CN120309203A - A method for preparing calcium hydroxide with high specific surface area and a preparation system thereof - Google Patents

Abstract

The present invention relates to the technical field of calcium hydroxide preparation methods, and specifically to a method for preparing calcium hydroxide with a high specific surface area and a preparation system thereof, comprising the following steps: raw material pretreatment, primary digestion, secondary digestion, tertiary digestion and post-treatment, using a tertiary digestion process to replace the drying step to reduce energy consumption; using a composite dispersant formula to improve particle dispersibility to ensure that the specific surface area is ≥45 m/g; using a rotary kiln high-activity calcium oxide raw material to improve the production efficiency of calcium hydroxide, and by optimizing key steps such as raw material pretreatment, primary digestion, secondary digestion, tertiary digestion and post-treatment, significantly improving the specific surface area and reaction activity of calcium hydroxide, while reducing energy consumption and cost. The preparation method not only solves the technical bottleneck in the traditional calcium hydroxide preparation process, but also provides strong support for the realization of large-scale industrial production.

Description

Preparation method and preparation system of high-specific-surface-area calcium hydroxide

Technical Field

The invention relates to the technical field of calcium hydroxide preparation methods, in particular to a high specific surface area calcium hydroxide preparation method and a preparation system thereof.

Background

In the field of industrial desulfurization, calcium hydroxide is an important raw material for dry desulfurization due to the characteristics of low cost, moderate reaction activity and the like. However, the conventional preparation process has three core problems, which severely limit the industrial application of the preparation process:

1. The prior art (such as CN 119750923A) relies on a secondary drying step, the energy consumption per ton of the product is up to 120 kWh, and the total cost is more than 30 percent. This not only increases the production costs, but also violates the current industry trend for low carbon manufacturing.

2. The particle agglomeration and the specific surface area are insufficient, that is, the conventional process adopts a single dispersing agent (such as CN 119018922A), the agglomeration phenomenon of calcium hydroxide particles cannot be effectively inhibited, the specific surface area is only 35-40 m/g, and the requirement of dry desulfurization on high-activity adsorbent (more than or equal to 40 m/g) is difficult to meet.

3. The raw material activity is uneven and the reaction efficiency is low, namely, the ordinary calcium oxide (CaO purity is less than or equal to 90 percent) has large activity difference due to unstable calcination process, the digestion reaction is incomplete, the ratio of residual unreacted particles is more than 5 percent, and the reaction efficiency of the final product is directly influenced.

In view of the above problems, there is a need in the industry for a low energy consumption, high dispersibility, high activity calcium hydroxide preparation method, while meeting the needs of large-scale continuous production.

Disclosure of Invention

The invention aims to provide a preparation method and a system for calcium hydroxide with high specific surface area, which are used for solving the problems of high energy consumption, complex process, insufficient particle agglomeration and specific surface area, uneven raw material activity and low reaction efficiency in the traditional calcium hydroxide preparation process.

In order to achieve the above object, the embodiment of the present application provides the following technical solutions:

In one aspect, the embodiment of the application provides a preparation method of high specific surface area calcium hydroxide, which comprises the following steps:

(1) Raw material pretreatment, namely crushing high-activity calcium oxide calcined by a rotary kiln into 0-20 mm particles, wherein the purity of the calcium oxide is more than or equal to 93%;

(2) Primary digestion, namely mixing crushed calcium oxide with water according to the mass ratio of water to calcium of 1:3, and mechanically stirring for 30 minutes at 80-90 ℃ to form primary digestion slurry;

(3) Secondary digestion, namely adding a composite dispersing agent into the primary digestion slurry, wherein the composite dispersing agent consists of polycarboxylate, fatty alcohol polyoxyethylene ether and sodium silicate according to the mass ratio of 5:3:2, the addition amount is 0.5-1.2% of the total mass of the slurry, and the secondary digestion slurry is formed by reacting for 1 hour at the constant temperature of 60-70 ℃;

(4) Aging the secondary digestion slurry for 2 hours at normal temperature to promote the formation of a microporous structure and obtain a calcium hydroxide product;

(5) Post-treatment, namely separating unreacted particles from a calcium hydroxide product through a 325-mesh screening device, and directly packaging the product;

wherein the three-stage digestion process does not need a drying step in the whole process, final calcium hydroxide ratio the surface area is more than or equal to 45 m/g, is suitable for dry desulfurization.

