Magnesium-carbon hydrated material processing technology

Abstract

The invention relates to the technical field of building material processing, in particular to a magnesium-carbon hydrated material processing technology. Comprising the following steps: weighing a magnesian raw material, a carbonaceous raw material and an additive in proportion, adding the weighed materials into three-dimensional mixing equipment, and mixing the materials for 20-30 minutes by the three-dimensional mixing equipment at a rotating speed of 20-30 r / min to obtain a premix; the premix is conveyed into a hydration reaction kettle, water accounting for 20%-30% of the mass of the premix is added into the hydration reaction kettle, then a stirring device is started, the stirring speed of the stirring device is 15 r / min-25 r / min, the reaction temperature is controlled to be 50 DEG C-70 DEG C, the reaction time is 3 h-5 h, and a mixed material is obtained; and carrying out drying treatment on the mixed material for 2-4 hours at the drying temperature of 80-100 DEG C to obtain the magnesium-carbon hydrated material. According to the invention, by selecting the three-dimensional mixing equipment and controlling related parameters during mixing, the problem of non-uniform mixing of raw materials in the processing technology of the magnesium-carbon hydrated material in the prior art is solved, so that the quality of the processed magnesium-carbon water is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of building material processing, in particular to a magnesium carbonate material processing technology. Background Art

[0002] In the field of building materials, magnesium carbonate is an important basic material. Due to its good fire resistance, mechanical strength and chemical stability, it is widely used in the metallurgy, building materials and other industries. At present, there are significant defects in the raw material mixing link in the existing magnesium carbonate processing technology. Most traditional processes use simple stirring equipment, such as ordinary single-axis stirrers to mix magnesium raw materials, carbonaceous raw materials and additives. Due to the single stirring method of such equipment, it is difficult to achieve full dispersion of micron-level particles, resulting in only macroscopic stacking of materials during the mixing process, and it is impossible to ensure the uniform distribution of each component. This uneven mixing situation causes great differences in the performance of different parts of the magnesium carbonate. In actual use, problems such as insufficient local strength and unstable fire resistance are prone to occur. For example, a company uses traditional stirring equipment to produce magnesium carbonate. After testing, it was found that the carbon content in different parts of the same batch of products fluctuated by as much as 15%, which seriously affected the stability of product quality and could not meet the needs of high-end application scenarios.

[0003] In summary, in the prior art, the raw materials are mixed unevenly in the processing technology of magnesium carbonate, resulting in low quality of the processed magnesium carbonate. Summary of the Invention

[0004] In order to overcome the technical defect of uneven mixing of raw materials in the processing technology of magnesium carbonate material in the above-mentioned technology, which leads to low quality of the processed magnesium carbonate material, the purpose of the present invention is to provide a magnesium carbonate material processing technology. By selecting three-dimensional mixing equipment and controlling relevant parameters during mixing, the problem of uneven mixing of raw materials in the processing technology of magnesium carbonate material in the existing technology is solved, so as to improve the quality of the processed magnesium carbonate material.

[0005] The present invention discloses a magnesium carbohydrate processing process, comprising the following steps:

[0006] Step S100: After weighing the magnesium raw material, the carbon raw material and the additive in proportion, the magnesium raw material, the carbon raw material and the additive are added to a three-dimensional mixing device respectively, and the three-dimensional mixing device is mixed at a speed of 20 r / min to 30 r / min for 20 min to 30 min to obtain a premix;

[0007] Step S200: transporting the premix to a hydration reactor, adding water accounting for 20% to 30% of the mass of the premix to the hydration reactor, and then starting a stirring device. The stirring speed of the stirring device is 15 rpm to 25 rpm, and the reaction temperature is controlled to 50° C. to 70° C. by a heating device. The reaction time is 3 h to 5 h. After the stirring device completes the stirring, the mixture is discharged to obtain a mixed material.

[0008] Step S300: drying the mixed material at a drying temperature of 80° C. to 100° C. for 2 to 4 hours to obtain magnesium carbonate.

[0009] Preferably, the magnesia raw material is light-burned magnesium powder, the carbonaceous raw material is flake graphite, and the additive is silicon micropowder;

[0010] The mass ratio of the magnesium raw material, the carbon raw material and the additive is (60-70): (20-30): (5-10).

[0011] Preferably, the particle size of the light-burned magnesium powder is 200-325 mesh, the particle size of the flake graphite is 100-200 mesh, and the particle size of the silicon micropowder is 1000-1500 mesh.

[0012] Preferably, the three-dimensional mixing device is a double-cone mixer, which includes a cylinder with spiral blades provided on the inner wall of the cylinder. The relationship between the pitch P of the spiral blades and the inner diameter D of the cylinder satisfies: P=0.5D~0.8D.

[0013] Preferably, at least one temperature sensor and a time controller are respectively provided in the hydration reactor; wherein,

[0014] The temperature sensor monitors the stirring reaction temperature of the premix in the hydration reactor in real time, and transmits the stirring reaction temperature to the control system in real time. When the stirring reaction temperature is 50°C to 70°C higher than the set reaction temperature, the control system automatically adjusts the power of the heating device to keep the stirring reaction temperature at the set reaction temperature.

[0015] The time controller monitors the stirring reaction time of the premix in the hydration reactor in real time, and transmits the stirring reaction time to the control system in real time. When the stirring reaction time is equal to or greater than the set reaction time of 3h to 5h, the control system issues an alarm to indicate the end of the reaction.

[0016] Preferably, a vacuum drying oven is used for the drying process in step S300, and the vacuum degree of the vacuum drying oven is -0.08 MPa to -0.1 MPa.

[0017] Preferably, the step of discharging the mixed material after the stirring device completes stirring comprises the following steps:

[0018] After the stirring device stirs the premix and water in the hydration reactor for 3 to 5 hours, the premix after the reaction in the hydration reactor is sampled to obtain a sample material;

[0019] The sample material is tested for humidity and hydration reaction degree. When the humidity detection value of the sample material is less than the humidity detection threshold and the hydration reaction degree value of the sample material is within the set standard range, the premix in the hydration reactor is discharged to obtain the mixed material. The humidity detection threshold is 20% to 25%, and the set standard range is 90% to 95%.

