Continuous mineralization system
By designing a continuous mineralization system, the problem of efficient and continuous mineralization reaction of phosphogypsum was solved, the efficient utilization of phosphogypsum and the fixation of carbon dioxide were achieved, valuable products were generated, the reaction efficiency was improved and energy consumption was reduced.
Patent Information
- Application Number
- CN202422937290.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-29
- Publication Date
- 2025-10-21
- Estimated Expiration
- 2034-11-29
AI Technical Summary
In the existing technology, an efficient continuous mineralization reaction device for phosphogypsum has not yet been developed, resulting in low utilization of phosphogypsum and the inability of intermittent reaction devices to achieve efficient and continuous operation.
A continuous mineralization system was designed, including a phosphogypsum supply device, a mineralization reactor, a circulation system, a flue gas supply device, a flue gas heat exchanger, a liquid-solid separator, and a crystallization tower. The circulation system enables continuous contact reaction between phosphogypsum and carbon dioxide in the flue gas. The waste heat of the cement kiln flue gas is used for evaporation and crystallization, thereby increasing the gas-liquid-solid reaction area and achieving continuous feeding and discharging.
The reaction efficiency is improved, the efficient utilization of phosphogypsum is achieved, valuable calcium carbonate and ammonium sulfate products are generated, carbon dioxide emissions are reduced, and resource recycling and energy conservation are achieved.
Smart Images
Figure CN223454233U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to the field of energy saving and environmental protection technology, and relates to a continuous mineralization system. BACKGROUND
[0002] Phosphogypsum is a by-product of wet-process phosphoric acid production, and 5 tons of phosphogypsum will be produced for every ton of phosphoric acid produced, but the comprehensive utilization rate of phosphogypsum is only 40%, far from reaching the balance between production and use. Large amounts of phosphogypsum are stored, which not only occupies land but also easily pollutes the surrounding environment.
[0003] The main component of phosphogypsum is dihydrate gypsum (CaSO4·2H2O), and the theoretical carbon fixation amount is 0.25 tons of carbon dioxide per ton. The cement industry is a major carbon emitter, and the use of phosphogypsum to mineralize CO2 has become a research hotspot for the comprehensive utilization of phosphogypsum resources. Using phosphogypsum to directly mineralize carbon dioxide in industrial flue gas in an ammonia atmosphere, the reaction can theoretically proceed spontaneously at normal temperature and pressure because the Gibbs free energy is less than zero. The generated calcium carbonate and ammonium sulfate products are both high-value products, of which calcium carbonate can be used as a cement production raw material, and ammonium sulfate can be used as a fertilizer. Since the reaction is directly with carbon dioxide, it can effectively avoid the energy consumption generated by carbon capture, and truly achieve "waste treatment with waste, turning waste into treasure". However, at present, no industrial integrated reaction device has been developed for this technology, and the related reaction devices are basically intermittent reaction devices, which cannot achieve efficient continuous operation. SUMMARY
[0004] The utility model aims at providing a kind of continuity mineralization system, to solve the technical problems that the high-efficiency continuous mineralization reaction of phosphogypsum cannot be realized in prior art.
[0005] The continuous mineralization system comprises a phosphogypsum supply device, a mineralization reaction kettle, a circulation system, a flue gas supply device, a flue gas heat exchanger, a liquid-solid separator and a crystallization tower. The phosphogypsum supply device is connected to the feed inlet of the mineralization reaction kettle through a pipeline. The ammonia water inlet of the mineralization reaction kettle is connected to an ammonia water tank. The liquid inlet end of the circulation system is communicated with the circulation outlet at the lower part of the mineralization reaction kettle through a circulation pipeline. The discharge end of the circulation system is connected to the circulation feed inlet of the mineralization reaction kettle. The flue gas supply device supplies flue gas to the circulation system through the flue gas heat exchanger. The heat exchange medium on the flue gas heat exchanger is transported to the crystallization tower through a pipeline. The discharge outlet of the mineralization reaction kettle is connected to the liquid-solid separator through a pipeline. The liquid-solid separator is provided with a solid outlet and a liquid outlet. The liquid outlet is connected to the crystallization tower through a pipeline.
[0006] Preferably, the circulating system comprises a slurry pump and an absorption tower, the circulating outlet of the lower part of the mineralization reactor is connected to the slurry pump and the absorption tower in sequence through a circulating pipeline, and the flue gas inlet of the absorption tower is connected to a flue gas supply device.
[0007] Preferably, the circulating system further comprises a cyclone, the cyclone is arranged between the slurry pump and the absorption tower and connected through a pipeline, the large particle outlet of the cyclone is directly connected to the mineralization reactor, and the small particle slurry outlet of the cyclone is connected to the absorption tower.