Preferably, the calcination temperature of the calcium oxide raw material is 900-1100 ℃ and the calcination time is 2-4 hours.

Preferably, the mechanical stirring speed in the step (2) is 200-400 rpm, and the stirring paddle is of a double-layer oblique blade structure.

Preferably, the polycarboxylate is an acrylic acid-maleic anhydride copolymer having a molecular weight of 3000-5000 g/mol.

Preferably, the viscosity of the slurry is monitored in real time in step (3), and the dispersant is automatically added to an upper limit of 1.2% when the viscosity exceeds 200 cP.

Preferably, the ageing process of step (4) is carried out in a closed vessel with a relative humidity controlled between 60 and 80%.

Preferably, the screening device of step (5) is equipped with an ultrasonic vibration module at a vibration frequency of 20-40 kHz.

The beneficial effects of the invention are as follows:

the preparation method and the system of the high specific surface area calcium hydroxide provided by the invention have the advantages of remarkably breaking through three aspects of energy conservation, consumption reduction, product performance improvement and industrial application through an innovative three-stage digestion process and a composite dispersing agent formula.

Firstly, in the aspect of energy conservation and consumption reduction, the three-stage digestion process is adopted to completely omit the drying step necessary for the traditional process, the integral energy consumption is reduced by more than 20 percent through the staged treatment of the primary high-temperature digestion quick start reaction, the secondary medium-temperature digestion optimization of particle dispersion and the three-stage normal-temperature aging stabilization of a pore structure, the cost can be saved by about 15 percent per ton of products, the green low-carbon production is truly realized, and secondly, in the aspect of product performance, the unique compound dispersant formula (polycarboxylate 50%, fatty alcohol polyoxyethylene ether 30% and sodium silicate 20%) ensures that the specific surface area of calcium hydroxide is stabilized to 45-48 m/g through the synergistic effect of all the components, the specific surface area is improved by more than 30 percent compared with the traditional process, the particle agglomeration rate is reduced by 35 percent, the pore size distribution is more uniform, and the characteristics lead to excellent reactivity and sulfur capacity in dry desulfurization application.

In the aspect of industrial application, the system adopts a modularized design and an intelligent control system, realizes full-process automatic production from raw material pretreatment to finished product packaging, can achieve 5 ten thousand tons of annual productivity, controls the fluctuation range of product performance within +/-2%, and completely meets the requirements of stability and economy of large-scale industrial production. Practical application shows that when the calcium hydroxide produced by the method is used for replacing baking soda in SDS dry desulfurization, the desulfurization efficiency can reach 92-95%, the running cost is reduced by 18-25%, and the method has obvious economic benefit and environmental benefit.

The innovations not only solve the technical problems of high energy consumption, unstable product performance, low industrialization degree and the like existing in the traditional calcium hydroxide preparation process, but also provide a high-efficiency, economical and sustainable solution for the environment-friendly desulfurization field, and have great significance in promoting technical progress of industries.

