Fertilizer internal additive taking fly ash as raw material and preparation method of fertilizer internal additive

Abstract

The invention discloses a fertilizer internal additive using fly ash as a raw material and a preparation method thereof, and relates to the technical field of fertilizer internal additives, the fertilizer internal additive comprises the following raw materials by weight: 15-25 parts of fly ash, 5-15 parts of starch, 0.3-0.6 part of an initiator, 0.05-0.2 part of a cross-linking agent, 35-60 parts of acrylic acid, 2.5-5 parts of a dispersant, and 40-60 parts of deionized water. According to the fertilizer internal additive taking the fly ash as the raw material and the preparation method of the fertilizer internal additive, the fly ash is pretreated, so that acid soil can be neutralized to a certain extent, and the pH value of the soil is more suitable for crop growth; the treated fly ash is helpful for soil particles to form a good aggregate structure, and the porosity of the soil is increased, so that water and fertilizer can be better preserved, and plant roots can better breathe and grow.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizer additives, in particular to a fertilizer additive using fly ash as a raw material and a preparation method thereof. Background Art

[0002] Fly ash is the fine ash collected from the flue gas after coal combustion and is the main solid waste discharged by coal-fired power plants. Its main components include silicon dioxide, aluminum oxide, iron oxide, calcium oxide, etc., and also contain a small amount of magnesium, potassium, sodium and other elements. Fly ash particles are fine and have good physical and chemical properties, such as large specific surface area, high porosity, strong adsorption performance, etc. Due to its smooth surface and mostly spherical shape, fly ash is formed by cooling after absorbing heat from the hot surface under suspended combustion conditions.

[0003] In the fertilizer industry, some companies add fertilizer additives to beautify the appearance and unify the color during the production of fertilizers as anti-counterfeiting marks. If fly ash can be made into fertilizer additives, it can not only control the appearance of the fertilizer, but also because fly ash contains P, K, Mg, B, Mn, Ca, Fe, Si and other elements required by plants, the appropriate application of fly ash can promote the growth of crops and increase production. It can also make full use of waste resources, turn waste into treasure, and continuously improve the utilization level of fly ash. It has good compatibility with the ecological environment, is biodegradable, and is pollution-free and non-toxic to the environment. However, when the existing fly ash is added directly, its effect cannot be fully exerted; for this reason, the present invention provides a fertilizer additive using fly ash as a raw material and a preparation method thereof to solve the above problems. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a fertilizer additive using fly ash as a raw material and a preparation method thereof, which solves the problems mentioned in the above background technology.

[0005] To achieve the above objectives, the present invention is implemented through the following technical scheme: a fertilizer additive using fly ash as raw material, comprising the following raw materials in parts by weight: 15 to 25 parts of fly ash, 5 to 15 parts of starch, 0.3 to 0.6 parts of initiator, 0.05 to 0.2 parts of cross-linking agent, 35 to 60 parts of acrylic acid, 2.5 to 5 parts of dispersant, and 40 to 60 parts of deionized water.

[0006] Preferably, the initiator is potassium persulfate; and the cross-linking agent is N,N-methylenebisacrylamide.

[0007] Preferably, the dispersant is a mixture of octylphenol polyoxyethylene ether-10 and sodium methylene bisnaphthalene sulfonate, and the mass ratio of octylphenol polyoxyethylene ether-10 to sodium methylene bisnaphthalene sulfonate is 1:(8.5-10).

[0008] A method for preparing a fertilizer additive using fly ash as a raw material, specifically comprising the following preparation steps: Step 1: pre-treating fly ash; Step 2: adding a dispersant and deionized water to the treated fly ash, stirring and mixing, to obtain a solution 1; Step 3, add acrylic acid dropwise to an ice water bath at 0-2°C, stir until it is completely dissolved, slowly add sodium hydroxide, continue stirring, and after the reaction is complete, stir for 3-5 minutes to obtain Solution 2; Step 4: Pour solution 1 into solution 2, stir evenly, add crosslinking agent and initiator, heat to 70-75°C, react for 35-50 minutes, and dry in a vacuum drying oven to obtain the fertilizer additive.

[0009] Preferably, in step 1, the specific method for pretreating the fly ash is: S1, grinding, sieving and drying the fly ash in sequence, then mixing with sodium hydroxide solution and stirring evenly; S2, placed in a muffle furnace at 260-300°C for 2.5-3h; S3, take it out, wait for it to cool to room temperature, crush it and grind it, and then wash it with distilled water for 3 to 5 times until it becomes neutral; S4. Place in a constant temperature drying oven at 100-105℃ for drying.

