Coal-based solid waste co2 deep mineralization processing device and method

Abstract

The application belongs to the technical field of hazardous waste treatment, and specifically discloses a coal-based solid waste CO2 deep mineralization processing device and method, the processing device comprising a reaction tower, a hydrolysis device and a reaction tank; the reaction tower is used for generating mineralized slag with main phases of CaCO3, MgCO3 and Al2(CO3)3 by mixing a Ca, Mg and Al-rich stock solution with CO2; the hydrolysis device is used for generating flocculent Al(OH)3 and CO2 by reacting Al2(CO3)3 with water; the reaction tank is used for generating Al2O3 and water vapor by generating Al(OH)3, and Al2O3 is reacted with carbon to generate Al and CO2; the processing method comprises the steps of stock solution preparation, CO2 mineralization of the stock solution, Al2(CO3)3 hydrolysis, Al(OH)3 concentration and decomposition, and Al2O3 reduction. The processing device realizes the resource utilization of aluminum in coal-based solid waste, CO2 is reasonably recycled in the reaction system, and the processing process is green and environmentally friendly.

Description

Technical Field

[0001] This invention relates to the field of hazardous waste treatment technology, and in particular to a device and method for deep mineralization processing of CO2 from coal-based solid waste. Background Technology

[0002] Coal is my country's primary energy source and an important chemical raw material. Coal gangue from coal mining, fly ash from coal-fired power generation, bottom ash, desulfurization gypsum, and gasification slag from coal chemical processes constitute common coal-based solid waste. To avoid resource waste, coal-based solid waste is typically treated through incineration or chemical reactions to extract valuable metals such as aluminum and magnesium, improving resource utilization. The remaining waste residue can also be used as building material for road paving.

[0003] Existing methods for preparing filling materials by CO2 mineralization of coal-based solid waste are disclosed in Chinese patent CN202210280209.2, which describes "a method for preparing mine cemented filling materials by mineralizing CO2 from industrial / mining solid waste." This method includes the following steps: grinding industrial / mining solid waste and uniformly mixing it with ammonium nitrate; placing the mixed raw materials in a reactor for molten salt activation, collecting the ammonia gas generated during activation, and converting Ca, Mg, and Al in the activated raw materials into corresponding metal nitrates; leaching the activated mixture of metal nitrates with water, and filtering to obtain a water-leached residue mainly composed of SiO2 and a residue rich in Ca. 2+ Mg 2+ Al 3+ The invention involves the following steps: Ammonia gas, the obtained aqueous solution, and pre-prepared CO2 are introduced into a reaction vessel to undergo a carbonation reaction. The mixture is then filtered to obtain a filtrate containing ammonium nitrate and mineralized slag whose main phases are CaCO3, MgCO3, and Al2(CO3)3. The mineralized slag is then mixed with cement and gypsum to form a cementitious material. This cementitious material is then mixed with water and tailings to form a cemented backfill material. While this invention achieves the rational utilization of coal-based solid waste, the valuable aluminum is not extracted during use. Instead, the slag produced from the reaction of coal-based solid waste is directly crushed and mixed for road paving, resulting in insufficient utilization of valuable resources. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to provide a device and method for deep mineralization processing of CO2 in coal-based solid waste, so as to realize the enrichment and recovery of Al in coal-based solid waste and improve the economic value of coal-based solid waste.

[0005] Technical solution: The present invention provides a deep mineralization processing device for CO2 from coal-based solid waste, the processing device comprising:

[0006] The reaction tower supplies raw liquid rich in Ca, Mg, and Al to react with CO2 to produce mineralized slag with CaCO3, MgCO3, and Al2(CO3)3 as the main phases.

[0007] A hydrolysis device, wherein Al2(CO3)3 reacts with water to generate flocculent Al(OH)3 and CO2;

[0008] The reaction vessel supplies Al(OH)3 to generate Al2O3 and water vapor, and Al2O3 reacts with carbon to generate Al and CO2;

[0009] The first conveying pipe is inclined downward and connects the bottom of the reaction tower to the bottom of the hydrolysis device, so that the mineralized slag discharged from the reaction tower enters the hydrolysis device through the first conveying pipe.

[0010] The second delivery pipe is inclined downward and connects the bottom of the hydrolysis device to the reaction tank, allowing Al(OH)3-rich solution to enter the reaction tank.

[0011] Preferably, the hydrolysis device includes a box and a partition shell disposed inside the box;

[0012] The partition shell divides the box into a lower chamber and an upper chamber; the partition shell is provided with a first side plate corresponding to the outlet of the first conveying pipe, the first side plate is inclined upward, the lower end of the first side plate is higher than the outlet end of the first conveying pipe, and the first side plate is a mesh plate;

[0013] The partition shell has a partition plate longitudinally arranged at the high end of the first side plate. The partition plate divides the upper chamber of the hydrolysis device into a first chamber and a second chamber distributed to the left and right. The lower chamber is connected to the first chamber through the first side plate. The first chamber is connected to the second chamber through the overflow channel at the top of the partition plate.

[0014] The hydrolysis device contains water, the water level of which is higher than the first side plate, but does not completely fill the inner cavity of the hydrolysis device.

