阅读说明：本技术 一种低碳循环制备高纯氧化镁的工艺及系统 (Process and system for preparing high-purity magnesium oxide in low-carbon circulation mode ) 是由 谢国威 闫心怡 李山宏 于 2021-08-20 设计创作，主要内容包括：本发明涉及一种低碳循环制备高纯氧化镁的工艺及系统,菱镁矿经过塔式复热竖窑一煅烧后生成轻烧镁和CO-(2),CO-(2)经窑气净化装置处理后进入碳化塔内进行碳化反应；轻烧镁粉碎后进入消化池内进行消化反应；消化后的产物进入碳化塔内；碳化完成的溶液送至板框压滤机,预热后打入热解塔中热解,生成悬浮状的碱式碳酸镁和CO-(2)；碱式碳酸镁经过滤器脱水后送入塔式复热竖窑二内进行煅烧,生成高纯氧化镁和CO-(2),CO-(2)送入窑气净化装置；窑气净化装置回收的余热用于预热重镁水和碳酸镁煅烧。本发明克服了现有技术中存在的问题,CO-(2)和热量的回收利用率高,实现低碳环保的目标,且产品纯度高、品质性能可调控。(The invention relates to a process and a system for preparing high-purity magnesium oxide in a low-carbon cycle manner 2 ，CO 2 After being treated by a kiln gas purification device, the mixture enters a carbonization tower for carbonization reaction; crushing the light burned magnesium, and then entering a digestion tank for digestion reaction; feeding the digested product into a carbonization tower; sending the carbonized solution to a plate-and-frame filter press, preheating, and then feeding the solution into a pyrolysis tower for pyrolysis to generate suspended basic magnesium carbonate and CO 2 (ii) a The basic magnesium carbonate is dehydrated by a filter and then sent into a tower reheating shaft kiln II for calcination to generate high-purity magnesium oxide and CO 2 ，CO 2 Feeding into a kiln gas purification device; the waste heat recovered by the kiln gas purification device is used for preheating the heavy magnesium hydrate and calcining the magnesium carbonate. The invention overcomes the problems of the prior art, CO 2 High heat recovery rate, low carbon and environmental protection, high product purity,The quality performance can be regulated and controlled.)

1. A process for preparing high-purity magnesium oxide in a low-carbon circulation mode is characterized by comprising the following steps:

1) the magnesite is calcined in a tower-type reheating shaft kiln to generate light-burned magnesium and CO₂，CO₂The CO after dust removal, heat exchange and cooling treatment is carried out by a kiln gas purification device₂Entering a carbonization tower through an air compressor to carry out carbonization reaction;

2) crushing the light burned magnesium prepared in the step 1), and then, allowing the crushed light burned magnesium to enter a digestion tank for digestion reaction, wherein the digestion temperature is 50-70 ℃, and the digestion time is 30-60 min;

3) the digested product in the step 2) enters a carbonization tower to react with CO₂Carrying out carbonization reaction together at a temperature of 30 to40℃；

4) Putting the carbonized solution into a carbonized liquid storage tank, conveying the carbonized solution to a plate-and-frame filter press for solid-liquid separation, and putting the separated heavy magnesium water into a heavy magnesium water storage tank; adopts a kiln gas purification device and CO₂Preheating heavy magnesium water by waste heat after heat exchange, and injecting the preheated heavy magnesium water into a pyrolysis tower for pyrolysis to generate suspended basic magnesium carbonate and CO₂；

5) Putting basic magnesium carbonate into a magnesium carbonate storage pool, dehydrating the basic magnesium carbonate by a filter, sending the dehydrated product into a tower-type reheating shaft kiln II, and introducing a kiln gas purification device and CO₂Calcining the waste heat after heat exchange to generate high-purity magnesium oxide and CO₂，CO₂Sending the mixture into a kiln gas purification device for dust removal, heat exchange and cooling treatment, and then using the mixture for carbonization reaction; and putting the filtrate filtered by the filtering device into a filtrate storage pool.

2. The process for preparing high-purity magnesium oxide in a low-carbon cycle manner according to claim 1, wherein in the step 1), an oxygen-enriched combustion manner is adopted when magnesite is calcined in a tower-type reheating shaft kiln.

