A calcium carbide purification ash resource comprehensive utilization equipment

Abstract

A comprehensive utilization device for calcium carbide purified ash resources includes: an incinerator, a secondary combustion chamber, a flue gas cooler, a flue gas purification system, a dust collector, a water washing system, an acid washing system, a drying kiln, a reduction tank, a cooling heat exchange system, and a vacuum system. The incinerator is used to incinerate the purified ash. The flue gas generated from incineration sequentially enters the secondary combustion chamber and the flue gas cooler; then, it enters the flue gas purification system for desulfurization and denitrification; finally, it enters the drying kiln for waste heat utilization and is discharged into the atmosphere through the dust collector. The ash residue generated from incineration first enters the water washing system and the acid washing system for treatment, then enters the drying kiln for drying, and finally enters the reduction tank. Utilizing the flue gas temperature generated by the secondary combustion chamber and the flue gas cooler, a reduction reaction occurs to generate metallic magnesium, potassium vapor, and sodium vapor. The potassium and sodium vapors condense into metallic potassium and sodium in the cooling heat exchange system. The vacuum system provides a vacuum environment for the reduction tank and the cooling heat exchange system.

Description

Technical Field

[0001] This invention relates to a comprehensive utilization equipment for calcium carbide purification ash, belonging to the field of energy conservation and environmental protection in the calcium carbide industry. Background Technology

[0002] The production process in the calcium carbide industry generates a large amount of calcium carbide purification ash solid waste. According to relevant statistics, purification ash accounts for 3%-7% of calcium carbide production. As the world's largest calcium carbide producer, my country accounts for over 90% of global calcium carbide production capacity, resulting in an enormous annual generation of purification ash. Purification ash contains elements such as carbon, calcium, magnesium, aluminum, potassium, and sodium. Combustible components like carbon typically account for about 10-25%, CaO for 30-45%, MgO for 20-35%, potassium and sodium for 1-5%, with the remainder being impurities such as aluminum and silicon. Therefore, although purification ash is solid waste requiring treatment, it still contains some resources that can be utilized in subsequent comprehensive applications.

[0003] Currently, the calcium carbide industry commonly uses landfill and incineration to treat purified ash. However, both methods have problems. For landfill disposal, due to the fine particle size of the purified ash, prolonged exposure to sunlight can easily lead to oxidation and spontaneous combustion. Therefore, landfill disposal not only easily damages the ecological environment but also increases the risk of safety accidents at waste-generating units, transfer points, and landfill sites. For incineration, factories only burn off the carbon; the remaining ash still needs to be landfilled. Therefore, neither method can completely treat purified ash and effectively extract valuable components, resulting in the waste of potentially reusable resources and hindering sustainable development and efficient resource utilization for enterprises. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of existing technologies and provide a comprehensive utilization device for calcium carbide purification ash resources. This device further treats the flue gas and ash residue generated from the incineration of purification ash, reducing the environmental impact of the flue gas and ash residue. Simultaneously, it effectively extracts metallic magnesium, potassium, and sodium through a reduction reaction in the ash residue, achieving comprehensive utilization of the effective components in the purification ash. This solves the problems of existing methods being unable to completely process purification ash and effectively extract valuable components from it.

