Special magnesium slag-based silicon fertilizer for rice and preparation method of special magnesium slag-based silicon fertilizer

Abstract

The invention relates to the field of agricultural chemical fertilizers, in particular to a magnesium slag-based silicon fertilizer special for rice and a preparation method thereof.The silicon fertilizer is prepared from, by weight, 50-80 parts of magnesium slag, 0.1-5 parts of bentonite, 1-5 parts of polyaspartic acid, 1-5 parts of polyacrylamide, 0.5-5 parts of manganese sulfate, 1-10 parts of zinc sulfate heptahydrate, 1-10 parts of sodium molybdate, 10-30 parts of nitrogen fertilizer, 5-20 parts of phosphate fertilizer and 10-15 parts of potassium fertilizer. The silicon fertilizer disclosed by the invention has the advantages that the silicon fertilizer can thicken rice leaves and harden the texture, effectively prevent and treat insect pests, reduce the use amount of pesticides, reduce the erosion of the pesticides to land and the pollution to the environment, and protect the ecological environment; secondly, the fertilizer is high in seepage force and small in dosage, the utilization rate of the fertilizer can be increased, and the planting cost can be reduced; and good economic benefits and social benefits are achieved.

Description

Technical Field

[0001] The present invention relates to the field of agricultural fertilizers, and particularly to a magnesium slag-based special silicon fertilizer for rice and a preparation method thereof. Background Art

[0002] Magnesium slag is an industrial waste residue generated in the Pidgeon process for producing magnesium. According to statistics, 8.0 - 10.0t of magnesium slag is produced during the production of 1t of metallic magnesium. At present, the magnesium treatment slag of enterprises mainly focuses on landfill and stacking, polluting the land, hindering the growth of crops, and causing waste of resources and damage to the ecological environment. In addition, the Pidgeon process magnesium slag contains a large amount of β-2CaO·SiO2(s) with high activity. However, during the slag skimming and cooling process, when the temperature drops below 798K, it transforms into γ-2CaO·SiO2, with a 12% increase in volume. Therefore, it is prone to pulverization during cooling, resulting in more than 60% of the fine powder with a particle size below 147μm in the slag. Flowing into the air not only pollutes the environment but also causes discomfort to the human respiratory tract. Therefore, the rational utilization of magnesium slag is related to the development of enterprises and the improvement of the environment.

[0003] Magnesium slag contains a large amount of mineral elements such as Ca, Si, Mg, and Fe required for plant growth, with low content of harmful metals. Cr exists in the form of less toxic Cr 3+ The leaching mass concentrations of chromium, copper, and nickel are all lower than the standard limits of hazardous waste, with low pollution risk and the potential to improve soil fertility. Using magnesium slag as an agricultural resource can, to a certain extent, increase the yield of crops and has no adverse effects on crop growth and soil environment.

[0004] Rice is the largest food crop in China, accounting for 35% of the planting area in China, and plays a crucial role in China's food production. However, during the rice planting process, problems such as lodging, serious pests and diseases, and yields lower than the ideal level often occur, which severely restricts the high-quality production of rice in China. Traditional fertilizers mainly consist of nitrogen, phosphorus, and potassium, lacking the supplement of silicon element (silicon can enhance the stem strength of rice and improve the lodging resistance), and ignoring the function of soil improvement. Research shows that silicon fertilizer can significantly improve the stress resistance of rice (such as resistance to pests and diseases, resistance to salinity and alkalinity) and yield (with an increase of 10 - 20%), but existing silicon fertilizers mostly rely on high-purity silicate minerals, with high costs and not meeting the demand for the resource utilization of industrial solid wastes. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a magnesium slag-based special silicon fertilizer for rice and a preparation method thereof. This silicon fertilizer has strong pertinence, can enhance the stress resistance of rice such as resistance to pests and diseases and lodging resistance, improve the yield and quality of rice, and improve the soil for rice planting; and will enable the resource utilization of the solid waste magnesium slag and alleviate its pollution problem.

[0006] The present invention is realized through the following technical solutions: On the one hand, a preparation method of a magnesium slag-based special silicon fertilizer for rice is provided. The raw materials of the silicon fertilizer, by weight, include 50-80 parts of magnesium slag, 0.1-5 parts of bentonite, 1-5 parts of polyaspartic acid, 1-5 parts of polyacrylamide, 0.5-5 parts of manganese sulfate, 1-10 parts of zinc sulfate heptahydrate, 1-10 parts of sodium molybdate, 10-30 parts of nitrogen fertilizer, 5-20 parts of phosphate fertilizer, and 10-15 parts of potassium fertilizer.

[0007] Through the above technical solutions, magnesium slag is used to provide elements such as silicon, calcium, and magnesium; silicon elements strengthen the cell walls of rice and improve the lodging resistance; bentonite is used as a binder to enhance the granulation effect; polyaspartic acid belongs to a water-retaining agent and can effectively release nutrients slowly through the change of the water content in the paddy field, improving the utilization rate of nitrogen, phosphorus, and potassium; polyacrylamide is used to form soil aggregate structures, increasing the water retention rate by 40%; reducing fertilizer leaching; manganese sulfate is used to activate enzyme activity and promote chlorophyll synthesis; manganese deficiency causes leaf chlorosis; zinc sulfate heptahydrate is used to enhance photosynthesis and stress resistance; zinc deficiency in rice causes "stunted seedlings"; sodium molybdate participates in nitrogen metabolism and promotes grain formation; nitrogen fertilizer promotes tillering and protein synthesis; phosphate fertilizer can effectively promote the absorption of phosphorus elements and improve the utilization rate; potassium fertilizer enhances disease resistance and grain plumpness. Therefore, the available silicon in magnesium slag can increase the silicon absorption rate of rice by 1.9%-6.4%; the combined action of bentonite and polyacrylamide increases the soil water holding capacity by 2%-20% and reduces nutrient loss by more than 30%; zinc, molybdenum, and manganese respectively target the tillering stage, booting stage, and disease resistance, forming a full growth period nutrient coverage.

[0008] Further, the magnesium slag passes through a 100-mesh sieve to remove impurity particles in the magnesium slag.

