Medium element effervescent fertilizer capable of being mixed with phosphorus-potassium fertilizer and containing calcium and magnesium elements and preparation method thereof

Abstract

The invention provides a medium element effervescent fertilizer capable of being mixed with a phosphorus and potassium fertilizer and containing calcium and magnesium elements and a preparation method of the medium element effervescent fertilizer, and belongs to the technical field of agricultural fertilizers. The effervescent fertilizer comprises a magnesium source, a calcium source, solid organic acid, a fertilizer compatible agent, an anti-caking agent, a disintegrating agent and an adsorbent, the magnesium source is selected from one of anhydrous magnesium sulfate and magnesium acetate tetrahydrate, the calcium source is selected from one of calcium formate and calcium carbonate, and the solid organic acid is selected from one of citric acid and malic acid; in percentage by mass, the content of magnesium in the effervescent fertilizer is 2-5%, the content of calcium is 5-10%, the total content of calcium and magnesium is 10-15%, and the content of the solid organic acid is 27-63%. The effervescent fertilizer can realize simultaneous supplement of calcium and magnesium for plants, has good solubility, can be used together with phosphorus and potassium fertilizers by being mixed with water, is stable in system, does not generate precipitates, and does not block pipelines and nozzles.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural fertilizers, and in particular relates to a medium-element effervescent fertilizer containing calcium and magnesium elements that can be mixed with phosphorus and potassium fertilizers, and a preparation method thereof. Background Art

[0002] Calcium and magnesium are two indispensable medium-weight elements in the growth and development of plants. In agricultural production, if calcium and magnesium are lacking, crop photosynthesis will be hindered, inhibiting their growth and development, and the cell wall and cell membrane structure will be damaged, reducing the crop's resistance to diseases, ultimately leading to a decrease in crop yield and quality. In most cases, there is no lack of calcium and magnesium in the soil. The main reason for plants' lack of calcium and magnesium is that the calcium and magnesium in the soil cannot be well absorbed and transported and distributed, and calcium ions are mainly transported unidirectionally and over long distances through the xylem. The regulation and distribution of calcium in plants is greatly affected by transpiration pull, and organs with weak transpiration are prone to calcium deficiency, such as top leaves, petioles, fruits and other organs. Therefore, water-soluble fertilizers that are evenly sprayed on the entire plant or leaves after diluting with water can more effectively supplement calcium and magnesium.

[0003] At present, the water-soluble fertilizers on the market in my country are mainly solid and liquid. Among them, liquid water-soluble fertilizers use water as a carrier. When stored for a long time or with large temperature changes, precipitation or stratification may occur, affecting the use effect; the cost of packaging materials is also relatively high, and it is necessary to consider the possible leakage and bloating of the packaging; and the weight of liquid fertilizers is large, and the logistics cost is also high. As a solid fertilizer, effervescent fertilizers have relatively low costs in the processing and packaging process, and are more convenient to transport. In addition, solid fertilizers are not prone to deterioration or stratification during storage, and have a longer storage time. At the same time, after effervescent fertilizers are dissolved in water, a large amount of gas will be produced. The fertilizers rely on the gas driving force to quickly disintegrate and diffuse rapidly, and the dissolution speed is fast, which solves the problems of poor solubility of ordinary solid water-soluble fertilizers and clogging of pipes and nozzles.

[0004] Nowadays, my country's water-fertilizer integration technology is developing rapidly, and the utilization rate of water-soluble fertilizers has been greatly improved. Water-soluble fertilizers can be combined with irrigation systems to significantly reduce the use of water and fertilizers. In order to better improve the quality and yield of crops, crops are generally applied with a variety of types of fertilizers such as large-scale water-soluble fertilizers, medium-scale water-soluble fertilizers, and trace-scale water-soluble fertilizers at the same time, so that the nutrients absorbed by crops are more comprehensive; however, when fertilizing in the field, various types of fertilizers are generally mixed and sprayed. The mixed use of fertilizers can reduce the number of fertilizer applications, thereby saving manpower and time and improving work efficiency. However, the medium-scale water-soluble fertilizers currently sold on the market can hardly be mixed with large-scale phosphorus and potassium fertilizers at the same time. When they are diluted and mixed with water, the phosphorus ions react with calcium ions to form calcium phosphate, resulting in precipitation, loss of fertilizer effect and clogging of pipes and nozzles. Therefore, it is necessary to provide a new type of fertilizer to solve the above technical problems, so that farmers can mix various types of fertilizers when fertilizing, saving time and labor.