[0005] The technical solution of this invention is: A comprehensive utilization device for calcium carbide purification ash resources includes: an incinerator, a secondary combustion chamber, a flue gas cooler, a flue gas purification system, a dust collector, a water washing system, an acid washing system, a drying kiln, a reduction tank, a cooling heat exchange system, and a vacuum system. The incinerator is used to incinerate purified ash; after the purified ash is incinerated, flue gas and ash residue are produced. The flue gas generated after the ash is incinerated enters the secondary combustion chamber from the incinerator to raise the flue gas temperature; then, the flue gas enters the flue gas cooler from the secondary combustion chamber to cool down; finally, the flue gas enters the flue gas purification system from the flue gas cooler to desulfurize and denitrify, becoming clean flue gas; the clean flue gas enters the drying kiln for waste heat utilization, and after waste heat utilization, it is discharged into the atmosphere through a dust collector. The ash residue produced after the purification ash incineration first enters the water washing system from the incinerator for water washing and filtration to obtain filter cake. Then, the filter cake enters the acid washing system for acid washing and filtration to obtain pretreated ash residue. The pretreated ash residue enters the drying kiln for drying to obtain dried ash residue. The dried ash residue enters the reduction tank. The reduction tank uses the flue gas temperature generated by the secondary combustion chamber and flue gas cooler to cause the dried ash residue to undergo a reduction reaction with the reducing agent, generating metallic magnesium, potassium vapor and sodium vapor. The potassium vapor and sodium vapor then enter the cooling heat exchange system and are condensed to obtain metallic potassium and metallic sodium. The vacuum system provides a vacuum environment for the reduction tank and the cooling heat exchange system.

[0006] Furthermore, the reduction tank is divided into three sections, namely the first pipe section, the second pipe section and the third pipe section; the first pipe section, the second pipe section and the third pipe section are connected in sequence by an expansion joint; the first pipe section is located inside the secondary combustion chamber, the second pipe section is located inside the flue gas cooler, and the third pipe section is fitted with a circulating water cooling jacket. The dried ash reacts with the reducing agent in the first section to produce magnesium vapor, potassium vapor, and sodium vapor. The magnesium vapor, potassium vapor, and sodium vapor then enter the second section, where the magnesium vapor condenses into liquid magnesium. The liquid magnesium, potassium vapor, and sodium vapor then enter the third section, where the liquid magnesium condenses into metallic magnesium. Finally, the potassium vapor and sodium vapor are transferred to the cooling heat exchange system.

[0007] Furthermore, the temperature of the ash incinerated in the incinerator is 850 to 1050°C; the temperature of the flue gas in the secondary combustion chamber is 1100 to 1400°C; the temperature of the flue gas in the flue gas cooler is 800 to 900°C; the pressure in the first section of the reduction tank is absolute pressure of 1 to 25 Pa; and the temperature in the third section of the reduction tank is 400 to 600°C.

[0008] Furthermore, the reducing agent that reacts with the dry ash is ferrosilicon, and the catalyst used in the reduction reaction is fluorite; the molar ratio of the reducing agent to magnesium oxide in the dry ash is 2.2:1 to 3:1; and the amount of catalyst used is 1-3% of the sum of the amounts of dry ash and reducing agent used.

[0009] Furthermore, the cooling and heat exchange system includes a primary cooling heat exchanger, a secondary cooling heat exchanger, and a heat jacket; the primary and secondary cooling heat exchangers are connected by a pipe with an external heat jacket; the inlet of the primary cooling heat exchanger is connected to the outlet of the reduction tank by a pipe, and the outlet of the secondary cooling heat exchanger is connected to the vacuum system by a pipe; the heat jacket is used to heat the pipe when the potassium-sodium mixture blocks the pipe, melting the potassium-sodium mixture to clear the blockage; When potassium vapor and sodium vapor enter the cooling heat exchange system, they first enter the primary cooling heat exchanger. The primary cooling heat exchanger cools the potassium vapor and sodium vapor to 150 to 200°C using a primary refrigerant, causing them to condense into liquid potassium and liquid sodium, respectively. The liquid potassium and liquid sodium then enter the secondary cooling heat exchanger, which uses a secondary refrigerant to cool the liquid potassium and liquid sodium to below 50°C, causing them to condense into metallic potassium and metallic sodium, respectively.

[0010] Furthermore, the cooling heat exchange system also includes a backup cooling heat exchanger, two main valves, and two backup valves; The inlet of the standby cooling heat exchanger is connected to the outlet of the reduction tank through a pipe with an external heat jacket, and the outlet of the standby cooling heat exchanger is connected to the vacuum system through a pipe. A standby valve is provided on the pipe connecting the standby cooling heat exchanger to the reduction tank and a standby valve is provided on the pipe connecting the standby cooling heat exchanger to the vacuum system. A main valve is provided on the pipe connecting the primary cooling heat exchanger to the reduction tank and a main valve is provided on the pipe connecting the secondary cooling heat exchanger to the vacuum system.

