Method and device for coupling and recycling sodium sulfate and carbide slag in coal chemical industry
By coupling the sodium sulfate salt of coal chemical industry with calcium carbide slag, sodium hydroxide, sodium chloride and calcium sulfate, the problem of insufficient resource utilization in the coal chemical industry is solved, and efficient resource utilization and environmental protection are achieved.
Patent Information
- Application Number
- CN202411597302.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-11
- Publication Date
- 2024-12-17
AI Technical Summary
In the coal chemical industry, the treatment of sodium sulfate salt and calcium carbide slag has insufficient resource utilization, resulting in high costs and environmental pollution problems.
By coupling the sodium sulfate salt produced by the wastewater treatment device of coal chemical enterprises with the calcium carbide slag produced by the acetylene enterprise of the calcium carbide method, sodium hydroxide, sodium chloride and calcium sulfate, these compounds are used for resource reuse, such as in construction , used in papermaking, chemical industry and agriculture.
It effectively reduces the treatment cost of sodium sulfate salt and calcium carbide slag, reduces wastewater pollution, improves resource utilization, and reduces the demand for wood and soil alkalinity, and improves soil performance.
Smart Images
Figure CN119143167A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of coupled recycling of sodium sulfate and carbide slag, and specifically relates to a method and device for coupled recycling of coal chemical sodium sulfate salt and carbide slag. Background Art
[0002] The basic situation of my country's resources is "lack of oil, little gas, and relatively rich in coal", so coal has become one of the most important energy and chemical raw materials in my country. Therefore, using coal as a raw material and implementing clean and efficient utilization of coal resources are of great significance to maintaining the rapid growth of my country's economy and ensuring the country's energy security. The rapid development of the coal industry has not only brought into play the advantages of my country's coal resources, but also made a large supplement to oil and natural gas resources, ensuring my country's energy security and playing an important role in the field of sustainable development.
[0003] With the continuous development of the coal chemical industry, the consumption of water resources in the coal chemical industry is also gradually increasing, and the problem that follows is the generation of high-salt wastewater. Most of my country's coal is mainly concentrated in the northwest of Shaanxi, Gansu and Ningxia and Xinjiang, but the ecological environment there is fragile and water resources are quite scarce, accounting for only about 20% of the total water resources in the country. Therefore, the treatment of high-salt wastewater from coal chemical industry and water recycling are extremely important. With the strengthening of environmental protection efforts and the deepening of the concept of sustainable development, the requirements for zero discharge of wastewater are getting higher and higher. However, the sodium sulfate salt produced by wastewater treatment is temporarily managed as solid waste and sent to a qualified solid waste disposal center for treatment or landfill. However, there are few qualified treatment centers, limited treatment capacity, and high treatment costs. The treatment cost of each ton of sodium sulfate salt is about 500 to 1,000 yuan; protected by the traditional salt industry, it is difficult to find a suitable way to utilize the sodium sulfate salt produced by the by-product.
[0004] In addition, with the growing demand for polyvinyl chloride and 1,4-butanediol in my country, the industry has entered a period of rapid development. In 2023, my country's total PVC production capacity will reach 28.81 million tons / year, and BDO production capacity will reach 3.453 million tons / year, both ranking first in the world. Among them, the production of acetylene from coal-to-carbide and then PVC, BDO and other downstream products is an important part of the comprehensive utilization of coal resources. The carbide acetylene route accounts for about 80% of the total PVC production capacity and more than 90% of the total BDO production capacity. The pollution problem of solid waste carbide slag (the main component is calcium hydroxide) generated in the production process of carbide is becoming increasingly prominent. Taking the carbide acetylene method PVC as an example, about 1.2 tons of carbide slag are produced as a by-product for every ton of PVC produced. The huge amount of carbide slag solid waste has seriously restricted the sustainable development of the industry. Summary of the invention
[0005] Based on the existing technical problems, the present invention provides a method and device for coupling and recycling coal chemical sodium sulfate salt and carbide slag. The present invention couples the sodium sulfate salt produced by the wastewater treatment device of the coal chemical enterprise with the carbide slag produced by the carbide process acetylene production enterprise, and simultaneously produces sodium hydroxide, sodium chloride and calcium sulfate, so that the sodium sulfate waste salt and carbide slag solid waste are effectively utilized as resources. Calcium sulfate can be used in the construction industry for building materials, thermal insulation materials, coatings, reinforcing materials, etc.; it can also be used in the papermaking industry to replace part or most of the pulp, which can greatly reduce wood consumption, is beneficial to environmental protection, and reduces wastewater pollution; it can also be used in the chemical industry as a reinforcing material; it can be used in agriculture as a fertilizer, which can reduce soil alkalinity and improve soil performance. Sodium hydroxide can be used for coal chemical wastewater treatment, and sodium chloride is further sent to the coal chemical wastewater treatment device to prepare high-purity sodium chloride salt.
