Effervescent silicon-calcium-potassium-magnesium fertilizer tablet and preparation method thereof

Abstract

The invention belongs to the field of mineral fertilizers, and particularly discloses an effervescent silicon-calcium-potassium-magnesium fertilizer tablet and a preparation method thereof. The effervescent silicon-calcium-potassium-magnesium fertilizer tablet is prepared from the following raw materials in percentage by mass: 78-85% of a powdery silicon-calcium-potassium-magnesium fertilizer, 10-15% of an effervescing agent, 1-5% of a dispersing agent and 0.1-5% of a lubricating agent. The preparation method comprises the following steps: preparing the powdery silicon-calcium-potassium-magnesium fertilizer; weighing an acid source, a carbon dioxide source, a dispersing agent and a lubricating agent according to the mass to prepare an auxiliary agent; and weighing the prepared powdery silicon-calcium-potassium-magnesium fertilizer and the prepared auxiliary agent according to a certain mass ratio, adding into a mixer, uniformly mixing, pressing into round tablets by adopting a tablet press, finely selecting, and packaging the finished product after detecting to be qualified, thereby obtaining the effervescent silicon-calcium-potassium-magnesium fertilizer tablet. The effervescent silicon-calcium-potassium-magnesium fertilizer tablet provided by the invention overcomes the defect that the common granular silicon-calcium-potassium-magnesium fertilizer in the market is difficult to disintegrate in soil, and is simple in preparation process and suitable for industrial production and large-area popularization and application in planting.

Description

Technical Field

[0001] The invention relates to the field of mineral fertilizer processing, and in particular to an effervescent silicon-calcium-potassium-magnesium fertilizer tablet and a preparation method thereof. Background Art

[0002] Silicon calcium potassium magnesium fertilizer is a fertilizer containing water-soluble and citric acid-soluble silicon, calcium, potassium and magnesium, which is obtained by high-temperature conversion of insoluble potassium ore (potassium feldspar, etc.) and raw materials containing calcium and magnesium (GB / T 36207-2018 Silicon calcium potassium magnesium fertilizer). As a mineral fertilizer, silicon calcium potassium magnesium fertilizer has the functions of both soil conditioning and providing secondary elements, and has shown positive effects in crop planting.

[0003] At present, there are two main types of silicon calcium potassium magnesium fertilizer products on the market: powder and granules. Powder products have a large contact area with the soil and are easy to mix evenly with the soil, so they are better in supplying plant nutrition and improving the soil. Granular products are a practical need to save labor costs during the use of fertilizers. Generally, powdered silicon calcium potassium magnesium fertilizers are granulated by adding certain additives; but due to the characteristics of silicon calcium potassium magnesium fertilizers themselves being slightly soluble in water, granular products often disintegrate poorly in the soil after being applied to the soil, which has become one of the factors limiting the widespread use of such mineral fertilizer granular products.

[0004] Effervescent fertilizer is a new type of fertilizer, which will undergo an acid-base reaction when it comes into contact with water, generating carbon dioxide and expanding and disintegrating. At present, effervescent fertilizers have begun to appear on the market, but most of them are foliar fertilizers or fertilizers applied to hydroponic crops. For example, CN200810016791.1 discloses a foliar fertilizer effervescent tablet and a preparation method thereof, wherein the liquid fertilizer or plant nutrient solution original powder accounts for 35-60%, the acid agent accounts for 15-30%, the carbon dioxide agent accounts for 15-30%, the moistening adhesive accounts for 0.5-5% and the surfactant accounts for 0.5-3%; for another example, CN201810907442.2 discloses a formula for a concentrated effervescent tablet of hydroponic flower nutrient solution, which is characterized by containing nutrients required by multiple plants, one or more substances that generate gas in contact with water, one or more insecticides, one or more bactericidal substances, one or more trace element chelating agents, one or more plant growth regulators, one or more adhesives and one or more lubricants. The raw materials of these effervescent tablets are all water-soluble substances, and the dissolving medium is water, that is, the effervescent tablets need to be placed in water to disintegrate well, and cannot actually solve the problem of disintegration of mineral fertilizer particles that are slightly soluble in water in the soil. As for the effervescent silicon-calcium-potassium-magnesium fertilizer tablets, it is more important that they can also disintegrate well in the soil. On the other hand, both the CN200810016791.1 patent and the CN201810907442.2 patent adopt wet molding, that is, anhydrous ethanol is required to wet the adhesive; and the disadvantage of wet molding is that it is difficult to ensure that non-aqueous solvents such as ethanol are completely anhydrous, which may affect the stability of the product and increase production costs.