[0009] Further, the calcium content in the magnesium slag is ≥80wt%, and the calcium and magnesium content is ≥82wt%; wherein, the calcium content is calculated as the mass percentage of calcium oxide; the calcium and magnesium content is calculated as the mass percentage of calcium oxide and magnesium oxide.

[0010] Further, the bentonite is sodium-based bentonite.

[0011] Further, the nitrogen fertilizer is urea with a nitrogen content of about 46wt%; the phosphate fertilizer is superphosphate with a phosphorus content of 14-20wt%; the potassium fertilizer is potassium chloride with a potassium content of 50-60wt%.

[0012] Further, it includes the following steps: Step 1) Weigh magnesium slag, bentonite, polyaspartic acid, polyacrylamide, manganese sulfate, zinc sulfate heptahydrate, sodium molybdate, nitrogen fertilizer, phosphate fertilizer, and potassium fertilizer according to the above weight parts; in a blender, mix magnesium slag, bentonite, manganese sulfate, zinc sulfate heptahydrate, sodium molybdate, nitrogen fertilizer, phosphate fertilizer, and potassium fertilizer evenly to obtain a mixed powder, and then add polyaspartic acid and polyacrylamide thereto for mixing to obtain a mixed material; this can ensure that the fertilizer is effectively wrapped by the slow-release material, enabling the nutrients to be slowly released effectively along with the growth of rice.

[0013] Step 2) Pour the obtained mixed powder into a granulator and add a certain amount of water for granulation to form granular materials. Step 3) Put the obtained granular materials into a drying oven at 60°C - 80°C for drying to obtain the product.

[0014] Through the above technical solution, low-temperature drying at 60 - 80°C is adopted, and the moisture content of the finished product is ≤3%.

[0015] Furthermore, in Step 2), the granulator is selected from any one of a disc granulator, a sugar coating machine, and a high-speed granulator. Preferably, it is a high-speed granulator; using a high-speed granulator (such as SXJZ - 1500 type), 1 - 3 mm particles are formed through mechanical stirring force (rotation speed 200 - 400 r / min), and the granulation rate is ≥95%. Sodium-based bentonite is used as a binder, reducing the water addition amount to 5% - 20%.

[0016] Furthermore, in Step 2), the weight of the added water is controlled to be 1% - 15% of the total weight of the materials. Also provided is a magnesium slag-based special silicon fertilizer for rice prepared by the above preparation method. Calculated as SiO2, the effective silicon content of this silicon fertilizer is ≥20 wt%, the moisture content is ≤3 wt%, and the particles passing through a 2 mm standard sieve are ≥85 wt%. When this fertilizer is applied to rice, it can increase the content of silicon, calcium, and magnesium elements in the rice. Silicon can induce the deposition of lignin and pectin, enhance the cell wall structure, and reduce leaf water loss. The synergistic effect of calcium and magnesium can promote cell wall crosslinking, increase leaf toughness, and make the rice leaves thicker.

[0017] Beneficial effects 1) Each ton of silicon fertilizer consumes 0.5 - 0.8 tons of magnesium slag. Compared with water-soluble silicon fertilizer, the raw material cost of silicon fertilizer can be reduced by 50 - 60%. 2) The silicon fertilizer of the present invention strengthens the cell wall based on silicon, reducing the lodging rate by 50%; field trials show a 20% - 40% increase in yield, a 10 - 20% increase in the zinc content of rice; the leaf hardness increases, and the amount of pesticide used is reduced by 20%; the particle compressive strength is ≥10 N, and the particle size qualification rate is ≥90%. 3) Cr in magnesium slag 3+Low toxicity, leaching concentration < 100 mg / L, far lower than the limit value of hazardous waste; polyaspartic acid can chelate heavy metals, further reducing the transfer of Pb and Cd in farmland to rice; 4) The silicon fertilizer of the present invention complies with the standard NY / T797-2004, with available silicon (SiO2) ≥ 20%, and the heavy metal limit complies with GB38400-2019. Specific implementation mode

[0018] In order to make the objectives, technical solutions and advantages of the present invention clearer, the following further elaborates on the present invention in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] The magnesium slag-based special fertilizer for rice of the present invention has a reasonable fertilizer ratio, comprehensive nutrient elements, appropriate contents of major, medium and trace elements for the growth of most rice varieties, and good fertilizer absorption effect. The fertilizer has low cost, simple fertilizer production process and convenient fertilization method, which can greatly improve the yield and quality of rice. The magnesium slag-based special fertilizer for rice of the present invention can not only effectively alleviate the problem of magnesium slag pollution, but also provide a special silicon fertilizer for rice that can improve the water and fertilizer retention capacity of the soil, enhance the stress resistance of rice, and promote the growth of rice roots. Reduce waste disposal by converting industrial waste into industrial by-products.

[0020] Specifically, the magnesium slag is rich in silicon elements, which can increase the chlorophyll content of rice, extend the growth period, promote the growth of rice, and increase the rice yield. At the same time, it can also improve the lodging resistance and pest and disease resistance of rice. In addition, silicon can reduce the fixation of phosphate fertilizer in the soil, activate the phosphorus in the soil, regulate the demand for other nutrient elements such as nitrogen, phosphorus, and potassium at different growth stages of rice, and increase the utilization rates of nitrogen, phosphorus, and potassium by 1.9%, 6.4%, and 2.8% respectively. The polyacrylamide and bentonite in the magnesium slag-based special silicon fertilizer for rice have the effect of improving the physical properties of the soil. The two can enhance the water retention and fertilizer retention of the soil, increase the water content of the soil, affect the adsorption of the soil to fertilizers, inhibit the loss of fertilizer elements by stabilizing the water-stable aggregate structure and the adsorption of fertilizer elements, and improve the utilization rate of fertilizers. Polyaspartic acid is non-toxic to the environment and harmless to crops. On the one hand, as an amino acid substance, it can provide the amino acids required for rice to synthesize proteins. On the other hand, it can chelate heavy metals in the soil and water, reduce heavy metal residues, and reduce the heavy metal hazards in rice cultivation. The magnesium slag-based special silicon fertilizer for rice of the present invention has a balanced nutrition and contains trace elements required for rice growth. Manganese can promote the germination and growth of rice seeds and also enhance the activity of amylase. Although chlorophyll does not contain manganese, manganese affects the formation of chlorophyll. When manganese is deficient, the synthesis of chlorophyll is blocked and the photosynthetic intensity is inhibited; zinc can promote the synthesis of auxin, protein metabolism, promote the development of the reproductive organs of rice, and enhance its stress resistance; molybdenum participates in the photosynthesis and phosphorus metabolism of rice, the phosphatase activity of hydrolyzing various phosphates, and increases the synthesis of vitamin C in rice.