In a second aspect, the present embodiment provides a preparation system of a preparation method of high specific surface area calcium hydroxide, including:

the raw material pretreatment module is used for calcining limestone into high-activity calcium oxide and crushing the high-activity calcium oxide, and comprises a rotary kiln calcining device and a jaw crusher, wherein the rotary kiln calcining device is used for calcining the limestone at 900-1100 ℃ for 2-4 hours to obtain calcium oxide with CaO content of more than or equal to 93%, and the jaw crusher is used for crushing the calcined calcium oxide to 0-20 mm particles;

The primary digestion module is used for carrying out high-temperature mixing reaction on the crushed calcium oxide and water, and comprises a primary digestion kettle and a temperature-control stirring device, wherein the primary digestion kettle is used for mixing raw materials according to the mass ratio of water to calcium of 1:3 and reacting for 30 minutes at the stirring speed of 200-400 rpm at the temperature of 80-90 ℃;

The secondary digestion module is used for adding a composite dispersing agent into the primary digestion slurry to perform secondary reaction, and comprises a secondary digestion kettle and an automatic dispersing agent adding device, wherein the secondary digestion kettle is used for performing constant-temperature reaction for 1 hour at 60-70 ℃, and the automatic dispersing agent adding device is used for adding the composite dispersing agent consisting of polycarboxylate, fatty alcohol polyoxyethylene ether and sodium silicate according to the total mass of the slurry of 0.5-1.2 percent, wherein the total mass of the slurry is 5:3:2;

The three-stage digestion module is used for carrying out aging treatment on the secondary digestion slurry and comprises a three-stage aging bin and a humidity regulating device, wherein the three-stage aging bin ages the slurry for 2 hours at normal temperature, and the humidity regulating device controls the relative humidity of the environment to be 60-80%;

the post-treatment module is used for screening and packaging the aged calcium hydroxide product and comprises an ultrasonic vibration screening machine and a dust-free packaging machine, wherein the ultrasonic vibration screening machine is used for separating unreacted particles through a 325-mesh screen at a frequency of 20-40 kHz, and the dust-free packaging machine is used for directly packaging the qualified product;

And the central control module is used for monitoring and adjusting the operation parameters of each module and comprises a PLC controller and a sensor system, wherein the PLC controller receives temperature, viscosity and humidity signals from each module and correspondingly adjusts the stirring speed, the addition amount of the dispersing agent and the sieving frequency.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the embodiments of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic flow chart of a method for preparing high specific surface area calcium hydroxide according to an embodiment of the invention;

Fig. 2 is a schematic diagram of a preparation system of a preparation method of calcium hydroxide with high specific surface area according to an embodiment of the invention.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be noted that like reference numerals or letters refer to like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures. Meanwhile, in the description of the present invention, the terms "first", "second", and the like are used only to distinguish the description, and are not to be construed as indicating or implying relative importance.

Example 1:

as shown in fig. 1, the present embodiment provides a method for preparing calcium hydroxide with high specific surface area, which includes step S100, step S200, step S300, step S400, and step S500.

Step S100, raw material pretreatment, namely crushing the high-activity calcium oxide calcined by a rotary kiln into 0-20 mm particles, wherein the purity of the calcium oxide is more than or equal to 93%;

step 200, primary digestion, namely mixing crushed calcium oxide with water according to the mass ratio of water to calcium of 1:3, and mechanically stirring for 30 minutes at 80-90 ℃ to form primary digestion slurry;

Step S300, secondary digestion, namely adding a composite dispersing agent into the primary digestion slurry, wherein the composite dispersing agent consists of polycarboxylate, fatty alcohol polyoxyethylene ether and sodium silicate according to the mass ratio of 5:3:2, the addition amount is 0.5-1.2% of the total mass of the slurry, and the secondary digestion slurry is formed by reacting for 1 hour at the constant temperature of 60-70 ℃;

step S400, tertiary digestion, namely ageing the secondary digestion slurry for 2 hours at normal temperature, and promoting the formation of a micropore structure to obtain a calcium hydroxide product;

s500, post-treatment, namely separating unreacted particles from a calcium hydroxide product through a 325-mesh screening device, and directly packaging the product;

wherein the three-stage digestion process does not need a drying step in the whole process, final calcium hydroxide ratio the surface area is more than or equal to 45 m/g, is suitable for dry desulfurization.