[0006] In order to solve the above technical problems, the technical solution of the present invention is as follows: A method for coupling and recycling coal chemical sodium sulfate and carbide slag, comprising the following steps: (1) Carbide slag slurry preparation: Carbide slag and water are mixed and stirred to prepare slurry to obtain carbide slag slurry a and carbide slag slurry b; (2) adding sodium sulfate to the carbide slag slurry a obtained in step (1) to react the sodium sulfate with the calcium hydroxide in the carbide slag slurry to generate calcium sulfate and sodium hydroxide, and obtaining a sodium hydroxide turbid solution and a calcium sulfate precipitation slurry a; adding hydrochloric acid to the carbide slag slurry b obtained in step (1) to obtain a calcium chloride turbid solution and a carbide residue slurry; (3) the turbid sodium hydroxide solution of step (2) is passed into a sodium hydroxide clarification tank for clarification to obtain a sodium hydroxide clear solution; the turbid calcium chloride solution obtained in step (2) is passed into a calcium chloride clarification tank for clarification to obtain a calcium chloride clear solution, the calcium chloride clear solution enters a calcium chloride reaction tank, and sodium sulfate is added to the calcium chloride reaction tank to obtain a calcium sulfate precipitation slurry b and a sodium chloride solution, the sodium chloride solution is passed into a sodium chloride clarification tank for clarification to obtain a sodium chloride clear solution; (4) The sodium hydroxide clear solution obtained in step (3) is sent to a coal chemical wastewater treatment device for pH adjustment; the sodium chloride clear solution obtained in step (3) is sent to an evaporation crystallization device or a nanofiltration device of the coal chemical wastewater treatment device; (5) The calcium sulfate precipitation slurry a obtained in step (2) and the calcium sulfate precipitation slurry b obtained in step (3) are respectively sent to the deliquating device a and the deliquating device c for deliquating to obtain calcium sulfate product a and calcium sulfate product b respectively. The calcium carbide residue slurry in step (2) is sent to the deliquating device b for deliquating; the sodium hydroxide solution removed by the deliquating device a is sent to the sodium hydroxide clarification tank, the calcium chloride solution removed by the deliquating device b is sent to the calcium chloride clarification tank, and the sodium chloride solution removed by the deliquating device c is sent to the sodium chloride clarification tank.
[0007] Furthermore, the sodium sulfate is a sodium sulfate solution or a sodium sulfate solid, and the sodium sulfate is sodium sulfate produced by a coal chemical wastewater treatment device.
[0008] A device for coupling and recycling sodium sulfate and carbide slag in coal chemical industry, comprising a carbide slag reaction pool and a deliquescence device, wherein the carbide slag reaction pool comprises a carbide slag reaction pool a and a carbide slag reaction pool b, and the deliquescence device comprises a deliquescence device a, a deliquescence device b, and a deliquescence device c, wherein the carbide slag reaction pool a, a sodium hydroxide clarification pool, and a sodium hydroxide clear liquid pool are smoothly connected in sequence; the sodium hydroxide clear liquid pool is connected to a coal chemical industry wastewater treatment device; the carbide slag reaction pool b, a calcium chloride clarification pool, a calcium chloride reaction pool, a sodium chloride clarification pool, a sodium chloride clear liquid pool, and an evaporation crystallization device or a nanofiltration device of the coal chemical industry wastewater treatment device are sequentially connected, and the carbide slag reaction pool a is connected by a nanofiltration device. The pipeline is connected with the deliquidation device a, the liquid outlet of the deliquidation device a is connected to the inlet of the sodium hydroxide buffer tank through the pipeline, and the outlet of the sodium hydroxide buffer tank is connected to the sodium hydroxide clarification tank through the pipeline and the sodium hydroxide pump; the calcium carbide slag reaction tank b is connected with the deliquidation device b through the pipeline, the liquid outlet of the deliquidation device b is connected to the inlet of the calcium chloride buffer tank through the pipeline, and the outlet of the calcium chloride buffer tank is connected to the calcium chloride clarification tank through the pipeline and the calcium chloride pump; the calcium chloride reaction tank is connected with the deliquidation device c through the pipeline, the liquid outlet of the deliquidation device c is connected to the inlet of the sodium chloride buffer tank through the pipeline, and the outlet of the sodium chloride buffer tank is connected to the sodium chloride clarification tank through the pipeline and the sodium chloride pump.