[0005] Therefore, it is necessary to innovate the product preparation concept based on powdered silicon-calcium-potassium-magnesium fertilizers. By adding specific additives and selecting specific processes, it can not only meet the molding requirements so as to facilitate application and transportation, but also solve the problem of poor disintegration of this product in the soil, thus facilitating nutrient release. No research in this area has been reported so far. Summary of the invention

[0006] In order to solve the above technical problems existing in the prior art, the object of the present invention is to provide an effervescent silicon-calcium-potassium-magnesium fertilizer tablet and a preparation method thereof.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] An effervescent silicon-calcium-potassium-magnesium fertilizer tablet comprises the following components by weight percentage: 78-85% of powdered silicon-calcium-potassium-magnesium fertilizer, 10-15% of effervescent agent, 1-5% of dispersant and 0.1-5% of lubricant.

[0009] Furthermore, the powdered silicon-calcium-potassium-magnesium fertilizer is prepared by mixing limestone, dolomite and potassium feldspar, sintering at high temperature or melting, and then grinding to a certain fineness to obtain a powder. The main nutrients are effective silicon, effective calcium, effective potassium and effective magnesium that can be absorbed by plant roots.

[0010] Furthermore, the indicators of the powdered silicon-calcium-potassium-magnesium fertilizer are: SiO2≥30%, CaO≥28.0%, K2O≥5.0%, MgO≥4.0%, and pH is 9.5-11.5.

[0011] Furthermore, calculated by weight percentage, the effervescent agent includes 60-70% of an acid source and 30-40% of a carbon dioxide source.

[0012] Furthermore, calculated by weight percentage, the tablet raw material includes 80% of powdered silicon-calcium-potassium-magnesium fertilizer, 6.8-11.3% of an acid source, 3.2-7.4% of a carbon dioxide source, 1.1-5% of a dispersant, and 0.2-5% of a lubricant.

[0013] Furthermore, the acid source is selected from one or more of anhydrous citric acid, alginic acid, humic acid, oxalic acid, malic acid, tartaric acid, and acid residue.

[0014] Furthermore, the carbon dioxide source is selected from one or more of potassium bicarbonate, potassium carbonate, calcium carbonate and magnesium carbonate.

[0015] Furthermore, the dispersant is selected from one or more of hydroxyethyl cellulose, triethylhexyl phosphoric acid, polyacrylamide, fatty acid polyethylene glycol ester, and sodium lignin sulfonate.

[0016] Furthermore, the lubricant is selected from one or more of magnesium stearate, PEG6000, PEG4000, sodium lauryl sulfate (magnesium), sodium stearyl fumarate (potassium), and L-leucine.