[0010] Preferably, in S1, the mass ratio of fly ash to sodium hydroxide solution is 5:(7-8).

[0011] Preferably, the fly ash has a particle size of 0.2 to 1.5 mm.

[0012] Preferably, in S1, the fly ash is ground and passed through a 100-120 mesh sieve, and then placed in a drying oven at 80-85° C. for 5-6 hours.

[0013] Beneficial Effects The present invention provides a fertilizer additive using fly ash as raw material and a preparation method thereof. Compared with the prior art, the additive has the following beneficial effects: (1) The fertilizer additive using fly ash as raw material and its preparation method can neutralize acidic soil to a certain extent by pretreating fly ash, so that the pH value of soil is more suitable for crop growth; the treated fly ash helps soil particles to form a good aggregate structure and increases the porosity of the soil, which can better retain water and fertilizer, allowing plant roots to breathe and grow better; and the fly ash itself contains a variety of trace elements such as silicon, calcium, and magnesium. After being treated with sodium hydroxide, these elements are more easily absorbed and utilized by plants in the soil, thereby supplementing the nutrients necessary for plant growth; at the same time, the smooth spherical structure of the fly ash after pretreatment is broken, exposing the rough and porous irregular surface inside, on which a large number of adsorption sites that can bind to heavy metal ions are distributed, thereby improving the adsorption capacity of heavy metals.

[0014] (2) The fertilizer additive using fly ash as raw material and its preparation method improve the release and effectiveness of trace elements in fly ash through the addition reaction of acrylic acid, sodium hydroxide, N,N-methylenebisacrylamide and potassium persulfate, thereby providing more comprehensive nutritional supplements for plants; and the polymer formed during the reaction has a three-dimensional network structure, which can bond soil particles together, increase soil porosity, improve soil aeration, and allow plant roots to breathe and grow better. At the same time, the loose soil structure is also conducive to the activity of microorganisms in the soil and promotes the circulation of nutrients in the soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The SEM images of the fly ash before and after pretreatment are provided for a fertilizer additive using fly ash as raw material and a preparation method thereof of the present invention; Figure 2 A comparative diagram of organic matter content determination provided by a fertilizer additive using fly ash as raw material and a preparation method thereof of the present invention; Figure 3 A comparison chart of heavy metal adsorption measurement provided for a fertilizer additive using fly ash as raw material and a preparation method thereof according to the present invention. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] Example 1 A method for preparing a fertilizer additive using fly ash as a raw material, specifically comprising the following preparation steps: Step 1: pretreat 15g of fly ash with a particle size of 0.2mm: grind the fly ash and pass it through a 100-mesh sieve, then place it in a drying oven at 80°C for 5 hours, then mix it with a sodium hydroxide solution and stir it evenly; then place it in a muffle furnace at 260°C and treat it for 2.5 hours; take it out, wait for it to cool to room temperature, crush it, and then wash it with distilled water 3 times until it is neutral; finally place it in a constant temperature drying oven at 100°C for drying; Among them, the mass ratio of fly ash to sodium hydroxide solution is 5:7; Step 2: Add 2.5 g of a mixture of octylphenol polyoxyethylene ether-10 and sodium methylene bisnaphthalene sulfonate in a mass ratio of 1:8.5 and 40 g of deionized water to the treated fly ash, and stir to mix to obtain a solution 1; Step 3: Add 35 g of acrylic acid dropwise into an ice-water bath at 0°C, stir until it is completely dissolved, then slowly add 0.8 g of sodium hydroxide and continue stirring. After the reaction is complete, stir for 3 minutes to obtain Solution 2. Step 4: Pour solution 1 into solution 2, stir evenly, add 0.05 g of N, N-methylenebisacrylamide and 0.3 g of potassium persulfate, heat to 70°C, react for 35 minutes, and dry in a vacuum drying oven to obtain the fertilizer additive.