[0009] The carbide slag reaction tank a and the calcium chloride reaction tank are both provided with sodium sulfate adding devices, and the carbide slag reaction tank b is provided with a hydrochloric acid adding pipeline.
[0010] Furthermore, stirring devices are provided in the carbide slag reaction tank a, the carbide slag reaction tank b and the calcium chloride reaction tank.
[0011] Furthermore, the deliquoring device is a plate and frame filter press, a chamber filter press, a vertical filter press, or a belt filter press.
[0012] Furthermore, the bottom of the sodium hydroxide clarification tank, the bottom of the calcium chloride clarification tank, and the bottom of the sodium chloride clarification tank are configured as conical structures, and are respectively connected to the deliquidation device a, the deliquidation device b, and the deliquidation device c through pipelines.
[0013] Furthermore, the sodium sulfate adding devices are all connected to the nanofiltration device of the coal chemical wastewater treatment device, and the nanofiltration device provides sodium sulfate solution for the carbide slag reaction tank a and the calcium chloride reaction tank.
[0014] Furthermore, the sodium sulfate adding devices are connected to the sodium sulfate freezing crystallization device of the coal chemical wastewater treatment device, and the sodium sulfate freezing crystallization device provides solid sodium sulfate for the carbide slag reaction tank a and the calcium chloride reaction tank. Beneficial Effects
[0015] 1. The present invention couples sodium sulfate salt produced by a coal chemical wastewater treatment device with carbide slag to simultaneously produce sodium hydroxide, sodium chloride and calcium sulfate. The produced sodium hydroxide is used in the coal chemical wastewater treatment device to adjust the pH, and the produced sodium chloride clear liquid is sent to the coal chemical wastewater treatment device for evaporation and crystallization to produce high-purity sodium chloride salt, or the produced sodium chloride clear liquid is sent to a nanofiltration device of the coal chemical wastewater treatment device for concentration and purification, and then sent to evaporation and crystallization to produce high-purity sodium chloride salt; calcium sulfate is used in construction, papermaking, chemical industry and agriculture, etc. Calcium sulfate is used in the construction industry for building materials, heat insulation materials, coatings, reinforcing materials, etc.; it is used in the papermaking industry to replace part or most of the pulp, which can greatly reduce wood consumption, is beneficial to environmental protection, and reduces wastewater pollution; it can be used in the chemical industry as a reinforcing material; it can be used in agriculture as a fertilizer, which can reduce soil alkalinity and improve soil performance. The present invention enables the sodium sulfate waste salt and carbide slag solid waste produced by the coal chemical wastewater treatment device to be effectively utilized as resources.
[0016] 2. The present invention reacts carbide slag with hydrochloric acid, clarifies the turbid calcium chloride solution obtained by the reaction, and then reacts with sodium sulfate to produce calcium sulfate precipitate and sodium chloride solution. This method separates most of the impurities in the carbide slag from calcium, thereby obtaining high-purity calcium sulfate, which can be used in the chemical industry or the papermaking industry.
[0017] 3. The present invention directly reacts carbide slag with sodium sulfate, and while producing sodium hydroxide, calcium sulfate is mixed with the carbide residue, thereby obtaining low-purity calcium sulfate, which can be used in construction and agriculture.