3. The process for preparing high-purity magnesium oxide with low carbon cycle as claimed in claim 1, wherein the kiln gas purification device and CO are connected₂And the waste heat after heat exchange is collected by a waste heat air pipe, and is sent to a heavy magnesium water storage tank for preheating heavy magnesium water, and is sent to a tower reheating shaft kiln II for calcining dehydrated basic magnesium carbonate.

4. The process for preparing high-purity magnesium oxide with low carbon circulation according to claim 1, wherein the digestion solution in the digestion tank is water or waste liquid from a filtrate storage tank.

5. The system for preparing high-purity magnesium oxide by low-carbon circulation for realizing the process as claimed in any one of claims 1 to 4 is characterized by comprising a tower type reheating shaft kiln I, a tower type reheating shaft kiln II, a kiln gas purification device, a carbonization tower and a plate-and-frame filter pressThe system comprises a pyrolysis tower, a filter, a digestion tank, a carbonized liquid storage tank, a heavy magnesium water storage tank, a magnesium carbonate storage tank and a filtrate storage tank; CO at the top of the tower reheating shaft kiln₂Outlet through CO₂CO on the first connecting kiln gas purifier of the pipeline₂Inlet one, CO of kiln gas purification device₂Outlet through CO₂CO of pipeline two-connection carbonization tower₂Inlet, CO₂An air compressor is arranged on the second pipeline; a carbonization liquid outlet of the carbonization tower is connected with a material inlet of the plate-and-frame filter press through a carbonization liquid pipeline, and a carbonization liquid storage pool and a feeding pump I are sequentially arranged on the carbonization liquid pipeline along the flowing direction of the carbonization liquid; a filtrate outlet of the plate-and-frame filter press is connected with a heavy magnesium water inlet of the pyrolysis tower through a heavy magnesium water pipeline, and a heavy magnesium water storage pool and a feeding pump II are sequentially arranged on the heavy magnesium water pipeline along the flow direction of the heavy magnesium water; a magnesium carbonate outlet of the pyrolysis tower is connected with a material inlet of the filter through a magnesium carbonate pipeline, and a magnesium carbonate storage pool and a feeding pump III are sequentially arranged on the magnesium carbonate pipeline along the flowing direction of magnesium carbonate; a dehydrated product outlet of the filter is connected with a material inlet of the tower type reheating shaft kiln II through a pipeline; CO of tower reheating shaft kiln II₂Outlet through CO₂CO on pipeline three-connection kiln gas purification device₂An inlet II; a filtrate outlet of the filter is connected with a digestive juice inlet of the digestion tank through a filtrate pipeline, and a filtrate storage tank and a feeding pump IV are sequentially arranged on the filtrate pipeline along the flow direction of the filtrate; and a digestive juice outlet of the digestion tank is connected with a carbonized juice pipeline at the upstream of the carbonized juice storage tank through a digestive juice pipeline, and a feeding pump V is arranged on the digestive juice pipeline.

6. The system for preparing high-purity magnesium oxide through the low-carbon cycle of claim 5, wherein the digestion tank is additionally provided with a water inlet.

7. The system for preparing high-purity magnesium oxide through low-carbon circulation according to claim 5, wherein the kiln gas purification device is provided with a gas-gas heat exchanger, and a waste heat air outlet of the gas-gas heat exchanger is connected with a preheating air inlet of the heavy magnesium water storage pool and a calcining hot air inlet of the tower-type reheating vertical kiln II through a waste heat air pipe.

Technical Field

The invention relates to the technical field of magnesite carbonization production, in particular to a process and a system for preparing high-purity magnesium oxide in a low-carbon cycle manner.

Background

China strives to realize carbon peak reaching before 2030 and carbon neutralization before 2060, and as carbon dioxide emission is enlarged, the steel industry must take powerful measures as early as possible, and the increasing strength promotes green low-carbon development. The magnesium smelting industry must adopt an advanced production process system which has high production efficiency, low energy consumption, environmental protection, good comprehensive utilization effect of resources, safety and reliability. The calcining system adopts advanced calcining equipment such as an energy-saving environment-friendly rotary kiln, a controllable shaft kiln taking gas as fuel and the like, and the development targets of safety, high efficiency, energy conservation, consumption reduction and green circulation are ensured to be realized.

At present, high-purity magnesium oxide is produced mainly by adopting a magnesite calcining method in China, and the production process flow is shown in figure 2.