[0020] Preferably, when performing humidity detection on the sample material, the humidity detection value is calculated based on the drying loss method, and the calculation formula is:

[0021]

[0022] Wherein, H represents the humidity detection value of the sample material, m1 represents the initial mass of the sample material, and m2 represents the mass after the stirring device stirs the premix and water in the hydration reactor for 3h to 5h.

[0023] Preferably, when the hydration reaction degree of the sample material is detected, the hydration reaction degree value is calculated based on the content of specific hydration products in the sample material detected by X-ray diffraction method, and the calculation formula is:

[0024]

[0025] Wherein, X represents the value of the degree of hydration reaction, I h Expressed as the diffraction intensity of a specific hydration product, I t is the sum of the diffraction intensities of the sample material.

[0026] Compared with the existing technology, the above technical solution has the following beneficial effects:

[0027] 1. By using a three-dimensional mixing device, compared with the single-shaft agitator and other single-stirring devices used in the prior art, the present invention solves the problem of uneven mixing of raw materials in the processing of magnesium carbonate hydrate in the prior art, making the mixing of raw materials more uniform, thereby improving the quality of the processed magnesium carbonate;

[0028] 2. The present invention clearly sets the relevant parameters of the three-dimensional mixing device after the raw materials are added to the three-dimensional mixing device. The appropriate three-dimensional mixing device speed can ensure that the raw materials have appropriate movement intensity and trajectory in the three-dimensional mixing device. When the speed is too low, the raw materials will not move sufficiently in the three-dimensional mixing device, and the mixing effect will be poor. When the speed is too high, the raw materials may be segregated under the action of centrifugal force, etc., which also affects the mixing effect. In the present invention, by setting the speed of the three-dimensional mixing device to 20r / min~30r / min, it can ensure that the raw materials perform multi-directional composite movement, and at the same time, the raw materials will not be segregated due to excessively high speed, thereby improving the uniform mixing of the raw materials. In addition, the set speed can make the raw materials interpenetrate, diffuse, and shear with moderate force when mixing the raw materials. At the same time, the speed is a low speed of the three-dimensional mixing device, so the equipment can reduce power consumption when working at a low speed.

[0029] 3. The present invention also sets the mixing time of the three-dimensional mixing equipment to 20 minutes to 30 minutes. Since the raw materials of the magnesium carbonate material are light-burned magnesium powder, flake graphite and silicon powder, etc., their particle size and physical and chemical properties are different, and sufficient time is required for interaction to achieve uniform dispersion. The mixing time of 20 minutes to 30 minutes set by the present invention allows sufficient interpenetration, diffusion and shearing between the raw materials, further improving the uniform mixing of the raw materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The figure is a schematic diagram of the process steps of a magnesium carbohydrate processing technology of the present invention. DETAILED DESCRIPTION

[0031] The advantages of the present invention are further described below with reference to the accompanying drawings and specific embodiments.

[0032] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

[0033] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. As used in this disclosure and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0034] It should be understood that although the terms first, second, third, etc. may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining."

[0035] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0036] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal communication between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0037] In the following description, the suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present invention and have no specific meaning. Therefore, "module" and "component" can be used interchangeably.

[0038] The present invention provides a magnesium carbohydrate processing process, comprising the following steps: step S100: after weighing a magnesium raw material, a carbon raw material and an additive in proportion, respectively adding the magnesium raw material, the carbon raw material and the additive into a three-dimensional mixing device, and mixing the three-dimensional mixing device at a rotation speed of 20 to 30 r / min for 20 to 30 minutes to obtain a premix; step S200: conveying the premix to a hydration reactor, adding water accounting for 20% to 30% of the mass of the premix into the hydration reactor, and then starting a stirring device, the stirring speed of the stirring device is 15 to 25 r / min, and the reaction temperature is controlled to 50 to 70° C. by a heating device, the reaction time is 3 to 5 hours, and the stirring device is discharged after stirring is completed to obtain a mixed material; step S300: drying the mixed material in an environment with a drying temperature of 80 to 100° C. for 2 to 4 hours to obtain the magnesium carbohydrate.

[0039] In this embodiment, see Figure 1 As shown, this embodiment will describe in detail a magnesium carbohydrate processing process, which specifically includes the following steps:

[0040] Step S100: Accurately weigh the magnesium raw material, carbonaceous raw material, and additives in proportion. This is essential for ensuring product quality stability. The mass ratio of different raw materials directly affects the performance of the magnesium carbonate hydrate. The magnesium raw material, carbonaceous raw material, and additives weighed according to their mass ratio are added to a three-dimensional mixing device. The three-dimensional mixing device is set to mix the magnesium raw material, carbonaceous raw material, and additives at a speed of 20 to 30 r / min for 20 to 30 minutes, thereby obtaining a premix. It should be noted that the three-dimensional mixing device includes, but is not limited to, a double-cone mixer. The parameters of setting the speed of the three-dimensional mixing device to 20 to 30 r / min and the mixing time of the magnesium raw material, carbonaceous raw material, and additives to 20 to 30 minutes are within the ranges obtained through extensive experimentation and verification. When the speed is set to 20 to 30 r / min, the magnesium raw material, carbonaceous raw material, and additives within the double-cone mixer have appropriate movement intensity and trajectory. When the speed is too low, the movement of the magnesium raw material, carbon raw material, and additives is insufficient, and the mutual force between them is insufficient, making it difficult to achieve full fusion. When the speed is too high, the magnesium raw material, carbon raw material, and additives will be too close to the inner wall of the double-cone mixer due to excessive centrifugal force, and will not be able to effectively roll and diffuse within the cylinder. At the same time, the particle structure of some magnesium raw material, carbon raw material, and additives may be destroyed, thereby affecting their mixing uniformity. In addition, the mixing time of the magnesium raw material, carbon raw material, and additives in the three-dimensional mixing equipment is set to 20 minutes to 30 minutes. This is because magnesium raw material, carbon raw material, and additives of different particle sizes and properties require sufficient time to interact with each other to achieve uniform dispersion. When the mixing time is too short, the magnesium raw material, carbon raw material, and additives are not fully mixed. When the mixing time is too long, although the mixing uniformity can be improved, the improvement effect is limited, and the energy consumption and operating costs of the double-cone mixer are increased.