[0018] 4. The present invention can also be flexibly adjusted according to the purity of calcium hydroxide in carbide slag. When the purity of calcium hydroxide is high, it can be used to prepare calcium sulfate and sodium chloride. When the purity of calcium hydroxide is low, it can be used to prepare calcium sulfate and sodium hydroxide. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a schematic diagram of the structure of the present invention a; Figure 2 It is a structural schematic diagram b of the present invention; In the figure: 1-carbide slag reaction tank a; 2-sodium hydroxide clarification tank; 3-sodium hydroxide clear liquid tank; 4-coal chemical wastewater treatment device; 5-dehydration device a; 6-sodium hydroxide buffer tank; 7-sodium hydroxide pump; 8-carbide slag reaction tank b; 9-calcium chloride clarification tank; 10-calcium chloride reaction tank; 11-sodium chloride clarification tank; 12-sodium chloride clear liquid tank; 13-evaporation crystallization device; 14-dehydration device b; 15-calcium chloride buffer tank; 16-calcium chloride pump; 17-dehydration device c; 18-sodium chloride buffer tank; 19-sodium chloride pump; 20-hydrochloric acid addition pipeline; 21-sodium sulfate addition device; 22-nanofiltration device. DETAILED DESCRIPTION Example 1
[0020] Reference Figure 1 In order to effectively utilize the sodium sulfate solid waste resources and carbide slag solid waste resources generated by the coal chemical wastewater treatment device, the two are coupled to simultaneously produce sodium hydroxide, sodium chloride and calcium sulfate, thereby reducing the cost of enterprises in processing sodium sulfate solid waste and carbide slag solid waste. The present invention provides a method for coupling and reusing coal chemical sodium sulfate salt and carbide slag, comprising the following steps: (1) Carbide slag slurry preparation: Carbide slag and water are mixed and stirred to prepare slurry to obtain carbide slag slurry a and carbide slag slurry b; (2) adding sodium sulfate to the carbide slag slurry a obtained in step (1) to react the sodium sulfate with the calcium hydroxide in the carbide slag slurry to generate calcium sulfate and sodium hydroxide, and obtaining a sodium hydroxide turbid solution and a calcium sulfate precipitation slurry a; adding hydrochloric acid to the carbide slag slurry b obtained in step (1) to obtain a calcium chloride turbid solution and a carbide residue slurry; (3) the turbid sodium hydroxide solution of step (2) is passed into a sodium hydroxide clarification tank 2 for clarification to obtain a sodium hydroxide clear solution; the turbid calcium chloride solution obtained in step (2) is passed into a calcium chloride clarification tank 9 for clarification to obtain a calcium chloride clear solution, the calcium chloride clear solution enters a calcium chloride reaction tank 10, and sodium sulfate is added to the calcium chloride reaction tank 10 to obtain a calcium sulfate precipitation slurry b and a sodium chloride solution, the sodium chloride solution is passed into a sodium chloride clarification tank 11 for clarification to obtain a sodium chloride clear solution; (4) The sodium hydroxide clear solution obtained in step (3) is sent to the coal chemical wastewater treatment device 4 for pH adjustment; the sodium chloride clear solution obtained in step (3) is sent to the evaporation crystallization device 13 of the coal chemical wastewater treatment device 4; (5) The calcium sulfate precipitation slurry a obtained in step (2) and the calcium sulfate precipitation slurry b obtained in step (3) are respectively sent to the deliquating device a5 and the deliquating device c17 for deliquating to obtain calcium sulfate product a and calcium sulfate product b respectively. The calcium carbide residue slurry in step (2) is sent to the deliquating device b14 for deliquating; the sodium hydroxide solution removed by the deliquating device a5 is sent to the sodium hydroxide clarification tank 2, the calcium chloride solution removed by the deliquating device b14 is sent to the calcium chloride clarification tank 9, and the sodium chloride solution removed by the deliquating device c17 is sent to the sodium chloride clarification tank 11.
[0021] The sodium sulfate is a sodium sulfate solution, and the sodium sulfate is sodium sulfate produced by the nanofiltration device 22 of the coal chemical wastewater treatment device 4.