[0015] Preferably, the partition housing is provided with a second side plate on the rear side of the partition plate. The second side plate is inclined downward and the lower end of the second side plate is lower than the inlet end of the second conveying pipe.

[0016] Preferably, the top surface of the second side plate slopes inward from both sides to form two collection slopes; the inlet end of the second conveying pipe is located between the two sets of collection slopes.

[0017] Preferably, the hydrolysis device is equipped with a water inlet pipe and a slag discharge pipe; the water inlet pipe is located at the top of the tank and at the corresponding position above the second side plate; the lower end of the slag discharge pipe is connected to a waste slag tank, and the slag discharge pipe is connected to a control valve.

[0018] Preferably, the processing device further includes an air intake device, which includes a conveying pipeline connected to the outlet of the hydrolysis device and the reaction tank respectively, and an air pump connected to the conveying pipeline. A control valve is provided at the connection between the conveying pipeline and the hydrolysis device and the reaction tank. The outlet of the conveying pipeline is connected to the inlet of the reaction tower.

[0019] Preferably, a drive motor is fixedly installed on the top of the reaction vessel, and a stirring shaft extending into the reaction vessel is fixedly connected to the output end of the drive motor. A stirring blade is provided at the lower end of the stirring shaft.

[0020] Preferably, the reaction vessel is provided with a heating tube, which is spirally attached to the inner wall of the reaction vessel and is located away from the stirring blades.

[0021] This invention also discloses a method for deep mineralization processing of CO2 from coal-based solid waste, the processing method comprising the following steps:

[0022] Step S1: Introduce the raw liquid rich in Ca, Mg and Al into the reaction tower, and inject carbon dioxide and ammonia into the reaction tower at a volume of 1.5 to 2.5 times that of the raw liquid. The mineralization reaction is carried out at a reaction temperature of 20 to 90°C and a reaction pressure of 0.15 to 2.0 kPa for 60 to 120 minutes to generate mineralized slag with CaCO3, MgCO3 and Al2(CO3)3 as the main phases.

[0023] Step S2: The reaction liquid in the reaction tower is discharged, and the mineralized slag is transported to the lower chamber of the hydrolysis device through the first conveying pipe. Al2(CO3)3 in the mineralized slag reacts violently with water to generate flocculent Al(OH)3 and CO2. The flocculent Al(OH)3 enters the first chamber through the first side plate along with the reaction liquid. In the first chamber, the flocculent Al(OH)3 floats on the surface of the liquid along with a large number of CO2 bubbles and enters the second chamber through the overflow channel. In the second chamber, as the CO2 bubbles burst, the flocculent Al(OH)3 precipitates onto the second side plate and is collected by the slopes on both sides and discharged into the reaction tank through the second conveying pipe. The reaction waste in the hydrolysis device is blocked by the first and second side plates and is located in the lower chamber. After the reaction is completed, it is discharged into the waste tank for storage through the slag discharge pipe.

[0024] Step S3: During the reaction process in step S2, the gas intake device is started simultaneously to collect the CO2 escaping from the hydrolysis device and introduce it into the reaction tower to promote the mineralization reaction process;

[0025] Step S4: Start the reaction vessel and heat the Al(OH)3 liquid to 85~95℃ through the heating tube for evaporation and concentration. Start the stirring device to stir the Al(OH)3 liquid and evacuate the reaction vessel through the vacuum device. Under vacuum conditions, Al(OH)3 decomposes by heating to generate Al2O3 and water vapor. The water vapor is discharged from the reaction vessel.

[0026] Step S5: After Al(OH)3 is decomposed by heat in step S4, carbon powder with a ratio of 1.1 to 1.3 times the mass of alumina is added as a catalyst, the reaction vessel is started and the reaction raw materials are heated. The reaction is carried out at a reaction temperature of 140 to 150 °C for 60 to 120 min, so that Al2O3 decomposes to generate CO2 and Al.

[0027] Step S6: During the reaction process in step S5, the gas intake device is started simultaneously to introduce CO2 into the reaction tower to promote the mineralization reaction; after the reaction in the reaction tank is completed, the generated Al is discharged.

[0028] Preferably, the preparation steps of the stock solution in step S1 are as follows:

[0029] Step S 11 Coal-based solid waste is added to a crusher and grinder for crushing and grinding to obtain granular powder with a particle size of 60~200μm;

[0030] Step S 12 The granular powder and ammonium nitrate are added to the reactor at a mass ratio of 1:2 to carry out a molten salt activation reaction. The reaction is carried out at an activation temperature of 20~90℃ for 2~4 h. The Ca, Mg and Al in the granular powder are converted into the corresponding nitrate mixture, and the generated ammonia gas is collected and injected into the reaction tower as raw material.