[0041] Step S200: The premix obtained in step S100 is transferred to a hydration reactor. Water representing 20% ​​to 30% of the premix's mass is added to the hydration reactor, and the premix in the hydration reactor is stirred at a preset speed by a stirring device to obtain a mixed material. It should be noted that the preset speed of the stirring device is 15 to 25 rpm. When the stirring device is set at a speed of 15 to 25 rpm, the materials are thoroughly mixed and dispersed in the hydration reactor. If the stirring device speed is too slow, contact and reaction between the premixes are insufficient, which can easily lead to localized uneven reaction. If the stirring device speed is too fast, significant shear forces are generated, potentially damaging the premix's structure and affecting the quality of the final product. Simultaneously, the reaction temperature is controlled at 50°C to 70°C by a heating device, and the reaction time is set at 3 to 5 hours. This reaction temperature and time have been verified as optimal reaction conditions through experimentation and practice. Reaction temperature has a significant impact on the rate and product of the hydration reaction. When the reaction temperature is too low, the reaction rate is slow, which can extend the production cycle and may lead to incomplete reaction. When the reaction temperature is too high, the reaction will be too intense, resulting in excessive side reactions that can damage the structure and properties of the final product. The appropriate reaction time ensures that the reaction proceeds fully and the premix is ​​converted into the target product as much as possible.

[0042] It should also be noted that the hydration reactor is a container used to contain premix and water and provide space for hydration reaction.

[0043] It should be noted that, in this embodiment, the premix obtained in step S100 is conveyed to the hydration reactor by methods including but not limited to gravity conveying, screw conveyor conveying, and pneumatic conveying.

[0044] When gravity conveying is used, the premix is ​​conveyed using its own gravity. An inclined pipe or chute is installed between the three-dimensional mixing device described in step S100 and the hydration reactor. The premix is ​​fed into the hydration reactor under the action of gravity along the pipe or chute. This method is simple and easy to implement, and is suitable for situations where the premix has high fluidity, the conveying distance is short, and there is a significant height difference between the three-dimensional mixing device and the hydration reactor.

[0045] When using a screw conveyor for transport, install it between the outlet of the three-dimensional mixing device described in step S100 and the inlet of the hydration reactor described in step S200. The screw conveyor propels the premix forward through rotating spiral blades, transporting the premix from one location to another. This method allows for horizontal, inclined, and even vertical transport of the premix, providing strong adaptability and ensuring continuous and stable delivery of the premix to the hydration reactor. It also provides excellent sealing properties, reducing dust generation and making it suitable for transporting a wide range of premixes.

[0046] When using pneumatic conveying, the premix is ​​transported by leveraging the pressure differential created by air flow within the pipeline. The outlet of the three-dimensional mixing device described in step S100 is connected to a pneumatic conveying pipeline, where a fan generates airflow to blow the premix into the hydration reactor. This method offers high efficiency, allows for long-distance transport, and reduces contamination during transport, ensuring material purity. It is particularly suitable for conveying powdered premixes.

[0047] Step S300: In this step, the mixed material obtained in step S200 is dried to remove moisture. The mixed material obtained after the hydration reaction in step S200 contains a large amount of moisture. Failure to dry the mixed material will affect the storage and transportation of the final magnesium carbonate hydrate, as well as its performance. For example, residual moisture may cause a secondary hydration reaction during storage, altering the product's internal structure and reducing its fire resistance and mechanical strength. Therefore, drying is an essential step to ensure product quality and stability.

[0048] In this example, the drying temperature is set between 80°C and 100°C, and the drying time is between 2 and 4 hours. This parameter range is determined based on material properties and production requirements. If the temperature is too low, water evaporation will be slow, which will extend the drying time and reduce production efficiency. If the temperature is too high, the internal structure of the mixture may change, affecting product performance. In actual production, for mixtures of different batches and varying humidity levels, this parameter range can be flexibly adjusted to achieve optimal drying results.

[0049] Furthermore, the magnesia raw material is light-burned magnesium powder, the carbonaceous raw material is flake graphite, and the additive is silicon micropowder; the mass ratio of the magnesia raw material, the carbonaceous raw material and the additive is (60-70): (20-30): (5-10).

[0050] In this embodiment, step S100 will be described again, specifically describing the raw materials of the magnesium raw material, carbonaceous raw material and additives and their proportions. In this embodiment, the magnesium raw material is light-burned magnesium powder, which is a magnesium material with high activity. It can fully combine with other ingredients in the hydration reaction to provide the product with good fire resistance and mechanical strength. The carbonaceous raw material is flake graphite, which has good lubricity, conductivity and high temperature resistance. After addition, it can enhance the thermal shock resistance and toughness of the magnesium carbon hydrate. The additive is silicon micropowder. The silicon micropowder has fine particles and a large specific surface area. It can fill the gaps between the material particles, improve the fluidity and density of the material, and participate in the hydration reaction to improve the strength and durability of the magnesium carbon hydrate.

[0051] The mass ratio of magnesium raw material, carbon raw material and additives is (60-70): (20-30): (5-10). This ratio range is verified through extensive experiments and practical applications. When the proportion of magnesium raw material is less than 60%, the refractory performance and strength of the product will be significantly reduced; exceeding 70%, it will lead to increased raw material costs and may affect product quality due to incomplete reaction. If the proportion of carbon raw material is less than 20%, the thermal shock resistance and toughness of the product will be insufficient; if it is greater than 30%, the refractoriness of the product will be reduced. If the proportion of silicon micropowder additive is less than 5%, its filling and reinforcing effects cannot be fully exerted; if it is greater than 10%, the material will become too viscous, affecting mixing and molding.

