Potassium magnesium sulphate fertilizer and preparation process thereof

Abstract

The invention discloses a potash magnesium sulphate fertilizer and a preparation process thereof, and relates to the technical field of chemical fertilizer production, and the preparation process comprises the following steps: putting a magnesium sulfate raw material and a second-stage mother solution into a reaction container according to a mass ratio of (3-4): 1, and reacting to obtain a reaction product which is a mixture of a potash magnesium sulphate fertilizer crude product, sodium chloride and excessive magnesium sulfate; a flotation reagent is added into a mixture of the potash magnesium sulphate fertilizer crude product, sodium chloride and excessive magnesium sulfate, and the potash magnesium sulphate fertilizer crude product is separated and floated out; further carrying out solid-liquid separation on the selected foam containing the potash magnesium sulphate fertilizer crude product after flotation to obtain a wet-based potash magnesium sulphate fertilizer; and finally, drying the wet-based potash magnesium sulphate fertilizer to obtain a finished product potash magnesium sulphate fertilizer. According to the potash magnesium sulphate fertilizer and the preparation process thereof, the magnesium sulfate and the second-stage mother liquor are utilized, and residual components in the second-stage mother liquor are fully utilized, so that the waste of raw materials is reduced, the utilization rate of the raw materials in the whole production process is improved, and the production cost is reduced.

Description

Technical Field

[0001] The invention relates to a fertilizer production technology, and in particular to a potassium magnesium sulfate fertilizer and a preparation process thereof. Background Art

[0002] As a high-quality fertilizer rich in sulfur, magnesium, potassium and other middle elements, potassium sulfate magnesium fertilizer plays an indispensable role in modern agriculture. These middle elements have significant effects on improving crop resistance, promoting photosynthesis, and enhancing crop quality and yield. Sulfur is one of the important elements that constitute protein in plants and is involved in regulating the activity of various enzymes; magnesium is an important component of chlorophyll molecules and is directly related to the photosynthesis efficiency of plants; and potassium is crucial to maintaining osmotic pressure in plants, promoting nutrient transport and improving crop resistance.

[0003] However, the current production process of potassium magnesium sulfate fertilizer does face a series of challenges. Traditional processes often rely on high-energy consumption and high-pollution processes, and the utilization rate of raw materials is not high, resulting in high production costs. This not only limits the large-scale production and widespread application of potassium magnesium sulfate fertilizer, but also puts considerable pressure on the environment. In addition, some steps in the traditional process may produce harmful by-products, further increasing the environmental burden.

[0004] As a common waste in salt pans, magnesium sulfate ore has a difficult problem to deal with. These wastes not only occupy a large amount of land resources, but also may enter the natural environment through wind erosion, water erosion and other pathways, causing pollution to soil and water sources. Therefore, how to transform these wastes into valuable resources, realize resource reuse and circular economy, and improve the production process of potassium magnesium sulfate fertilizer has become an urgent problem to be solved. Summary of the invention

[0005] The purpose of the present invention is to provide a potassium magnesium sulfate fertilizer and a preparation process thereof to solve the above-mentioned deficiencies in the prior art.

[0006] In order to achieve the above object, the present invention provides the following technical solution: a preparation process of potassium magnesium sulfate fertilizer, comprising:

[0007] S1, prepare magnesium sulfate raw material and the second stage mother liquor produced in the potassium sulfate production process;

[0008] S2, magnesium sulfate raw material and the second stage mother liquor are put into a reaction vessel according to a mass ratio of 3-4: 1 for reaction. After the reaction is completed, the reaction product obtained is a mixture of crude potassium magnesium sulfate fertilizer, sodium chloride and excess magnesium sulfate;

[0009] S3, adding a flotation agent to a mixture of crude potassium-magnesium sulfate fertilizer, sodium chloride and excess magnesium sulfate, separating and floating the crude potassium-magnesium sulfate fertilizer, and discharging sodium chloride and excess magnesium sulfate with the tail liquid;

[0010] S4, further performing solid-liquid separation on the selected foam containing crude potassium-magnesium sulfate fertilizer after flotation to obtain wet-based potassium-magnesium sulfate fertilizer;

[0011] S5. Finally, the wet-base potassium-magnesium sulfate fertilizer is dried until the moisture content is less than 2.0%, thereby obtaining a finished potassium-magnesium sulfate fertilizer.