[0017] The present invention also discloses a method for preparing the effervescent silicon-calcium-potassium-magnesium fertilizer tablets, comprising the following steps:

[0018] Step 1, preparing powdered silicon-calcium-potassium-magnesium fertilizer: using potassium feldspar and limestone or dolomite as raw materials, sequentially undergoing crushing, grinding, rotary kiln calcining, cooling in a cooler, crushing and grinding to obtain powdered silicon-calcium-potassium-magnesium fertilizer;

[0019] Step 2, preparing the auxiliary agent: weigh the acid source, carbon dioxide source, dispersant, and lubricant respectively, and then mix them evenly with a mixer;

[0020] Step 3, mixing raw materials: weigh the powdered silicon-calcium-potassium-magnesium fertilizer prepared in step 1 and the additive prepared in step 2 according to a certain mass ratio, add them into a mixer and mix them evenly;

[0021] Step 4, tableting and packaging: the uniformly mixed materials are pressed into round tablets by a tablet press, wherein the pressure is controlled at 20-50Mpa, the diameter of the round tablets is 10-30mm, and the thickness is 3-7mm. After selection and qualified testing, the finished products are packaged to obtain effervescent silicon-calcium-potassium-magnesium fertilizer tablets.

[0022] At present, the effervescent principle of effervescent tablets is that the effervescent disintegrant used includes an acid source and a carbon dioxide source. After the effervescent tablet is placed in water, the organic acid and the basic carbonate (bicarbonate) react (effervescent reaction) to generate and release a large amount of carbon dioxide gas. On the other hand, the disintegration mechanism known to ordinary technicians in the field includes: ① the formation of erosion holes: the soluble components contained in the particles dissolve rapidly after contacting water to form erosion holes; ② the solid bridge rupture mechanism: after water penetrates the granules, the "solid bridge" dissolves and the binding force disappears. ③ the gas generation mechanism: the particles containing the effervescent disintegrant generate CO2 gas after contacting water. ④ the water absorption and expansion mechanism: the disintegrant absorbs water and expands, the volume increases, and the binding force of the particles is destroyed. ⑤ the moist heat mechanism: the particles absorb water and moisten to generate moist heat, causing the air in the particles to expand. Specifically in this application, (1) silicon calcium potassium magnesium fertilizer has special physical properties. ① Silicon calcium potassium magnesium fertilizer is a citrate-soluble fertilizer with a pH between 9.5 and 11.5. Historically, citrate-soluble fertilizers have used 2% citric acid (citric acid) solution as the extract of the active ingredient, that is, organic acid helps to promote its dissolution and nutrient release. ② The powdered silicon calcium potassium magnesium fertilizer obtained by high-temperature sintering and then grinding includes CaSiO3, Ca2(Mg,Al)(Si,Al)O7, KAlSi2O6 and KAlSiO4, etc., which are mainly in the form of crystals. Among these minerals, CaSiO3 is more likely to react with acid, while the other mineral components are more difficult to react with acid. (2) The soil environment is completely different from the pure water environment in which the effervescent tablet works. Its humidity is limited and there is a certain CO2 partial pressure. The effervescence and disintegration of silicon calcium potassium magnesium fertilizer tablets are more difficult in the soil environment. Therefore, the selection of acid and carbon dioxide sources not only considers the interaction with the plant rhizosphere and the interactive influence with the soil environment, but also considers the reaction with various minerals in the powdered silicon calcium potassium magnesium fertilizer, and also considers the gas production mechanism. In addition to acid and carbon dioxide sources, the selection of dispersants and lubricants in additives also considers the material properties and the actual effect of dry tableting.

[0023] The advantages and positive effects of the present invention are:

[0024] (1) During the preparation process, the present application adopts a dry pressing molding technology without adding an adhesive, thereby avoiding the contact between the acid source and the carbon dioxide source in the fertilizer and water to the greatest extent, which is beneficial to improving the stability of the effervescent tablet fertilizer;

[0025] (2) By precisely controlling the pressure, the present application ensures that the tablets have good disintegration properties while maintaining appropriate strength. This prevents both insufficient tablet strength due to insufficient pressure and difficulty in disintegration due to excessive pressure;

[0026] (3) The tablets exhibited very low powdering rate during transportation and were able to completely disintegrate in soil;

[0027] (4) The preparation process is simple, cost-effective, and very suitable for industrial production. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field without creative work based on the embodiments of the present invention are within the scope of protection of the present invention.