[0052] Furthermore, the particle size of the light-burned magnesium powder is 200 mesh to 325 mesh, the particle size of the flake graphite is 100 mesh to 200 mesh, and the particle size of the silicon micropowder is 1000 mesh to 1500 mesh.

[0053] In this embodiment, the particle sizes of the light-burned magnesium powder, flake graphite, and silicon micropowder described in the above embodiments are described in detail. The particle size of the light-burned magnesium powder is 200 mesh to 325 mesh, the particle size of the flake graphite is 100 mesh to 200 mesh, and the particle size of the silicon micropowder is 1000 mesh to 1500 mesh. Raw materials of different particle sizes behave differently during the mixing process, and the appropriate particle size combination can significantly improve the mixing uniformity. For example, if the particle size of the light-burned magnesium powder is too large, when it is mixed with flake graphite and silicon micropowder, it is difficult to fully contact and disperse with silicon micropowder of smaller particle size, and local aggregation is likely to occur, resulting in uneven mixing; while if the particle size is too small, although it can increase the specific surface area, it is easy to agglomerate during the mixing process, which is also not conducive to uniform mixing. When the particle size of light-burned magnesium powder is between 200 mesh and 325 mesh, it can be matched with flake graphite of 100 mesh to 200 mesh and silicon micropowder of 1000 mesh to 1500 mesh. In the three-dimensional mixing equipment, it can achieve mutual interpenetration and diffusion under the action of spiral blades by virtue of its own particle size characteristics, thus achieving a good mixing effect.

[0054] Furthermore, the three-dimensional mixing device is a double-cone mixer, which includes a cylinder with spiral blades provided on the inner wall of the cylinder. The relationship between the pitch P of the spiral blades and the inner diameter D of the cylinder satisfies: P=0.5D~0.8D.

[0055] In this embodiment, the three-dimensional mixing equipment described in the above embodiment will be described in detail. The three-dimensional mixing equipment is a double-cone mixer. The double-cone mixer includes a cylinder, which is mainly used to accommodate magnesium raw materials, carbon raw materials and additives. A spiral blade is provided on the inner wall of the cylinder to mix the magnesium raw materials, carbon raw materials and additives in the cylinder. The relationship between the pitch P of the spiral blade and the inner diameter D of the cylinder satisfies P=0.5D~0.8D.

[0056] It should be noted that in this embodiment, the traditional single-axis mixing equipment is replaced by a double-cone mixer. The unique double-cone barrel structure of the double-cone mixer enables it to give the magnesium raw material, carbon raw material and additives complex motion trajectories during operation. Unlike ordinary single-axis mixers that can only make the magnesium raw material, carbon raw material and additives move in a circular motion within a plane, the double-cone mixer can drive the magnesium raw material, carbon raw material and additives to move in multiple directions along the barrel wall, up and down, left and right, inside and outside. This mode of movement greatly increases the opportunities for the magnesium raw material, carbon raw material and additives to interpenetrate, diffuse and shear each other, thereby achieving full dispersion of micron-sized particles and effectively solving the problem of insufficient raw material mixing in the existing technology. For example, when mixing light-burned magnesium powder, flake graphite and silicon micropowder, the double-cone mixer can allow raw materials of different particle sizes and densities to fully contact each other, ensuring mixing uniformity.

[0057] It should be noted that the relationship between the spiral blade pitch P and the inner diameter D of the cylinder satisfies P = 0.5D to 0.8D. Since the magnesium raw material, carbonaceous raw material, and additive are mixed within the cylinder by the spiral blade, the appropriate ratio of the spiral blade pitch P to the inner diameter D of the cylinder determines the movement speed and trajectory of the magnesium raw material, carbonaceous raw material, and additive within the double-cone mixer. If the pitch P is too small, the magnesium raw material, carbonaceous raw material, and additive rise and fall too quickly within the cylinder, resulting in a short residence time within the cylinder and inadequate mixing. If the pitch P is too large, the magnesium raw material, carbonaceous raw material, and additive move slowly, reducing mixing efficiency and even causing material accumulation. For example, when the inner diameter D of the double-cone mixer cylinder is 1 meter, setting the spiral blade pitch P between 0.5m and 0.8m allows the materials to tumble and diffuse at an appropriate speed within the cylinder.

[0058] Furthermore, at least one temperature sensor and a time controller are respectively provided in the hydration reactor; wherein, the temperature sensor monitors the stirring reaction temperature of the premix when being stirred in the hydration reactor in real time, and transmits the stirring reaction temperature to the control system in real time. When the stirring reaction temperature is greater than the set reaction temperature of 50°C to 70°C, the control system automatically adjusts the power of the heating device to keep the stirring reaction temperature at the set reaction temperature value; the time controller monitors the stirring reaction time of the premix when being stirred in the hydration reactor in real time, and transmits the stirring reaction time to the control system in real time. When the stirring reaction time is equal to or greater than the set reaction time of 3h to 5h, the control system issues an alarm to prompt the end of the reaction.

[0059] In this embodiment, the hydration reactor will be described in detail again. A temperature sensor and a time controller are respectively provided in the hydration reactor. The temperature sensor is used to monitor the stirring reaction temperature of the premix when it is stirred in the hydration reactor in real time, and transmit the monitored stirring reaction temperature to the control system in real time. The control system compares the stirring reaction temperature with the preset stirring reaction temperature threshold. When the stirring reaction temperature threshold is greater than the stirring reaction temperature threshold, the control system will adjust the power of the heating device to reduce the reaction temperature value. It should be noted that the stirring reaction temperature threshold described in this embodiment is within the range of reaction temperature of 50°C to 70°C.