Wherein in step S100 of the present embodiment, the calcination temperature of the calcium oxide raw material is 900-1100 ℃ and the calcination time is 2-4 hours.

Wherein the mechanical stirring speed in the step S200 of the embodiment is 200-400 rpm, and the stirring paddle is of a double-layer oblique blade structure.

Wherein in step S300 of the present embodiment, the polycarboxylate is an acrylic acid-maleic anhydride copolymer having a molecular weight of 3000 to 5000 g/mol.

Wherein in the step S300 of the embodiment, the viscosity of the slurry is monitored in real time, and when the viscosity exceeds 200 cP, the dispersant is automatically added to the upper limit of 1.2 percent.

Wherein the aging process in step S400 of the present embodiment is performed in a closed vessel with the relative humidity controlled at 60-80%.

Wherein the screening device in step S500 of the present embodiment is equipped with an ultrasonic vibration module with a vibration frequency of 20-40 kHz.

In the embodiment, the rotary kiln temperature-control calcination technology is adopted, and limestone is calcined for 2-4 hours at 900-1100 ℃ to ensure that the purity of calcium oxide is more than or equal to 93%. And then crushing the calcined calcium oxide into 0-20 mm uniform particles by using a jaw crusher so as to meet the requirements of the subsequent digestion process.

The high-purity calcium oxide (CaO is more than or equal to 93 percent) is obtained through accurate temperature control calcination, a high-quality raw material basis is provided for subsequent digestion reaction, a jaw crusher crushes raw materials to uniform particles, the uniformity and efficiency of digestion reaction are improved, the generation of residual particles is reduced, the high-purity calcium oxide and the uniform particles ensure the consistency of raw material activity, and a solid basis is laid for subsequent process.

In the embodiment, crushed calcium oxide is mixed with water at the temperature of 80-90 ℃ in the ratio of water to calcium of 1:3, and forced stirring is carried out for 30 minutes by adopting a double-layer oblique blade stirring paddle (200-400 rpm) to form primary digestion slurry. The high temperature environment of 80-90 ℃ accelerates the reaction of calcium oxide and water to quickly start the reaction, and the double-layer oblique blade stirring paddle provides strong stirring effect to ensure that the uniformity of the slurry reaches more than 95 percent and avoid the problems of local overheating or incomplete reaction.

Compared with the traditional process, the method has the advantages that the energy consumption is remarkably reduced by optimizing the stirring conditions and controlling the temperature.

In the embodiment, a composite dispersing agent is added into the primary digestion slurry, wherein the dispersing agent consists of polycarboxylate (50%), fatty alcohol-polyoxyethylene ether (30%) and sodium silicate (20%) according to the mass ratio, and the addition amount is 0.5-1.2% of the total mass of the slurry. The reaction was carried out at a constant temperature of 60-70℃for 1 hour to form a secondary digested slurry. Meanwhile, the viscosity of the slurry is monitored in real time, and when the viscosity exceeds 200 cP, the dispersant is automatically added to the upper limit of 1.2%. The composite dispersing agent effectively inhibits the agglomeration phenomenon of calcium hydroxide particles through the synergistic effect of polycarboxylate, fatty alcohol polyoxyethylene ether and sodium silicate, and remarkably improves the specific surface area (45-48 m/g). The viscosity of the slurry is monitored in real time, and the dispersing agent is automatically added, so that the stability and the dispersing effect of the digestion process are ensured. The use of the composite dispersant reduced the particle agglomeration rate by 35% and the pore size distribution was more uniform (d50=2-5 μm) compared to the single dispersant.

In the embodiment, the secondary digestion slurry is transferred into a closed container and aged for 2 hours at normal temperature, and the relative humidity of the environment is controlled to be 60-80% through a humidity control device, so that the stable formation of a micropore structure is promoted. The closed container effectively isolates the influence of the external environment on the aging process, and ensures the stability of the pore structure. The humidity control device is used for accurately controlling the relative humidity of the environment, so that the uniform formation of a micropore structure is promoted, and the micropore volume is increased (by 20%). The three-stage digestion process narrows the fluctuation range of the specific surface area of the calcium hydroxide to +/-1 m/g, and improves the stability and consistency of the product.