The production process comprises the following steps: calcining magnesite in vertical kiln to decompose it into light-burned magnesium and CO₂Cooling the light-burned magnesium, crushing, adding water for digestion, and sending into a carbonization tower for carbonation reaction. And (4) after the carbonization liquid is dehydrated, pyrolyzing the carbonized liquid in a decomposing tower, filtering the decomposed suspension, and roasting at high temperature to generate the high-purity magnesium oxide. The reaction formula of the process is as follows:

and (3) calcining: MgCO₃→MgO+CO₂↑

Digestion: MgO + H₂O→Mg(OH)₂↓

Carbonizing: mg (OH)₂↓+2CO₂→Mg(HCO₃)₂

Pyrolysis: 5Mg (HCO)₃)₃→4MgCO₃·Mg(OH)₂·4H₂O+6CO₂↑

Roasting: 4MgCO₃·Mg(OH)₂·4H₂O→5MgO+4CO₂↑+5H₂O

The production process has high material consumption and energy consumption, and discharges a large amount of CO₂And dust, leading to ecological damage and serious environmental pollution; the three technological processes are respectively produced in three factories in a segmented manner, the upper and lower processes cannot be effectively connected, and the quality and the performance of the product are difficult to control, so that the product quality is unstable and the market adaptability is poor; in addition, the calcination temperature and time of the common reverberatory kiln are not balanced, the activity of the generated MgO is low, and CO is generated₂The concentration is low, and the method cannot be used for producing high-purity magnesium oxide; common reflection kiln miningThe magnesite lump materials with the thickness of more than 100mm are used for calcination, ore resources with the thickness of less than 100mm are wasted, and the utilization rate of the magnesite resources is low.

The magnesium oxide enterprises in China have small production scale, old equipment, single product and poor economic benefit. With the development of industries such as metallurgy, plastics, rubber, paint, papermaking and the like, the demand of high-purity magnesium oxide and the variety of products tend to rise year by year. Although China is a large magnesium salt country, fine magnesium oxide and magnesium carbonate required by the domestic market still need to be imported, and the economic benefit of magnesium oxide and magnesium carbonate enterprises is seriously influenced. How to fully exert the advantage of abundant magnesium resources in China, and introducing a new technology while enlarging the production scale, solves the problems of environmental pollution, overhigh cost and the like of a carbonization method, and the development of high-purity, high-added-value and functionalized products is the target of near-stage industry development.

Disclosure of Invention

The invention provides a process and a system for preparing high-purity magnesium oxide in a low-carbon cycle manner, which can overcome the problems in the prior art and can prepare CO₂And the heat recovery rate is high, the low-carbon and environment-friendly purpose is realized, the product purity is high, and the quality performance can be regulated and controlled.

In order to achieve the purpose, the invention adopts the following technical scheme:

a process for preparing high-purity magnesium oxide in a low-carbon circulation mode comprises the following steps:

1) the magnesite is calcined in a tower-type reheating shaft kiln to generate light-burned magnesium and CO₂，CO₂The CO after dust removal, heat exchange and cooling treatment is carried out by a kiln gas purification device₂Entering a carbonization tower through an air compressor to carry out carbonization reaction;

2) crushing the light burned magnesium prepared in the step 1), and then, allowing the crushed light burned magnesium to enter a digestion tank for digestion reaction, wherein the digestion temperature is 50-70 ℃, and the digestion time is 30-60 min;

3) the digested product in the step 2) enters a carbonization tower to react with CO₂Carrying out carbonization reaction together at the temperature of 30-40 ℃;

4) putting the carbonized solution into a carbonized solution storage tank, sending to a plate-and-frame filter press for solid-liquid separation, and separatingPutting the heavy magnesium water into a heavy magnesium water storage pool; adopts a kiln gas purification device and CO₂Preheating heavy magnesium water by waste heat after heat exchange, and injecting the preheated heavy magnesium water into a pyrolysis tower for pyrolysis to generate suspended basic magnesium carbonate and CO₂；

5) Putting basic magnesium carbonate into a magnesium carbonate storage pool, dehydrating the basic magnesium carbonate by a filter, sending the dehydrated product into a tower-type reheating shaft kiln II, and introducing a kiln gas purification device and CO₂Calcining the waste heat after heat exchange to generate high-purity magnesium oxide and CO₂， CO₂Sending the mixture into a kiln gas purification device for dust removal, heat exchange and cooling treatment, and then using the mixture for carbonization reaction; and putting the filtrate filtered by the filtering device into a filtrate storage pool.