[0011] Furthermore, when there is no fault in the pipelines where the primary and secondary cooling heat exchangers are located, the two main pipeline valves are in the open state and the two backup pipeline valves are in the closed state; the cooling heat exchange system uses the primary and secondary cooling heat exchangers to cool potassium vapor and sodium vapor to obtain metallic potassium and metallic sodium. When a fault occurs in the pipelines containing the primary and secondary cooling heat exchangers, the two main valves are closed and the two backup valves are open. The cooling heat exchange system uses the backup cooling heat exchangers to cool the potassium vapor and sodium vapor to obtain metallic potassium and metallic sodium.

[0012] Furthermore, when using the vacuum system to extract air from the reduction tank, both main valves and both backup valves are open to accelerate the extraction speed; once the reduction tank reaches the predetermined vacuum level, the two backup valves are closed.

[0013] Furthermore, the water washing system performs water washing and filtration treatment on the ash residue as follows: The water washing system first adds clean water to the ash residue; the temperature of the clean water is 25 to 35°C, the pH value is 7.5-8.0, and the clean water is aerated in advance to remove carbon dioxide; the ratio of clean water to ash residue is 3:1 to 6:1; the ash residue after adding clean water forms a uniform slurry, thereby removing the free potassium and sodium impurities originally attached to the surface of the ash residue; then, the water washing system performs a filtration operation on the uniform slurry to obtain a filter cake.

[0014] Furthermore, the pickling system performs pickling and filtration treatment on the filter cake as follows: First, the pickling system uniformly mixes the filter cake with a mixed acid; the mixed acid is a mixture of hydrochloric acid and sulfuric acid in a 3:1 ratio, and the ratio of the mixed acid to the filter cake is 3:1 to 5:1 when the mixed acid and filter cake are uniformly mixed; after the filter cake and mixed acid are uniformly mixed, a reaction begins, and the internal temperature of the pickling system is controlled at 30 to 45°C during the reaction; the reaction time of the filter cake and mixed acid is 60 to 90 minutes, and the pH value of the reaction environment is maintained above 4.5 during the reaction. During the reaction, calcium in the filter cake is partially leached out, and bound potassium and sodium are leached out, finally obtaining an acid slurry; then, the pickling system filters the acid slurry to obtain pretreated ash residue.

[0015] The advantages of this invention compared to the prior art are: (1) This invention further treats the flue gas and ash residue generated by the incineration of purified ash, thereby reducing the impact of flue gas and ash residue on the environment. At the same time, it effectively extracts magnesium, potassium and sodium metals by reducing the ash residue, thus realizing the comprehensive utilization of the effective components in the purified ash.

[0016] (2) By using the heat of flue gas generated after the purification ash is incinerated to reduce the external energy supply required for the ash reduction reaction, the present invention improves the efficiency of comprehensive resource utilization.

[0017] (3) The present invention uses a water washing system and an acid washing system to take advantage of the difference in reactivity and solubility of K and Na with calcium and magnesium to initially remove free K and Na impurities and bound K and Na impurities, thereby avoiding the influence of K and Na impurities on the reduction reaction and improving the extraction rate of effective resources in the purified ash.

[0018] (4) By condensing potassium and sodium in a cooling heat exchange system and magnesium in a reduction tank, the present invention achieves physical separation and segregation of different metals, avoids the mixed precipitation of potassium, sodium and magnesium, thereby improving the purity of magnesium extraction and obtaining high-purity potassium and sodium metals.

[0019] (5) The cooling heat exchange system set in this invention contains two-stage cooling heat exchangers, which can gradually control the condensation and precipitation of metallic potassium and metallic sodium, thereby improving the extraction purity of metallic potassium and metallic sodium.