[0031] Step S 13 Deionized water was added to the nitrate mixture at a liquid-to-solid ratio of 2:1 to 4:1 for soaking to obtain an aqueous extract rich in Ca, Mg, and Al, which is the stock solution.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. In the hydrolysis device of the present invention, the concentrated slurry of mineralized slag enters the lower chamber of the hydrolysis device through a first conveying pipe. Al2(CO3)3 in the mineralized slag reacts violently with water, with the reaction equation being Al2(CO3)3 + 3H2O = 2Al(OH)3 + 3CO2. The remaining components of the mineralized slag do not react with water, thus separating aluminum from other mineralized slag components and achieving aluminum recovery, facilitating subsequent aluminum processing. The slag phase of the mineralized slag is blocked by the first side plate and cannot enter the first chamber, remaining in the lower chamber. The generated flocculent Al(OH)3 and CO2, as well as the reaction liquid, can freely enter the first chamber through the first side plate. When the flocculent Al(OH)3 generated in the first chamber rises with the bubble-like CO2 and enters the second chamber through the overflow channel, the CO2 gradually breaks up on the liquid surface and dissolves into the air. The flocculent Al(OH)3 will be deposited on the second side plate and collected by the collection slopes on both sides of the second side plate, and finally enter the reaction tank through the second conveying pipe. This setting facilitates the separation of mineralized slag waste from the generated flocculent Al(OH)3, thereby purifying the Al(OH)3 solution and facilitating subsequent evaporation, concentration and pyrolysis in the reaction tank.

[0034] 2. The Al(OH)3 solution is heated and concentrated in a reaction vessel until the remaining contents are Al(OH)3 slurry. Heating continues until the Al(OH)3 slurry decomposes to produce water and Al2O3, until the Al(OH)3 slurry is completely converted to Al2O3. Then, catalyst carbon powder is added to the reaction vessel, and the heating element is restarted. The carbon powder reacts with the alumina to produce Al and CO2 from the carbon dioxide and aluminum. Once the aluminum extraction is complete, the discharge pipe is opened to discharge the aluminum and carbon powder. The aluminum can then be melted, purified, and cast into molds for use as building materials.

[0035] 3. The suction device can return the carbon dioxide generated in the hydrolysis device and reaction tank to the reaction tower for CO2 mineralization process; in addition, CO2 can also be returned to the lower chamber of the hydrolysis device through the backflush pipeline to backflush and stir the mineralized slag, so that Al2(CO3)3 and water can be fully mixed and reacted, and carbon dioxide can be rationally utilized, making the reaction process green and environmentally friendly. Attached Figure Description

[0036] Figure 1 This is a three-dimensional structural diagram of the mineralization processing apparatus of the present invention;

[0037] Figure 2 for Figure 1 Schematic diagram of the internal structure of the hydrolysis unit in the medium mineralization processing plant;

[0038] Figure 3 for Figure 2 Schematic diagram of the internal structure of the hydrolysis unit;

[0039] Figure 4 for Figure 3 A three-dimensional schematic diagram of the internal structure of the hydrolysis unit;

[0040] Figure 5 for Figure 3 Cross-sectional view of the medium-sized waste residue tank;

[0041] Figure 6 for Figure 1 Cross-sectional view of the intermediate reaction tower structure;

[0042] Figure 7 for Figure 1 Cross-sectional view of the intermediate reaction vessel structure;

[0043] Figure 8 This is a schematic diagram of the processing method of the present invention.

[0044] Figure label:

[0045] 1. Reaction tower; 11. Feed pipe; 12. Discharge pipe;

[0046] 2. Hydrolysis device; 21. Separating shell; 211. First side plate; 212. Separating plate; 213. Lower chamber; 214. First chamber; 215. Second chamber; 216. Liquid inlet; 217. Liquid outlet; 218. Overflow channel; 219. Second side plate; 220. Collection slope; 22. Slag discharge pipe; 23. Waste residue tank; 24. Water supply pipe;

[0047] 3. Reaction vessel; 31. Drive motor; 32. Stirring shaft; 33. Heating tube; 34. Stirring blades;

[0048] 4. Suction device; 41. Air pump; 42. Delivery pipeline; 43. Control valve; 44. Backflush pipeline;

[0049] 5. First conveying pipe; 6. Second conveying pipe. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will be described in conjunction with the accompanying drawings of the embodiments of the present invention. Figure 1-8 The technical solutions of the embodiments of the present invention will be clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0051] Example 1:

[0052] like Figure 1-8As shown, this invention discloses a deep CO2 mineralization processing device for coal-based solid waste. The processing device includes a reaction tower 1, a hydrolysis device 2, and a reaction tank 3. A feed pipe 11 is installed at the top of the reaction tower 1 to allow for the addition of raw liquid. A discharge pipe 12 is installed at the bottom of the reaction tower 1, and a filter screen is installed in conjunction with the discharge pipe 12. After the reaction in the reaction tower 1 is completed, liquid-solid separation can be achieved through the filter screen. Control valves are installed on both the feed pipe 11 and the discharge pipe 12 to control the feeding or discharging. A first conveying pipe 5 is installed between the reaction tower 1 and the hydrolysis device 2. The first conveying pipe 5 is inclined downwards and connects the bottom of the reaction tower 1 and the bottom of the hydrolysis device 2, allowing the mineralized slag discharged from the reaction tower 1 to enter the hydrolysis device 2 via the first conveying pipe 5. A second conveying pipe 6 is installed between the hydrolysis device 2 and the reaction tank 3. The second conveying pipe 6 is inclined downwards and connects the bottom of the hydrolysis device 2 and the reaction tank 3, allowing an Al(OH)3-rich solution to enter the reaction tank 3 for reaction.