[0005] Existing published patents have been able to produce some types of effervescent fertilizers, but most of them are macro-element and trace element effervescent fertilizers. For example, the Chinese patent application with application date of November 21, 2008 and publication number of CN101423443A discloses a water-soluble fertilizer effervescent composition and a preparation method thereof, but this product provides calcium and magnesium as medium-element fertilizers; the Chinese invention patent with application date of July 4, 2008 and publication number of CN101306960B discloses a calcium fertilizer and a method for making an effervescent tablet thereof, which can provide plants with a certain amount of calcium but cannot provide plants with magnesium. When mixed with macro-element phosphorus and potassium fertilizers, precipitation will occur, and the state is unstable during production and storage, which has limitations.

[0006] Effervescent fertilizers that contain calcium and magnesium at the same time and meet the national standard of "NY 2266-2012 Medium-element water-soluble fertilizers" (the total content of calcium and magnesium must be greater than 10%) have not yet appeared. On the basis of meeting the standards for medium-element water-soluble fertilizers, effervescent fertilizers that can be stored for a long time without deliquescing, are heat-stable at 54°C and do not swell, and can be mixed with large-element phosphorus and potassium fertilizers at the same time to meet the absorption of calcium and magnesium by different crops have not yet been produced using the latest research technologies at home and abroad. Summary of the invention

[0007] The first purpose of the present invention is to provide a medium-element effervescent fertilizer containing calcium and magnesium elements that can be mixed with phosphorus and potassium fertilizers. The total calcium and magnesium content of the effervescent fertilizer is 10-15%, the solubility is good, and the fertilizer can be mixed with water at the same time. The system is stable and does not produce precipitation.

[0008] The second object of the present invention is to provide a method for preparing a medium-element effervescent fertilizer containing calcium and magnesium elements that can be mixed with phosphorus and potassium fertilizers, so as to prepare a medium-element effervescent fertilizer containing calcium and magnesium elements that can be mixed with phosphorus and potassium fertilizers without producing precipitation.

[0009] To achieve the above first purpose, the technical solution adopted by the present invention is:

[0010] The invention discloses a medium-element effervescent fertilizer containing calcium and magnesium elements and capable of being mixed with phosphorus and potassium fertilizers. The components of the effervescent fertilizer include a magnesium source, a calcium source, a solid organic acid, a fertilizer compatibility agent, an anticaking agent, a disintegrant, and an adsorbent. The magnesium source is selected from one of anhydrous magnesium sulfate and magnesium acetate tetrahydrate, the calcium source is selected from one of calcium formate and calcium carbonate, and the solid organic acid is selected from one of citric acid and malic acid. In terms of mass percentage, the magnesium content of the effervescent fertilizer is 2%-5%, the calcium content is 5%-10%, the total calcium and magnesium content is 10-15%, and the solid organic acid content is 27-63%.

[0011] The invention is a pioneering invention. The effervescent fertilizer contains calcium and magnesium elements at the same time, conforms to the national standard "NY 2266-2012 water-soluble fertilizer of medium elements", has a total calcium and magnesium content of 10-15%, and has the effects of promoting photosynthesis, increasing chlorophyll content, improving leaf quality, and enhancing the ability of crops to resist adversities such as sunburn and high temperature. The effervescent fertilizer has good solubility and effervescent effect. After the product enters water, it quickly disintegrates and diffuses rapidly. Under the impetus of gas, the fertilizer quickly dissolves and can be directly sprayed on plant leaves, so as to more effectively supplement the calcium and magnesium elements of the plant. The effervescent fertilizer containing calcium and magnesium can be mixed with phosphorus and potassium fertilizers at the same time, and the mixed solution system is stable without precipitation. The mixed solution can be directly sprayed and used when fertilizing in the field, so as to save time and labor.

[0012] Preferably, the fertilizer compatibility agent includes one of Agrilan 1028 compatible stabilizer and DRT-1000 fertilizer compatibility agent, and the content of the fertilizer compatibility agent in the effervescent fertilizer is 2-3%, so that the mixed solution system can be evenly suspended.

[0013] Preferably, the adsorbent includes white carbon black, and the content of the adsorbent in the effervescent fertilizer is 2-3%. Using white carbon black as an adsorbent can adsorb fertilizer compatible additives and promote uniform mixing of the fertilizer compatible additives.

[0014] Preferably, the anticaking agent includes anhydrous sodium sulfate and magnesium stearate, and the content of the anticaking agent in the effervescent fertilizer is 2-3%, so as to prevent the effervescent fertilizer from agglomerating during the preparation process or storage.