[0021] The fertilizer of the present invention can thicken the rice leaves and make them hard in texture, effectively prevent pests, reduce the amount of pesticides used, reduce the erosion of pesticides on the land and environmental pollution, and protect the ecological environment; secondly, this fertilizer has strong penetrability and low dosage, can improve the utilization rate of fertilizers, and can reduce the planting cost; spraying this fertilizer can increase the zinc content in rice, increase the health care function of rice, and has good economic and social benefits.

[0022] Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention. The experimental methods not specified in the following embodiments are usually carried out under conventional conditions or according to the conditions recommended by the manufacturers. Unless otherwise stated, all percentages, ratios, proportions or parts are by weight.

[0023] The reagents and raw materials used in the examples and comparative examples of the present invention can be obtained through commercial channels without special instructions.

[0024] The preparation method of the magnesium slag-based special silicon fertilizer for rice involved in the following examples is as follows: First, select appropriate magnesium slag and sieve it through a 100-mesh sieve to ensure uniform particle size of the magnesium slag. Screen out 50 - 80 parts of magnesium slag for standby. Weigh 0.1 - 5 parts of sodium-based bentonite. Sodium-based bentonite has good properties such as adhesiveness, which helps in the subsequent granulation process. Prepare 1 - 5 parts of polyaspartic acid and 1 - 5 parts of polyacrylamide. These two substances can play roles such as improving soil structure and enhancing fertilizer efficiency in fertilizers. Weigh 0.5 - 5 parts of manganese sulfate, 1 - 10 parts of zinc sulfate heptahydrate, and 1 - 10 parts of sodium molybdate. These trace elements play an indispensable role in the growth and development of rice. Select nitrogen fertilizer. Here, 10 - 30 parts of urea with a nitrogen content of about 46 wt% is used; for phosphate fertilizer, 5 - 20 parts of superphosphate with a phosphorus content of 14 - 20 wt% is selected; for potassium fertilizer, 10 - 15 parts of potassium chloride with a potassium content of 50 - 60 wt% is used.

[0025] Put the above-mentioned weighed raw materials such as magnesium slag, bentonite, polyaspartic acid, polyacrylamide, manganese sulfate, zinc sulfate heptahydrate, sodium molybdate, nitrogen fertilizer, phosphate fertilizer, and potassium fertilizer into a blender and mix them evenly to obtain a mixed powder. During the mixing process, ensure that all raw materials are evenly dispersed to avoid uneven local composition.

[0026] Pour the mixed powder into a granulator for granulation. The granulator can make the mixed powder into granules with uniform size and suitable shape according to the set parameters. The purpose of granulation is to facilitate the storage, transportation, and application of fertilizers, and at the same time, it is also beneficial to the slow release and uniform distribution of fertilizers in the soil.

[0027] Put the made granules into a drying oven at 60 - 80 °C for drying. Within this temperature range, the moisture in the granules can be effectively removed, making the fertilizer granules reach an appropriate dryness, improving their stability and shelf life, and finally obtaining the finished magnesium slag-based special silicon fertilizer for rice.

[0028] Example 1 A magnesium slag-based special silicon fertilizer for rice, the raw material composition by weight is as follows: Magnesium slag (sieved through 100 mesh) 70 parts Sodium-based bentonite 2 parts Polyaspartic acid 2.8 parts Polyacrylamide 3 parts Manganese sulfate 2 parts Zinc sulfate heptahydrate 5.2 parts Sodium molybdate 5.3 parts Urea (nitrogen content 46%) 22 parts Superphosphate (P2O5 content 16%) 15.5 parts Potassium chloride (K2O content 55%) 13 parts The preparation method includes the following steps: Raw material pretreatment: Crush the magnesium slag and sieve it through a 100-mesh sieve, and control the fine powder content ≤ 60%; Mixing: Put each raw material into a double-shaft mixer and stir at a speed of 200 r / min for 20 minutes to obtain a mixed powder; Granulation: Feed the mixed powder into a high-speed granulator (model SXJZ-1500), spray 10% by mass of water, and set the granulation pressure at 1.5 MPa to form spherical particles with a particle size of 3-5 mm; Drying: Place the particles in a hot air circulation drying oven at 70 °C for 2 hours, and control the moisture content ≤ 8%; Screening: Pass through a 2-4 mesh sieve, and the screening qualification rate ≥ 95% to obtain the finished silicon fertilizer.

[0029] Example 2 A magnesium slag-based special silicon fertilizer for rice, the raw material composition by weight is: Magnesium slag (passed through a 100-mesh sieve) 51 parts Sodium-based bentonite 3.4 parts Polyaspartic acid 2.8 parts Polyacrylamide 3 parts Manganese sulfate 2.7 parts Zinc sulfate heptahydrate 5.6 parts Sodium molybdate 6.1 parts Urea (containing 46% nitrogen) 22 parts Superphosphate (containing 16% P2O5) 15 parts Potassium chloride (containing 55% K2O) 13 parts The preparation method includes the following steps: Mixing: Use a three-dimensional motion mixer, with a mixing time of 30 minutes and a mixing uniformity ≥ 98%; Granulation: Use a disk granulator, the water spraying amount is 15% of the total mass of the raw materials, the inclination angle of the granulation disk is 55°, and the rotation speed is 25 r / min; Drying: Dry at 80 °C for 1.5 hours, and the particle compressive strength ≥ 10 N; Coating: Spray a diatomite coating agent on the particles (the dosage is 2% of the particle mass) to enhance the slow-release performance.