[0020] (6) The cooling heat exchange system provided in this invention contains a backup cooling heat exchanger, which effectively ensures that the system can still be used normally when the original two-stage heat exchangers in the cooling heat exchange system fail, thereby improving the reliability of the system. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the system component connections in a calcium carbide purification ash resource comprehensive utilization device of the present invention; Figure 2 This is a schematic diagram of the reduction tank in a comprehensive utilization device for calcium carbide purification ash resources according to the present invention. Detailed Implementation

[0022] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings.

[0023] like Figure 1 As shown, the present invention provides a comprehensive utilization equipment for calcium carbide purification ash resources, including: an incinerator 1, a secondary combustion chamber 2, a flue gas cooler 3, a flue gas purification system 4, a dust collector 5, a water washing system 6, an acid washing system 7, a drying kiln 8, a reduction tank 9, a cooling heat exchange system, and a vacuum system 13. The incinerator 1 is used to incinerate purified ash; after the purified ash is incinerated, flue gas and ash residue are produced. The flue gas generated after the ash is incinerated enters the secondary combustion chamber 2 from the incinerator 1 to raise the flue gas temperature; then, the flue gas enters the flue gas cooler 3 from the secondary combustion chamber 2 to cool down; finally, the flue gas enters the flue gas purification system 4 from the flue gas cooler 3 to desulfurize and denitrify, becoming clean flue gas; the clean flue gas enters the drying kiln 8 for waste heat utilization, and after waste heat utilization, it is discharged into the atmosphere through the dust collector 5. The ash residue produced after the purification ash incineration first enters the water washing system 6 from the incinerator 1 for water washing and filtration to obtain a filter cake; then, the filter cake enters the acid washing system 7 for acid washing and filtration to obtain pretreated ash residue; the pretreated ash residue enters the drying kiln 8 for drying to obtain dried ash residue; the dried ash residue enters the reduction tank 9; the reduction tank 9 uses the flue gas temperature generated by the secondary combustion chamber 2 and the flue gas cooler 3 to cause the dried ash residue to undergo a reduction reaction with the reducing agent to generate metallic magnesium, potassium vapor and sodium vapor; the potassium vapor and sodium vapor then enter the cooling heat exchange system and are condensed to obtain metallic potassium and metallic sodium; the vacuum system 13 provides a vacuum environment for the reduction tank 9 and the cooling heat exchange system.

[0024] Furthermore, such as Figure 2As shown, the reduction tank 9 is divided into three sections, namely the first pipe section, the second pipe section and the third pipe section; the first pipe section, the second pipe section and the third pipe section are connected in sequence through expansion joints; the first pipe section is located inside the secondary combustion chamber 2, the second pipe section is located inside the flue gas cooler 3, and the third pipe section is fitted with a circulating water cooling jacket. The dried ash reacts with the reducing agent in the first section to produce magnesium vapor, potassium vapor, and sodium vapor. The magnesium vapor, potassium vapor, and sodium vapor then enter the second section, where the magnesium vapor condenses into liquid magnesium. The liquid magnesium, potassium vapor, and sodium vapor then enter the third section, where the liquid magnesium condenses into metallic magnesium. Finally, the potassium vapor and sodium vapor are transferred to the cooling heat exchange system.

[0025] Furthermore, the temperature at which the incinerator 1 incinerates the purified ash is 850 to 1050°C; the temperature of the flue gas in the secondary combustion chamber 2 is 1100 to 1400°C; the temperature of the flue gas in the flue gas cooler 3 is 800 to 900°C; the pressure in the first section of the reduction tank 9 is absolute pressure of 1 to 25 Pa; and the temperature in the third section of the reduction tank 9 is 400 to 600°C.

[0026] The first pipe section of the reduction tank 9 has a length of 3 to 5 m and a diameter of 330 to 370 mm; the second pipe section has a length of 2 to 5 m and a diameter of 330 to 370 mm; and the third pipe section has a length of 2 to 5 m and a diameter of 330 to 370 mm.

[0027] The secondary combustion chamber 2 heats the flue gas by adding auxiliary fuels such as natural gas, coal gas, diesel, and pulverized coal; the flue gas cooler 3 cools the flue gas by mixing in cold air or spraying atomized water droplets.