[0029] The invention discloses an effervescent silicon-calcium-potassium-magnesium fertilizer tablet. The components in the formula include the following ingredients by weight percentage: 78-85% of powdered silicon-calcium-potassium-magnesium fertilizer, 10-15% of effervescent agent, 1-5% of dispersant and 0.1-5% of lubricant.

[0030] The powdered silicon-calcium-potassium-magnesium fertilizer is prepared by sintering natural mineral ingredients such as limestone, dolomite, potassium feldspar, etc. at high temperature, and then grinding them to a certain fineness to obtain a powder. The main nutrients are effective silicon, effective calcium, effective potassium, effective magnesium, etc. that can be absorbed by plant roots.

[0031] Calculated by weight percentage, the effervescent agent includes 60-70% of an acid source and 30-40% of a carbon dioxide source.

[0032] Preferably, the acid source is selected from one or more of the following substances: anhydrous citric acid, alginic acid, humic acid, oxalic acid, malic acid, tartaric acid, acid residue, etc.

[0033] The carbon dioxide source is selected from one or more of the following substances: potassium bicarbonate, potassium carbonate, calcium carbonate, magnesium carbonate, etc.

[0034] The dispersant is selected from one or more of the following substances: hydroxyethyl cellulose, triethylhexyl phosphoric acid, polyacrylamide, fatty acid polyethylene glycol ester, sodium lignin sulfonate, etc.

[0035] The lubricant is selected from one or more of the following substances: magnesium stearate, PEG6000, PEG4000, sodium lauryl sulfate (magnesium), sodium stearyl fumarate (potassium), L-leucine, etc.

[0036] The above additives are all known substances and are also common substances in the processing of fertilizers and pesticide formulations.

[0037] The preparation method of the effervescent silicon-calcium-potassium-magnesium fertilizer tablet provided by the invention is direct powder tableting, that is, on the basis of preparing powdered silicon-calcium-potassium-magnesium fertilizer and auxiliary agents, firstly weighing the powdered silicon-calcium-potassium-magnesium fertilizer and auxiliary agents according to mass, mixing them evenly with a mixer, and then using a tablet press to press them into round tablets with a diameter of 10-30 mm and a thickness of 3-7 mm, and the pressure is controlled at 20-50 MPa; and after selection and testing, the finished products are packaged to obtain the effervescent silicon-calcium-potassium-magnesium fertilizer tablets.

[0038] The preparation of the effervescent silicon-calcium-potassium-magnesium fertilizer tablets of Example 1-5 is carried out according to the following steps:

[0039] (1) Preparation of powdered silicon-calcium-potassium-magnesium fertilizer: Potash feldspar and limestone or dolomite are used as raw materials, and the powdered silicon-calcium-potassium-magnesium fertilizer is obtained by crushing, grinding, rotary kiln calcination, cooling in a cooler, crushing and grinding in sequence. The indicators are: SiO2≥30%, CaO≥28.0%, K2O≥5.0%, MgO≥4.0%, and pH is 9.5-11.5.

[0040] (2) Preparation of auxiliary agents: The acid source in the effervescent agent is selected from anhydrous citric acid and alginic acid (mass ratio of 1:3), the carbon dioxide source is selected from potassium bicarbonate and potassium carbonate (mass ratio of 1:8), the dispersant is selected from hydroxyethyl cellulose, and the lubricant is selected from PEG6000. The acid source, carbon dioxide source, dispersant, and lubricant are weighed according to the mass percentage in Table 1, and then mixed evenly using a mixer.

[0041] (3) Raw material mixing: The powdered silicon-calcium-potassium-magnesium fertilizer prepared in step 1 and the auxiliary agent prepared in step 2 are weighed in a mass ratio of 80:20, added into a mixer and mixed evenly.