[0030] Example 3 A magnesium slag-based special silicon fertilizer for rice, the raw material composition by weight is: Magnesium slag (passed through a 100-mesh sieve) 79 parts Sodium-based bentonite 2.9 parts Polyaspartic acid 4.1 parts Polyacrylamide 3 parts Manganese sulfate 3.5 parts Zinc sulfate heptahydrate 5.2 parts Sodium molybdate 5 parts Urea (containing 46% nitrogen) 19 parts Superphosphate (containing 16% P2O5) 16 parts Potassium chloride (containing 55% K2O) 12.4 parts The preparation method includes the following steps: Mixing: Using a three-dimensional motion mixer, mixing time is 30 minutes, and the mixing uniformity ≥ 98%; Granulation: Using a disk granulator, the water spraying amount is 15% of the total mass of the raw materials, the inclination angle of the granulation disk is 55°, and the rotation speed is 25 r / min; Drying: Drying at 80°C for 1.5 hours, and the particle compressive strength ≥ 10 N; Coating: Spraying diatomite coating agent on the particles (the dosage is 2% of the particle mass) to enhance the slow-release performance.

[0031] Example 4 A special silicon fertilizer for rice based on magnesium slag, the raw material composition by weight is: Magnesium slag (passed through 100-mesh sieve) 53 parts Sodium-based bentonite 0.1 part Polyaspartic acid 2.8 parts Polyacrylamide 3 parts Manganese sulfate 3.2 parts Zinc sulfate heptahydrate 5.2 parts Sodium molybdate 5 parts Urea (containing 46% nitrogen) 18 parts Superphosphate (containing 16% P2O5) 14 parts Potassium chloride (containing 55% K2O) 13 parts The preparation method includes the following steps: Mixing: Using a three-dimensional motion mixer, mixing time is 30 minutes, and the mixing uniformity ≥ 98%; Granulation: Using a disk granulator, the water spraying amount is 15% of the total mass of the raw materials, the inclination angle of the granulation disk is 55°, and the rotation speed is 25 r / min; Drying: Drying at 80°C for 1.5 hours, and the particle compressive strength ≥ 10 N; Coating: Spraying diatomite coating agent on the particles (the dosage is 2% of the particle mass) to enhance the slow-release performance.

[0032] Example 5 A special silicon fertilizer for rice based on magnesium slag, the raw material composition by weight is: Magnesium slag (passed through 100-mesh sieve) 56 parts Sodium-based bentonite 4.8 parts Polyaspartic acid 3.2 parts Polyacrylamide 3 parts Manganese sulfate 2.4 parts Zinc sulfate heptahydrate 5.5 parts Sodium molybdate 4.2 parts Urea (containing 46% nitrogen) 18 parts Superphosphate (containing 16% P2O5) 14.6 parts Potassium chloride (containing 55% K2O) 13.2 parts The preparation method includes the following steps: Mixing: Using a three-dimensional motion mixer, the mixing time is 30 minutes, and the mixing uniformity is ≥98%; Granulation: Using a disk granulator, the water spraying amount is 15% of the total mass of the raw materials, the inclination angle of the granulation disk is 55°, and the rotation speed is 25 r / min; Drying: Drying at 80°C for 1.5 hours, and the particle compressive strength is ≥10 N; Coating: Spraying a diatomite coating agent on the particles (the dosage is 2% of the particle mass) to enhance the slow-release performance.

[0033] Example 6 A special silicon fertilizer for rice based on magnesium slag, the raw material composition by weight is: Magnesium slag (screened through 100 mesh) 52 parts Sodium-based bentonite 2.9 parts Polyaspartic acid 1.2 parts Polyacrylamide 3 parts Manganese sulfate 2.3 parts Zinc sulfate heptahydrate 5.3 parts Sodium molybdate 4.8 parts Urea (containing 46% nitrogen) 18.9 parts Superphosphate (containing 16% P2O5) 15.4 parts Potassium chloride (containing 55% K2O) 13.2 parts The preparation method includes the following steps: Mixing: Using a three-dimensional motion mixer, the mixing time is 30 minutes, and the mixing uniformity is ≥98%; Granulation: Using a disk granulator, the water spraying amount is 15% of the total mass of the raw materials, the inclination angle of the granulation disk is 55°, and the rotation speed is 25 r / min; Drying: Drying at 80°C for 1.5 hours, and the particle compressive strength is ≥10 N; Coating: Spraying a diatomite coating agent on the particles (the dosage is 2% of the particle mass) to enhance the slow-release performance.

[0034] Example 7 A special silicon fertilizer for rice based on magnesium slag, the raw material composition by weight is: Magnesium slag (screened through 100 mesh) 49 parts Sodium-based bentonite 2.7 parts Polyaspartic acid 4.9 parts Polyacrylamide 3 parts Manganese sulfate 2.4 parts Zinc sulfate heptahydrate 4.8 parts Sodium molybdate 4 parts Urea (containing 46% nitrogen) 19.6 parts Superphosphate (containing 16% P2O5) 15.3 parts Potassium chloride (containing 55% K2O) 11 parts The preparation method includes the following steps: Mixing: Using a three-dimensional motion mixer, the mixing time is 30 minutes, and the mixing uniformity ≥ 98%; Granulation: Using a disk granulator, the water spraying amount is 15% of the total mass of the raw materials, the inclination angle of the granulation disk is 55°, and the rotation speed is 25 r / min; Drying: Drying at 80°C for 1.5 hours, the particle compressive strength ≥ 10 N; Coating: Spraying a diatomite coating agent on the particles (the dosage is 2% of the particle mass) to enhance the slow-release performance.