[0053] like Figure 2-4 As shown, the hydrolysis device 2 includes a housing and a partition shell 21 disposed within the housing. The partition shell 21 divides the housing into a lower chamber 213 and an upper chamber. A first side plate 211 is disposed on the partition shell 21 corresponding to the outlet of the first conveying pipe 5. The first side plate 211 is inclined upward, with its lower end higher than the outlet end of the first conveying pipe 5. A liquid inlet 216 is disposed on the partition shell 21 corresponding to the first conveying pipe 5. The first side plate 211 is configured as a mesh plate. The lower chamber 213 is connected to the first chamber 214 through the first side plate 211. The hydrolysis device 2 is filled with water, the water level of which is higher than the first side plate 211, but does not completely fill the inner cavity of the hydrolysis device 2. A partition plate 212 is longitudinally arranged at the high end of the first side plate 211 of the partition housing 21. The partition plate 212 divides the upper chamber of the hydrolysis device 2 into a first chamber 214 and a second chamber 215 distributed to the left and right. An overflow channel 218 is formed between the partition plate 212 and the top plate of the housing. The first chamber 214 is connected to the second chamber 215 through the overflow channel 218 at the top of the partition plate 212. A second side plate 219 is arranged behind the partition plate 212 of the partition housing 21. The second side plate 219 is inclined downward, and the lower end of the second side plate 219 is lower than the inlet end of the second conveying pipe 6. The partition housing 21 and the inlet end of the second conveying pipe 6 are respectively provided with liquid outlets 217. The second conveying pipe 6 is connected to the hydrolysis device through the liquid outlets 217. The top surface of the second side plate 219 is inclined inward from both sides to form two collection slopes 220. The inlet end of the second conveying pipe 6 is located between the two sets of collection slopes.

[0054] like Figure 1-2As shown, the processing device also includes a suction device 4, which includes a conveying pipeline 42 connected to the outlet of the hydrolysis device 2 and the reaction tank 3 respectively, and an air pump 41 connected to the conveying pipeline 42. A control valve 43 is provided at the connection between the conveying pipeline 42 and the hydrolysis device 2 and the reaction tank 3; the outlet of the conveying pipeline 42 is connected to the inlet of the reaction tower 1. A heating tube 33 is provided inside the reaction tank 3, and the heating tube 33 is spirally attached to the inner wall of the reaction tank.

[0055] The processing apparatus of this invention requires the use of a crushing and grinding mill and a reactor, which are existing technologies. First, the coal-based solid waste needs to be crushed and ground by the crushing and grinding mill. After being crushed and ground, it is added to the reactor and activated with ammonium nitrate to generate a mixture of Ca, Mg and Al metal nitrates. Then, the metal nitrate mixture is subjected to water leaching treatment to obtain a water leaching solution rich in Ca, Mg and Al, which is the original solution.

[0056] The raw solution is added into the reaction tower 1 through the feed pipe 11, and CO2 and NH3 are added to the reaction tower 1 to carry out a mineralization reaction. The Ca, Mg and Al ions in the raw solution react to form particulate precipitates. The main phases of the particulate precipitates are calcium carbonate, magnesium carbonate and aluminum carbonate particles, which settle to the bottom of the reaction tower 1 to form mineralization slag. After the mineralization is completed, the feed pipe 12 is opened and the reaction liquid is filtered and concentrated through the filter screen to remove the particles generated by the mineralization reaction. The filtrate is discharged through the feed pipe 12 and can be recycled to purify it into a high-purity ammonium nitrate liquid, which is then reintroduced into the reactor to prepare the raw solution.

[0057] The concentrated slurry of mineralized slag enters the lower chamber 213 of the hydrolysis device 2 through the first conveying pipe 5. During the reaction, Al2(CO3)3 in the mineralized slag reacts violently with water, and the reaction equation is Al2(CO3)3 + 3H2O = 2Al(OH)3 + 3CO2. The remaining components of the mineralized slag do not react with water. Calcium carbonate does not react with water, and magnesium carbonate is slightly soluble in water. The slag phase of the mineralized slag is blocked by the first side plate 211 and cannot enter the first chamber 214. The generated flocculent Al(OH)3 and CO2, as well as the reaction liquid, can freely enter the first chamber 214 through the first side plate 211 and are blocked in the lower chamber 213. When the flocculent Al(OH)3 generated in the first chamber 214 rises with the bubble-like CO2 and enters the second chamber 215 through the overflow channel 218, the CO2 will gradually break up and dissolve in the air on the liquid surface. The flocculent Al(OH)3 will be deposited on the second side plate 219 and collected by the collection slopes on both sides of the second side plate, and finally enter the reaction tank 3 through the second delivery pipe 6.