[0060] The time controller monitors the stirring reaction time of the premix in the hydration reactor in real time and sends the stirring reaction time to the control system. The control system compares the stirring reaction time with a preset stirring reaction time threshold. When the stirring reaction time is equal to or greater than the stirring reaction time threshold, the control system prompts an alarm indicating the end of the reaction. It should be noted that the stirring reaction time threshold described in this embodiment is 3 hours to 5 hours.

[0061] Furthermore, in step S300 , a vacuum drying oven is used for drying, and the vacuum degree of the vacuum drying oven is -0.08 MPa to -0.1 MPa.

[0062] In this embodiment, the equipment for the drying process in step S300 will be described in detail. The use of a vacuum drying oven in step S300 has significant advantages over the traditional atmospheric pressure drying method. In a vacuum environment, the air pressure on the surface of the mixed material decreases, and the boiling point of water also decreases. This means that the moisture in the mixed material can evaporate quickly at a lower temperature, avoiding the changes in the performance of the magnesium carbonate material that may be caused by high-temperature drying. For example, if the temperature of traditional atmospheric pressure drying is too high, it may cause changes in the internal structure of the magnesium carbonate material, resulting in a decrease in its fire resistance and a weakening of its mechanical strength; while the vacuum drying oven can achieve efficient drying under relatively mild temperature conditions, effectively protecting the physical and chemical properties of the magnesium carbonate material. The vacuum degree of a vacuum drying oven is -0.08MPa to -0.1MPa. This range is determined based on extensive experiments and production practices. When the vacuum degree is lower than -0.08MPa, the vacuum environment has little effect on lowering the boiling point of water, and the advantages of vacuum drying cannot be fully utilized. The drying efficiency improvement is limited, making it difficult to meet production needs. When the vacuum degree is higher than -0.1MPa, although the boiling point of water can be further reduced, the sealing and pressure resistance requirements of the equipment are greatly increased, which will increase equipment cost and maintenance difficulty. At the same time, an excessive vacuum environment may cause the loss of some volatile components in the material, affecting product quality. At a vacuum degree of -0.08 to -0.1MPa, it can ensure rapid evaporation of water and achieve efficient drying while balancing equipment cost and product quality.

[0063] Furthermore, the step of discharging the premix after the stirring device completes stirring to obtain a mixed material specifically includes the following steps: after the stirring device stirs the premix and water in the hydration reactor for 3h to 5h, sampling the premix after the reaction in the hydration reactor to obtain a sample material; performing humidity detection and hydration reaction degree detection on the sample material, when the humidity detection value of the sample material is less than the humidity detection threshold and the hydration reaction degree value of the sample material is within the set standard range, discharging the premix in the hydration reactor to obtain a mixed material, the humidity detection threshold is 20% to 25%, and the set standard range is 90% to 95%.

[0064] In this embodiment, after the stirring device completes stirring, a sampling test is performed in the step of discharging the material to obtain the mixed material, which specifically includes the following steps:

[0065] After the stirring device stirs the premix and water in the hydration reactor for 3 to 5 hours, the material in the hydration reactor is sampled to obtain a sample material. The sample material is tested for humidity and hydration reaction degree. When the humidity detection value of the sample material is less than a humidity detection threshold and the hydration reaction degree value of the sample material is within a set standard range, the premix in the hydration reactor is discharged to obtain a mixed material. The humidity detection threshold is 20% to 25%, and the set standard range is 90% to 95%.

[0066] Furthermore, when the humidity of the sample material is tested, the humidity test value is calculated based on the drying loss method, and the calculation formula is: Wherein, H represents the humidity detection value of the sample material, m1 represents the initial mass of the sample material, and m2 represents the mass after the stirring device stirs the premix and water in the hydration reactor for 3h to 5h.

[0067] It should be noted that, in this embodiment, the humidity detection of the sample material in the above embodiment will be described in detail. Specifically, when the humidity of the sample material is detected, the humidity detection value is calculated based on the drying weight loss method, and its principle is based on the characteristics of water evaporation when heated. Under certain temperature conditions, the sample material is dried, and the water in the sample material will all evaporate and escape. The moisture content in the sample material is weighed to determine the humidity detection value of the sample material. The specific calculation formula is: Wherein, H represents the humidity detection value of the sample material, m1 represents the initial mass of the sample material, and m2 represents the mass after the stirring device stirs the premix and water in the hydration reactor for 3h to 5h.

[0068] Furthermore, when the hydration reaction degree of the sample material is detected, the hydration reaction degree value is calculated based on the content of specific hydration products in the sample material detected by X-ray diffraction method, and the calculation formula is: Wherein, X represents the value of the degree of hydration reaction, I h Expressed as the diffraction intensity of a specific hydration product, I t is the sum of the diffraction intensities of the sample material.

[0069] In this embodiment, the hydration reaction degree detection of the sample material in the above embodiment will be described in detail. Specifically, when the hydration reaction degree detection of the sample material is performed, the content of the specific hydration product in the sample material is detected based on the X-ray diffraction method to calculate the value of the hydration reaction degree. The principle is based on the different X-ray diffraction characteristics of different crystalline substances. During the hydration reaction of magnesium carbonate hydrate, specific hydration products are generated, and these hydration products have unique crystal structures. When X-rays are irradiated on the reaction products, hydration products with different crystal structures will cause the X-rays to diffract at different angles and intensities. By detecting the diffraction intensity of the specific hydration product and the sum of the diffraction intensities of all products, the hydration reaction degree can be determined. The specific calculation formula is: Wherein, X represents the value of the degree of hydration reaction, I h Expressed as the diffraction intensity of a specific hydration product, I t is the sum of the diffraction intensities of the sample material.

[0070] Furthermore, the stirring device is a frame-type stirrer, and the relationship between the blade width b of the frame-type stirrer and the inner diameter R of the hydration reactor satisfies: b=0.1R~0.2R.