[0018] Example 2 A method for preparing a fertilizer additive using fly ash as a raw material, specifically comprising the following preparation steps: Step 1: pretreat 20g of fly ash with a particle size of 0.9mm: grind the fly ash and pass it through a 110-mesh sieve, then place it in a drying oven at 83°C for 5.5h, then mix it with a sodium hydroxide solution and stir it evenly; then place it in a muffle furnace at 280°C and treat it for 2.8h; take it out, wait for it to cool to room temperature, crush it, and then wash it with distilled water 4 times until it is neutral; finally place it in a constant temperature drying oven at 102°C for drying; Among them, the mass ratio of fly ash to sodium hydroxide solution is 5:7.5; Step 2: Add 3.5 g of a mixture of octylphenol polyoxyethylene ether-10 and sodium methylene bisnaphthalene sulfonate in a mass ratio of 1:9.2 and 50 g of deionized water to the treated fly ash, and stir to mix to obtain a solution 1; Step 3: Add 50 g of acrylic acid dropwise into an ice-water bath at 1°C, stir until it is completely dissolved, then slowly add 1.2 g of sodium hydroxide and continue stirring. After the reaction is complete, stir for 4 minutes to obtain Solution 2. Step 4: Pour solution 1 into solution 2, stir evenly, add 0.12 g of N,N-methylenebisacrylamide and 0.5 g of potassium persulfate, heat to 72°C, react for 45 minutes, and dry in a vacuum drying oven to obtain a fertilizer additive.

[0019] Example 3 A method for preparing a fertilizer additive using fly ash as a raw material, specifically comprising the following preparation steps: Step 1: pretreat 25g of fly ash with a particle size of 1.5mm: grind the fly ash and pass it through a 120-mesh sieve, then place it in a drying oven at 85°C for 6 hours, then mix it with a sodium hydroxide solution and stir it evenly; then place it in a muffle furnace at 300°C and treat it for 3 hours; take it out, wait for it to cool to room temperature, crush it, and then wash it with distilled water 5 times until it is neutral; finally place it in a constant temperature drying oven at 105°C for drying; Among them, the mass ratio of fly ash to sodium hydroxide solution is 5:8; Step 2: Add 5 g of a mixture of octylphenol polyoxyethylene ether-10 and sodium methylene bisnaphthalene sulfonate in a mass ratio of 1:10 and 60 g of deionized water to the treated fly ash, and stir to mix to obtain a solution 1; Step 3: Add 60 g of acrylic acid dropwise into a 2°C ice water bath, stir until it is completely dissolved, then slowly add 1.5 g of sodium hydroxide and continue stirring. After the reaction is complete, stir for 5 minutes to obtain Solution 2. Step 4: Pour solution 1 into solution 2, stir evenly, add 0.2 g of N, N-methylenebisacrylamide and 0.6 g of potassium persulfate, heat to 75°C, react for 50 minutes, and dry in a vacuum drying oven to obtain a fertilizer additive.

[0020] Comparative Example 1 A method for preparing a fertilizer additive using fly ash as a raw material, specifically comprising the following preparation steps: Step 1: add 2.5 g of a mixture of octylphenol polyoxyethylene ether-10 and sodium methylene bisnaphthalene sulfonate in a mass ratio of 1:8.5 and 40 g of deionized water to 15 g of fly ash, stir and mix to obtain solution 1; Step 2: Add 35 g of acrylic acid dropwise to an ice-water bath at 0°C, stir until it is completely dissolved, then slowly add 0.8 g of sodium hydroxide and continue stirring. After the reaction is complete, stir for 3 minutes to obtain Solution 2. Step 3: Pour solution 1 into solution 2, stir evenly, add 0.05 g of N, N-methylenebisacrylamide and 0.3 g of potassium persulfate, heat to 70°C, react for 35 minutes, and dry in a vacuum drying oven to obtain the fertilizer additive.

[0021] Comparative Example 2 A method for preparing a fertilizer additive using fly ash as a raw material, specifically comprising the following preparation steps: Step 1: pretreat 15g of fly ash with a particle size of 0.2mm: grind the fly ash and pass it through a 100-mesh sieve, then place it in a drying oven at 80°C for 5 hours, then mix it with a sodium hydroxide solution and stir it evenly; then place it in a muffle furnace at 260°C and treat it for 2.5 hours; take it out, wait for it to cool to room temperature, crush it, and then wash it with distilled water 3 times until it is neutral; finally place it in a constant temperature drying oven at 100°C for drying; Among them, the mass ratio of fly ash to sodium hydroxide solution is 5:7; Step 2: Add 2.5 g of a mixture of octylphenol polyoxyethylene ether-10 and sodium methylene bisnaphthalene sulfonate in a mass ratio of 1:8.5 and 40 g of deionized water to the treated fly ash, stir and mix, and grind to obtain a fertilizer additive.

[0022] Sample preparation: 20g of nitrogen fertilizer, 10g of phosphate fertilizer, 10g of potash fertilizer and 2g of fertilizer additives were mixed to prepare compound fertilizer; impurities in the soil were removed, and the soil was air-dried and passed through a 2mm nylon sieve. Cu(NO3)2·4H2O, Pb(NO3)2, and Cd(NO3)2·4H20 aqueous solutions were added to the soil and stirred continuously to mix evenly. The soil moisture was maintained at 60% of the maximum moisture content within 30 days by weighing method, and the concentrations of Cd, Cu and Pb were adjusted to 15.33mg / kg, 611.33mg / kg and 1784.80mg / kg, respectively, and 2% of the sample was added.