[0015] Preferably, the disintegrant includes sodium carboxymethyl starch, and the content of the disintegrant in the effervescent fertilizer is 1-2%, so that the effervescent fertilizer has a better effervescent effect.

[0016] Preferably, the calcium source is calcium formate, and the effervescent fertilizer consists of the following components in mass fractions: 17-34% calcium formate, 10-27% magnesium source, 27-44% solid organic acid, 5-6% alkali source, 2-3% fertilizer compatibility agent, 2-3% adsorbent, 2-3% anticaking agent, and 1-2% disintegrant.

[0017] Further preferably, the alkali source comprises one of sodium carbonate, sodium bicarbonate, potassium carbonate and potassium bicarbonate.

[0018] Preferably, the calcium source is calcium carbonate, and the effervescent fertilizer is composed of the following components in mass fraction: 13-20% calcium carbonate, 10-27% magnesium source, 53-63% solid organic acid, 2-3% fertilizer compatibility agent, 2-3% adsorbent, 2-3% anticaking agent, and 1-2% disintegrant.

[0019] To achieve the above second object, the preparation steps adopted by the present invention include:

[0020] The method for preparing the above-mentioned medium-element effervescent fertilizer containing calcium and magnesium elements that can be mixed with phosphorus and potassium fertilizers comprises the following steps:

[0021] 1) mixing the fertilizer compatibility agent and the adsorbent to obtain a mixture A;

[0022] 2) The calcium source, magnesium source, alkali source, disintegrant and anti-caking agent are mixed, and then the solid organic acid and mixture A are added and mixed, and dried to obtain an effervescent fertilizer.

[0023] The preparation method of the present invention first mixes the fertilizer compatibility agent with the adsorbent to achieve good dispersion in the effervescent fertilizer, and when mixed with phosphorus and potassium fertilizers, the compatibility agent is quickly dispersed into the mixed system to reduce the appearance of insoluble matter. In addition, the preparation method has a simple process and is suitable for large-scale industrial production.

[0024] Preferably, the drying temperature is 50-60° C., the drying vacuum degree is -0.08 MPa to -0.10 MPa, and the drying time is 120 min to 150 min. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a graph showing the mixing results of common commercially available medium-element water-soluble fertilizers and two types of phosphorus and potassium fertilizers in an embodiment of the present invention;

[0026] Figure 2 This is a graph showing the mixing results of the effervescent fertilizer of formula 23 and two kinds of phosphorus and potassium fertilizers in Example 7 of the present invention. DETAILED DESCRIPTION

[0027] The present invention mainly aims at the technical problems that the effervescent fertilizer in the prior art cannot contain calcium and magnesium elements at the same time, is easy to deliquesce when placed, is unstable in 54°C heat storage, cannot be mixed with phosphorus and potassium fertilizers of large elements at the same time, and blocks pipelines and nozzles, such as Figure 1As shown, the commercially available medium-element water-soluble fertilizer and the Chaosheng phosphorus-potassium fertilizer (left) of Zhengzhou Zhengshi Chemical Products Co., Ltd. and the phosphorus-potassium 8-element phosphorus-potassium fertilizer (right) of Henan Nongli'an Agricultural Technology Co., Ltd. all showed precipitation, and the present invention provides a medium-element effervescent fertilizer containing calcium and magnesium elements that can be mixed with phosphorus-potassium fertilizer and a preparation method thereof, by controlling the calcium and magnesium content, adding solid organic acid to react with calcium ions, and making the dissolved system stable without precipitation under the action of a fertilizer compatible agent, and further realizing efficient dissolution of effervescent fertilizer by anticaking agents, disintegrants, adsorbents and alkaline sources. Calcium and magnesium are supplemented to plants at the same time, and the effervescent fertilizer has good solubility and can be mixed with phosphorus-potassium fertilizers at the same time without precipitation, which has the advantages of saving time and labor.