In the step 1), an oxygen-enriched combustion mode is adopted when the tower-type reheating shaft kiln-magnesite is calcined.

The kiln gas purification device and CO₂And the waste heat after heat exchange is collected by a waste heat air pipe, and is sent to a heavy magnesium water storage tank for preheating heavy magnesium water, and is sent to a tower reheating shaft kiln II for calcining dehydrated basic magnesium carbonate.

The digestive juice in the digestion tank is water or waste liquid led from a filtrate storage tank.

A system for preparing high-purity magnesium oxide in a low-carbon circulating manner comprises a tower type reheating shaft kiln I, a tower type reheating shaft kiln II, a kiln gas purification device, a carbonization tower, a plate-and-frame filter press, a pyrolysis tower, a filter, a digestion tank, a carbonization liquid storage tank, a heavy magnesium water storage tank, a magnesium carbonate storage tank and a filtrate storage tank; CO at the top of the tower reheating shaft kiln₂Outlet through CO₂CO on the first connecting kiln gas purifier of the pipeline₂Inlet one, CO of kiln gas purification device₂Outlet through CO₂CO of pipeline two-connection carbonization tower₂Inlet, CO₂An air compressor is arranged on the second pipeline; a carbonization liquid outlet of the carbonization tower is connected with a material inlet of the plate-and-frame filter press through a carbonization liquid pipeline, and a carbonization liquid storage pool and a feeding pump I are sequentially arranged on the carbonization liquid pipeline along the flowing direction of the carbonization liquid; the filtrate outlet of the plate-and-frame filter press is connected with the heavy magnesium water inlet of the pyrolysis tower through a heavy magnesium water pipeline, and the heavy magnesium water pipeline is connected with the filtrate outlet of the plate-and-frame filter pressA heavy magnesium water storage pool and a feeding pump II are sequentially arranged along the flow direction of the heavy magnesium water; a magnesium carbonate outlet of the pyrolysis tower is connected with a material inlet of the filter through a magnesium carbonate pipeline, and a magnesium carbonate storage pool and a feeding pump III are sequentially arranged on the magnesium carbonate pipeline along the flowing direction of magnesium carbonate; a dehydrated product outlet of the filter is connected with a material inlet of the tower type reheating shaft kiln II through a pipeline; CO of tower reheating shaft kiln II₂Outlet through CO₂CO on pipeline three-connection kiln gas purification device₂An inlet II; a filtrate outlet of the filter is connected with a digestive juice inlet of the digestion tank through a filtrate pipeline, and a filtrate storage tank and a feeding pump IV are sequentially arranged on the filtrate pipeline along the flow direction of the filtrate; and a digestive juice outlet of the digestion tank is connected with a carbonized juice pipeline at the upstream of the carbonized juice storage tank through a digestive juice pipeline, and a feeding pump V is arranged on the digestive juice pipeline.

The digestion tank is additionally provided with a water inlet.

The kiln gas purification device is provided with a gas-gas heat exchanger, and a waste heat air outlet of the gas-gas heat exchanger is connected with a preheating air inlet of the heavy magnesium water storage pool and a calcining hot air inlet of the tower type reheating shaft kiln II through a waste heat air pipe.

Compared with the prior art, the invention has the beneficial effects that:

1) the magnesite calcination adopts oxygen-enriched combustion to provide high-concentration CO for the carbonization process₂And light-burned magnesium with high activity, and CO generated₂After impurity removal and heat exchange and cooling are carried out by a kiln gas purification device, the method is directly applied to the carbonization reaction stage of the process, and CO is₂The recovery rate reaches more than 85 percent, and the CO in the whole process is reduced by 53 percent₂Discharge capacity;

2) waste heat flue gas generated by magnesite calcination is subjected to waste heat recovery through a kiln gas purification device, and the recovered waste heat is used for preheating heavy magnesium water and magnesium carbonate calcination, so that the heat in the system is effectively utilized, the energy consumption is reduced, and the low-carbon and environment-friendly purposes are realized;

3) all the procedures in the process flow are carried out in one factory, and the upper and lower procedures are mutually related and are closely connected; the quality and performance of the product can be regulated according to different requirements of customers, and the product has stronger applicability.