[0008] Preferably, the circulating system further comprises a heater, and the heater is arranged before the absorption tower.
[0009] Preferably, the phosphogypsum slurry in the circulating system and the heat-exchanged kiln tail flue gas enter the absorption tower at the same time, and the phosphogypsum slurry and the heat-exchanged kiln tail flue gas are reversely contacted in the absorption tower, and the absorption tower is provided with a filler.
[0010] Preferably, the phosphogypsum supply device comprises a phosphogypsum slurry preparation tank, the phosphogypsum slurry preparation tank and the mineralization reactor are both provided with a stirrer, the phosphogypsum slurry preparation tank is provided with material inlets and liquid inlets for inputting phosphogypsum and process water respectively, and the outlet of the phosphogypsum slurry preparation tank is connected to the mineralization reactor through a pipeline.
[0011] Preferably, the evaporation water outlet of the crystallization tower is connected to the liquid inlet of the phosphogypsum slurry preparation tank through a pipeline.
[0012] Preferably, the flue gas supply device comprises a pipeline for inputting kiln tail flue gas and a flue gas fan, the pipeline for inputting kiln tail flue gas is connected to the flue gas fan through a flue gas heat exchanger, and the outlet of the flue gas fan is connected to the absorption tower through a pipeline.
[0013] The utility model has the following advantages: 1, the reaction device in the prior art is an intermittent reaction device, the utility model improves the reaction efficiency, ensures that the reaction efficiency can realize the dynamic balance of adding raw materials and outputting products after the first closed reaction is finished, namely, continuous feeding and discharging can be realized, and the problem of discontinuous reaction in the intermittent reaction device is overcome.
[0014] 2, the waste heat in the cement kiln flue gas is used to evaporate and crystallize the ammonium sulfate mother liquor, the waste heat in the flue gas is recycled, and a large amount of energy is saved.
[0015] 3, the device is provided with an absorption tower, small balls are arranged in the absorption tower, the contact area of the gas-liquid-solid three-phase reaction is increased, and the reaction rate is accelerated.
[0016] 4, the evaporation water generated in the ammonium sulfate evaporation and crystallization process can be used to prepare phosphogypsum through condensation, and the water is recycled.
[0017] 5. The utility model uses CO2 in cement kiln flue gas as carbon source, truly realizes carbon dioxide utilization in cement industry, reduces the discharge of CO2 in cement production. Simultaneously uses phosphogypsum as reaction raw material, and the product generated is all valuable product, realizes "waste treatment with waste, waste into treasure" goal. BRIEF DESCRIPTION OF DRAWINGS
[0018] Figure 1 It is structural schematic diagram of a continuous mineralization system of the utility model.
[0019] The reference signs in the drawings are as follows: 1, phosphogypsum slurry preparation kettle, 2, mineralization reaction kettle, 3, ammonia water tank, 4, slurry pump, 5, heater, 6, cyclone, 7, absorption tower, 8, flue gas fan, 9, flue gas heat exchanger, 10, liquid-solid separator, 11, crystallization tower. DETAILED DESCRIPTION
[0020] The specific embodiment of the utility model is further explained in detail below by the description of the embodiments with reference to the drawings, to help the technical personnel in the field to have more complete, accurate and in-depth understanding of the inventive concept and technical scheme of the utility model.
[0021] As Figure 1 The utility model discloses a continuous mineralization system, including phosphogypsum supply device 1, mineralization reaction kettle 2, circulating system, flue gas supply device, flue gas heat exchanger 9, liquid-solid separator 10 and crystallization tower 11, the phosphogypsum supply device is connected to the feed inlet of mineralization reaction kettle 2 through pipeline to supply phosphogypsum slurry, the ammonia water inlet of mineralization reaction kettle 2 is connected ammonia water tank 3 and is supplied with ammonia water, the liquid inlet end of circulating system is communicated with the circulating outlet of the lower part of mineralization reaction kettle 2 through circulating pipeline, the discharge end of circulating system is connected to the circulating feed inlet of mineralization reaction kettle 2, and the phosphogypsum slurry absorbed with carbon dioxide in flue gas is circulated and transported to mineralization reaction kettle 2, the flue gas supply device is supplied with flue gas through flue gas heat exchanger 9, and the heat exchange medium on flue gas heat exchanger 9 is transported to crystallization tower 11 through pipeline, and crystallization tower 11 carries out drying crystallization using the heat of heat exchange medium, the discharge port of mineralization reaction kettle 2 is connected to liquid-solid separator 10 through pipeline, and the solid outlet of liquid-solid separator 10 exports separated solid material, that is, calcium carbonate, and the liquid outlet of liquid-solid separator 10 is connected to crystallization tower 11 through pipeline, and ammonium sulfate crystallization is output under the heat of heat exchange medium.