[0012] Further, the magnesium sulfate raw material Mg in S1 2+ Content ≥4%, SO4 2- Content ≥ 20%, the second stage mother liquor K + Content>7%.

[0013] Furthermore, the reaction temperature in S2 is 25° C. and the reaction time is 120 min.

[0014] Furthermore, the flotation agent in S3 is sodium hexadecyl sulfate.

[0015] Furthermore, the dosage of sodium hexadecyl sulfate is 100-200 g / ton of ore, and its concentration is 2%.

[0016] Furthermore, the temperature of the drying process in S5 is 75-80°C.

[0017] A potassium magnesium sulfate fertilizer is prepared by a preparation process of a potassium magnesium sulfate fertilizer.

[0018] Compared with the prior art, the potassium magnesium sulfate fertilizer and the preparation process thereof provided by the present invention utilize magnesium sulfate and the second-stage mother liquor, fully utilize the residual components in the second-stage mother liquor, reduce the waste of raw materials, and improve the raw material utilization rate of the entire production process;

[0019] Compared with the traditional process, the present invention can better utilize the intermediate products in the production process and reduce the cost of raw materials. Since the utilization rate of raw materials is improved, the reaction conditions and process flow are optimized in the production process, and unnecessary operation steps are reduced, the production cost is reduced;

[0020] By precisely controlling the reaction conditions, separation and purification, and drying of finished products, potassium sulfate magnesium fertilizer with stable quality and high purity can be produced, which is conducive to meeting the needs of agricultural production, and provides a new resource utilization model for the potassium sulfate production industry and related industries, promoting the sustainable development of the industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0022] Figure 1 A schematic diagram of the overall process of the preparation process provided by an embodiment of the present invention;

[0023] Figure 2 K provided in the embodiment of the present invention + Content diagram;

[0024] Figure 3 The Na provided in the embodiment of the present invention + Content diagram;

[0025] Figure 4 Mg provided by the embodiment of the present invention 2+ Content diagram;

[0026] Figure 5 SO4 provided by the embodiment of the present invention 2- Content diagram;

[0027] Figure 6 The Cl provided in the embodiment of the present invention - Content diagram. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0029] Embodiment 1:

[0030] See also Figure 1 , a potassium magnesium sulfate fertilizer and a preparation process thereof, comprising:

[0031] S1, prepare magnesium sulfate raw material and the second stage mother liquor produced in the potassium sulfate production process, wherein Mg 2+ Content ≥4%, SO4 2- Content ≥ 20%, the second stage mother liquor K + Content>7%;

[0032] The raw material of magnesium sulfate is magnesium sulfate ore, which is a byproduct of magnesium sulfate subtype brine mineral resources. Magnesium sulfate subtype brine mineral resources are a kind of groundwater resources rich in magnesium sulfate, usually existing in a specific geological environment. These brine resources are rich in magnesium, sulfur and other elements, and are important raw materials for the production of magnesium sulfate and other chemical products. In the process of development and utilization of magnesium sulfate subtype brine mineral resources, some byproducts will be produced. These byproducts are mainly: in the production process of magnesium sulfate, due to the reaction conditions, the purity of the reaction substances or other factors in the reaction process, some reaction byproducts will be produced. These byproducts may include incompletely reacted raw materials, intermediates, and generated impurities.

[0033] The second stage mother liquor is an intermediate product from the potassium sulfate production process, which contains a certain amount of useful components such as potassium ions and sulfate ions. At present, many potassium sulfate production processes do not fully utilize the components in the second stage mother liquor. The present invention aims to fully utilize the components in the second stage mother liquor to improve the raw material utilization rate and reduce the production cost.

[0034] The raw materials of magnesium sulfate must meet certain quality requirements, namely Mg 2+ The content must be greater than or equal to 4%, SO4 2- The content must be greater than or equal to 20%. These high levels of ions ensure the magnesium and sulfur content in the final product, thereby increasing the nutritional value of the fertilizer. The second stage mother liquor is a by-product of the potassium sulfate production process. + The content must be greater than 7%, providing potassium for the final product. 2+ and SO4 2- The content of K directly determines the content of magnesium and sulfur in the fertilizer, which in turn affects the fertilizer efficiency and applicability. + The content is an important indicator for evaluating the quality of the second-stage mother liquor and directly affects the potassium content in the final product.