In the embodiment, an ultrasonic vibration screening machine (20-40 kHz) is matched with a 325-mesh screen to screen the calcium hydroxide product so as to remove unreacted particles and impurities. And then, directly packaging the qualified products into finished products by using a dust-free packaging machine without secondary treatment. The ultrasonic vibration screening machine effectively prevents the screen from being blocked by high-frequency vibration, the screening efficiency is improved to 98%, and the unreacted particle removal rate is more than 99.5%. Dust-free packaging, namely ensuring the cleanliness of the finished product in the packaging process by the dust-free packaging machine, avoiding secondary pollution, and obviously reducing the production cost and the labor input by directly packaging without secondary treatment.

2. Example Effect verification

Comparative example analysis

To verify the technical effect of this example, comparative example experiments were performed. In the comparative example, the complex dispersant and the three-stage digestion process were not used, and calcium hydroxide was prepared only using the conventional process. The results show that the specific surface area of the calcium hydroxide prepared in the comparative example is only 36.5 m/g, the desulfurization efficiency is 72%, and the energy consumption is as high as 110 kWh/ton.

Effects of embodiments of the invention

The specific surface area of the calcium hydroxide prepared in the embodiment of the invention reaches 47.3 m/g (data in the embodiment 1), the desulfurization efficiency is improved to 94%, and the energy consumption is reduced to 82 kWh/ton. This significant improvement benefits from the synergistic effect of the tertiary digestion process and the complex dispersant, as well as the optimal control of the individual steps.

The embodiment details a preparation method of high specific surface area calcium hydroxide, by optimizing key steps such as raw material pretreatment, primary digestion, secondary digestion, tertiary digestion, post-treatment and the like, the specific surface area and the reactivity of the calcium hydroxide are remarkably improved, and meanwhile, the energy consumption and the cost are reduced. The preparation method not only solves the technical bottleneck in the traditional calcium hydroxide preparation process, but also provides powerful support for realizing large-scale industrial production.

It is expected that in the future, with the increasing strictness of environmental protection policies and the increasing demand of industrial desulfurization, the calcium hydroxide with high specific surface area is used as a high-efficiency and economic desulfurizing agent and plays an important role in the field of dry desulfurization. Meanwhile, with the continuous progress of technology and the continuous optimization of technology, the preparation cost of calcium hydroxide is further reduced, the performance is more excellent, and the preparation method makes a greater contribution to environmental protection industry

The preparation method of the high specific surface area calcium hydroxide provided by the embodiment has the advantages of remarkably breaking through three aspects of energy conservation and consumption reduction, product performance improvement and industrial application through an innovative three-stage digestion process and a composite dispersing agent formula.

Firstly, in the aspect of energy conservation and consumption reduction, the three-stage digestion process is adopted to completely omit the drying step necessary for the traditional process, the integral energy consumption is reduced by more than 20 percent through the staged treatment of the primary high-temperature digestion quick start reaction, the secondary medium-temperature digestion optimization of particle dispersion and the three-stage normal-temperature aging stabilization of a pore structure, the cost can be saved by about 15 percent per ton of products, the green low-carbon production is truly realized, and secondly, in the aspect of product performance, the unique compound dispersant formula (polycarboxylate 50%, fatty alcohol polyoxyethylene ether 30% and sodium silicate 20%) ensures that the specific surface area of calcium hydroxide is stabilized to 45-48m/g through the synergistic effect of the components, the agglomeration rate is improved by more than 30 percent compared with the traditional process, meanwhile, the particle size distribution is more uniform, and the characteristics lead the product to have excellent reactivity and sulfur capacity in dry desulfurization application.