[0058] When the second delivery pipe 6 is opened, the solution containing flocculent Al(OH)3 in the hydrolysis device 2 is placed into the reaction tank 3, and then the second delivery pipe 6 is closed. The heating pipe 33 is started to heat the Al(OH)3 solution. Water evaporates and forms water vapor, which is discharged through the vent pipe until the remaining substance in the reaction tank is Al(OH)3 slurry. Heating of the Al(OH)3 slurry continues, and the Al(OH)3 slurry decomposes to produce water and Al2O3 until the Al(OH)3 slurry is completely converted into Al2O3. Then, catalyst carbon powder is added to the reaction tank 3, and the heating pipe 33 is started again. Heating causes the carbon powder to react with alumina to produce carbon dioxide and aluminum. The reaction equation is 2Al2O3 + 3C → 4Al + 3CO2. Once the aluminum extraction in the reaction tank 3 is complete, the discharge pipe is opened to discharge the aluminum and carbon powder. The aluminum can then be melted, purified, and cast into molds for use as building materials.

[0059] During the reaction process of hydrolysis device 2 and reaction tank 3, the corresponding control valve of the gas suction device 4 can be activated to output the CO2 generated in hydrolysis device 2 or reaction tank 3 to reaction tower 1 to carry out mineralization reaction of the original liquid, thereby improving the utilization efficiency of CO2.

[0060] Example 2:

[0061] Based on Example 1, such as Figure 4-5 As shown, the hydrolysis device 2 is equipped with a water inlet pipe 24 and a slag discharge pipe 22; the water inlet pipe 24 is located at the top of the tank, corresponding to the position above the second side plate 219. The lower end of the slag discharge pipe 22 is connected to a waste residue tank 23, and the slag discharge pipe 22 is also connected to a control valve.

[0062] In this embodiment, the hydrolysis device discharges the mineralized slag particles accumulated in the tank into the waste slag tank 23 through the slag discharge pipe 22, avoiding the large accumulation of particulate material in the hydrolysis device 2 from affecting the subsequent hydrolysis reaction of aluminum carbonate; as the liquid level drops during the slag discharge process, the generated flocculent Al(OH)3 falls onto the second side plate 219, the water supply pipe 24 is opened to flush water onto the collection slope of the second side plate, and the second conveying pipe 6 is opened so that the Al(OH)3 remaining on the second side plate can be carried into the reaction tank 3 by the impact of the water flow. Then the second conveying pipe 6 is closed to raise the water level in the hydrolysis device 2 for subsequent use.

[0063] Example 3:

[0064] Based on Example 1, such as Figure 1 and Figure 7 As shown, a drive motor 31 is fixedly installed on the top of the reaction vessel 3. The output end of the drive motor 31 is fixedly connected to a stirring shaft 32 that extends into the reaction vessel. A stirring blade 34 is installed at the lower end of the stirring shaft 32, and the heating tube 33 is far away from the stirring blade 34. There is no interference between the heating tube 33 and the stirring blade 34.

[0065] In this embodiment, the drive motor 31 drives the stirring shaft 32 to rotate, which in turn drives the stirring blade 34 to rotate. During the concentration and decomposition of Al(OH)3 crystal slurry, the evaporation and pyrolysis processes can be accelerated. During the reaction of carbon powder and alumina, the generation efficiency can be promoted by stirring.

[0066] Example 4:

[0067] Based on Example 1, such as Figure 2 As shown, a backflush pipeline 44 is also provided at the rear end of the air pump 41 in the delivery pipeline 42. The air outlet end of the backflush pipeline 44 is fixedly connected to the bottom of the hydrolysis device 2, and a control valve 43 is provided at the outlet end of the backflush pipeline 44.

[0068] In this embodiment, the CO2 generated by the hydrolysis device 2 and the reaction tank 3 can be blown into the lower chamber 213 of the hydrolysis device 2 through the air pump 41 and the backflush pipe 44. This backflushes and agitates the mineralized slag particles accumulated in the lower chamber 213, allowing the aluminum carbonate, which has not been in contact with water, to fully contact with water, generating carbon dioxide and aluminum hydroxide. The carbon dioxide and aluminum hydroxide are then carried upwards by the airflow to the first side plate 211, facilitating the collection of aluminum hydroxide. Furthermore, no water is initially added to the hydrolysis device 2; water is added after the mineralized slag particles are added to initiate the reaction.

[0069] Example 5:

[0070] This invention also discloses a method for deep mineralization processing of CO2 from coal-based solid waste, the processing method comprising the following steps:

[0071] (1) A raw solution rich in Ca, Mg, and Al was introduced into reaction tower 1. Carbon dioxide and ammonia were injected into reaction tower 1 at a volume of 1.5 times that of the raw solution. The mineralization reaction was carried out for 120 min at a reaction temperature of 20 ℃ and a reaction pressure of 0.15 kPa to generate mineralized slag with CaCO3, MgCO3, and Al2(CO3)3 as the main phases. The specific preparation steps of the raw solution are as follows:

[0072] ① Coal-based solid waste is added to a crusher and grinder for crushing and grinding to obtain granular powder with a particle size of 150μm;

[0073] ② The granular powder and ammonium nitrate were added to the reactor at a mass ratio of 1:2 to carry out a molten salt activation reaction. The reaction was carried out at an activation temperature of 20 °C for 4 h. The Ca, Mg and Al in the granular powder were converted into the corresponding nitrate mixture, and the generated ammonia gas was collected and injected into the reaction tower 1 as raw material.