[0035] S2, the magnesium sulfate raw material and the second stage mother liquor are put into a reaction vessel in a mass ratio of 3-4:1 for reaction, the reaction temperature is 25 ° C, and the reaction time is 120min; after the reaction is completed, the reaction product obtained is a mixture of crude potassium magnesium sulfate fertilizer, sodium chloride and excess magnesium sulfate;

[0036] The magnesium sulfate raw material and the second-stage mother liquor are added into the reaction vessel in a mass ratio of 3-4:1, and reacted at 25°C for 120 minutes. This reaction process will produce crude potassium magnesium sulfate fertilizer, but there will also be impurities such as sodium chloride and excess magnesium sulfate, which require further treatment.

[0037] S3, adding a flotation agent sodium hexadecyl sulfate to a mixture of crude potassium magnesium sulfate fertilizer, sodium chloride and excess magnesium sulfate, separating and floating the crude potassium magnesium sulfate fertilizer, and discharging sodium chloride and excess magnesium sulfate with the tail liquid; the dosage of the sodium hexadecyl sulfate is 100-200 g / ton of ore, and the concentration is 2%;

[0038] Sodium hexadecyl sulfate, a flotation agent, is added to the reaction product to separate the crude potassium-magnesium sulfate fertilizer from the mixture by utilizing its selective adsorption capacity. Sodium chloride and excess magnesium sulfate are discharged with the tail liquid. The dosage and concentration of the agent must be precisely controlled to ensure the flotation effect.

[0039] The control of dosage and concentration directly affects the flotation effect, and further affects the purity and yield of the product.

[0040] The selection of flotation reagents is of great significance for improving separation efficiency and reducing costs.

[0041] S4, further performing solid-liquid separation on the selected foam containing crude potassium-magnesium sulfate fertilizer after flotation to obtain wet-based potassium-magnesium sulfate fertilizer;

[0042] The selected foam containing crude potassium magnesium sulfate fertilizer obtained after flotation is subjected to solid-liquid separation to remove excess water and impurities to obtain wet-based potassium magnesium sulfate fertilizer. This step is crucial to improving the drying efficiency of the product and the quality of the final product.

[0043] The effect of solid-liquid separation directly affects the efficiency of the subsequent drying process and the moisture content of the final product.

[0044] Mechanical damage to the product must be avoided during the separation process to ensure product integrity

[0045] S5. Finally, the wet-base potassium-magnesium sulfate fertilizer is dried at a temperature of 75-80° C. until the moisture content is less than 2.0%, thereby obtaining a finished potassium-magnesium sulfate fertilizer.

[0046] The wet-base potassium-magnesium sulfate fertilizer is dried at a temperature of 75-80°C until the moisture content is less than 2.0% to obtain the finished potassium-magnesium sulfate fertilizer. The control of drying temperature and time is crucial to the quality and stability of the product.

[0047] Drying temperature and time directly affect the moisture content and stability of the product.

[0048] Proper drying conditions can ensure that the product has low moisture content and good storage stability.

[0049] Embodiment 2:

[0050] See also Figure 2-Figure 6This embodiment provides a technical solution based on the first embodiment: a potassium magnesium sulfate fertilizer, the potassium magnesium sulfate fertilizer product K + The content is 25.01%, Na + The content is 0.83%, Mg 2+ The content is 7.05%, SO4 2- The content is 50.01%, Cl - The content is 1.64%.

[0051] The potassium magnesium sulfate fertilizer has the following characteristics:

[0052] 1. Rich in nutrients

[0053] High potassium content: This fertilizer contains K + The content is 25.01%. Potassium is an important ion in plants and plays an important role in plant growth, photosynthesis, water regulation and stress resistance. Potassium can promote the development of plant roots, improve plant disease resistance and adversity resistance, and enhance plant resistance to drought, cold, salinity and other stresses.

[0054] Adequate magnesium content: Mg 2+ The content is 7.05%. Magnesium is one of the important components in plants and is involved in photosynthesis, enzyme activation and DNA synthesis. The supply of magnesium can increase the chlorophyll content of plants, improve photosynthesis efficiency, and thus promote plant growth and yield. Magnesium can also greatly promote the absorption of phosphorus by crops, promote the formation of crop growth enzymes, promote the formation of vitamins, carbohydrates, proteins and fats, and prevent crops from falling leaves prematurely and fruit dropping during maturity.