[0028] Furthermore, the reducing agent that reacts with the dry ash is ferrosilicon, and the catalyst used in the reduction reaction is fluorite; the molar ratio of the reducing agent to magnesium oxide in the dry ash is 1.1:2 to 1.5:2; and the amount of catalyst used is 1-3% of the sum of the amounts of dry ash and reducing agent used.

[0029] Furthermore, the cooling and heat exchange system includes a primary cooling heat exchanger 10, a secondary cooling heat exchanger 11, and a heat jacket 16; the primary cooling heat exchanger 10 and the secondary cooling heat exchanger 11 are connected by a pipe with the heat jacket 16 externally mounted; the inlet of the primary cooling heat exchanger 10 is connected to the outlet of the reduction tank 9 by a pipe, and the outlet of the secondary cooling heat exchanger 11 is connected to the vacuum system 13 by a pipe; the heat jacket 16 is used to heat the pipe when the potassium-sodium mixture blocks the pipe, melting the potassium-sodium mixture to clear the blockage; When potassium vapor and sodium vapor enter the cooling heat exchange system, they first enter the primary cooling heat exchanger 10. The primary cooling heat exchanger 10 cools the potassium vapor and sodium vapor to 150 to 200°C using a primary refrigerant, causing them to condense into liquid potassium and liquid sodium, respectively. The liquid potassium and liquid sodium then enter the secondary cooling heat exchanger 11, which uses a secondary refrigerant to cool the liquid potassium and liquid sodium to below 50°C, causing them to condense into metallic potassium and metallic sodium, respectively. This invention achieves physical separation and segregation of different metals by condensing potassium and sodium in a cooling heat exchange system and magnesium in a reduction tank. This avoids the mixed precipitation of potassium, sodium, and magnesium, thereby improving the purity of magnesium extraction and yielding high-purity potassium and sodium metals. Furthermore, the cooling heat exchange system in this invention contains a two-stage cooling heat exchanger, allowing for gradual control of the condensation and precipitation of potassium and sodium, thus further improving the extraction purity of potassium and sodium.

[0030] The primary refrigerant used in the primary cooling heat exchanger 10 is steam condensate (0.4-1.0 MPaG) or heat transfer oil (temperature 150-200℃); the secondary refrigerant used in the secondary cooling heat exchanger 11 is liquid nitrogen or chilled water.

[0031] The heat jacket 16 heats the pipe to between 100 and 120°C.

[0032] Furthermore, the cooling heat exchange system also includes a backup cooling heat exchanger 12, two main valves 14 and two backup valves 15; The inlet of the standby cooling heat exchanger 12 is connected to the outlet of the reduction tank 9 through a pipe with an external heat jacket 16, and the outlet of the standby cooling heat exchanger 12 is connected to the vacuum system 13 through a pipe; a standby valve 15 is provided on the pipe connecting the standby cooling heat exchanger 12 to the reduction tank 9, and a standby valve 15 is provided on the pipe connecting the standby cooling heat exchanger 12 to the vacuum system 13; a main valve 14 is provided on the pipe connecting the primary cooling heat exchanger 10 to the reduction tank 9, and a main valve 14 is provided on the pipe connecting the secondary cooling heat exchanger 11 to the vacuum system 13.

[0033] Furthermore, when there is no fault in the pipelines where the primary cooling heat exchanger 10 and the secondary cooling heat exchanger 11 are located, the two main pipeline valves 14 are in the open state and the two backup pipeline valves 15 are in the closed state; the cooling heat exchange system uses the primary cooling heat exchanger 10 and the secondary cooling heat exchanger 11 to cool potassium vapor and sodium vapor to obtain metallic potassium and metallic sodium. When a fault occurs in the pipelines of the primary cooling heat exchanger 10 and the secondary cooling heat exchanger 11, the two main valves 14 are closed and the two backup valves 15 are open. The cooling heat exchange system uses the backup cooling heat exchanger 12 to cool the potassium vapor and sodium vapor to obtain metallic potassium and metallic sodium.