[0071] In this embodiment, the stirring device in the above embodiment will be described in detail. The stirring device is a frame-type stirrer. The relationship between the blade width b of the frame-type stirrer and the inner diameter R of the hydration reactor satisfies b = 0.1R ~ 0.2R. For example, when the inner diameter R of the hydration reactor is 2m, the blade width b of the frame-type stirrer is set to between 0.2m and 0.4m.

[0072] It should be noted that, for ease of understanding, the above content will be specifically described below with examples, including Examples 1 to 3, using endpoint values ​​and intermediate values ​​of each range value for specific description.

[0073] Example 1

[0074] Step S100: Weigh 60 kg of light-burned magnesium powder (200 mesh), 30 kg of flake graphite (particle size 100 mesh), and 10 kg of silicon micropowder (1000 mesh), and add them to a double-cone mixer. The pitch P of the spiral blade of the double-cone mixer is 0.5 m, and the inner diameter D of the cylinder is 1 m. The light-burned magnesium powder, flake graphite, and silicon micropowder taken symmetrically are stirred and mixed for 30 minutes by setting the speed of the double-cone mixer to 20 r / min, so that the light-burned magnesium powder, flake graphite, and silicon micropowder are fully subjected to multi-directional compound movement up and down, left and right, inside and outside in the cylinder to achieve uniform mixing to obtain a premix.

[0075] Step S200: The premix is ​​transported to a hydration reactor with an inner diameter R of 2m, and water accounting for 20% of the mass of the premix, i.e., 20kg of water, is added. A frame agitator is used to stir the premix and water in the hydration reactor. The blade width b of the frame agitator is 0.2m, and the stirring speed is 15r / min. The reaction temperature is controlled at 50°C by a heating device, and the reaction time lasts for 5h. During the reaction process, a temperature sensor monitors the stirring reaction temperature in real time, and a time controller monitors the stirring reaction time in real time to ensure that the reaction proceeds stably. After mixing is completed, a sample material is obtained by sampling, and the sample material is tested for humidity and hydration reaction degree. When the humidity detection value is less than the humidity detection threshold and the hydration reaction degree is within the standard range, the premix is ​​discharged and the mixed material is obtained.

[0076] Step S300: placing the mixed material into a vacuum drying oven, drying it at a vacuum degree of -0.08 MPa and a drying temperature of 80° C. for 4 hours to obtain a finished magnesium carbonate material.

[0077] After testing, the finished product has a refractoriness of 1650℃ and a compressive strength of 45MPa. The specific testing methods are as follows:

[0078] Refractoriness: According to the standard refractoriness test process, a truncated triangular pyramid sample that meets the requirements is prepared from the magnesium carbonate material obtained in Example 1. Its dimensions are strictly controlled to be 2 mm long on the upper base, 8 mm long on the lower base, and 30 mm high. The sample is placed in a silicon carbon rod high-temperature furnace and slowly heated at a heating rate of 5°C / min. As the temperature gradually rises, the sample begins to soften and deform. When the temperature reaches 1650°C, the top of the sample bends and contacts the chassis. Therefore, the refractoriness of the finished product of Example 1 is 1650°C. This refractoriness indicates that this finished product can withstand a certain degree of thermal shock in a high-temperature environment, has certain high-temperature resistance, and can meet the requirements of some industrial scenarios with refractoriness requirements in this range.

[0079] Compressive strength: The magnesium carbonate obtained in Example 1 was processed into rectangular test blocks with a size of 40 mm × 40 mm × 160 mm. Three test blocks were prepared in each group for parallel testing. After the test blocks were cured to 28 days of age, they were placed in the center of the lower pressure plate of a high-precision pressure testing machine and loaded uniformly at a loading rate of 1 MPa / s. The load values ​​at the time of failure of the three test blocks were recorded as 72000 N, 71000 N, and 70000 N, respectively. According to the compressive strength calculation formula: Where A = 40 × 40 = 1600 mm 2 The average compressive strength can be calculated as This means that the magnesium carbonate material in Example 1 has a certain bearing capacity in terms of bearing pressure and can withstand a certain degree of pressure in practical applications.

[0080] Example 2

[0081] Step S100: Weigh 65 kg of light-burned magnesium powder (260 mesh), 25 kg of flake graphite (particle size 150 mesh), and 8 kg of silicon micropowder (1250 mesh), and add them to a double-cone mixer. The pitch P of the spiral blade of the double-cone mixer is 0.72 m, and the inner diameter D of the cylinder is 1.2 m. The light-burned magnesium powder, flake graphite, and silicon micropowder taken symmetrically are stirred and mixed by setting the speed of the double-cone mixer to 25 r / min for 23 minutes, so that the light-burned magnesium powder, flake graphite, and silicon micropowder are fully subjected to multi-directional compound motion up and down, left and right, and inside and outside in the cylinder to achieve uniform mixing to obtain a premix.

[0082] Step S200: The premix is ​​transported to a hydration reactor with an inner diameter R of 2.2m, and water (19.6kg) is added, which accounts for 20% of the mass of the premix. A frame agitator is used to stir the premix and water in the hydration reactor. The blade width b of the frame agitator is 0.22m, and the stirring speed is 20r / min. The reaction temperature is controlled at 60°C by a heating device, and the reaction time lasts for 4 hours. During the reaction process, a temperature sensor monitors the stirring reaction temperature in real time, and a time controller monitors the stirring reaction time in real time to ensure that the reaction proceeds stably. After mixing is completed, a sample material is obtained by sampling, and the sample material is tested for humidity and hydration reaction degree. When the humidity detection value is less than the humidity detection threshold and the hydration reaction degree is within the standard range, the premix is ​​discharged and the mixed material is obtained.

[0083] Step S300: placing the mixed material into a vacuum drying oven, and drying it at a vacuum degree of -0.09 MPa and a drying temperature of 90° C. for 3 hours to obtain a finished magnesium carbonate material.