[0022] A device for coupling and recycling sodium sulfate and carbide slag in coal chemical industry, comprising a carbide slag reaction tank and a deliquescence device, wherein the carbide slag reaction tank comprises a carbide slag reaction tank a1 and a carbide slag reaction tank b8, and the carbide slag reaction tank also has a pulping function, so that the carbide slag is configured into slurry; the deliquescence device comprises a deliquescence device a5, a deliquescence device b14, and a deliquescence device c17, and the deliquescence device is a plate and frame filter press, so that the solid and liquid after the reaction are separated; the carbide slag reaction tank a1, the sodium hydroxide clarification tank 2, and the sodium hydroxide clear liquid tank 3 are smoothly connected in sequence; the sodium hydroxide clear liquid tank 3 is connected to a coal chemical wastewater treatment device 4, so that the sodium hydroxide clear liquid is used in the coal chemical wastewater treatment device 4 to adjust the pH; the carbide slag reaction tank b8, the calcium chloride clarification tank 9, the calcium chloride reaction tank 10, the sodium chloride clarification tank 11, the sodium chloride clear liquid tank 12, the coal chemical wastewater treatment device 4 is connected to the sodium hydroxide ...13, the sodium hydroxide clarification tank 14, the sodium hydroxide clarification tank 15, the sodium hydroxide clarification tank 16, the sodium hydroxide clarification tank 17, the sodium hydroxide clarification tank 18, the sodium hydroxide clarification tank 19, the sodium hydroxide clarification tank 20, the sodium hydroxide clarification tank 21, the sodium hydroxide clarification tank 22, the sodium hydroxide clarification tank 23, the sodium hydroxide clarification tank 24, the sodium hydroxide clarification tank 25 The evaporation crystallization device 13 of the treatment device 4 is connected in sequence. The carbide slag reaction tank a1 is connected with the deliquidation device a5 through a pipeline. The liquid outlet of the deliquidation device a5 is connected to the inlet of the sodium hydroxide buffer tank 6 through a pipeline. The outlet of the sodium hydroxide buffer tank 6 is connected to the sodium hydroxide clarification tank 2 through a pipeline and a sodium hydroxide pump 7; the carbide slag reaction tank b8 is connected with the deliquidation device b14 through a pipeline. The liquid outlet of the deliquidation device b14 is connected to the inlet of the calcium chloride buffer tank 15 through a pipeline. The outlet of the calcium chloride buffer tank 15 is connected to the calcium chloride clarification tank 9 through a pipeline and a calcium chloride pump 16; the calcium chloride reaction tank 10 is connected with the deliquidation device c17 through a pipeline. The liquid outlet of the deliquidation device c17 is connected to the inlet of the sodium chloride buffer tank 18 through a pipeline. The outlet of the sodium chloride buffer tank 18 is connected to the sodium chloride clarification tank 11 through a pipeline and a sodium chloride pump 19.
[0023] The carbide slag reaction pool a1 and the calcium chloride reaction pool 10 are both connected to the sodium sulfate adding device 21, so that the sodium sulfate salt produced by the coal chemical wastewater treatment device 4 can be added to the carbide slag reaction pool a1 and the calcium chloride reaction pool 10, and a hydrochloric acid adding pipeline 20 is set on the carbide slag reaction pool b8.
[0024] Stirring devices are provided in the carbide slag reaction tank a1, the carbide slag reaction tank b8 and the calcium chloride reaction tank 10 to enable the reaction to proceed fully.
[0025] The bottom of the sodium hydroxide clarification tank 2, the bottom of the calcium chloride clarification tank 9, and the bottom of the sodium chloride clarification tank 11 are set as a conical structure, and are respectively connected to the deliquating device a5, the deliquating device b14, and the deliquating device c17 through pipelines, so that the calcium sulfate sludge at the bottom of the sodium hydroxide clarification tank 2, the calcium carbide residue sludge at the bottom of the calcium chloride clarification tank 9, and the calcium sulfate sludge at the bottom of the sodium chloride clarification tank 11 can be discharged and deliquated.
[0026] The sodium sulfate adding device 21 is connected to the nanofiltration device 22 of the coal chemical wastewater treatment device 4 , and the nanofiltration device 22 provides sodium sulfate solution for the carbide slag reaction tank a1 and the calcium chloride reaction tank 10 . Example 2