[0035] Example 8 A special silicon fertilizer for rice based on magnesium slag, the raw material composition by weight is: Magnesium slag (sieved through 100 mesh) 54 parts Sodium-based bentonite 3.4 parts Polyaspartic acid 4.1 parts Polyacrylamide 1 part Manganese sulfate 2.3 parts Zinc sulfate heptahydrate 4.7 parts Sodium molybdate 6 parts Urea (containing 46% nitrogen) 17 parts Superphosphate (containing 16% P2O5) 14 parts Potassium chloride (containing 55% K2O) 13 parts The preparation method includes the following steps: Mixing: Using a three-dimensional motion mixer, the mixing time is 30 minutes, and the mixing uniformity ≥ 98%; Granulation: Using a disk granulator, the water spraying amount is 15% of the total mass of the raw materials, the inclination angle of the granulation disk is 55°, and the rotation speed is 25 r / min; Drying: Drying at 80°C for 1.5 hours, the particle compressive strength ≥ 10 N; Coating: Spraying a diatomite coating agent on the particles (the dosage is 2% of the particle mass) to enhance the slow-release performance.

[0036] Example 9 A special silicon fertilizer for rice based on magnesium slag, the raw material composition by weight is: Magnesium slag (sieved through 100 mesh) 52 parts Sodium-based bentonite 3.1 parts Polyaspartic acid 3.6 parts Polyacrylamide 5 parts Manganese sulfate 2.4 parts Zinc sulfate heptahydrate 5.2 parts Sodium molybdate 5.3 parts Urea (containing 46% nitrogen) 19 parts Superphosphate (containing 16% P2O5) 18 parts Potassium chloride (containing 55% K2O) 13.4 parts The preparation method includes the following steps: Mixing: Using a three-dimensional motion mixer, the mixing time is 30 minutes, and the mixing uniformity is ≥98%; Granulation: Using a disk granulator, the water spraying amount is 15% of the total mass of the raw materials, the inclination angle of the granulation disk is 55°, and the rotation speed is 25 r / min; Drying: Drying at 80°C for 1.5 hours, and the particle compressive strength is ≥10 N; Coating: Spraying a diatomite coating agent on the particles (the dosage is 2% of the particle mass) to enhance the slow-release performance.

[0037] Example 10 A special silicon fertilizer for rice based on magnesium slag, the raw material composition by weight is: Magnesium slag (screened through 100 mesh) 54 parts Sodium-based bentonite 2.8 parts Polyaspartic acid 3.2 parts Polyacrylamide 3 parts Manganese sulfate 0.5 part Zinc sulfate heptahydrate 5.1 parts Sodium molybdate 5.3 parts Urea (containing 46% nitrogen) 18.4 parts Superphosphate (containing 16% P2O5) 14.6 parts Potassium chloride (containing 55% K2O) 12.5 parts The preparation method includes the following steps: Mixing: Using a three-dimensional motion mixer, the mixing time is 30 minutes, and the mixing uniformity is ≥98%; Granulation: Using a disk granulator, the water spraying amount is 15% of the total mass of the raw materials, the inclination angle of the granulation disk is 55°, and the rotation speed is 25 r / min; Drying: Drying at 80°C for 1.5 hours, and the particle compressive strength is ≥10 N; Coating: Spraying a diatomite coating agent on the particles (the dosage is 2% of the particle mass) to enhance the slow-release performance.

[0038] Example 11 A special silicon fertilizer for rice based on magnesium slag, the raw material composition by weight is: Magnesium slag (screened through 100 mesh) 51 parts Sodium-based bentonite 2.5 parts Polyaspartic acid 3.5 parts Polyacrylamide 3 parts Manganese sulfate 4.7 parts Zinc sulfate heptahydrate 5.2 parts Sodium molybdate 4.9 parts Urea (containing 46% nitrogen) 19.8 parts 12 parts of superphosphate (containing 16% P2O5) 14 parts of potassium chloride (containing 55% K2O) The preparation method comprises the following steps: Mixing: Using a three-dimensional motion mixer, with a mixing time of 30 minutes and a mixing uniformity of ≥98%; Granulation: Using a disk granulator, with a water spraying amount of 15% of the total mass of the raw materials, a granulation disk inclination angle of 55°, and a rotation speed of 25 r / min; Drying: Drying at 80°C for 1.5 hours, with a particle compressive strength of ≥10 N; Coating: Spraying a diatomite coating agent on the particles (with a dosage of 2% of the particle mass) to enhance the slow-release performance.

[0039] Example 12 A magnesium slag-based special silicon fertilizer for rice, with the raw material composition by weight parts as follows: 50 parts of magnesium slag (screened through 100 mesh) 2.9 parts of sodium-based bentonite 3.7 parts of polyaspartic acid 3 parts of polyacrylamide 2.3 parts of manganese sulfate 1 part of zinc sulfate heptahydrate 4.8 parts of sodium molybdate 24 parts of urea (containing 46% nitrogen) 12 parts of superphosphate (containing 16% P2O5) 10.9 parts of potassium chloride (containing 55% K2O) The preparation method comprises the following steps: Mixing: Using a three-dimensional motion mixer, with a mixing time of 30 minutes and a mixing uniformity of ≥98%; Granulation: Using a disk granulator, with a water spraying amount of 15% of the total mass of the raw materials, a granulation disk inclination angle of 55°, and a rotation speed of 25 r / min; Drying: Drying at 80°C for 1.5 hours, with a particle compressive strength of ≥10 N; Coating: Spraying a diatomite coating agent on the particles (with a dosage of 2% of the particle mass) to enhance the slow-release performance.

[0040] Example 13 A magnesium slag-based special silicon fertilizer for rice, with the raw material composition by weight parts as follows: 54 parts of magnesium slag (screened through 100 mesh) 4 parts of sodium-based bentonite 3 parts of polyaspartic acid 2.9 parts of polyacrylamide 1.9 parts of manganese sulfate 9 parts of zinc sulfate heptahydrate 5.4 parts of sodium molybdate 18.5 parts of urea (containing 46% nitrogen) Superphosphate (containing 16% P2O5) 15.3 parts Potassium chloride (containing 55% K2O) 11 parts The preparation method comprises the following steps: Mixing: Using a three-dimensional motion mixer, the mixing time is 30 minutes, and the mixing uniformity ≥ 98%; Granulation: Using a disk granulator, the water spraying amount is 15% of the total mass of the raw materials, the inclination angle of the granulation disk is 55°, and the rotation speed is 25 r / min; Drying: Drying at 80 °C for 1.5 hours, and the particle compressive strength ≥ 10 N; Coating: Spraying a diatomite coating agent on the particles (the dosage is 2% of the particle mass) to enhance the slow-release performance.