[0028] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0029] Example 1

[0030] This embodiment is to screen the critical value of calcium and magnesium content in the formula, including the following steps: designing a medium element calcium and magnesium fertilizer formula, in accordance with the national standard "NY 2266-2012 Medium Element Water-soluble Fertilizer", the total content of calcium and magnesium in the formula must be greater than 10%, because it is more difficult for crops to absorb calcium ions, so the calcium ion content in the formula should not be lower than the magnesium ion content, sorbitol and anhydrous sodium sulfate are used as fillers in the formula, and solid organic acid is added to the formula for raw materials that only dissolve under acidic conditions. The proportions (mass percentages) of the components of the formula are shown in Table 1:

[0031] Table 1 Formula of medium element calcium and magnesium fertilizer

[0032]

[0033]

[0034] Carry out a small test to verify the above formula and verify whether the formula is qualified according to the following standards:

[0035] Refer to "NY / T 1117-2010 Determination of calcium, magnesium, sulfur and chlorine content in water-soluble fertilizers" to test the calcium and magnesium content of the product;

[0036] Refer to "NY / T 1973-2010 Determination of water-insoluble matter content and pH of water-soluble fertilizers" to test the solubility and pH of the product;

[0037] Refer to GB / T 8577-2010 Determination of free water content in compound fertilizers - Karl Fischer method to test the moisture content of the product;

[0038] Refer to "GB / T 19136-2021 Determination of Thermal Storage Stability of Pesticides" to conduct thermal storage of the product and test the product stability.

[0039] The test results of qualified products should be:

[0040] Ca+Mg≥10%; pH (250 times solution)=3-9; water-insoluble matter content≤1%; moisture content≤1%; after 14 days of hot storage at 54℃, the product does not swell or clump.

[0041] The test results are shown in Table 2:

[0042] Table 2 Test results of medium element calcium and magnesium fertilizer formula

[0043]

[0044]

[0045] From the results in Table 2, it can be seen that the solubility of samples of formula 1-4, 1-8, and 1-9 is poor, and they do not meet the standard of water-insoluble matter ≤1%, and the formula is unqualified; after 14 days of hot storage, the product of formula 1-10 has bloating and caking phenomena, and the formula is unqualified; the samples of formula 1-1, 1-2, 1-3, 1-5, 1-6, and 1-7 meet the test standards, and the formula is qualified.

[0046] Furthermore, the samples of formula 1-1, 1-2, 1-3, 1-5, 1-6, and 1-7 were mixed and verified with the Chaosheng phosphorus and potassium products sold by Zhengzhou Zhengshi Chemical Products Co., Ltd. and the phosphorus and potassium eight-element phosphorus and potassium fertilizer sold by Henan Nonglian Agricultural Technology Co., Ltd. The mixing method was: add 1g of calcium and magnesium fertilizer sample and 1g of phosphorus and potassium fertilizer sample to 100mL of water respectively, and let it stand for half an hour for observation.

[0047] The observation results are as follows: after mixing, a large amount of insoluble matter is immediately produced for the samples of formula 1-1, 1-2, and 1-3, and precipitation occurs, and they cannot be mixed with phosphorus and potassium fertilizers; after mixing, the solution system of formula 1-5, 1-6, and 1-7 is almost clear and transparent, but a small amount of insoluble matter is produced, and a layer of insoluble matter appears on the bottom after standing for half an hour.

[0048] Summary: When the calcium source is calcium carbonate with a calcium content of 5-8%, and the magnesium source is anhydrous magnesium sulfate or magnesium acetate tetrahydrate with a magnesium content of 2-5%, adding solid organic acid citric acid can improve the mixing effect with macronutrient phosphorus and potassium fertilizers. The reason is that solid organic acid reacts with calcium ions. Under the protection of solid organic acid, anhydrous magnesium sulfate or magnesium acetate tetrahydrate acts as a buffer, and the mixed solution is acidic, so that the sample does not produce precipitation reaction with phosphate in water.

[0049] Example 2

[0050] This embodiment is the screening of compatible adjuvants for effervescent formula fertilizers, comprising the following steps:

[0051] Step (1): first adsorb the fertilizer compatible additive, add white carbon black and the fertilizer compatible additive into a container, mix and stir evenly, use a pulverizer to disperse the agglomerated white carbon black, and stir and mix evenly again to obtain a mixture A;

[0052] Step (2): Calcium formate and anhydrous magnesium sulfate are added into a container, and then sodium bicarbonate, sodium carboxymethyl starch, anhydrous sodium sulfate and magnesium stearate are added, mixed and stirred for 20-30 minutes to obtain a mixture B.

[0053] Step (3): Add citric acid and mixture A to mixture B and stir for 10-20 minutes to mix well.

[0054] Step (4): Drying is performed by vacuum drying method, the drying temperature is 50-60°C, the vacuum degree is -0.08MPa to -0.10MPa, and the drying time is 120min to 150min. After drying, the material temperature is lowered to room temperature before discharging and testing.