[0034] Furthermore, the failure of the pipelines containing the primary cooling heat exchanger 10 and the secondary cooling heat exchanger 11 refers to: blockage in the pipelines containing the primary cooling heat exchanger 10 and the secondary cooling heat exchanger 11, or a failure in the primary cooling heat exchanger 10 or the secondary cooling heat exchanger 11 itself; the cooling heat exchange system provided by the present invention contains a backup cooling heat exchanger, which effectively ensures that the system can still be used normally when the original two-stage heat exchangers in the cooling heat exchange system fail, thereby improving the reliability of the system.

[0035] Furthermore, when the vacuum system 13 is used to extract air from the reduction tank 9, both main valves 14 and both backup valves 15 are in the open state to accelerate the extraction speed; when the reduction tank 9 reaches the predetermined vacuum level, the two backup valves 15 are closed.

[0036] Furthermore, the washing system 6 performs washing and filtration treatment on the ash residue as follows: The washing system 6 first adds clean water to the ash residue; the temperature of the clean water is 25 to 35°C, the pH value is 7.5-8.0, and the clean water is aerated in advance to remove carbon dioxide; the ratio of clean water to ash residue is 3:1 to 6:1; the ash residue after adding clean water forms a uniform slurry, thereby removing the free potassium and sodium impurities originally attached to the surface of the ash residue; then, the washing system 6 performs a filtration operation on the uniform slurry to obtain a filter cake.

[0037] Furthermore, the pickling system 7 performs pickling and filtration treatment on the filter cake as follows: The pickling system 7 first uniformly mixes the filter cake with a mixed acid; the mixed acid is a mixture of hydrochloric acid and sulfuric acid in a 3:1 ratio, and the ratio of the mixed acid to the filter cake is 3:1 to 5:1 when the mixed acid and filter cake are uniformly mixed; after the filter cake and mixed acid are uniformly mixed, a reaction begins, and the internal temperature of the pickling system 7 is controlled at 30 to 45°C during the reaction; the reaction time of the filter cake and mixed acid is 60 to 90 minutes, and the pH value of the reaction environment is maintained above 4.5 during the reaction. During the reaction, calcium in the filter cake is partially leached out, and bound potassium and sodium are leached out, finally obtaining an acid slurry; then, the pickling system 7 filters the acid slurry to obtain pretreated ash residue.

[0038] This invention utilizes a water washing system and an acid washing system to preliminarily remove free and bound K and Na impurities by taking advantage of the differences in reactivity and solubility of K and Na with calcium and magnesium. This avoids the impact of K and Na impurities on the reduction reaction and improves the extraction rate of effective resources in the purified ash.

[0039] In summary, this invention reduces the environmental impact of flue gas and ash residue generated from the incineration of purified ash by further treating them. Simultaneously, it effectively extracts metallic magnesium, potassium, and sodium through a reduction reaction of the ash residue, achieving comprehensive utilization of the effective components in the purified ash. Furthermore, by using the heat from the flue gas generated after the incineration of purified ash in the reduction reaction of the ash residue, this invention effectively reduces the external energy supply required for the ash residue reduction reaction and improves the efficiency of comprehensive resource utilization.

[0040] The parts of this invention not described in detail are common knowledge to those skilled in the art.