[0084] After testing, the finished product has a refractoriness of 1700°C and a compressive strength of 52MPa. The specific testing methods are as follows:

[0085] Refractoriness: According to the standard refractoriness test process, a truncated triangular pyramid sample that meets the requirements is prepared from the magnesium carbonate material obtained in Example 2. Its dimensions are strictly controlled to be 2 mm long on the upper base, 8 mm long on the lower base, and 30 mm high. The sample is placed in a silicon carbon rod high-temperature furnace and slowly heated at a heating rate of 5°C / min. As the temperature gradually rises, the sample begins to soften and deform. When the temperature reaches 1700°C, the top of the sample bends and contacts the chassis. Therefore, the refractoriness of the finished product of Example 2 is 1650°C. This refractoriness shows that this finished product can withstand a certain degree of thermal shock in a high-temperature environment, has certain high-temperature resistance, and can meet the requirements of some industrial scenarios with refractoriness in this range.

[0086] Compressive strength: The magnesium carbonate obtained in Example 2 was processed into rectangular test blocks with a size of 40 mm × 40 mm × 160 mm. Three test blocks were prepared in each group for parallel testing. After the test blocks were cured to 28 days of age, they were placed in the center of the lower pressure plate of a high-precision pressure testing machine and loaded uniformly at a loading rate of 1 MPa / s. The load values ​​at the time of failure of the three test blocks were recorded as 83200 N, 81600 N, and 82400 N, respectively. According to the compressive strength calculation formula: Where A = 40 × 40 = 1600 mm 2 The average compressive strength can be calculated as This means that the magnesium carbonate material in Example 2 has a certain bearing capacity in terms of bearing pressure and can withstand a certain degree of pressure in practical applications.

[0087] Example 3

[0088] Step S100: Weigh 70 kg of light-burned magnesium powder (325 mesh), 20 kg of flake graphite (particle size 200 mesh), and 8 kg of silicon micropowder (1250 mesh), and add them to a double-cone mixer. The pitch P of the spiral blade of the double-cone mixer is 0.64 m, and the inner diameter D of the cylinder is 0.8 m. The light-burned magnesium powder, flake graphite, and silicon micropowder taken symmetrically are stirred and mixed for 20 minutes by setting the speed of the double-cone mixer to 30 r / min, so that the light-burned magnesium powder, flake graphite, and silicon micropowder are fully subjected to multi-directional compound movement up and down, left and right, and inside and outside in the cylinder to achieve uniform mixing to obtain a premix.

[0089] Step S200: The premix is ​​transported to a hydration reactor with an inner diameter R of 1.8m, and water (19.6kg) is added, accounting for 20% of the premix's mass. A frame agitator is used to stir the premix and water in the hydration reactor. The blade width b of the frame agitator is 0.18m, and the stirring speed is 25r / min. The reaction temperature is controlled at 70°C by a heating device, and the reaction time lasts for 3 hours. During the reaction process, a temperature sensor monitors the stirring reaction temperature in real time, and a time controller monitors the stirring reaction time in real time to ensure that the reaction proceeds stably. After mixing is completed, a sample material is obtained by sampling, and the sample material is tested for humidity and hydration reaction degree. When the humidity detection value is less than the humidity detection threshold and the hydration reaction degree is within the standard range, the premix is ​​discharged and the mixed material is obtained.

[0090] Step S300: placing the mixed material into a vacuum drying oven, and drying it at a vacuum degree of -0.1 MPa and a drying temperature of 100° C. for 3 hours to obtain a finished magnesium carbonate material.

[0091] After testing, the finished product has a refractoriness of 1680°C and a compressive strength of 48MPa. The specific testing methods are as follows:

[0092] Refractoriness: According to the standard refractoriness test process, a truncated triangular pyramid sample that meets the requirements is prepared from the magnesium carbonate hydrate obtained in Example 2. Its dimensions are strictly controlled to be 2 mm long on the upper base, 8 mm long on the lower base, and 30 mm high. The sample is placed in a silicon carbon rod high-temperature furnace and slowly heated at a heating rate of 5°C / min. As the temperature gradually rises, the sample begins to soften and deform. When the temperature reaches 1680°C, the top of the sample bends and contacts the chassis. Therefore, the refractoriness of the finished product of Example 2 is 1680°C. This refractoriness indicates that this finished product can withstand a certain degree of thermal shock in a high-temperature environment, has certain high-temperature resistance, and can meet the requirements of some industrial scenarios with refractoriness in this range.

[0093] Compressive strength: The magnesium carbonate obtained in Example 2 was processed into rectangular test blocks with a size of 40 mm × 40 mm × 160 mm. Three test blocks were prepared in each group for parallel testing. After the test blocks were cured to 28 days of age, they were placed in the center of the lower pressure plate of a high-precision pressure testing machine and loaded uniformly at a loading rate of 1 MPa / s. The load values ​​at the time of failure of the three test blocks were recorded as 76800 N, 75200 N, and 78400 N, respectively. According to the compressive strength calculation formula: Where A = 40 × 40 = 1600 mm 2 The average compressive strength can be calculated as This means that the magnesium carbonate material in Example 3 has a certain bearing capacity in terms of bearing pressure and can withstand a certain degree of pressure in practical applications.

[0094] In addition, it should be noted that the magnesium carbonate obtained in Examples 1 to 3 above was subjected to a thermal shock resistance performance test. A rectangular sample with a size of 25 mm × 25 mm × 150 mm was cut out, and 3 samples were prepared in each group to ensure that the surface of the sample was flat and free of obvious defects. The sample was placed in a high-temperature furnace and heated to 800°C at a heating rate of 5°C / min. It was kept warm for 30 minutes to make the interior of the sample stable and uniform. The sample was then taken out and immediately immersed in 20°C cold water for rapid cooling for 3s to 5s. After removal, natural interference was removed and the above cycle process was repeated until a through crack or fracture appeared in the sample. The accumulated number of cycles was used as an evaluation index for thermal shock resistance.

[0095] After testing, the sample in Example 1 developed through cracks after 12 cycles, the sample in Example 2 developed through cracks after 15 cycles, and the sample in Example 3 developed through cracks after 13 cycles.