[0055] To ensure that the raw materials do not absorb moisture during processing, the above processing steps must be carried out under the condition of air humidity ≤ 50%. The specific proportions of each component are shown in Table 3:

[0056] The fertilizer compatible adjuvants are:

[0057] Additive ① is SP-6900 barrel mix compatibility agent from Jiangsu Qingyu Chemical Technology Co., Ltd.;

[0058] Additive ② is SP-6967 barrel-mix compatible synergist from Jiangsu Qingyu Chemical Technology Co., Ltd.;

[0059] Additive ③ is VF-10 barrel mix compatibility agent produced by Guangzhou Fangzhong Chemical Co., Ltd.;

[0060] Additive ④ is FTRT Fangduoduo barrel mix compatibility agent produced by Guangzhou Fangzhong Chemical Co., Ltd.;

[0061] Additive ⑤ is Agrilan 1028 compatible stabilizer from Nanjing Jierun Technology Co., Ltd.;

[0062] Auxiliary agent ⑥ is a lignin dispersant produced by Nanjing Jierun Technology Co., Ltd.;

[0063] The auxiliary agent ⑦ is the DRT-1000 fertilizer compatibility agent produced by Beijing Avite Biotechnology Co., Ltd.

[0064] Table 3 Example 2 Effervescent Fertilizer Formula and Proportion

[0065]

[0066]

[0067] The above formula samples were tested, and the testing method was as follows:

[0068] Refer to "NY / T 1117-2010 Determination of calcium, magnesium, sulfur and chlorine content of water-soluble fertilizers" to test the calcium and magnesium content of the product, refer to "NY / T 1973-2010 Determination of water-insoluble content and pH of water-soluble fertilizers" to test the solubility and pH of the product, refer to "GB / T8577-2010 Determination of free water content in compound fertilizers Karl Fischer method" to test the water content of the product, and refer to "GB / T19136-2021 Determination of thermal storage stability of pesticides" to perform thermal storage on the product and test the product stability. The test results of qualified products should be: Ca+Mg≥10%, pH (250 times liquid) = 3-5, water-insoluble content ≤1%, moisture content ≤1%; after 14 days of thermal storage at 54℃, the product does not swell or clump.

[0069] The test results are shown in Table 4:

[0070] Table 4 Example 2 effervescent fertilizer testing results

[0071]

[0072] All samples meet the testing standards and the formula is qualified.

[0073] After the sample is put into water, observe whether there is effervescence, and mix the sample with phosphate and potash fertilizers for verification, and observe the mixing effect. The phosphate and potash fertilizers are selected from the same product as in Example 1, and the main raw material of this product is an alkaline phosphate and potash fertilizer containing phosphate and sulfate at the same time; after mixing, the mixed system needs to be able to completely dissolve without precipitation, or be able to stably and evenly suspend within half an hour without stratification and precipitation, and will not clog the spray nozzle when spraying. Whether the mixed system can pass through a 75 μm pore size filter screen is used to judge whether the nozzle will be clogged when spraying. The mixing method is: 1g of calcium and magnesium fertilizer sample and 1g of phosphate and potash fertilizer sample are added to 100mL of water, respectively, and the mixture is allowed to stand for half an hour for observation.

[0074] The samples had good effervescent effects. Only formula ⑤ and formula ⑦, after being mixed with phosphorus and potassium fertilizers, had no precipitation after standing for more than half an hour. The mixed system was uniform and stable, and could pass through a 75μm pore filter, and could be mixed and used normally in the field. These two formulas used Agrilan 1028 compatible stabilizer from Nanjing Jierun Technology Co., Ltd. and DRT-1000 fertilizer compatible agent from Beijing Avit Biotechnology Co., Ltd. respectively; the other formulas produced a layer of insoluble matter at the bottom after being mixed and standing for half an hour.

[0075] Summary: It shows that when the fertilizer compatibility agent is Agrilan 1028 compatible stabilizer of Nanjing Jierun Technology Co., Ltd. and DRT-1000 fertilizer compatibility agent of Beijing Avite Biotechnology Co., Ltd., there is no precipitation after the effervescent fertilizer and phosphorus and potassium fertilizer are mixed and left to stand for more than half an hour.

[0076] Example 3

[0077] The present embodiment is the ratio screening of the acid source, i.e., solid organic acid, in the effervescent fertilizer formula, comprising the following steps:

[0078] Step (1): first adsorb the fertilizer compatible additive, add white carbon black and the fertilizer compatible additive into a container, mix and stir evenly, use a pulverizer to disperse the agglomerated white carbon black, and stir and mix evenly again to obtain a mixture A;

[0079] Step (2): Add EDTA-calcium and anhydrous magnesium sulfate into a container, then add sodium bicarbonate, sodium carboxymethyl starch, anhydrous sodium sulfate and magnesium stearate, mix and stir for 20-30 minutes to obtain a mixture B.