[0074] ③ Add deionized water to the nitrate mixture at a liquid-to-solid ratio of 2:1 to soak it, and obtain an aqueous extract rich in Ca, Mg and Al, which is the stock solution.

[0075] (2) The reaction liquid in the reaction tower 1 is discharged, and the mineralized slag is transported to the lower chamber 213 in the hydrolysis device 2 through the first conveying pipe 5. Al2(CO3)3 in the mineralized slag reacts violently with water to generate flocculent Al(OH)3 and CO2. The flocculent Al(OH)3 enters the first chamber 214 through the first side plate 211 along with the reaction liquid. In the first chamber 214, the flocculent Al(OH)3 floats on the liquid surface with a large number of CO2 bubbles and enters the second chamber 215 through the overflow channel 218. In the second chamber 215, the flocculent Al(OH)3 precipitates onto the second side plate 219 as the CO2 bubbles break and is collected by the two side collection slopes 220 and discharged into the reaction tank 3 through the second conveying pipe 6. The reaction waste in the hydrolysis device 2 is blocked by the first side plate 211 and the second side plate 219 and is located in the lower chamber 213. After the reaction is completed, it is discharged into the waste tank 23 for storage through the slag discharge pipe 22.

[0076] (3) The gas suction device 4 is started simultaneously in the reaction process of the hydrolysis device 2 to collect the CO2 escaping from the hydrolysis device 2 and introduce it into the reaction tower 1 to promote the mineralization reaction process, or return it to the lower chamber through the backflush pipe 44 to backflush the mineralized slag to form turbulence or vortex, so that Al2(CO3)3 in the mineralized slag reacts fully with water.

[0077] (4) After the reaction in the hydrolysis device 2 is completed, the Al(OH)3 liquid is transported to the reaction tank 3 through the second conveying pipe 6. The reaction tank 3 is started, and the Al(OH)3 liquid is heated to 85 °C through the heating pipe 33 for evaporation and concentration. The stirring device is started to stir the Al(OH)3 liquid to accelerate the evaporation process. The reaction tank is evacuated by the vacuum device. Under vacuum conditions, the Al(OH)3 is concentrated into crystal slurry at a faster rate. After the concentration is completed, Al(OH)3 continues to be heated and decomposed to generate Al2O3 and water vapor. The water vapor is discharged from the reaction tank 3.

[0078] (5) After Al(OH)3 is decomposed by heat, it is converted into Al2O3. Carbon powder with a ratio of 1.1 times the mass of alumina is added as a catalyst. The reaction vessel 3 is started to heat the reaction raw materials. The reaction is carried out at a reaction temperature of 140 °C for 120 min, so that Al2O3 decomposes to generate CO2 and Al. It should be noted that the reaction vessel is in a vacuum state throughout the reaction process to reduce the decomposition temperature of Al2O3.

[0079] (6) During the Al2O3 decomposition process in reaction tank 3, the gas intake device 4 is started simultaneously to introduce CO2 into reaction tower 1 to promote the mineralization reaction; after the reaction is completed, the generated Al is discharged.

[0080] Example 6:

[0081] This invention also discloses a method for deep mineralization processing of CO2 from coal-based solid waste, the processing method comprising the following steps:

[0082] (1) A raw solution rich in Ca, Mg, and Al is introduced into reaction tower 1. Carbon dioxide and ammonia are injected into reaction tower 1 at a volume of 2.0 times that of the raw solution. The mineralization reaction is carried out for 90 min at a reaction temperature of 20-90 ℃ and a reaction pressure of 1.0 kPa to generate mineralized slag with CaCO3, MgCO3, and Al2(CO3)3 as the main phases. The specific preparation steps of the raw solution are as follows:

[0083] ① Coal-based solid waste is added to a crusher and grinder for crushing and grinding to obtain granular powder with a particle size of 150μm;

[0084] ② The granular powder and ammonium nitrate were added to the reactor at a mass ratio of 1:2 to carry out a molten salt activation reaction. The reaction was carried out at an activation temperature of 55 °C for 3 h. The Ca, Mg and Al in the granular powder were converted into the corresponding nitrate mixture, and the generated ammonia gas was collected and injected into the reaction tower 1 as raw material.

[0085] ③ Add deionized water to the nitrate mixture at a liquid-to-solid ratio of 3:1 to soak it, and obtain an aqueous extract rich in Ca, Mg and Al, which is the stock solution.

[0086] (2) The reaction liquid in the reaction tower 1 is discharged, and the mineralized slag is transported to the lower chamber 213 in the hydrolysis device 2 through the first conveying pipe 5. Al2(CO3)3 in the mineralized slag reacts violently with water to generate flocculent Al(OH)3 and CO2. The flocculent Al(OH)3 enters the first chamber 214 through the first side plate 211 along with the reaction liquid. In the first chamber 214, the flocculent Al(OH)3 floats on the liquid surface with a large number of CO2 bubbles and enters the second chamber 215 through the overflow channel 218. In the second chamber 215, the flocculent Al(OH)3 precipitates onto the second side plate 219 as the CO2 bubbles break and is collected by the two side collection slopes 220 and discharged into the reaction tank 3 through the second conveying pipe 6. The reaction waste in the hydrolysis device 2 is blocked by the first side plate 211 and the second side plate 219 and is located in the lower chamber 213. After the reaction is completed, it is discharged into the waste tank 23 for storage through the slag discharge pipe 22.