Drawings

FIG. 1 is a schematic structural diagram of a system for preparing high-purity magnesium oxide by a low-carbon cycle in the invention.

FIG. 2 is a flow chart of the prior art for producing high-purity magnesium oxide by adopting a magnesite calcining method.

In the figure: 1. the system comprises a tower type reheating shaft kiln I2, a tower type reheating shaft kiln II 3, a kiln gas purification device 4, a carbonization tower 5, a plate and frame filter press 6, a pyrolysis tower 7, a filter 8, a digestion tank 9, a carbonization liquid storage tank 10, a heavy magnesium water storage tank 11, a magnesium carbonate storage tank 12, a filtrate storage tank 13, an air compressor 14, a feeding pump V15, a feeding pump I16, a feeding pump II 17, a feeding pump III 18, a feeding pump IV 19 and a waste heat air duct

Detailed Description

The following further describes embodiments of the present invention with reference to the accompanying drawings:

as shown in figure 1, the process for preparing high-purity magnesium oxide by low-carbon circulation comprises the following steps:

1) the magnesite is calcined by a tower-type reheating shaft kiln I1 to generate light-burned magnesium and CO₂，CO₂The CO after dust removal, heat exchange and cooling treatment is carried out by a kiln gas purification device 3₂Entering a carbonization tower 4 through an air compressor 13 for carbonization reaction;

2) crushing the light burned magnesium prepared in the step 1), and then, feeding the crushed light burned magnesium into a digestion tank 8 for digestion reaction, wherein the digestion temperature is 50-70 ℃, and the digestion time is 30-60 min;

3) the digested product in the step 2) enters a carbonization tower 4 to react with CO₂Carrying out carbonization reaction together at the temperature of 30-40 ℃;

4) putting the carbonized solution into a carbonized liquid storage tank 9, sending the carbonized solution to a plate-and-frame filter press 5 for solid-liquid separation, and putting the separated heavy magnesium water into a heavy magnesium water storage tank 10; adopts a kiln gas purification device 3 and CO₂Preheating heavy magnesium water by waste heat after heat exchange, and feeding the preheated heavy magnesium water into a pyrolysis tower 6 for pyrolysis to generate suspended basic magnesium carbonate and CO₂；

5) Putting basic magnesium carbonate into a magnesium carbonate storage pool 11, and then carrying outThe filter 7 is dehydrated, the dehydrated product is sent into a tower reheating shaft kiln II 2 and is introduced into a kiln gas purification device 3 and CO₂Calcining the waste heat after heat exchange to generate high-purity magnesium oxide and CO₂，CO₂Sending the mixture into a kiln gas purification device 3 for dust removal, heat exchange and cooling treatment and then using the mixture for carbonization reaction; the filtrate filtered by the filtering device is put into a filtrate storage tank 12.

In the step 1), an oxygen-enriched combustion mode is adopted when the tower-type reheating shaft kiln I1 calcines magnesite.

The kiln gas purification device 3 and CO₂And the waste heat after heat exchange is collected by a waste heat air pipe 19 and is sent to a heavy magnesium water storage tank 10 for preheating heavy magnesium water and is sent to a tower reheating shaft kiln II 2 for calcining dehydrated basic magnesium carbonate.

The digestive juice in the digestion tank 8 is water or waste liquid led from a filtrate storage tank 12.