In the aspect of industrial application, the system adopts a modularized design and an intelligent control system, realizes full-process automatic production from raw material pretreatment to finished product packaging, can achieve 5 ten thousand tons of annual productivity, controls the fluctuation range of product performance within +/-2%, and completely meets the requirements of stability and economy of large-scale industrial production. Practical application shows that when the calcium hydroxide produced by the method is used for replacing baking soda in SDS dry desulfurization, the desulfurization efficiency can reach 92-95%, the running cost is reduced by 18-25%, and the method has obvious economic benefit and environmental benefit.

The innovations not only solve the technical problems of high energy consumption, unstable product performance, low industrialization degree and the like existing in the traditional calcium hydroxide preparation process, but also provide a high-efficiency, economical and sustainable solution for the environment-friendly desulfurization field, and have great significance in promoting technical progress of industries.

Example 2:

as shown in fig. 2, the present embodiment provides a preparation system of a preparation method of high specific surface area calcium hydroxide, comprising:

The raw material pretreatment module 71 is used for calcining limestone into high-activity calcium oxide and crushing the high-activity calcium oxide, and comprises a rotary kiln calcining device and a jaw crusher, wherein the rotary kiln calcining device is used for calcining the limestone at 900-1100 ℃ for 2-4 hours to obtain calcium oxide with CaO content of more than or equal to 93%, and the jaw crusher is used for crushing the calcined calcium oxide to 0-20 mm particles;

The primary digestion module 72 is used for carrying out high-temperature mixing reaction on the crushed calcium oxide and water, and comprises a primary digestion kettle and a temperature-controlled stirring device, wherein the primary digestion kettle is used for mixing raw materials according to the mass ratio of water to calcium of 1:3 and reacting for 30 minutes at the stirring speed of 200-400rpm at the temperature of 80-90 ℃;

the secondary digestion module 73 is used for adding a composite dispersing agent into the primary digestion slurry to perform secondary reaction, and comprises a secondary digestion kettle and an automatic dispersing agent adding device, wherein the secondary digestion kettle is used for performing constant-temperature reaction for 1 hour at 60-70 ℃, and the automatic dispersing agent adding device is used for adding the composite dispersing agent consisting of polycarboxylate, fatty alcohol polyoxyethylene ether and sodium silicate according to the total mass of the slurry of 0.5-1.2 percent, wherein the total mass of the slurry is 5:3:2;

A tertiary digestion module 74 for aging the secondary digested slurry, comprising a tertiary aging bin for aging the slurry at normal temperature for 2 hours and a humidity control device for controlling the ambient relative humidity to 60-80%;

a post-treatment module 75 for sieving and packaging the aged calcium hydroxide product, comprising an ultrasonic vibration sieve and a dust-free packaging machine, wherein the ultrasonic vibration sieve separates unreacted particles through a 325 mesh screen at a frequency of 20-40kHz, and the dust-free packaging machine directly packages the acceptable product;

The central control module 76 is used for monitoring and adjusting the operation parameters of each module, and comprises a PLC controller and a sensor system, wherein the PLC controller receives temperature, viscosity and humidity signals from each module, and correspondingly adjusts the stirring speed, the adding amount of the dispersing agent and the sieving frequency.

It should be noted that, regarding the apparatus in the above embodiments, the specific manner in which the respective modules perform the operations has been described in detail in the embodiments regarding the method, and will not be described in detail herein.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (8)

1. The preparation method of the calcium hydroxide with the high specific surface area is characterized by comprising the following steps of:

crushing the high-activity calcium oxide calcined by the rotary kiln into 0-20 mm particles, wherein the purity of the calcium oxide is more than or equal to 93%;

Mixing the crushed calcium oxide with water according to the mass ratio of water to calcium of 1:3, and mechanically stirring for 30 minutes at 80-90 ℃ to form primary digestion slurry;