[0096] It should also be noted that the magnesium carbonate obtained in Examples 1 to 3 was subjected to a chemical stability test, and cylindrical samples with a diameter of 50 mm and a height of 50 mm were cut, with 3 samples 2 taken from each group. The samples were placed in a 10% sulfuric acid solution with a volume of 5 times the volume of the sample, and soaked at room temperature of 20±2°C for 72 hours. After the soaking, the sample was removed and washed with clean water. After drying, the surface changes of the sample were observed, and the mass loss rate and strength loss rate of the sample were measured. The mass loss rate was calculated by the formula: Where M represents the mass loss rate, m n is the mass of the sample before immersion, m u is the mass of the sample after immersion. The strength loss rate is calculated by testing the tensile strength of the sample before and after immersion. The calculation formula is: Among them, S represents the strength loss rate, R n Expressed as compressive strength before immersion, R u Expressed as compressive strength after immersion.

[0097] After testing, the mass loss rate of the sample of magnesium carbonate material in Example 1 was 8.5%, and the strength loss rate was 22%; the mass loss rate of the sample of magnesium carbonate material in Example 2 was 6.2%, and the strength loss rate was 18%; the mass loss rate of the sample of magnesium carbonate material in Example 3 was 7.8%, and the strength loss rate was 20%.

[0098] It should be noted that the embodiments of the present invention have better practicability and do not impose any form of limitation on the present invention. Any technician familiar with the field may use the technical content disclosed above to change or modify it into an equivalent effective embodiment. However, any modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A magnesium carbonate processing process, characterized in that: The following steps are involved: Step S100: After weighing the magnesium raw material, the carbonaceous raw material and the additive in proportion, the magnesium raw material, the carbonaceous raw material and the additive are respectively added to a three-dimensional mixing device, and the three-dimensional mixing device is mixed at a speed of 20 r / min to 30 r / min for 20 min to 30 min to obtain a premix; Step S200: transporting the premix to a hydration reactor, adding water accounting for 20% to 30% of the mass of the premix to the hydration reactor, and then starting a stirring device. The stirring speed of the stirring device is 15 rpm to 25 rpm, and the reaction temperature is controlled to 50° C. to 70° C. by a heating device. The reaction time is 3 h to 5 h. After the stirring is completed, the stirring device is discharged to obtain a mixed material. Step S300: drying the mixed material at a drying temperature of 80° C. to 100° C. for 2 to 4 hours to obtain the magnesium carbonate material.

2. The magnesium carbonate processing technology according to claim 1, characterized in that: The magnesium raw material is light-burned magnesium powder, the carbon raw material is flake graphite, and the additive is silicon micropowder; The mass ratio of the magnesium raw material, the carbonaceous raw material and the additive is (60-70): (20-30): (5-10).

3. The magnesium carbonate processing technology according to claim 2, characterized in that: The particle size of the light-burned magnesium powder is 200-325 meshes, the particle size of the flake graphite is 100-200 meshes, and the particle size of the silicon micropowder is 1000-1500 meshes.

4. The magnesium carbonate processing process according to claim 1, wherein: The three-dimensional mixing device is a double-cone mixer, which includes a cylinder, an inner wall of which is provided with spiral blades, and a relationship between a pitch P of the spiral blades and an inner diameter D of the cylinder satisfies: P=0.5D-0.8D.

5. The magnesium carbonate processing technology according to claim 1, characterized in that: The hydration reactor is provided with at least one temperature sensor and a time controller; wherein, The temperature sensor monitors the stirring reaction temperature of the premix in the hydration reactor in real time, and transmits the stirring reaction temperature to the control system in real time. When the stirring reaction temperature is greater than the set reaction temperature by 50°C to 70°C, the control system automatically adjusts the power of the heating device to keep the stirring reaction temperature at the set reaction temperature. The time controller monitors the stirring reaction time of the premix in the hydration reactor in real time, and transmits the stirring reaction time to the control system in real time. When the stirring reaction time is equal to or greater than the set reaction time of 3h to 5h, the control system issues an alarm to indicate the end of the reaction.

6. The magnesium carbonate processing process according to claim 1, characterized in that: In step S300 , a vacuum drying oven is used for drying, and the vacuum degree of the vacuum drying oven is -0.08 MPa to -0.1 MPa.

7. The magnesium carbonate processing process according to claim 1, characterized in that: The step of discharging the mixed material after the stirring device completes stirring to obtain the mixed material specifically includes the following steps: After the stirring device stirs the premix and water in the hydration reactor for 3 hours to 5 hours, sampling the premix after the reaction in the hydration reactor to obtain a sample material; The sample material is subjected to humidity detection and hydration reaction degree detection. When the humidity detection value of the sample material is less than a humidity detection threshold and the hydration reaction degree value of the sample material is within a set standard range, the premix in the hydration reaction kettle is discharged to obtain the mixed material. The humidity detection threshold is 20% to 25%, and the set standard range is 90% to 95%.

8. The magnesium carbonate processing process according to claim 7, characterized in that: When performing humidity detection on the sample material, the humidity detection value is calculated based on the drying loss method, and the calculation formula is: Wherein, H represents the humidity detection value of the sample material, m1 represents the initial mass of the sample material, and m2 represents the mass of the premix and water in the hydration reactor after the stirring device stirs them for 3 to 5 hours.

9. The magnesium carbonate processing process according to claim 7, characterized in that: When the hydration reaction degree of the sample material is detected, the value of the hydration reaction degree is calculated based on the content of specific hydration products in the sample material detected by X-ray diffraction method, and the calculation formula is: Wherein, X represents the value of the degree of hydration reaction, I h Expressed as the diffraction intensity of a specific hydration product, I t is the sum of the diffraction intensities of the sample material.

10. The magnesium carbonate processing process according to claim 1, characterized in that: The stirring device is a frame-type stirrer, and the relationship between the blade width b of the frame-type stirrer and the inner diameter R of the hydration reactor satisfies: b=0.1R~0.2R.

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