[0042] (4) Tablet packaging: The uniformly mixed material is tableted by a tablet press machine with the pressure controlled at 32 MPa, and the tablets are compressed into round tablets with a diameter of 10 mm and a thickness of 4 mm. After selection and testing, the finished products are packaged to obtain effervescent silicon-calcium-potassium-magnesium fertilizer tablets.

[0043] Table 1 is a comparison of the distribution ratios of each group of auxiliary agents in Examples 1 to 5 and the effects of the control products.

[0044] Table 1 The proportion, strength and disintegration performance of each component in Examples 1 to 5

[0045]

[0046]

[0047] Note: 1. CK in the table is a control example, which is a common granular silicon calcium potassium magnesium fertilizer product on the market. The main ingredients are: powdered silicon calcium potassium magnesium fertilizer 80%, bentonite 14%, lignin and its derivatives 6%.

[0048] 2. The maximum disintegration time is controlled within 30 seconds. If the particles are completely disintegrated within 30 seconds, the complete disintegration time is recorded. If there are still particles that have not disintegrated after 30 seconds, the current disintegration rate is recorded and the disintegration time is stopped.

[0049] It can be found from Table 1 that with the increase of the proportion of effervescent agent added, the tablet strength first increases and then decreases, but the disintegration rate gradually increases and the disintegration time gradually shortens. The tablet strength is related to the proportion of effervescent agent, dispersant and lubricant added; while the disintegration rate and disintegration time are more correlated with the proportion of effervescent agent added. The more effervescent agent is added, the higher the disintegration rate.

[0050] After that, according to the 5 embodiments and control examples CK in Table 1, the test was carried out in farmland soil by hole application. The soil type is calcareous tidal soil, and the basic chemical properties are pH 7.93, organic matter 12.54g / kg, total nitrogen 0.84g / kg, available phosphorus 9.65mg / kg, and available potassium 100.31mg / kg. The test process is: digging a pit (20cm long, 20cm wide, and 10cm deep), putting in 100 tablets of test tablets (embodiment) / 100 particles (control example), and then covering the soil, after which the soil moisture content is controlled at 70% of the field water holding capacity. The disintegration rate of tablets / particles in soil was observed at 7 days, 15 days, and 30 days respectively. The test results are shown in Table 2.

[0051] Table 2 Relationship between disintegration rate and time in soil

[0052]

[0053] It can be seen from Table 1 and Table 2 that although each embodiment and control example can disintegrate in water, the disintegration in soil is quite different. The control example can disintegrate well in water, but the disintegration rate of the control example in soil is only about 10%. The effervescent silicon calcium potassium magnesium fertilizer tablet can also disintegrate well in soil. This shows that the present invention can solve the problem of poor disintegration of granular silicon calcium potassium magnesium fertilizer in soil, thereby improving the use effect of the fertilizer.

[0054] In the above embodiments, the formulations of embodiments 3, 4, and 5 can all disintegrate well in the soil, and the tablet strength of embodiment 3 is the highest. Considering that the cost increases with the increase in the amount of effervescent agent added, the formulation of embodiment 3 has the best effect after comprehensively considering the use effect and preparation cost.

[0055] The present invention is also applicable to mineral fertilizers such as silicon fertilizer, silicon-calcium fertilizer, silicon-calcium-potassium fertilizer, silicon-calcium-potassium-magnesium fertilizer, potassium-calcium fertilizer, potassium-silicon fertilizer, and other fertilizers and derivative products whose main nutrients are citric acid-soluble effective silicon, effective calcium, effective potassium, effective magnesium, etc. that can be absorbed by plant roots.

[0056] The above embodiments are preferred examples for implementing the present invention, and the present invention is not limited to the above embodiments. Any non-essential additions and substitutions made by those skilled in the art based on the technical features of the technical solution of the present invention shall fall within the protection scope of the present invention.