[0041] Example 14 A magnesium slag-based special silicon fertilizer for rice, the raw material composition by weight is: Magnesium slag (sieved through 100 mesh) 55 parts Sodium-based bentonite 4.1 parts Polyaspartic acid 3 parts Polyacrylamide 2.9 parts Manganese sulfate 2.2 parts Zinc sulfate heptahydrate 5.3 parts Sodium molybdate 1 part Urea (containing 46% nitrogen) 24 parts Superphosphate (containing 16% P2O5) 14.2 parts Potassium chloride (containing 55% K2O) 15.3 parts The preparation method comprises the following steps: Mixing: Using a three-dimensional motion mixer, the mixing time is 30 minutes, and the mixing uniformity ≥ 98%; Granulation: Using a disk granulator, the water spraying amount is 15% of the total mass of the raw materials, the inclination angle of the granulation disk is 55°, and the rotation speed is 25 r / min; Drying: Drying at 80 °C for 1.5 hours, and the particle compressive strength ≥ 10 N; Coating: Spraying a diatomite coating agent on the particles (the dosage is 2% of the particle mass) to enhance the slow-release performance.

[0042] Example 15 A magnesium slag-based special silicon fertilizer for rice, the raw material composition by weight is: Magnesium slag (sieved through 100 mesh) 53 parts Sodium-based bentonite 4.3 parts Polyaspartic acid 3 parts Polyacrylamide 4 parts Manganese sulfate 2.3 parts Zinc sulfate heptahydrate 5.1 parts Sodium molybdate 10 parts Urea (containing 46% nitrogen) 18.5 parts 14 parts of superphosphate (containing 16% P2O5) 13.2 parts of potassium chloride (containing 55% K2O) The preparation method includes the following steps: Mixing: Using a three-dimensional motion mixer, the mixing time is 30 minutes, and the mixing uniformity is ≥98%; Granulation: Using a disk granulator, the water spraying amount is 15% of the total mass of the raw materials, the inclination angle of the granulation disk is 55°, and the rotation speed is 25 r / min; Drying: Drying at 80°C for 1.5 hours, and the particle compressive strength is ≥10 N; Coating: Spraying a diatomite coating agent on the particles (the dosage is 2% of the particle mass) to enhance the slow-release performance.

[0043] Example 16 A special silicon fertilizer for rice based on magnesium slag, the raw material composition by weight is as follows: 51 parts of magnesium slag (screened through 100 mesh) 4.6 parts of sodium-based bentonite 3.7 parts of polyaspartic acid 3.3 parts of polyacrylamide 2.1 parts of manganese sulfate 4.9 parts of zinc sulfate heptahydrate 5 parts of sodium molybdate 10 parts of urea (containing 46% nitrogen) 14.6 parts of superphosphate (containing 16% P2O5) 14 parts of potassium chloride (containing 55% K2O) The preparation method includes the following steps: Mixing: Using a three-dimensional motion mixer, the mixing time is 30 minutes, and the mixing uniformity is ≥98%; Granulation: Using a disk granulator, the water spraying amount is 15% of the total mass of the raw materials, the inclination angle of the granulation disk is 55°, and the rotation speed is 25 r / min; Drying: Drying at 80°C for 1.5 hours, and the particle compressive strength is ≥10 N; Coating: Spraying a diatomite coating agent on the particles (the dosage is 2% of the particle mass) to enhance the slow-release performance.

[0044] Example 17 A special silicon fertilizer for rice based on magnesium slag, the raw material composition by weight is as follows: 53 parts of magnesium slag (screened through 100 mesh) 3.2 parts of sodium-based bentonite 3 parts of polyaspartic acid 4.1 parts of polyacrylamide 2.5 parts of manganese sulfate 5.2 parts of zinc sulfate heptahydrate 5.2 parts of sodium molybdate Urea (nitrogen content 46%) 29 parts Superphosphate (P2O5 content 16%) 16.2 parts Potassium chloride (K2O content 55%) 11.6 parts The preparation method comprises the following steps: Mixing: Using a three-dimensional motion mixer, mixing time is 30 minutes, mixing uniformity ≥ 98%; Granulation: Using a disc granulator, water spraying amount is 15% of the total mass of raw materials, inclination angle of granulation disc is 55°, rotation speed is 25 r / min; Drying: Drying at 80 °C for 1.5 hours, particle compressive strength ≥ 10 N; Coating: Spraying diatomite coating agent on the particles (dosage is 2% of the particle mass) to enhance the slow-release performance.

[0045] Example 18 A special silicon fertilizer for rice based on magnesium slag, the raw material composition by weight is: Magnesium slag (screened through 100 mesh) 51 parts Sodium-based bentonite 3 parts Polyaspartic acid 3 parts Polyacrylamide 3.5 parts Manganese sulfate 1.8 parts Zinc sulfate heptahydrate 4.7 parts Sodium molybdate 5.2 parts Urea (nitrogen content 46%) 21 parts Superphosphate (P2O5 content 16%) 5 parts Potassium chloride (K2O content 55%) 13 parts The preparation method comprises the following steps: Mixing: Using a three-dimensional motion mixer, mixing time is 30 minutes, mixing uniformity ≥ 98%; Granulation: Using a disc granulator, water spraying amount is 15% of the total mass of raw materials, inclination angle of granulation disc is 55°, rotation speed is 25 r / min; Drying: Drying at 80 °C for 1.5 hours, particle compressive strength ≥ 10 N; Coating: Spraying diatomite coating agent on the particles (dosage is 2% of the particle mass) to enhance the slow-release performance.