[0087] (3) The gas suction device 4 is started simultaneously in the reaction process of the hydrolysis device 2 to collect the CO2 escaping from the hydrolysis device 2 and introduce it into the reaction tower 1 to promote the mineralization reaction process, or return it to the lower chamber through the backflush pipe 44 to backflush the mineralized slag to form turbulence or vortex, so that Al2(CO3)3 in the mineralized slag reacts fully with water.

[0088] (4) After the reaction in the hydrolysis device 2 is completed, the Al(OH)3 liquid is transported to the reaction tank 3 through the second conveying pipe 6. The reaction tank 3 is started, and the Al(OH)3 liquid is heated to 90 °C through the heating pipe 33 for evaporation and concentration. The stirring device is started to stir the Al(OH)3 liquid to accelerate the evaporation process. The reaction tank is evacuated by the vacuum device. Under vacuum conditions, the Al(OH)3 is concentrated into crystal slurry at a faster rate. After the concentration is completed, Al(OH)3 continues to be heated and decomposed to generate Al2O3 and water vapor. The water vapor is discharged from the reaction tank 3.

[0089] (5) After Al(OH)3 is decomposed by heat, it is converted into Al2O3. Carbon powder with a ratio of 1.2 times the mass of alumina is added as a catalyst. The reaction vessel 3 is started to heat the reaction raw materials. The reaction is carried out at a reaction temperature of 145 °C for 90 min, so that Al2O3 decomposes to generate CO2 and Al. It should be noted that the reaction vessel is in a vacuum state throughout the reaction process to reduce the decomposition temperature of Al2O3.

[0090] (6) During the Al2O3 decomposition process in reaction tank 3, the gas intake device 4 is started simultaneously to introduce CO2 into reaction tower 1 to promote the mineralization reaction; after the reaction is completed, the generated Al is discharged.

[0091] Example 7:

[0092] This invention also discloses a method for deep mineralization processing of CO2 from coal-based solid waste, the processing method comprising the following steps:

[0093] (1) A raw solution rich in Ca, Mg, and Al was introduced into reaction tower 1. Carbon dioxide and ammonia were injected into reaction tower 1 at a volume of 2.5 times that of the raw solution. The mineralization reaction was carried out at a reaction temperature of 90 ℃ and a reaction pressure of 2.0 kPa for 60 min, generating a mineralized slag with CaCO3, MgCO3, and Al2(CO3)3 as the main phases. The specific preparation steps of the raw solution are as follows:

[0094] ① Coal-based solid waste is added to a crusher and grinder for crushing and grinding to obtain granular powder with a particle size of 60~200μm;

[0095] ② The granular powder and ammonium nitrate were added to the reactor at a mass ratio of 1:2 to carry out a molten salt activation reaction. The reaction was carried out at an activation temperature of 90 °C for 4 h. The Ca, Mg and Al in the granular powder were converted into the corresponding nitrate mixture, and the generated ammonia gas was collected and injected into the reaction tower 1 as raw material.

[0096] ③ Add deionized water to the nitrate mixture at a liquid-to-solid ratio of 4:1 to soak it, and obtain an aqueous extract rich in Ca, Mg and Al, which is the stock solution.

[0097] (2) The reaction liquid in the reaction tower 1 is discharged, and the mineralized slag is transported to the lower chamber 213 in the hydrolysis device 2 through the first conveying pipe 5. Al2(CO3)3 in the mineralized slag reacts violently with water to generate flocculent Al(OH)3 and CO2. The flocculent Al(OH)3 enters the first chamber 214 through the first side plate 211 along with the reaction liquid. In the first chamber 214, the flocculent Al(OH)3 floats on the liquid surface with a large number of CO2 bubbles and enters the second chamber 215 through the overflow channel 218. In the second chamber 215, the flocculent Al(OH)3 precipitates onto the second side plate 219 as the CO2 bubbles break and is collected by the two side collection slopes 220 and discharged into the reaction tank 3 through the second conveying pipe 6. The reaction waste in the hydrolysis device 2 is blocked by the first side plate 211 and the second side plate 219 and is located in the lower chamber 213. After the reaction is completed, it is discharged into the waste tank 23 for storage through the slag discharge pipe 22.

[0098] (3) The gas suction device 4 is started simultaneously in the reaction process of the hydrolysis device 2 to collect the CO2 escaping from the hydrolysis device 2 and introduce it into the reaction tower 1 to promote the mineralization reaction process, or return it to the lower chamber through the backflush pipe 44 to backflush the mineralized slag to form turbulence or vortex, so that Al2(CO3)3 in the mineralized slag reacts fully with water.