[0080] Step (3): Add citric acid and mixture A to mixture B and stir for 10-20 minutes to mix well.

[0081] Step (4): Drying is performed by vacuum drying method, the drying temperature is 50-60°C, the vacuum degree is -0.08MPa to -0.10MPa, and the drying time is 120min to 150min. After drying, the material temperature is lowered to room temperature before discharging and testing.

[0082] The above steps must be carried out when the air humidity is ≤50%.

[0083] The components and proportions of each formula are shown in Table 5:

[0084] Table 5 Example 3 effervescent fertilizer formula and proportioning:

[0085]

[0086] The above formula samples were tested using the same testing method as in Example 2. The test results are shown in Table 6:

[0087] Table 6 Example 3 effervescent fertilizer testing results

[0088]

[0089]

[0090] Test results: The samples passed the stability test and had good effervescent effects; however, when verifying the mixing with phosphorus and potassium fertilizers, it was found that a large amount of insoluble precipitation was immediately produced after mixing, and the samples could not be mixed with phosphorus and potassium fertilizers. The amount of solid organic acid citric acid added in this formula was relatively small.

[0091] Summary: This shows that the mixing effect of effervescent fertilizer is not good when adding low doses of solid organic acid.

[0092] Example 4

[0093] The present embodiment is the screening of alkali source in the effervescent fertilizer formula, comprising the following steps:

[0094] Step (1): first adsorb the fertilizer compatible additive, add white carbon black and the fertilizer compatible additive into a container, mix and stir evenly, use a pulverizer to disperse the agglomerated white carbon black, and stir and mix evenly again to obtain a mixture A;

[0095] Step (2): Add calcium carbonate and anhydrous magnesium sulfate or magnesium acetate tetrahydrate into a container, then add sodium carboxymethyl starch, anhydrous sodium sulfate and magnesium stearate, mix and stir for 20-30 minutes to obtain a mixture B.

[0096] Step (3): Add citric acid and mixture A to mixture B and stir for 10-20 minutes to mix well.

[0097] Step (4): Drying is performed by vacuum drying method, the drying temperature is 50-60°C, the vacuum degree is -0.08MPa to -0.10MPa, and the drying time is 120min to 150min. After drying, the material temperature is lowered to room temperature before discharging and testing.

[0098] The above steps must be carried out when the air humidity is ≤50%.

[0099] The components and proportions of each formula are shown in Table 7:

[0100] Table 7 Example 4 effervescent fertilizer formula and proportioning:

[0101]

[0102] The above formula samples were tested using the same testing method as in Example 2. The test results are shown in Table 8:

[0103] Table 8 Example 4 effervescent fertilizer testing results

[0104]

[0105] Test results: All samples passed the stability test and had good effervescent effects. After being mixed with phosphorus and potassium fertilizers, there was no precipitation after standing for more than half an hour. The mixed system was uniform and stable and could pass through a 75μm pore size filter and could be mixed and used normally in the field.

[0106] Summary: This shows that when the calcium source is calcium carbonate, the calcium source can also be used as an alkali source, and the qualified detection standards can still be met without adding additional alkali sources.

[0107] Example 5

[0108] The present embodiment is the screening of acid source in the effervescent fertilizer formula, comprising the following steps:

[0109] Step (1): first adsorb the fertilizer compatible additive, add white carbon black and the fertilizer compatible additive into a container, mix and stir evenly, use a pulverizer to disperse the agglomerated white carbon black, and stir and mix evenly again to obtain a mixture A;

[0110] Step (2): Add calcium carbonate and anhydrous magnesium sulfate into a container, then add sodium carboxymethyl starch, anhydrous sodium sulfate and magnesium stearate, mix and stir for 20-30 minutes to obtain a mixture B.

[0111] Step (3): Add one of oxalic acid, fumaric acid, tartaric acid and malic acid to mixture B and mixture A, and stir for 10-20 minutes to mix.

[0112] Step (4): Drying is performed by vacuum drying method, the drying temperature is 50-60°C, the vacuum degree is -0.08MPa to -0.10MPa, and the drying time is 120min to 150min. After drying, the material temperature is lowered to room temperature before discharging and testing.

[0113] The above steps must be carried out when the air humidity is ≤50%.