[0046] Example 19 A special silicon fertilizer for rice based on magnesium slag, the raw material composition by weight is: Magnesium slag (screened through 100 mesh) 56 parts Sodium-based bentonite 3.1 parts Polyaspartic acid 3.2 parts Polyacrylamide 3.6 parts Manganese sulfate 1.7 parts Zinc sulfate heptahydrate 4.5 parts Sodium molybdate 4.8 parts Urea (nitrogen content 46%) 19.7 parts Superphosphate (P2O5 content 16%) 20 parts Potassium chloride (K2O content 55%) 13.2 parts The preparation method includes the following steps: Mixing: Using a three-dimensional motion mixer, mixing time is 30 minutes, mixing uniformity ≥ 98%; Granulation: Using a disk granulator, the water spraying amount is 15% of the total mass of the raw materials, the inclination angle of the granulation disk is 55°, and the rotation speed is 25 r / min; Drying: Drying at 80°C for 1.5 hours, the particle compressive strength ≥ 10 N; Coating: Spraying diatomite coating agent on the particles (the dosage is 2% of the particle mass) to enhance the slow-release performance.

[0047] Example 20 A special silicon fertilizer for rice based on magnesium slag, the raw material composition by weight is: Magnesium slag (screened through 100 mesh) 52 parts Sodium-based bentonite 3.5 parts Polyaspartic acid 3.2 parts Polyacrylamide 4.1 parts Manganese sulfate 1.9 parts Zinc sulfate heptahydrate 5.2 parts Sodium molybdate 5.2 parts Urea (nitrogen content 46%) 19.8 parts Superphosphate (P2O5 content 16%) 14.2 parts Potassium chloride (K2O content 55%) 10 parts The preparation method includes the following steps: Mixing: Using a three-dimensional motion mixer, mixing time is 30 minutes, mixing uniformity ≥ 98%; Granulation: Using a disk granulator, the water spraying amount is 15% of the total mass of the raw materials, the inclination angle of the granulation disk is 55°, and the rotation speed is 25 r / min; Drying: Drying at 80°C for 1.5 hours, the particle compressive strength ≥ 10 N; Coating: Spraying diatomite coating agent on the particles (the dosage is 2% of the particle mass) to enhance the slow-release performance.

[0048] Example 21 A special silicon fertilizer for rice based on magnesium slag, the raw material composition by weight is: Magnesium slag (screened through 100 mesh) 51 parts Sodium-based bentonite 3.3 parts Polyaspartic acid 2.8 parts Polyacrylamide 3.1 parts Manganese sulfate 2.2 parts Zinc sulfate heptahydrate 4.8 parts 4.3 parts of sodium molybdate Urea (nitrogen content 46%) 23 parts Superphosphate (containing P2O5 16%) 14.2 parts Potassium chloride (containing K2O55%) 20 parts The preparation method comprises the following steps: Mixing: Use a three-dimensional motion mixer, the mixing time is 30 minutes, and the mixing uniformity is ≥98%; Granulation: Use a disc granulator, the water spraying amount is 15% of the total mass of the raw materials, the granulation disc inclination angle is 55°, and the speed is 25r / min; Drying: Dry at 80℃ for 1.5 hours, the compressive strength of the particles is ≥10N; Coating: Spray diatomaceous earth coating agent (the dosage is 2% of the particle mass) on the particles to enhance the sustained release performance.

[0049] Embodiment 22 No fertilizer is added during the rice cultivation process.

[0050] The above Examples 1-22 were applied to the growth of rice, 50 kg was applied per mu of land, and the rice and soil were sampled and tested after the rice grew to maturity.

[0051] Table 1 Determination of physicochemical properties of rice, fertilizer and soil

[0052] Table 2 Measurement of physical and chemical properties of rice and soil

[0053] In summary, the magnesium slag content in Examples 2 and 3 is different from that in Example 1. Magnesium slag mainly provides calcium and magnesium nutrients and effective silicon content in the formula. However, excessive calcium and magnesium will hinder the plant's absorption of other nutrients, limiting the plant's growth and thus affecting the final yield. Compared with Example 1, the proportion of sodium bentonite in Examples 4 and 5 is changed. The appropriate addition will make the fertilizer have a certain compressive strength, and the decrease in the proportion of sodium bentonite will reduce the compressive strength of the fertilizer. It will make the fertilizer fragile during transportation, and the higher sodium bentonite will make the fertilizer too strong, which is not conducive to the crushing and absorption of the fertilizer.

[0054] Compared with Example 1, the proportion of polyaspartic acid in Examples 6 and 7 is changed. Polyaspartic acid is mainly responsible for regulating the moisture content of the soil. Maintaining the moisture content at 18% can effectively promote the growth of rice. Therefore, excessive addition or insufficient addition is not conducive to the growth of rice.

[0055] In Examples 8 and 9, compared with Example 1, the proportion of polyacrylamide changes. Polyacrylamide mainly plays a role in packaging nutrients in the formula, enabling the slow release of nutrient elements and having a more lasting effect on rice. Therefore, compared with Example 1, the plant heights of rice in Examples 8 and 9 are lower than that in Example 1.

[0056] In Examples 10 and 11, compared with Example 1, the proportion of manganese sulfate changes. Manganese element can effectively promote the growth of rice and is beneficial to the synthesis of chlorophyll. However, excessive manganese element will also cause the phenomenon of leaf chlorosis in plants. Therefore, the manganese element should be set within a certain proportion range, at which the chlorophyll content in the leaves is the highest.

[0057] In Examples 12 and 13, compared with Example 1, the proportion of zinc sulfate changes. Zinc is an essential trace element for plants, but excessive accumulation will have a toxic effect on plant growth, affecting physiological metabolism, nutrient balance, and antioxidant systems. The root length of rice can grow better under the action of Example 1.

[0058] In Examples 14 and 15, compared with Example 1, the proportion of sodium molybdate changes. Molybdenum (Mo) is an essential trace element for plants. Molybdenum element can promote the content of antioxidant enzyme (SOD). SOD can effectively resist adverse environments. Therefore, the SPD content in Example 1 is higher than that in Example 14. However, excessive Mo will lead to the accumulation of Mo-protein complexes, affecting protein metabolism and inhibiting amino acid synthesis, thus affecting plant growth. Therefore, the SOD content in Example 15 decreases compared with that in Example 1.