[0022] The circulation system extracts the unreacted phosphogypsum slurry, and after the reaction with the flue gas, the phosphogypsum slurry is transported back to the mineralization reactor 2, and the circulation and flue gas absorption are realized here, and the mineralization reaction efficiency is effectively improved. The mixed slurry from the outlet of the absorption tower 7 reenters the mineralization reactor, and the circulation is continuously carried out until the reaction is complete after a certain time, and then the continuous phosphogypsum feeding and discharging (output of the slurry after reaction) are carried out. Due to the above structural improvement, the reaction process of phosphogypsum and ammonia water in the system is substantially increased, and the circulation transportation is more fully contacted with carbon dioxide in the flue gas, so that the reaction efficiency is increased in continuous production, the dynamic balance of continuous feeding and discharging is ensured, and industrial continuous production is realized.
[0023] The circulation system includes a slurry pump 4 and an absorption tower 7, and the circulation outlet at the lower part of the mineralization reactor 2 is connected to the slurry pump 4 and the absorption tower 7 in sequence through a circulation pipeline, and the flue gas inlet of the absorption tower 7 is connected to a flue gas supply device. The phosphogypsum slurry in the circulation system and the heat-exchanged kiln tail flue gas enter the absorption tower 7 at the same time, and the reverse contact is carried out in the absorption tower 7 to absorb carbon dioxide in the flue gas. The absorption tower 7 is provided with a filler, which is mainly used to increase the gas-liquid-solid reaction area and accelerate the reaction rate. The phosphogypsum slurry is continuously circulated to ensure the uniformity of the phase state of the slurry and prevent the phosphogypsum from settling to cause the blockage of the device pipeline. The mineralization reactor 2 is provided with a stirrer, so that the phosphogypsum slurry can be continuously stirred during the reaction process, and the uniformity of the phase state of the slurry is further ensured.
[0024] The circulation system further includes a cyclone 6, and the cyclone 6 is connected through a pipeline between the slurry pump 4 and the absorption tower 7. The large-particle outlet of the cyclone 6 is directly connected to the mineralization reactor 2, and the small-particle slurry outlet of the cyclone 6 is connected to the absorption tower 7. The cyclone 6 is arranged on the pipeline of the circulation system, and can separate the large-particle and small-particle materials of the circulating phosphogypsum slurry. The large-particle material is separated and then enters the mineralization reactor for reaction; and the small-particle slurry containing phosphogypsum enters the absorption tower 7 through another outlet of the cyclone 6. The large-particle material can be further dispersed into smaller small-particle material by the stirrer. The separation on one hand increases the efficiency of dispersing the large-particle material, and on the other hand avoids the large-particle material with poor reaction efficiency from entering the absorption tower 7 to affect the absorption efficiency of carbon dioxide, and improves the reaction efficiency of the system.
[0025] The circulation system further includes a heater 5, and the heater 5 is arranged before the absorption tower 7. In the embodiment, the heater 5 is specifically arranged between the cyclone 6 and the slurry pump 4. The heater 5 is arranged on the circulation pipeline to investigate the reaction rate at different temperatures. After the phosphogypsum slurry is input into the ammonia water and passes through the heater 5, the reaction efficiency is promoted, and carbon dioxide is better absorbed. The reacted material is transported back to the mineralization reactor 2 to avoid the direct discharge of the heated and escaped ammonia gas, and the air pollution is reduced.
[0026] The reaction equation occurred in the mineralization reactor 2 is as follows: CaSO4 2H2O + CO2 + NH4OH → (NH4)2SO4 + CaCO3 + H2O.
[0027] 2NH4OH → (NH4)2SO4 + CaCO3 + H2O. After the reaction, the complete reaction product is calcium carbonate and ammonium sulfate mother liquor, which enters the liquid-solid separator 10, and after filtration separation, the obtained calcium carbonate solid can be used as a cement production raw material, and the obtained mother liquor enters the next unit ammonium sulfate crystallization tower 11.
[0028] The phosphogypsum supply device comprises a phosphogypsum slurry preparation tank 1, a stirrer is arranged in the phosphogypsum slurry preparation tank 1, the phosphogypsum slurry preparation tank 1 is provided with a material inlet and a liquid inlet for respectively inputting phosphogypsum and process water, and the outlet of the phosphogypsum slurry preparation tank 1 is connected to the mineralization reactor 2 through a pipeline. The phosphogypsum and the process water are stirred by the stirrer in the phosphogypsum slurry preparation tank 1 to form corresponding phosphogypsum slurry. The evaporation water outlet of the crystallization tower 11 is connected to the liquid inlet of the phosphogypsum slurry preparation tank 1 through a pipeline, so that the evaporation water can be recycled, and water resource waste is reduced.