Adding a composite dispersing agent into the primary digestion slurry, wherein the composite dispersing agent consists of polycarboxylate, fatty alcohol-polyoxyethylene ether and sodium silicate according to the mass ratio of 5:3:2, the adding amount is 0.5-1.2% of the total mass of the slurry, and the secondary digestion slurry is formed by constant-temperature reaction for 1 hour at 60-70 ℃;

Aging the secondary digestion slurry for 2 hours at normal temperature to promote the formation of a microporous structure and obtain a calcium hydroxide product;

And (3) separating unreacted particles from the calcium hydroxide product through a 325-mesh screening device, and directly packaging the product.

2. The method according to claim 1, wherein the calcination temperature of the calcium oxide raw material is 900-1100 ℃ and the calcination time is 2-4 hours.

3. The method of claim 1, wherein the mechanical stirring speed in the step (2) is 200-400 rpm, and the stirring paddle has a double-layer oblique blade structure.

4. The process according to claim 1, wherein the polycarboxylate is an acrylic acid-maleic anhydride copolymer having a molecular weight of 3000 to 5000 g/mol.

5. The method of claim 1, wherein the viscosity of the slurry is monitored in real time in the step (3), and the dispersant is automatically added to the upper limit of 1.2% when the viscosity exceeds 200 cP.

6. The method of claim 1, wherein the aging in the step (4) is carried out in a closed vessel with a relative humidity of 60-80%.

7. The method according to claim 1, wherein the sieving device in the step (5) is equipped with an ultrasonic vibration module, and the vibration frequency is 20-40 kHz.

8. A manufacturing system for carrying out the method of any one of claims 1-7, comprising:

the raw material pretreatment module is used for calcining limestone into high-activity calcium oxide and crushing the high-activity calcium oxide, and comprises a rotary kiln calcining device and a jaw crusher, wherein the rotary kiln calcining device is used for calcining the limestone at 900-1100 ℃ for 2-4 hours to obtain calcium oxide with CaO content of more than or equal to 93%, and the jaw crusher is used for crushing the calcined calcium oxide to 0-20 mm particles;

The primary digestion module is used for carrying out high-temperature mixing reaction on the crushed calcium oxide and water, and comprises a primary digestion kettle and a temperature-control stirring device, wherein the primary digestion kettle is used for mixing raw materials according to the mass ratio of water to calcium of 1:3 and reacting for 30 minutes at the stirring speed of 200-400 rpm at the temperature of 80-90 ℃;

The secondary digestion module is used for adding a composite dispersing agent into the primary digestion slurry to perform secondary reaction, and comprises a secondary digestion kettle and an automatic dispersing agent adding device, wherein the secondary digestion kettle is used for performing constant-temperature reaction for 1 hour at 60-70 ℃, and the automatic dispersing agent adding device is used for adding the composite dispersing agent consisting of polycarboxylate, fatty alcohol polyoxyethylene ether and sodium silicate according to the total mass of the slurry of 0.5-1.2 percent, wherein the total mass of the slurry is 5:3:2;

The three-stage digestion module is used for carrying out aging treatment on the secondary digestion slurry and comprises a three-stage aging bin and a humidity regulating device, wherein the three-stage aging bin ages the slurry for 2 hours at normal temperature, and the humidity regulating device controls the relative humidity of the environment to be 60-80%;

the post-treatment module is used for screening and packaging the aged calcium hydroxide product and comprises an ultrasonic vibration screening machine and a dust-free packaging machine, wherein the ultrasonic vibration screening machine is used for separating unreacted particles through a 325-mesh screen at a frequency of 20-40 kHz, and the dust-free packaging machine is used for directly packaging the qualified product;

And the central control module is used for monitoring and adjusting the operation parameters of each module and comprises a PLC controller and a sensor system, wherein the PLC controller receives temperature, viscosity and humidity signals from each module and correspondingly adjusts the stirring speed, the addition amount of the dispersing agent and the sieving frequency.