[0055] High sulfur content: SO4 2- The content is 50.01%. Sulfur is one of the important components for plant growth and development. It participates in plant protein synthesis, enzyme activation, cell division and other processes, and plays an important regulatory role in plant growth and development.

[0056] 2. Promoting effect on crops

[0057] Promote photosynthesis: Magnesium is the core component of chlorophyll, which plays a decisive role in photosynthesis. Therefore, the magnesium element in this fertilizer can greatly promote the photosynthesis of crops, thereby accelerating the growth and development of crops.

[0058] Improve stress resistance: Potassium can enhance the stress resistance of plants, making them more resistant to adverse environmental factors such as drought and cold. This is of great significance for improving crop yield and quality.

[0059] Improve soil environment: This fertilizer is weakly alkaline and is particularly suitable for acidic soil. It can neutralize the pH of the soil, improve soil structure, increase soil fertility and water retention capacity, and provide a good environment for the root growth of crops.

[0060] 3. Wide Applicability

[0061] This potassium magnesium sulfate fertilizer is suitable for a variety of crops, such as rice, corn, sugarcane, peanuts, tobacco, potatoes, beets, fruits, vegetables, etc. It can provide these crops with comprehensive and balanced nutrients to meet their nutritional needs during growth.

[0062] Embodiment three:

[0063] See also Figure 2-Figure 6 This embodiment provides a technical solution based on the first embodiment: magnesium sulfate raw material, second stage mother liquor, wet-based potassium magnesium sulfate fertilizer and K in potassium magnesium sulfate fertilizer + 、Na + Mg 2+ 、SO4 2- and C l - The content was tested.

[0064] K + Content detection:

[0065] Flame photometry: Use a flame photometer to measure the emission spectrum intensity of potassium ions in the sample and compare it with the standard solution to determine the potassium ion content.

[0066] Na + Content detection:

[0067] Flame photometry: Also use a flame photometer to measure the emission spectrum intensity of sodium ions in the sample, compare it with the standard solution, and determine the sodium ion content.

[0068] Mg 2+ Content detection:

[0069] EDTA titration method: Under appropriate pH conditions, use EDTA standard solution to titrate the magnesium ions in the sample, determine the titration endpoint by the color change of the indicator, and then calculate the magnesium ion content.

[0070] SO4 2- Content detection:

[0071] Gravimetric method: Add excess barium chloride solution to react with sulfate ions to generate barium sulfate precipitate, which is then filtered, washed, dried and weighed. The sulfate ion content is calculated based on the mass of the precipitate.

[0072] C l - Content detection:

[0073] Silver nitrate titration: Under appropriate conditions, use a standard silver nitrate solution to titrate the chloride ions in the sample, and determine the titration endpoint by the color change of the indicator (potassium chromate), thereby calculating the chloride ion content.

[0074] Before using the analytical instrument, calibration and verification are required to ensure the accuracy of the measurement results; ensure that the chemical reagents used have sufficient purity and stability to avoid interference with the analysis results. During the detection process, it is necessary to strictly abide by the operating procedures and experimental steps to ensure the accuracy and reliability of the analysis results. Through the above steps and methods, the magnesium sulfate raw material, the second stage mother liquor, the wet base potassium magnesium sulfate fertilizer and the K in the potassium magnesium sulfate fertilizer are measured. + 、Na + Mg 2+ 、SO4 2- , Cl - The content is accurately tested, and the specific test results are as follows:

[0075] name <![CDATA[K + (%)]]> <![CDATA[Na + (%)]]> <![CDATA[Mg 2+ (%)]]> <![CDATA[SO4 2- (%)]]> <![CDATA[Cl - (%)]]> Magnesium sulfate 0.44 19.79 4.54 20.12 29.32 Second stage mother liquor 7.61 0.49 2.15 5.80 9.66 Wet-based potassium magnesium sulfate fertilizer 16.00 0.85 5.16 39.30 2.30 Potassium magnesium sulfate fertilizer products 25.01 0.83 7.05 50.01 1.64

[0076] The above table lists the five main ions (K + 、Na + Mg 2+ 、SO4 2- , Cl - ) percentage content.