[0027] Reference Figure 2 In order to effectively utilize the sodium sulfate solid waste resources and carbide slag solid waste resources generated by the coal chemical wastewater treatment device, the two are coupled to simultaneously produce sodium hydroxide, sodium chloride and calcium sulfate, thereby reducing the cost of enterprises in processing sodium sulfate solid waste and carbide slag solid waste. The present invention provides a method for coupling and reusing coal chemical sodium sulfate salt and carbide slag, comprising the following steps: (1) Carbide slag slurry preparation: Carbide slag and water are mixed and stirred to prepare slurry to obtain carbide slag slurry a and carbide slag slurry b; (2) adding sodium sulfate to the carbide slag slurry a obtained in step (1) to react the sodium sulfate with the calcium hydroxide in the carbide slag slurry to generate calcium sulfate and sodium hydroxide, and obtaining a sodium hydroxide turbid solution and a calcium sulfate precipitation slurry a; adding hydrochloric acid to the carbide slag slurry b obtained in step (1) to obtain a calcium chloride turbid solution and a carbide residue slurry; (3) the turbid sodium hydroxide solution of step (2) is passed into a sodium hydroxide clarification tank 2 for clarification to obtain a sodium hydroxide clear solution; the turbid calcium chloride solution obtained in step (2) is passed into a calcium chloride clarification tank 9 for clarification to obtain a calcium chloride clear solution, the calcium chloride clear solution enters a calcium chloride reaction tank 10, and sodium sulfate is added to the calcium chloride reaction tank 10 to obtain a calcium sulfate precipitation slurry b and a sodium chloride solution, the sodium chloride solution is passed into a sodium chloride clarification tank 11 for clarification to obtain a sodium chloride clear solution; (4) The sodium hydroxide clear liquid obtained in step (3) is sent to the coal chemical wastewater treatment device 4 for pH adjustment; the sodium chloride clear liquid obtained in step (3) is sent to the nanofiltration device 22 of the coal chemical wastewater treatment device 4, and the nanofiltration device 22 concentrates and purifies the sodium chloride clear liquid and then sends it to the evaporation crystallization device 13; (5) The calcium sulfate precipitation slurry a obtained in step (2) and the calcium sulfate precipitation slurry b obtained in step (3) are respectively sent to the deliquating device a5 and the deliquating device c17 for deliquating to obtain calcium sulfate product a and calcium sulfate product b respectively. The calcium carbide residue slurry in step (2) is sent to the deliquating device b14 for deliquating; the sodium hydroxide solution removed by the deliquating device a5 is sent to the sodium hydroxide clarification tank 2, the calcium chloride solution removed by the deliquating device b14 is sent to the calcium chloride clarification tank 9, and the sodium chloride solution removed by the deliquating device c17 is sent to the sodium chloride clarification tank 11.
[0028] The sodium sulfate is sodium sulfate solid, and the sodium sulfate is sodium sulfate solid produced by the sodium sulfate freezing crystallization device of the coal chemical wastewater treatment device 4.
[0029] A device for coupling and recycling sodium sulfate and carbide slag in coal chemical industry, comprising a carbide slag reaction tank and a deliquescence device, wherein the carbide slag reaction tank comprises a carbide slag reaction tank a1 and a carbide slag reaction tank b8, and the carbide slag reaction tank also has a pulping function, so that the carbide slag is configured into a slurry; the deliquescence device comprises a deliquescence device a5, a deliquescence device b14, and a deliquescence device c17, and the deliquescence device is a chamber filter press, so that the solid and liquid after the reaction are separated; the carbide slag reaction tank a1, a sodium hydroxide clarification tank 2, and a sodium hydroxide clear liquid tank 3 are smoothly connected in sequence; the sodium hydroxide clear liquid tank 3 is connected to a coal chemical wastewater treatment device 4, so that the sodium hydroxide clear liquid is used in the coal chemical wastewater treatment device 4 to adjust the pH; the carbide slag reaction tank b8, a calcium chloride clarification tank 9, a calcium chloride reaction tank 10, a sodium chloride clarification tank 11, a sodium chloride clear liquid tank 12, and a nanofiltration device 22 of the coal chemical wastewater treatment device 4 are connected in sequence, and the nanofiltration device 22 is connected through a pipe The channel is connected to the evaporation crystallization device 13; the sodium chloride clear liquid is concentrated and purified in the nanofiltration device 22 and then sent to the evaporation crystallization device 13 to produce sodium chloride; the calcium carbide slag reaction tank a1 is connected to the deliquescence device a5 through a pipeline, the liquid outlet of the deliquescence device a5 is connected to the inlet of the sodium hydroxide buffer tank 6 through a pipeline, and the outlet of the sodium hydroxide buffer tank 6 is connected to the sodium hydroxide clarification tank 2 through a pipeline and a sodium hydroxide pump 7; the calcium carbide slag reaction tank b8 is connected to the deliquescence device b14 through a pipeline, the liquid outlet of the deliquescence device b14 is connected to the inlet of the calcium chloride buffer tank 15 through a pipeline, and the outlet of the calcium chloride buffer tank 15 is connected to the calcium chloride clarification tank 9 through a pipeline and a calcium chloride pump 16; the calcium chloride reaction tank 10 is connected to the deliquescence device c17 through a pipeline, the liquid outlet of the deliquescence device c17 is connected to the inlet of the sodium chloride buffer tank 18 through a pipeline, and the outlet of the sodium chloride buffer tank 18 is connected to the sodium chloride clarification tank 11 through a pipeline and a sodium chloride pump 19.