[0114] The components and proportions of each formula are shown in Table 9:

[0115] Table 9 Example 5 effervescent fertilizer formula and proportioning:

[0116]

[0117]

[0118] The above formula samples were tested using the same testing method as in Example 2. The test results are shown in Table 10:

[0119] Table 10 Example 5 effervescent fertilizer testing results

[0120]

[0121] Test results: Through sample stability testing, it was found that the formula After dissolution, some water-insoluble substances are produced, and the formula is unqualified; only the formula The formula is qualified and has good effervescent effect. After mixing with phosphorus and potassium fertilizers, there is no precipitation after standing for more than half an hour. The mixed system is uniform and stable and can pass through a 75μm pore size filter. It can be mixed and used normally in the field. This formula uses solid organic acid malic acid.

[0122] Summary: Citric acid and malic acid have a good effect on improving the mixed use of medium-element water-soluble fertilizers and phosphorus and potassium fertilizers. The simultaneous use of the above two solid organic acids and fertilizer compatibility agents can effectively solve the situation where they cannot be mixed in the field.

[0123] Example 6

[0124] The present embodiment is the screening of alkali source in the effervescent fertilizer formula, comprising the following steps:

[0125] Step (1): first adsorb the fertilizer compatible additive, add white carbon black and the fertilizer compatible additive into a container, mix and stir evenly, use a pulverizer to disperse the agglomerated white carbon black, and stir and mix evenly again to obtain a mixture A;

[0126] Step (2): Calcium formate and anhydrous magnesium sulfate are added into a container, and then sodium carbonate, potassium carbonate, potassium bicarbonate, sodium carboxymethyl starch, anhydrous sodium sulfate, and magnesium stearate are added, mixed, and stirred for 20-30 minutes to obtain a mixture B.

[0127] Step (3): Add citric acid and mixture A to mixture B and stir for 10-20 minutes to mix well.

[0128] Step (4): Drying is performed by vacuum drying method, the drying temperature is 50-60°C, the vacuum degree is -0.08MPa to -0.10MPa, and the drying time is 120min to 150min. After drying, the material temperature is lowered to room temperature before discharging and testing.

[0129] The above steps must be carried out when the air humidity is ≤50%.

[0130] The components and proportions of each formula are shown in Table 11:

[0131] Table 11 Example 6 effervescent fertilizer formula and proportioning:

[0132]

[0133] The above formula samples were tested using the same testing method as in Example 2. The test results are shown in Table 12:

[0134] Table 12 Example 6 effervescent fertilizer testing results

[0135]

[0136] Test results: All samples passed the stability test and had good effervescent effects. After being mixed with phosphorus and potassium fertilizers, there was no precipitation after standing for more than half an hour. The mixed system was uniform and stable and could pass through a 75μm pore size filter and could be mixed and used normally in the field.

[0137] Summarize: when the alkali source is sodium carbonate, potassium carbonate, potassium bicarbonate, and the sodium bicarbonate of Example 2, the effervescent fertilizer is tested to be qualified.

[0138] Example 7

[0139] The present embodiment is the screening of the final range of calcium and magnesium content in the effervescent fertilizer formula, comprising the following steps:

[0140] Step (1): first adsorb the fertilizer compatible additive, add white carbon black and the fertilizer compatible additive into a container, mix and stir evenly, use a pulverizer to disperse the agglomerated white carbon black, and stir and mix evenly again to obtain a mixture A;

[0141] Step (2): Add calcium formate or calcium carbonate and anhydrous magnesium sulfate into a container, then add sodium bicarbonate, sodium carboxymethyl starch, anhydrous sodium sulfate and magnesium stearate, mix and stir for 20-30 minutes to obtain a mixture B.

[0142] Step (3): Add citric acid and mixture A to mixture B and stir for 10-20 minutes to mix well.

[0143] Step (4): Drying is performed by vacuum drying method, the drying temperature is 50-60°C, the vacuum degree is -0.08MPa to -0.10MPa, and the drying time is 120min to 150min. After drying, the material temperature is lowered to room temperature before discharging and testing.

[0144] The above steps must be carried out when the air humidity is ≤50%.

[0145] The components and proportions of each formula are shown in Table 13:

[0146] Table 13 Example 7 effervescent fertilizer formula and proportioning:

[0147]

[0148] The above formula samples were tested using the same testing method as in Example 2. The test results are shown in Table 14:

[0149] Table 14 Example 7 effervescent fertilizer testing results

[0150]

[0151] Test results: The samples passed the stability test and had good effervescent effect; the formula With recipe Mixed with phosphorus and potassium fertilizers, formula The results of mixing with phosphorus and potassium fertilizers are as follows Figure 2 As shown, no matter it is mixed with Chaosheng Phosphorus Potassium Fertilizer (left) or Phosphorus Potassium 8-element Phosphorus Potassium Fertilizer (right), the solution has no precipitation. With recipe There is no precipitation after standing for more than half an hour, the mixed system is uniform and stable, and can pass through the 75μm pore size filter, and can be mixed and used normally in the field; formula Precipitation occurred after mixing.