[0077] From magnesium sulfate ore to the second-stage mother liquor, to the wet-based potassium magnesium sulfate fertilizer, and finally to the potassium magnesium sulfate fertilizer product, the ion content has changed significantly. + The content increased significantly, from 0.44% in magnesium sulfate ore to 25.01% in potassium magnesium sulfate fertilizer products; Na + The content is greatly reduced, from 19.79% in magnesium sulfate ore to 0.83% in potassium magnesium sulfate fertilizer products; Mg 2+ The content also increased, but the increase was less than that of K + ; SO4 2- The content also increased significantly, from 20.12% in magnesium sulfate ore to 50.01% in potassium magnesium sulfate fertilizer products. - The content is greatly reduced, from 29.32% in magnesium sulfate ore to 1.64% in potassium magnesium sulfate fertilizer products.

[0078] K in potassium magnesium sulfate fertilizer products + The content is as high as 25.01%, which is much higher than the raw material magnesium sulfate ore and the second stage mother liquor. The high potassium content helps the growth and development of plants and improves the yield and quality of crops.

[0079] Na + It has a negative impact on plant growth, especially under certain conditions such as saline-alkali land; Na in potassium magnesium sulfate fertilizer products + The content is extremely low (0.83%), which helps to reduce soil salinization and improve soil suitability;

[0080] Mg 2+ and SO4 2- It is a nutrient element necessary for plant growth. Mg in potassium magnesium sulfate fertilizer products 2+ and SO4 2- The contents are as high as 7.05% and 50.01% respectively, which can meet the crops' demand for magnesium and sulfur and promote the healthy growth of crops;

[0081] C l - In some crops, it may have negative effects, especially in sensitive crops. - The content is extremely low (1.64%), suitable for crops that require a low-chlorine environment.

[0082] Potassium sulfate magnesium fertilizer products not only contain a high proportion of potassium, magnesium and sulfur, but also maintain a balance of other nutrients. This comprehensive nutritional characteristic enables potassium sulfate magnesium fertilizer products to fully meet the nutritional needs of crops and improve the stress resistance and yield of crops. In summary, potassium sulfate magnesium fertilizer products, with their high potassium, low sodium, rich magnesium and sulfur, and low chloride content, provide comprehensive nutritional support for crops, which helps promote the healthy growth of crops and increase yields.

[0083] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A preparation process for potassium magnesium sulfate fertilizer, characterized in that, include: S1, first prepare magnesium sulfate raw material and the second stage mother liquor produced in the potassium sulfate production process; S2, magnesium sulfate raw material and the second stage mother liquor are put into a reaction vessel according to a mass ratio of 3-4: 1 for reaction. After the reaction is completed, the reaction product obtained is a mixture of crude potassium magnesium sulfate fertilizer, sodium chloride and excess magnesium sulfate; S3, adding a flotation agent to a mixture of crude potassium-magnesium sulfate fertilizer, sodium chloride and excess magnesium sulfate, separating and floating the crude potassium-magnesium sulfate fertilizer, and discharging sodium chloride and excess magnesium sulfate with the tail liquid; S4, further performing solid-liquid separation on the selected foam containing crude potassium-magnesium sulfate fertilizer after flotation to obtain wet-based potassium-magnesium sulfate fertilizer; S5. Finally, the wet-base potassium-magnesium sulfate fertilizer is dried until the moisture content is less than 2.0%, thereby obtaining a finished potassium-magnesium sulfate fertilizer.

2. A preparation process for potassium magnesium sulfate fertilizer according to claim 1, characterized in that, Mg in the magnesium sulfate raw material S1 2+ Content ≥4%, SO4 2- Content ≥ 20%, the second stage mother liquor K + Content>7%.

3. A preparation process for potassium magnesium sulfate fertilizer according to claim 1, characterized in that, The reaction temperature in S2 is 25°C and the reaction time is 120 min.

4. A preparation process for potassium magnesium sulfate fertilizer according to claim 1, characterized in that, S3 The flotation agent is sodium hexadecyl sulfate.

5. A preparation process for potassium magnesium sulfate fertilizer according to claim 4, characterized in that, The dosage of sodium hexadecyl sulfonate is 100-200 g / ton of ore, and its concentration is 2%.

6. A preparation process for potassium magnesium sulfate fertilizer according to claim 1, characterized in that, The temperature of the drying process in step S5 is 75-80°C.

7. A potassium magnesium sulfate fertilizer, characterized in that: The fertilizer is prepared by the preparation process of the potassium magnesium sulfate fertilizer according to any one of claims 1 to 6.

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