[0030] The carbide slag reaction pool a1 and the calcium chloride reaction pool 10 are both connected to the sodium sulfate adding device 21, so that the sodium sulfate salt produced by the coal chemical wastewater treatment device 4 can be added to the carbide slag reaction pool a1 and the calcium chloride reaction pool 10, and a hydrochloric acid adding pipeline 20 is set on the carbide slag reaction pool b8.
[0031] Stirring devices are provided in the carbide slag reaction tank a1, the carbide slag reaction tank b8 and the calcium chloride reaction tank 10 to enable the reaction to proceed fully.
[0032] The bottom of the sodium hydroxide clarification tank 2, the bottom of the calcium chloride clarification tank 9, and the bottom of the sodium chloride clarification tank 11 are set as a conical structure, and are respectively connected to the deliquating device a5, the deliquating device b14, and the deliquating device c17 through pipelines, so that the calcium sulfate sludge at the bottom of the sodium hydroxide clarification tank 2, the calcium carbide residue sludge at the bottom of the calcium chloride clarification tank 9, and the calcium sulfate sludge at the bottom of the sodium chloride clarification tank 11 can be discharged and deliquated.
[0033] The sodium sulfate adding device 21 is connected to the sodium sulfate freezing crystallization device of the coal chemical wastewater treatment device 4, and the sodium sulfate freezing crystallization device provides solid sodium sulfate for the carbide slag reaction tank a1 and the calcium chloride reaction tank 10.
[0034] Another embodiment is different from the embodiment 1 in that the deliquoring device is a vertical filter press.
[0035] Another embodiment is different from the embodiment 1 in that the deliquoring device is a belt filter press.
[0036] The working principle of the present invention is: the present invention couples the sodium sulfate salt produced by the coal chemical wastewater treatment device 4 with the calcium carbide slag to simultaneously produce sodium hydroxide, sodium chloride and calcium sulfate; the produced sodium hydroxide is used for adjusting the pH of the coal chemical wastewater treatment device 4; the produced sodium chloride clear liquid is sent to the evaporation crystallization of the coal chemical wastewater treatment device 4 to produce high-purity sodium chloride salt; or the produced sodium chloride clear liquid is sent to the nanofiltration device 22 of the coal chemical wastewater treatment device 4 for concentration and purification and then sent to evaporation crystallization to produce high-purity sodium chloride salt; calcium sulfate is used in construction, papermaking, chemical industry and agriculture, etc. The present invention enables the sodium sulfate waste salt and calcium carbide slag solid waste produced by the coal chemical wastewater treatment device 4 to be effectively utilized as resources, greatly reducing the production cost of enterprises for processing sodium sulfate waste salt and calcium carbide slag.
[0037] Modifications and changes to the present invention made by the inventors familiar with the present invention are all within the patent scope of the present invention and are not limited to the embodiments.
Claims
1. A method for coupling and recycling coal chemical sodium sulfate and carbide slag, characterized in that: The following steps are involved: (1) Carbide slag slurry preparation: Carbide slag and water are mixed and stirred to prepare slurry to obtain carbide slag slurry a and carbide slag slurry b; (2) adding sodium sulfate to the carbide slag slurry a obtained in step (1) to react the sodium sulfate with the calcium hydroxide in the carbide slag slurry to generate calcium sulfate and sodium hydroxide, and obtaining a sodium hydroxide turbid solution and a calcium sulfate precipitation slurry a; adding hydrochloric acid to the carbide slag slurry b obtained in step (1) to obtain a calcium chloride turbid solution and a carbide residue slurry; (3) passing the turbid sodium hydroxide solution of step (2) into a sodium hydroxide clarification tank for clarification to obtain a sodium hydroxide clear solution; passing the turbid calcium chloride solution obtained in step (2) into a calcium chloride clarification tank for clarification to obtain a calcium chloride clear solution, the calcium chloride clear solution enters a calcium chloride reaction tank, and sodium sulfate is added to the calcium chloride reaction tank to obtain a calcium sulfate precipitation slurry b and a sodium chloride solution, the sodium chloride solution enters a sodium chloride clarification tank for clarification to obtain a sodium chloride clear solution; (4) The sodium hydroxide clear solution obtained in step (3) is sent to a coal chemical wastewater treatment device for pH adjustment; the sodium chloride clear solution obtained in step (3) is sent to an evaporation crystallization device or a nanofiltration device of the coal chemical wastewater treatment device; (5) The calcium sulfate precipitation slurry a obtained in step (2) and the calcium sulfate precipitation slurry b obtained in step (3) are respectively sent to a dehydration device a and a dehydration device c for dehydration to obtain calcium sulfate product a and calcium sulfate product b, respectively. The calcium carbide residue slurry in step (2) is sent to a dehydration device b for dehydration; The sodium hydroxide solution removed by the deliquidation device a is sent to the sodium hydroxide clarification tank, the calcium chloride solution removed by the deliquidation device b is sent to the calcium chloride clarification tank, and the sodium chloride solution removed by the deliquidation device c is sent to the sodium chloride clarification tank.