Claims

1. An effervescent silicon-calcium-potassium-magnesium fertilizer tablet, characterized in that: The composition comprises the following components by weight percentage: 78-85% of powdered silicon-calcium-potassium-magnesium fertilizer, 10-15% of effervescent agent, 1-5% of dispersant and 0.1-5% of lubricant.

2. The effervescent silicon-calcium-potassium-magnesium fertilizer tablet according to claim 1, wherein: The powdered silicon-calcium-potassium-magnesium fertilizer is prepared by mixing limestone, dolomite and potassium feldspar, sintering at high temperature or melting, and then grinding to a certain fineness to obtain a powder. The main nutrients are effective silicon, effective calcium, effective potassium and effective magnesium that can be absorbed by plant roots.

3. The effervescent silicon-calcium-potassium-magnesium fertilizer tablet according to claim 2, wherein: The powdered silicon-calcium-potassium-magnesium fertilizer has the following indicators: SiO2≥30%, CaO≥28.0%, K2O≥5.0%, MgO≥4.0%, and pH value of 9.5-11.

5.

4. The effervescent silicon-calcium-potassium-magnesium fertilizer tablet according to claim 1, wherein: Calculated by weight percentage, the effervescent agent includes 60-70% of an acid source and 30-40% of a carbon dioxide source.

5. The effervescent silicon-calcium-potassium-magnesium fertilizer tablet according to claim 1, characterized in that: Calculated by weight percentage, the raw materials of the tablets include 80% of powdered silicon-calcium-potassium-magnesium fertilizer, 6.8-11.3% of an acid source, 3.2-7.4% of a carbon dioxide source, 1.1-5% of a dispersant, and 0.2-5% of a lubricant.

6. The effervescent silicon-calcium-potassium-magnesium fertilizer tablet according to claim 4, characterized in that: The acid source is selected from one or more of anhydrous citric acid, alginic acid, humic acid, oxalic acid, malic acid, tartaric acid, and acid residue.

7. The effervescent silicon-calcium-potassium-magnesium fertilizer tablet according to claim 4, characterized in that: The carbon dioxide source is selected from one or more of potassium bicarbonate, potassium carbonate, calcium carbonate and magnesium carbonate.

8. The effervescent silicon-calcium-potassium-magnesium fertilizer tablet according to claim 1, characterized in that: The dispersant is selected from one or more of hydroxyethyl cellulose, triethylhexyl phosphoric acid, polyacrylamide, fatty acid polyethylene glycol ester, and sodium lignin sulfonate.

9. The effervescent silicon-calcium-potassium-magnesium fertilizer tablet according to claim 1, characterized in that: The lubricant is selected from one or more of magnesium stearate, PEG6000, PEG4000, sodium lauryl sulfate (magnesium), sodium stearyl fumarate (potassium), and L-leucine.

10. The method for preparing the effervescent silicon-calcium-potassium-magnesium fertilizer tablet according to any one of claims 1 to 9, characterized in that: The steps include: Step 1, preparing powdered silicon-calcium-potassium-magnesium fertilizer: using potassium feldspar and limestone or dolomite as raw materials, sequentially undergoing crushing, grinding, rotary kiln calcining, cooling in a cooler, crushing and grinding to obtain powdered silicon-calcium-potassium-magnesium fertilizer; Step 2, preparing the auxiliary agent: weigh the acid source, carbon dioxide source, dispersant, and lubricant respectively, and then mix them evenly with a mixer; Step 3, mixing raw materials: weigh the powdered silicon-calcium-potassium-magnesium fertilizer prepared in step 1 and the additive prepared in step 2 according to a certain mass ratio, add them into a mixer and mix them evenly; Step 4, tableting and packaging: the uniformly mixed materials are pressed into round tablets by a tablet press, wherein the pressure is controlled at 20-50Mpa, the diameter of the round tablets is 10-30mm, and the thickness is 3-7mm; then the materials are selected and packaged after being tested and qualified, and effervescent silicon-calcium-potassium-magnesium fertilizer tablets are obtained.

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