[0029] The flue gas supply device comprises a pipeline for inputting kiln tail flue gas and a flue gas fan 8, the pipeline for inputting kiln tail flue gas is connected to the flue gas fan 8 through a flue gas heat exchanger 9, and the outlet of the flue gas fan 8 is connected to the absorption tower 7 through a pipeline. In this way, the kiln tail flue gas is transported into the absorption tower 7 by the flue gas fan 8, and the temperature of the kiln tail flue gas is about 100 DEG C in this process, and the flue gas waste heat can be used to heat the heat exchange medium through the flue gas heat exchanger 9. In this way, the obtained energy is used for evaporation and crystallization of the ammonium sulfate mother liquor. The ammonium sulfate obtained after evaporation and crystallization can be used as a fertilizer, and the energy waste of the flue gas waste heat is avoided.
[0030] The above has been described by way of example in conjunction with the drawings, and obviously the specific implementation of the present application is not limited by the above mode, as long as various non-essential improvements are made by adopting the inventive concept and technical scheme of the present application, or the inventive concept and technical scheme are directly applied to other occasions without improvement, which are all within the protection scope of the present application.
Claims
1. A continuous mineralization system, characterized by: The device comprises a phosphogypsum supply device, a mineralization reactor (2), a circulating system, a flue gas supply device, a flue gas heat exchanger (9), a liquid-solid separator (10) and a crystallization tower (11), the phosphogypsum supply device is connected to the feed inlet of the mineralization reactor (2) through a pipeline, the ammonia water inlet of the mineralization reactor (2) is connected to an ammonia water tank (3), the liquid inlet end of the circulating system is communicated with the circulating outlet at the lower part of the mineralization reactor (2) through a circulating pipeline, the discharge end of the circulating system is connected to the circulating feed inlet of the mineralization reactor (2), the flue gas supply device supplies flue gas to the circulating system through the flue gas heat exchanger (9), the heat exchange medium on the flue gas heat exchanger (9) is transported to the crystallization tower (11) through a pipeline, the discharge outlet of the mineralization reactor (2) is connected to the liquid-solid separator (10) through a pipeline, the liquid-solid separator (10) is provided with a solid outlet and a liquid outlet, and the liquid outlet is connected to the crystallization tower (11) through a pipeline.
2. A continuous mineralization system according to claim 1, characterized in that: The circulating system comprises a slurry pump (4) and an absorption tower (7), the circulating outlet at the lower part of the mineralization reactor (2) is sequentially communicated with the slurry pump (4) and the absorption tower (7) through a circulating pipeline, and the flue gas inlet of the absorption tower (7) is connected to the flue gas supply device.
3. A continuous mineralization system according to claim 2, characterized in that: The circulating system further comprises a cyclone (6), the cyclone (6) is connected through a pipeline between the slurry pump (4) and the absorption tower (7), the large particle outlet of the cyclone (6) is directly communicated with the mineralization reactor (2), and the small particle slurry outlet of the cyclone (6) is connected to the absorption tower (7).
4. A continuous mineralization system according to claim 3, characterized in that: The circulating system further comprises a heater (5), and the heater (5) is arranged before the absorption tower (7).
5. A continuous mineralization system according to claim 4, characterized in that: The phosphogypsum slurry in the circulating system and the heat-exchanged kiln tail flue gas enter the absorption tower (7) at the same time, and the reverse contact is carried out in the absorption tower (7), and the absorption tower (7) is provided with a filler.
6. A continuous mineralization system according to any one of claims 1 to 5, characterized in that: The phosphogypsum supply device comprises a phosphogypsum slurry preparation tank (1), the phosphogypsum slurry preparation tank (1) and the mineralization reactor (2) are both provided with a stirrer, the phosphogypsum slurry preparation tank (1) is provided with material inlets and liquid inlets for respectively inputting phosphogypsum and process water, and the outlet of the phosphogypsum slurry preparation tank (1) is connected to the mineralization reactor (2) through a pipeline.
7. A continuous mineralization system according to claim 6, characterized in that: The evaporation water outlet of the crystallization tower (11) is connected to the liquid inlet of the phosphogypsum slurry preparation tank (1) through a pipeline.
8. The continuous mineralization system of claim 2, wherein: The flue gas supply device comprises a pipeline for inputting kiln tail flue gas and a flue gas fan (8), the pipeline for inputting kiln tail flue gas is connected to the flue gas fan (8) through a flue gas heat exchanger (9), and the outlet of the flue gas fan (8) is connected to the absorption tower (7) through a pipeline.