[0059] In Examples 16 and 17, compared with Example 1, the proportion of urea changes. Urea is used to provide the N element for the growth of rice. Less nitrogen element is not conducive to plant growth, and more urea does not significantly promote the growth of rice. Therefore, the urea proportion in Example 1 is the optimal proportion.

[0060] In Examples 18 and 19, compared with Example 1, the proportion of superphosphate changes. Superphosphate is used to provide phosphorus element. Phosphorus element is a beneficial element for plant growth. Less phosphorus element is not conducive to plant growth, and more superphosphate does not significantly promote the growth of rice. Therefore, the superphosphate proportion in Example 1 is the optimal proportion.

[0061] In Examples 20 and 21, compared with Example 1, the proportion of potassium chloride changes. Potassium chloride provides the potassium element for plant growth. Potassium mainly promotes plant growth and increases crop yield by regulating water balance, enhancing photosynthesis, promoting enzyme activity, and improving stress resistance. Less potassium element and more potassium chloride do not significantly promote the growth of rice. Therefore, the potassium chloride proportion in Example 1 is the optimal proportion.

[0062] The present invention optimizes the supply of nutrient elements, soil water retention, nutrient release rate and compressive strength of fertilizers by adjusting the proportions of components such as magnesium slag, sodium-based bentonite, polyaspartic acid, polyacrylamide, manganese sulfate, zinc sulfate, sodium molybdate, urea, superphosphate and potassium chloride. The research results show that the appropriate addition of magnesium slag can provide calcium and magnesium elements, increase the available silicon content in the soil to promote plant growth and increase production. The reasonable proportion of sodium-based bentonite can enhance the compressive strength of fertilizers, improve the integrity of fertilizers during transportation and reduce the problem of fragility. The optimal addition amount of polyaspartic acid can effectively regulate the water content of the soil and keep it at 18%, thus promoting the growth of rice. The function of polyacrylamide is to encapsulate nutrient components, enabling them to be slowly released and continuously act on rice. The appropriate addition of manganese sulfate can promote the growth of rice and increase the chlorophyll content. Zinc sulfate is an essential trace element for rice growth, and a reasonable proportion can promote physiological metabolism and the antioxidant system, but excessive accumulation will be toxic to plant growth, affect nutrient balance and reduce antioxidant capacity. The addition of sodium molybdate can promote the activity of superoxide dismutase and improve the stress resistance of rice. Urea can provide nitrogen elements to promote the growth of rice. The reasonable addition of superphosphate can provide phosphorus elements to promote root development and growth. Potassium chloride can provide potassium elements and promote the growth of rice by regulating water balance, enhancing photosynthesis, promoting enzyme activity and improving stress resistance. Therefore, by scientifically optimizing the proportions of each component, the present invention improves the nutrient supply capacity, soil water regulation capacity, nutrient release stability and mechanical strength of fertilizers, thus effectively promoting the growth of rice, increasing the yield of rice, enhancing the stress resistance of rice and making the agricultural application effect of fertilizers more superior.

[0063] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent substitution on some of the technical features. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing magnesium slag-based special silicon fertilizer for rice, characterized in that: The raw materials of the silicon fertilizer include, by weight, 50-80 parts of magnesium slag, 0.1-5 parts of bentonite, 1-5 parts of polyaspartic acid, 1-5 parts of polyacrylamide, 0.5-5 parts of manganese sulfate, 1-10 parts of zinc sulfate heptahydrate, 1-10 parts of sodium molybdate, 10-30 parts of nitrogen fertilizer, 5-20 parts of phosphate fertilizer and 10-15 parts of potash fertilizer.

2. The method for preparing magnesium slag-based special silicon fertilizer for rice according to claim 1, characterized in that: The magnesium slag is sieved through a 100-mesh sieve.

3. The method for preparing magnesium slag-based special silicon fertilizer for rice according to claim 1, characterized in that: The magnesium slag has a calcium content of ≥60wt%, and a calcium and magnesium content of ≥62wt%. ； Wherein, the calcium content is measured as the mass percentage of calcium oxide; the calcium and magnesium contents are measured as the mass percentage of calcium oxide and magnesium oxide.

4. The method for preparing magnesium slag-based special silicon fertilizer for rice according to claim 1, characterized in that: The bentonite is sodium bentonite.

5. The method for preparing magnesium slag-based special silicon fertilizer for rice according to claim 1, characterized in that: The nitrogen fertilizer is urea with a nitrogen content of about 46wt%; the phosphorus fertilizer is superphosphate with a phosphorus content of 14-20wt%; and the potassium fertilizer is potassium chloride with a potassium content of 50-60wt%.

6. The method for preparing magnesium slag-based special silicon fertilizer for rice according to claim 1, characterized in that: The following steps are involved: Step 1) magnesium slag, bentonite, polyaspartic acid, polyacrylamide, manganese sulfate, zinc sulfate heptahydrate, sodium molybdate, nitrogen fertilizer, phosphate fertilizer, and potash fertilizer are weighed according to the above weight parts; in a blender, magnesium slag, bentonite, manganese sulfate, zinc sulfate heptahydrate, sodium molybdate, nitrogen fertilizer, phosphate fertilizer, and potash fertilizer are uniformly mixed to obtain a mixed powder, and polyaspartic acid and polyacrylamide are added thereto for mixing to obtain a mixture; Step 2) pouring the obtained mixture into a granulator and adding a certain amount of water to granulate to prepare granular material; Step 3) The obtained granular material is placed in a drying oven at 60°C-80°C and dried to obtain the product.

7. The method for preparing magnesium slag-based special silicon fertilizer for rice according to claim 1, characterized in that: In step 2), the granulator is selected from any one of a disc granulator, a sugar coating machine, and a high-speed granulator.

8. The method for preparing magnesium slag-based special silicon fertilizer for rice according to claim 1, characterized in that: In step 2), the weight of water added is controlled to be 1%-15% of the total weight of the material.

9. A magnesium slag-based silicon fertilizer for rice prepared by the preparation method according to any one of claims 1 to 8, characterized in that: Calculated in terms of SiO2, the silicon fertilizer has an effective silicon content of ≥20wt%, a moisture content of ≤3wt%, and ≥85wt% of particles passing through a 2mm standard sieve.

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