[0023] Soil organic matter determination: Soil organic matter (OM) content was determined by potassium dichromate volumetric method, specifically: weigh 0.15g of air-dried soil into a high-temperature resistant glass tube, add 5mL0.8mol / L potassium dichromate solution and 5mL18.4mol / L sulfuric acid in sequence, heat in an oil bath at 180℃ for 5min, take out and cool to room temperature, transfer to a 250mL conical flask without loss, add 3 drops of indicator solution o-phenanthroline, and titrate with 0.2mol FeSO4 solution; the calculation formula is as follows: ; In the formula, is the consumption of FeSO4 when no fertilizer additives are added, mL; is the consumption of FeSO4 when adding fertilizer additives, mL; is the equivalent concentration of FeSO4.

[0024] Determination of heavy metal adsorption in soil: The total content of heavy metals (HMs) in the soil was digested with HNO3-HC1O4-HF and determined by flame atomic absorption AAS (PinAAcle900H).

[0025] like Figure 1 As shown in the figure, the surface of the fly ash without pretreatment is smooth, and no obvious pore structure is found; while the smooth spherical structure of the fly ash after pretreatment is broken, exposing the rough and porous irregular surface inside, on which are distributed a large number of adsorption sites that can bind to heavy metal ions. This structural change can greatly increase the specific surface area of ​​the material and its ability to fix heavy metals.

[0026] like Figure 2 and Figure 3 As shown, compared with Comparative Examples 1 and 2, the fertilizer additives prepared in Examples 1-3 can significantly increase the content of organic matter in the soil, thereby providing more nutrients for plants, improving soil structure, enhancing soil fertility and promoting plant growth; at the same time, the increase in organic matter content improves the soil's ability to adsorb heavy metals.

[0027] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0028] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0029] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a fertilizer additive using fly ash as raw material, characterized in that: The specific preparation steps include: Step 1: pre-treating fly ash; Step 2: adding a dispersant and deionized water to the treated fly ash, stirring and mixing, to obtain a solution 1; Step 3, add acrylic acid dropwise to an ice water bath at 0-2°C, stir until it is completely dissolved, slowly add sodium hydroxide, continue stirring, and after the reaction is complete, stir for 3-5 minutes to obtain Solution 2; Step 4: Pour solution 1 into solution 2, stir evenly, add a crosslinking agent and an initiator, heat to 70-75°C, react for 35-50 minutes, and dry in a vacuum drying oven to obtain a fertilizer additive; The fertilizer additive using fly ash as raw material comprises the following raw materials in parts by weight: 15-25 parts of untreated fly ash, 0.3-0.6 parts of initiator, 0.05-0.2 parts of cross-linking agent, 35-60 parts of acrylic acid, 2.5-5 parts of dispersant, 0.8-1.5 parts of sodium hydroxide, and 40-60 parts of deionized water; The initiator is potassium persulfate; the crosslinking agent is N,N-methylenebisacrylamide; the dispersant is a mixture of octylphenol polyoxyethylene ether-10 and sodium methylene bisnaphthalene sulfonate, and the mass ratio of octylphenol polyoxyethylene ether-10 to sodium methylene bisnaphthalene sulfonate is 1:(8.5-10).

2. The method for preparing a fertilizer additive using fly ash according to claim 1, characterized in that: In the step 1, the specific method for pre-treating the fly ash is: S1, grinding, sieving and drying the fly ash in sequence, then mixing with sodium hydroxide solution and stirring evenly; S2, placed in a muffle furnace at 260-300°C for 2.5-3h; S3, take it out, wait for it to cool to room temperature, crush it and grind it, and then wash it with distilled water for 3 to 5 times until it becomes neutral; S4. Place in a constant temperature drying oven at 100-105℃ for drying.

3. The method for preparing a fertilizer additive using fly ash as raw material according to claim 2, characterized in that: In the S1, the mass ratio of fly ash to sodium hydroxide solution is 5:(7-8).

4. The method for preparing a fertilizer additive using fly ash as raw material according to claim 2, characterized in that: The selected particle size of the fly ash is 0.2-1.5 mm.

5. The method for preparing a fertilizer additive using fly ash as raw material according to claim 2, characterized in that: In S1, the fly ash is ground and passed through a 100-120 mesh sieve, and then placed in a drying oven at 80-85° C. for 5-6 hours.

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