2. The method for coupling and recycling coal chemical sodium sulfate and carbide slag according to claim 1, characterized in that: The sodium sulfate is a sodium sulfate solution or a sodium sulfate solid, and the sodium sulfate is sodium sulfate produced by a coal chemical wastewater treatment device.
3. A device for coupling and recycling coal chemical sodium sulfate and carbide slag, used to implement a method for coupling and recycling coal chemical sodium sulfate and carbide slag, characterized in that: It comprises a carbide slag reaction tank and a deliquating device, wherein the carbide slag reaction tank comprises a carbide slag reaction tank a and a carbide slag reaction tank b, and the deliquating device comprises a deliquating device a, a deliquating device b and a deliquating device c. The carbide slag reaction tank a, a sodium hydroxide clarification tank and a sodium hydroxide clear liquid tank are smoothly connected in sequence; the sodium hydroxide clear liquid tank is connected to a coal chemical wastewater treatment device; the carbide slag reaction tank b, a calcium chloride clarification tank, a calcium chloride reaction tank, a sodium chloride clarification tank, a sodium chloride clear liquid tank and an evaporation crystallization device or a nanofiltration device of the coal chemical wastewater treatment device are sequentially connected, and the carbide slag reaction tank a is connected to the deliquating device a through a pipeline. The liquid outlet of the deliquidation device a is connected to the inlet of the sodium hydroxide buffer tank through a pipeline, and the outlet of the sodium hydroxide buffer tank is connected to the sodium hydroxide clarifier through a pipeline and a sodium hydroxide pump; the calcium carbide slag reaction tank b is connected to the deliquidation device b through a pipeline, and the liquid outlet of the deliquidation device b is connected to the inlet of the calcium chloride buffer tank through a pipeline, and the outlet of the calcium chloride buffer tank is connected to the calcium chloride clarifier through a pipeline and a calcium chloride pump; the calcium chloride reaction tank is connected to the deliquidation device c through a pipeline, and the liquid outlet of the deliquidation device c is connected to the inlet of the sodium chloride buffer tank through a pipeline, and the outlet of the sodium chloride buffer tank is connected to the sodium chloride clarifier through a pipeline and a sodium chloride pump; The carbide slag reaction tank a and the calcium chloride reaction tank are both provided with sodium sulfate adding devices, and the carbide slag reaction tank b is provided with a hydrochloric acid adding pipeline.
4. The device for coupling and recycling coal chemical sodium sulfate and carbide slag according to claim 3 is characterized in that: Stirring devices are arranged in the carbide slag reaction tank a, the carbide slag reaction tank b and the calcium chloride reaction tank.
5. The device for coupling and recycling coal chemical sodium sulfate and carbide slag according to claim 3 is characterized in that: The deliquoring device is a plate-and-frame filter press, a chamber filter press, a vertical filter press, or a belt filter press.
6. The device for coupling and recycling coal chemical sodium sulfate and carbide slag according to claim 3 is characterized in that: The bottom of the sodium hydroxide clarification tank, the bottom of the calcium chloride clarification tank, and the bottom of the sodium chloride clarification tank are configured as conical structures, and are respectively connected to the deliquating device a, the deliquating device b, and the deliquating device c through pipelines.
7. A device for coupling and recycling coal chemical sodium sulfate and carbide slag according to any one of claims 3 to 6, characterized in that: The sodium sulfate adding devices are all connected to the nanofiltration device of the coal chemical wastewater treatment device, and the nanofiltration device provides sodium sulfate solution for the carbide slag reaction tank a and the calcium chloride reaction tank.
8. A device for coupling and recycling coal chemical sodium sulfate and carbide slag according to any one of claims 3 to 6, characterized in that: The sodium sulfate adding devices are all connected to the sodium sulfate freezing crystallization device of the coal chemical wastewater treatment device, and the sodium sulfate freezing crystallization device provides solid sodium sulfate for the carbide slag reaction tank a and the calcium chloride reaction tank.