Claims

1. A comprehensive utilization device for calcium carbide purification ash resources, characterized in that... include: Incinerator (1), secondary combustion chamber (2), flue gas cooler (3), flue gas purification system (4), dust collector (5), water washing system (6), acid washing system (7), drying kiln (8), reduction tank (9), cooling heat exchange system and vacuum system (13); The incinerator (1) is used to incinerate purified ash; The purification ash produces flue gas and ash residue after incineration; The flue gas generated after the ash is incinerated enters the secondary combustion chamber (2) from the incinerator (1) to raise the flue gas temperature; then, the flue gas enters the flue gas cooler (3) from the secondary combustion chamber (2) to cool down; finally, the flue gas enters the flue gas purification system (4) from the flue gas cooler (3) to desulfurize and denitrify, and becomes clean flue gas. Clean flue gas enters the drying kiln (8) for waste heat utilization, and after waste heat utilization, it is discharged into the atmosphere through the dust collector (5); The ash residue produced after the purification ash is incinerated first enters the water washing system (6) from the incinerator (1) for water washing and filtration treatment to obtain filter cake; Then, the filter cake enters the pickling system (7) for pickling and filtration to obtain pretreated ash residue; the pretreated ash residue enters the drying kiln (8) for drying to obtain dried ash residue; the dried ash residue enters the reduction tank (9); the reduction tank (9) uses the flue gas temperature generated by the secondary combustion chamber (2) and the flue gas cooler (3) to cause the dried ash residue to undergo a reduction reaction with the reducing agent to generate metallic magnesium, potassium vapor and sodium vapor; the potassium vapor and sodium vapor then enter the cooling heat exchange system and condense to obtain metallic potassium and metallic sodium; the vacuum system (13) provides a vacuum environment for the reduction tank (9) and the cooling heat exchange system.

2. The comprehensive utilization equipment for calcium carbide purification ash resources according to claim 1, characterized in that: The reduction tank (9) is divided into three sections, namely the first pipe section, the second pipe section and the third pipe section; the first pipe section, the second pipe section and the third pipe section are connected in sequence through expansion joints; the first pipe section is located inside the secondary combustion chamber (2), the second pipe section is located inside the flue gas cooler (3), and the third pipe section is fitted with a circulating water cooling jacket. The dried ash reacts with the reducing agent in the first section to produce magnesium vapor, potassium vapor, and sodium vapor. The magnesium vapor, potassium vapor, and sodium vapor then enter the second section, where the magnesium vapor condenses into liquid magnesium. The liquid magnesium, potassium vapor, and sodium vapor then enter the third section, where the liquid magnesium condenses into metallic magnesium. Finally, the potassium vapor and sodium vapor are transferred to the cooling heat exchange system.

3. The comprehensive utilization equipment for calcium carbide purification ash resources according to claim 2, characterized in that: The incinerator (1) burns purified ash at a temperature of 850 to 1050°C; the flue gas in the secondary combustion chamber (2) is at a temperature of 1100 to 1400°C; the flue gas in the flue gas cooler (3) is at a temperature of 800 to 900°C; the pressure in the first section of the reduction tank (9) is absolute pressure of 1 to 25 Pa; and the temperature in the third section of the reduction tank (9) is at a temperature of 400 to 600°C.

4. The comprehensive utilization equipment for calcium carbide purification ash resources according to claim 2, characterized in that: The reducing agent that reacts with the dry ash is ferrosilicon, and the catalyst used in the reduction reaction is fluorite; the molar ratio of the reducing agent to magnesium oxide in the dry ash is 2.2:1 to 3:1; the amount of catalyst used is 1-3% of the sum of the amounts of dry ash and reducing agent used.

5. The equipment for comprehensive utilization of calcium carbide purification ash resources according to claim 1, characterized in that: The cooling and heat exchange system includes a primary cooling heat exchanger (10), a secondary cooling heat exchanger (11), and a heat jacket (16); the primary cooling heat exchanger (10) and the secondary cooling heat exchanger (11) are connected by a pipe with the heat jacket (16) externally mounted; the inlet of the primary cooling heat exchanger (10) is connected to the outlet of the reduction tank (9) by a pipe, and the outlet of the secondary cooling heat exchanger (11) is connected to the vacuum system (13) by a pipe; the heat jacket (16) is used to heat the pipe when the potassium-sodium mixture blocks the pipe, thereby melting the potassium-sodium mixture to clear the pipe. When potassium vapor and sodium vapor enter the cooling heat exchange system, they first enter the primary cooling heat exchanger (10). The primary cooling heat exchanger (10) uses a primary refrigerant to cool the potassium vapor and sodium vapor to 150 to 200°C, and they condense into liquid potassium and liquid sodium, respectively. The liquid potassium and liquid sodium then enter the secondary cooling heat exchanger (11). The secondary cooling heat exchanger (11) uses a secondary refrigerant to cool the liquid potassium and liquid sodium to below 50°C, and they condense into metallic potassium and metallic sodium, respectively.