[0099] (4) After the reaction in the hydrolysis device 2 is completed, the Al(OH)3 liquid is transported to the reaction tank 3 through the second conveying pipe 6. The reaction tank 3 is started, and the Al(OH)3 liquid is heated to 85~95℃ through the heating pipe 33 for evaporation and concentration. The stirring device is started to stir the Al(OH)3 liquid to accelerate the evaporation process. The reaction tank is evacuated by the vacuum device. Under vacuum conditions, the Al(OH)3 is concentrated into crystal slurry at a faster rate. After the concentration is completed, Al(OH)3 continues to be heated and decomposed to generate Al2O3 and water vapor. The water vapor is discharged from the reaction tank 3.

[0100] (5) After Al(OH)3 is decomposed by heat, it is converted into Al2O3. Carbon powder with a ratio of 1.3 times the mass of alumina is added as a catalyst. The reaction vessel 3 is started to heat the reaction raw materials and react at a reaction temperature of 150 °C for 60 min, so that Al2O3 decomposes to generate CO2 and Al. It should be noted that the reaction vessel is in a vacuum state throughout the reaction process to reduce the decomposition temperature of Al2O3.

[0101] (6) During the Al2O3 decomposition process in reaction tank 3, the gas intake device 4 is started simultaneously to introduce CO2 into reaction tower 1 to promote the mineralization reaction; after the reaction is completed, the generated Al is discharged.

[0102] The above are preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A device for deep mineralization and processing of CO2 from coal-based solid waste, characterized in that, The processing apparatus includes: The reaction tower (1) supplies raw liquid rich in Ca, Mg and Al to react with CO2 to generate mineralized slag with CaCO3, MgCO3 and Al2(CO3)3 as the main phases; Hydrolysis device (2), wherein the hydrolysis device (2) supplies Al2(CO3)3 to react with water to generate flocculent Al(OH)3 and CO2; The reaction vessel (3) supplies Al(OH)3 to generate Al2O3 and water vapor, and Al2O3 reacts with carbon to generate Al and CO2; The first conveying pipe (5) is inclined downward and connects the bottom end of the reaction tower (1) and the bottom end of the hydrolysis device (2). The mineralized slag discharged from the reaction tower (1) enters the hydrolysis device (2) through the first conveying pipe (5). The second delivery pipe (6) is inclined downward and connected to the bottom of the hydrolysis device (2) and the reaction tank (3) to allow the Al(OH)3-rich solution to enter the reaction tank (3); The hydrolysis device (2) includes a box and a partition shell (21) installed inside the box. The partition shell (21) divides the box into a lower chamber (213) and an upper chamber; the partition shell (21) is provided with a first side plate (211) corresponding to the outlet of the first conveying pipe, the first side plate (211) is inclined upward, the lower end of the first side plate (211) is higher than the outlet end of the first conveying pipe (5), and the first side plate (211) is a grid plate; the partition shell (21) is provided with a partition plate (212) longitudinally at the high end of the first side plate (211), the partition plate (212) The upper chamber of the hydrolysis device (2) is divided into a first chamber (214) and a second chamber (215) distributed to the left and right. The lower chamber (213) is connected to the first chamber (214) through the first side plate (211). The first chamber (214) is connected to the second chamber (215) through the overflow channel (218) at the top of the partition plate (212). The hydrolysis device (2) is filled with water, and the water level is higher than the first side plate (211) and does not fill the inner cavity of the hydrolysis device (2). The partition shell (21) is provided with a second side plate (219) on the rear side of the partition plate (212). The second side plate (219) is inclined downward, and the lower end of the second side plate (219) is lower than the inlet end of the second conveying pipe (6). The top surface of the second side plate (219) is inclined inward from both sides to form two collection slopes (220). The inlet end of the second conveying pipe (6) is located between the two sets of collection slopes. The hydrolysis device (2) is equipped with a water inlet pipe (24) and a slag discharge pipe (22); the water inlet pipe (24) is located at the top of the box and above the second side plate (219); the lower end of the slag discharge pipe (22) is connected to a waste slag tank (23), and the slag discharge pipe (22) is connected to a control valve.

2. The coal-based solid waste CO2 deep mineralization processing device according to claim 1, characterized in that, The processing device also includes an air suction device (4), which includes a conveying pipeline (42) connected to the air outlet of the hydrolysis device (2) and the reaction tank (3) respectively, and an air pump (41) connected to the conveying pipeline (42). A control valve (43) is provided at the connection between the conveying pipeline (42) and the hydrolysis device (2) and the reaction tank (3); the air outlet of the conveying pipeline (42) is connected to the air inlet of the reaction tower (1).

3. The coal-based solid waste CO2 deep mineralization processing device according to claim 1, characterized in that, A drive motor (31) is fixedly installed on the top of the reaction vessel (3), and a stirring shaft (32) extending into the reaction vessel is fixedly connected to the output end of the drive motor (31). A stirring blade (34) is provided at the lower end of the stirring shaft (32).

4. The coal-based solid waste CO2 deep mineralization processing device according to claim 2, characterized in that, The reaction vessel (3) is equipped with a heating tube (33), which is spirally attached to the inner wall of the reaction vessel and is far away from the stirring blade (34).

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