[0152] Summary: When the calcium ion content ranges from 5% to 10%, the magnesium ion content is 2% to 5%, and the total calcium and magnesium ion content is 10-15%, the prepared effervescent fertilizer can meet the qualified detection standards.

[0153] Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A medium-element effervescent fertilizer containing calcium and magnesium elements that can be mixed with phosphorus and potassium fertilizers, characterized in that: The components of the effervescent fertilizer include a magnesium source, a calcium source, a solid organic acid, a fertilizer compatibility agent, an anti-caking agent, a disintegrant, and an adsorbent. The magnesium source is selected from one of anhydrous magnesium sulfate and magnesium acetate tetrahydrate, the calcium source is selected from one of calcium formate and calcium carbonate, and the solid organic acid is selected from one of citric acid and malic acid. In terms of mass percentage, the magnesium content of the effervescent fertilizer is 2%-5%, the calcium content is 5%-10%, the total calcium and magnesium content is 10-15%, and the solid organic acid content is 27-63%.

2. The medium-element effervescent fertilizer that can be mixed with phosphorus and potassium fertilizers and contains calcium and magnesium elements according to claim 1, characterized in that: The fertilizer compatibility agent includes one of Agrilan 1028 compatible stabilizer and DRT-1000 fertilizer compatibility agent, and the content of the fertilizer compatibility agent in the effervescent fertilizer is 2-3%.

3. The medium-element effervescent fertilizer that can be mixed with phosphorus and potassium fertilizers and contains calcium and magnesium elements according to claim 1, characterized in that: The adsorbent comprises white carbon black, and the content of the adsorbent in the effervescent fertilizer is 2-3%.

4. The medium-element effervescent fertilizer that can be mixed with phosphorus and potassium fertilizers and contains calcium and magnesium elements according to claim 1, characterized in that: The anti-caking agent comprises anhydrous sodium sulfate and magnesium stearate, and the content of the anti-caking agent in the effervescent fertilizer is 2-3%.

5. The medium-element effervescent fertilizer that can be mixed with phosphorus and potassium fertilizers and contains calcium and magnesium elements according to claim 1, characterized in that: The disintegrant comprises sodium carboxymethyl starch, and the content of the disintegrant in the effervescent fertilizer is 1-2%.

6. The middle element effervescent fertilizer that can be mixed with phosphorus and potassium fertilizers and contains calcium and magnesium elements according to any one of claims 1 to 5, characterized in that: The calcium source is calcium formate, and the effervescent fertilizer is composed of the following components in mass fractions: 17-34% calcium formate, 10-27% magnesium source, 27-44% solid organic acid, 5-6% alkali source, 2-3% fertilizer compatibility agent, 2-3% adsorbent, 2-3% anticaking agent, and 1-2% disintegrant.

7. The medium-element effervescent fertilizer that can be mixed with phosphorus and potassium fertilizers and contains calcium and magnesium elements according to claim 6, characterized in that: The alkali source includes one of sodium carbonate, sodium bicarbonate, potassium carbonate and potassium bicarbonate.

8. The medium-element effervescent fertilizer that can be mixed with phosphorus and potassium fertilizers and contains calcium and magnesium elements according to claim 1, characterized in that: The calcium source is calcium carbonate, and the effervescent fertilizer is composed of the following components in mass fraction: 13-20% calcium carbonate, 10-27% magnesium source, 53-63% solid organic acid, 2-3% fertilizer compatibility agent, 2-3% adsorbent, 2-3% anticaking agent, and 1-2% disintegrant.

9. A method for preparing a medium-element effervescent fertilizer containing calcium and magnesium elements that can be mixed with phosphorus and potassium fertilizers, characterized in that: The preparation steps include: 1) Mixing the fertilizer compatibility agent and the adsorbent to obtain a mixture A; 2) Mix the calcium source, magnesium source, alkali source, disintegrant and anti-caking agent, add the solid organic acid and mixture A, mix well, and dry to obtain the effervescent fertilizer.

10. The preparation method according to claim 9, characterized in that: The drying temperature is 50-60° C., the drying vacuum degree is -0.08 MPa~-0.10 MPa, and the drying time is 120 min-150 min.

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