6. The comprehensive utilization equipment for calcium carbide purification ash resource as described in claim 5, characterized in that: The cooling and heat exchange system also includes a backup cooling heat exchanger (12), two main valves (14) and two backup valves (15). The inlet of the standby cooling heat exchanger (12) is connected to the outlet of the reduction tank (9) through a pipe with an external heat jacket (16), and the outlet of the standby cooling heat exchanger (12) is connected to the vacuum system (13) through a pipe; a standby valve (15) is provided on the pipe connecting the standby cooling heat exchanger (12) and the reduction tank (9), and a standby valve (15) is provided on the pipe connecting the standby cooling heat exchanger (12) and the vacuum system (13); a main valve (14) is provided on the pipe connecting the primary cooling heat exchanger (10) and the reduction tank (9), and a main valve (14) is provided on the pipe connecting the secondary cooling heat exchanger (11) and the vacuum system (13).

7. The comprehensive utilization equipment for calcium carbide purification ash resources according to claim 6, characterized in that: When there is no fault in the pipelines where the primary cooling heat exchanger (10) and the secondary cooling heat exchanger (11) are located, the two main pipeline valves (14) are in the open state and the two backup pipeline valves (15) are in the closed state; the cooling heat exchange system uses the primary cooling heat exchanger (10) and the secondary cooling heat exchanger (11) to cool potassium vapor and sodium vapor to obtain metallic potassium and metallic sodium. When the pipelines of the primary cooling heat exchanger (10) and the secondary cooling heat exchanger (11) malfunction, the two main valves (14) are closed and the two backup valves (15) are open; the cooling heat exchange system uses the backup cooling heat exchanger (12) to cool potassium vapor and sodium vapor to obtain metallic potassium and metallic sodium.

8. The comprehensive utilization equipment for calcium carbide purification ash resource as described in claim 6, characterized in that: When the vacuum system (13) is used to extract air from the reduction tank (9), both main valves (14) and two backup valves (15) are open to speed up the extraction. When the reduction tank (9) reaches the predetermined vacuum level, the two backup valves (15) are closed.

9. The comprehensive utilization equipment for calcium carbide purification ash resources according to claim 1, characterized in that: The washing system (6) washes and filters the ash residue as follows: The washing system (6) first adds clean water to the ash residue; the temperature of the clean water is 25 to 35°C, the pH value is 7.5-8.0, and the clean water is aerated in advance to remove carbon dioxide; the ratio of the clean water to the ash residue is 3:1 to 6:1; the ash residue after adding clean water forms a uniform slurry, thereby removing the free potassium and sodium impurities originally attached to the surface of the ash residue; then, the washing system (6) filters the uniform slurry to obtain a filter cake.

10. The comprehensive utilization equipment for calcium carbide purification ash resources according to claim 1, characterized in that: The pickling system (7) performs pickling and filtration on the filter cake as follows: The pickling system (7) first mixes the filter cake with the mixed acid in a uniform manner; the mixed acid is a mixture of hydrochloric acid and sulfuric acid in a ratio of 3:

1. When the mixed acid and the filter cake are mixed in a uniform manner, the ratio of the mixed acid to the filter cake is 3:1 to 5:

1. After the filter cake and the mixed acid are mixed in a uniform manner, a reaction begins. During the reaction, the pickling system (7) controls its internal temperature at 30 to 45°C. The reaction time between the filter cake and the mixed acid is 60 to 90 minutes. During the reaction, the pH value of the reaction environment is maintained above 4.

5. During the reaction, some of the calcium in the filter cake is leached out, and the bound potassium and sodium are leached out, finally obtaining the acid slurry. After that, the pickling system (7) filters the acid slurry to obtain pretreated ash residue.

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