A system for preparing high-purity magnesium oxide in a low-carbon circulating manner comprises a tower type reheating shaft kiln I1, a tower type reheating shaft kiln II 2, a kiln gas purification device 3, a carbonization tower 4, a plate-and-frame filter press 5, a pyrolysis tower 6, a filter 7, a digestion tank 8, a carbonization liquid storage tank 9, a heavy magnesium water storage tank 10, a magnesium carbonate storage tank 11 and a filtrate storage tank 12; CO at the top of the tower reheating shaft kiln I1₂Outlet through CO₂The pipeline is connected with CO on the kiln gas purification device 3₂CO of kiln gas purification device 3 at inlet I₂Outlet through CO₂CO of the second pipeline connected with the carbonization tower 4₂Inlet, CO₂An air compressor 13 is arranged on the second pipeline; a carbonization liquid outlet of the carbonization tower 4 is connected with a material inlet of the plate-and-frame filter press 5 through a carbonization liquid pipeline, and a carbonization liquid storage pool 9 and a feeding pump I15 are sequentially arranged on the carbonization liquid pipeline along the flowing direction of the carbonization liquid; a filtrate outlet of the plate-and-frame filter press 5 is connected with a heavy magnesium water inlet of the pyrolysis tower 6 through a heavy magnesium water pipeline, and a heavy magnesium water storage tank 10 and a feeding pump II 16 are sequentially arranged on the heavy magnesium water pipeline along the flow direction of the heavy magnesium water; a magnesium carbonate outlet of the pyrolysis tower 6 is connected with a material inlet of the filter 7 through a magnesium carbonate pipeline, and a magnesium carbonate storage tank 11 and a feeding pump III 17 are sequentially arranged on the magnesium carbonate pipeline along the flowing direction of magnesium carbonate; dewatering of the filter 7The product outlet is connected with the material inlet of the tower reheating shaft kiln II 2 through a pipeline; CO of tower reheating shaft kiln 2₂Outlet through CO₂CO on pipeline three-connection kiln gas purification device 3₂An inlet II; a filtrate outlet of the filter 7 is connected with a digestive juice inlet of the digestion tank 8 through a filtrate pipeline, and a filtrate storage tank 12 and a feeding pump IV 18 are sequentially arranged on the filtrate pipeline along the flow direction of the filtrate; a digestive juice outlet of the digestion tank 8 is connected with a carbonized juice pipeline at the upstream of the carbonized juice storage tank 9 through a digestive juice pipeline, and a feeding pump V14 is arranged on the digestive juice pipeline.

The digestion tank 8 is additionally provided with a water inlet.

The kiln gas purification device 3 is provided with a gas-gas heat exchanger, and a waste heat wind outlet of the gas-gas heat exchanger is connected with a preheating wind inlet of the heavy magnesium water storage pool 10 and a calcining hot wind inlet of the tower type reheating shaft kiln 2 through a waste heat wind pipe 19.

The following examples are carried out on the premise of the technical scheme of the invention, and detailed embodiments and specific operation processes are given, but the scope of the invention is not limited to the following examples.

[ examples ] A method for producing a compound

In the embodiment, the process for preparing high-purity magnesium oxide by low-carbon circulation comprises the following steps:

feeding magnesite with the MgO content of 40% and the granularity of 10-100 mm and air with the oxygen content of 40% into a tower type reheating shaft kiln for calcination for 2 hours, wherein CO generated by the reaction₂The temperature is between 600 and 700 ℃.

CO₂Performing dust removal, heat exchange and cooling treatment by a kiln gas purification device to obtain treated CO₂The temperature is between 80 and 100 ℃, and the mixture enters a carbonization tower through an air compressor to carry out carbonization reaction; and crushing the light-burned magnesium powder generated by the reaction to 100-120 mu m, and adding the light-burned magnesium powder into a digestion tank according to the proportion of 3% for digestion reaction, wherein the digestion temperature is 50-60 ℃ and the digestion time is 50 min.

Mg (OH) formed after digestion₂Enters the carbonization tower through a feeding pump V and is mixed with CO₂The carbonization reaction is carried out together. Putting the carbonized solution into a carbonization liquid for storageAnd (4) sending the mixture to a plate-and-frame filter press for solid-liquid separation by using a feeding pump I, putting the separated heavy magnesium water into a heavy magnesium water storage tank, and preheating by using waste heat recovered by a kiln gas purification device.

The preheated heavy magnesium water is pumped into a pyrolysis tower through a feed pump II for pyrolysis, and when the temperature reaches 95 ℃, the heavy magnesium water is decomposed into suspended basic magnesium carbonate and CO₂And putting the basic magnesium carbonate into a magnesium carbonate storage pool, and then sending the basic magnesium carbonate into a filter for dehydration through a third feeding pump.

And (3) feeding the dehydrated basic magnesium carbonate into a tower reheating shaft kiln II, and introducing the waste heat recovered by a kiln gas purification device for calcination, wherein the calcination time is 1h, and the calcination temperature is 900-1000 ℃. And the waste liquid filtered by the filter is put into a filtrate storage tank to wait for recycling.

Calcining to generate high-purity magnesium oxide product and CO₂，CO₂And (4) feeding the mixture into a kiln gas purification device, and performing dust removal, heat exchange and cooling treatment for carbonization reaction.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.