of the nano calcium carbonate slurry. Sugar substances can increase the solubility of calcium hydroxide slurry, increase the concentration of calcium ions, accelerate the reaction rate of carbon dioxide and calcium hydroxide, and reduce the particle size of the generated nano calcium carbonate.

[0064] The surface treatment agent is fumed silica, which can be adsorbed on the surface of nano calcium carbonate particles to form a protective film, further preventing the agglomeration between particles and improving the stability and dispersibility of nano calcium carbonate. The dosage is 1.2% of the weight of the nano calcium carbonate slurry. Fumed silica, with its ultra-fine particle size and large specific surface area, can supplement silicon, increase the lodging resistance, pest resistance, and stress resistance of plants, promote photosynthesis, promote root growth and development, and promote nutrient absorption and utilization. At the same time, it improves the dispersibility of suspended fertilizers and prevents agglomeration and sedimentation.

[0065] The chelating agent is EDTA or DTPA, which can prevent the agglomeration between particles and improve the dispersibility of nano calcium carbonate. The dosage is 1.5% of the weight of the nano calcium carbonate slurry.

[0066] The finished products of Examples 1-4 were sampled and used as experimental groups 1-4 respectively. Two types of foliar calcium and magnesium fertilizers a and b were purchased from the market (type a was Helikang-Kangli foliar fertilizer-calcium and magnesium type, type b was Kangpu-Gaimeipeng) as control groups a and b, and the experiment was carried out in groups. The experimental subjects were pakchoi, and the experimental conditions were as follows:

[0067] (1) Disinfection: Select seeds with larger and fuller grains for hydroponic experiments. Use 5% sodium hypochlorite to disinfect the selected seeds for 10 minutes and then rinse them with deionized water 7 to 8 times.

[0068] (2) Seedling cultivation: Soak the pakchoi seeds of uniform size and full grains in warm water at 50-60°C for 4-6 hours. Place the soaked seeds in a seedling tray covered with soaked gauze and place them in an incubator at 25°C for 2 days. Protect from light to simulate the germination environment.

[0069] (3) Planting: When the two-leaf stage is reached, select the pakchoi seedlings with the same growth potential and place them in a hydroponic device for hydroponics. Use 1 / 4 Hoagland nutrient solution for cultivation, and set the incubator conditions to 5000lx, 14h, 23℃ during the day, 10h, 18℃ at night, and 65% to 80% humidity.

[0070] (4) When the Chinese cabbage seedlings grow to the two-leaf and one-heart stage, foliar fertilizer is sprayed on them, and 1 / 2 Hoagland nutrient solution is used for cultivation to set up the treatment group.

[0071] When the pakchoi had grown 3-4 true leaves, the samples of Examples 1-4 and two foliar fertilizers on the market were diluted with water (125 g of fertilizer was added to every 100 kg of water) and sprayed twice. The physiological indicators of the pakchoi were measured every 5 days. The results are as follows:

[0072]

[0073]

[0074] It can be seen from the table above that the effects of experimental groups 1-4 are far better than foliar fertilizers a and b. Therefore, it can be seen that this program is beneficial to promoting the absorption and utilization of calcium and magnesium elements by plants.

[0075] According to the embodiments of the present invention as described above, these embodiments do not describe all the details in detail, nor do they limit the invention to specific embodiments. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and the modified use based on the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a suspended calcium magnesium fertilizer, characterized in that: The steps include: S1, according to the weight parts, prepare 70-80 parts of nano calcium carbonate slurry, 18-25 parts of nano magnesium oxide, 3-6 parts of antifreeze, 8-15 parts of anhydrous copper sulfate, 12-18 parts of fulvic acid, 6-12 parts of salicylic acid, 2-5 parts of γ-aminobutyric acid, 2-5 parts of cytokinin, 6-10 parts of sugar alcohol, 2-8 parts of dispersant and 1-5 parts of defoaming agent, wherein the dispersant is polymerized by acrylic acid, sodium methacrylate sulfonate and maleic anhydride in a weight ratio of 10:3:3; S2, adding the weighed nano calcium carbonate slurry into the reactor, stirring and heating, setting the speed to 250 rpm, heating the nano calcium carbonate slurry to 50-55° C., keeping warm, adding weighed anhydrous copper sulfate, fulvic acid, nano magnesium oxide, γ-aminobutyric acid, cytokinin, and sugar alcohol, stirring for 30-45 min to obtain a mixed slurry; S3, transfer all the mixed slurry to an ultrasonic disperser, then add weighed antifreeze, dispersant, and defoamer, mix and disperse for 12 minutes to obtain calcium magnesium fertilizer slurry; S4, the obtained calcium magnesium fertilizer slurry is sent to a filling device for packaging after filtering to obtain a liquid suspended calcium magnesium fertilizer; In step S1, the mass concentration of the nano calcium carbonate slurry is 100-200 g / L, and the preparation method thereof comprises the following steps: A1. Passing oxygen-enriched air into the lime kiln to calcine limestone at high temperature to obtain quicklime; A2, a certain amount of quicklime and water are mixed for digestion reaction to obtain a calcium hydroxide slurry with a mass concentration of 75-95g / L; A3. After the digestion reaction is completed, the calcium hydroxide slurry is sieved to remove coarse particles. The calcium hydroxide slurry is sequentially passed through 100 mesh, 200 mesh, and 300 mesh vibrating screens. The sieved calcium hydroxide slurry is sent to a carbonization reactor for stirring and heating. The temperature of the calcium hydroxide slurry is controlled at 20-35° C. A crystal form controller is added, wherein the crystal form controller is one or more of monosaccharides, disaccharides, polysaccharides, and sugar derivatives. The speed is set to 250 rpm, and CO2 is continuously introduced into the carbonization reactor for carbonization reaction. When the pH monitoring system measures that the pH of the slurry is ≤10.5, fumed silica is added. When the pH monitoring system measures that the pH of the slurry is ≤7.5, the introduction of CO2 is stopped to obtain a nano calcium carbonate slurry. A4. Reset the speed to 380 rpm, add weighed chelating agent, polyethylene glycol and silicone oil to the calcium carbonate slurry in sequence, stir for 25 to 30 minutes, and obtain the modified nano calcium carbonate slurry.

2. The preparation method of suspended calcium magnesium fertilizer according to claim 1, characterized in that: The chelating agent is EDTA or DTPA.

3. The preparation method of suspended calcium magnesium fertilizer according to claim 1, characterized in that: The antifreeze agent is prepared by mixing ethylene glycol, propylene glycol and pure water in a weight ratio of 3:3:

4.

4. The preparation method of suspended calcium magnesium fertilizer according to claim 1, characterized in that: The defoaming agent is dimethyl silicone oil.

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