A method for removing organic pollutants from industrial waste salt

Abstract

The present invention discloses a method for removing organic pollutants from industrial waste salt; it belongs to the technical field of industrial solid waste salt resource utilization. The method for removing organic pollutants from industrial waste salt of the present invention comprises sending industrial solid waste salt into a mixing device, and adding sodium hypochlorite to react; after the reaction, entering a drying device, and adding metal balls; the temperature of the drying device is 80-100°C, and the time is 0.5-2 hours; the dried industrial solid waste salt enters a thermal desorption device, in which the waste salt is heated to 550-650°C for 2-4 hours, and the waste salt from which the organic pollutants are removed enters a screening device; the metal balls and the waste salt are separated, and the separated waste salt enters a cooling device for subsequent treatment. The method avoids the problems of solid waste salt and macromolecular organic pollutants sticking to the wall, clogging, agglomeration / lumps, etc. during the thermal desorption process, so that the device can operate continuously and stably, solves the problem of air pollution, and reduces energy consumption.

Description

Technical Field

[0001] The invention relates to a method for removing organic pollutants from industrial waste salt, and belongs to the technical field of industrial solid waste salt resource utilization. Background Art

[0002] Industrial solid waste salt refers to solid salt recovered through evaporation and crystallization from highly concentrated, saline organic wastewater from the chemical, pharmaceutical, and pesticide industries. Records indicate that my country's total industrial solid waste salt output reached over 20 million tons in 2019. With my country's economic development and rising industrialization, the production of solid waste salt has also increased rapidly, with the chemical, pharmaceutical, and pesticide industries being major producers. During the evaporation and crystallization process of highly concentrated, saline organic wastewater, organic pollutants are carried in industrial waste salt to varying degrees through mechanisms such as entrapment, entrainment, and co-crystallization. Consequently, industrial waste salt is characterized by diverse sources, a wide variety of types, complex composition, high levels of toxic and hazardous substances, and severe environmental hazards. Directly discharged into the environment without treatment not only poses a threat to human health but also causes varying degrees of soil and air pollution, significantly damaging the ecological environment. Currently, many companies are forced to treat the solid salt they produce as hazardous waste, and the landfill disposal of solid waste salt results in significant resource waste and the risk of secondary pollution to the ecological environment. Because many companies are unable to promptly transfer and dispose of hazardous waste, waste accumulates year-round, placing a heavy economic burden on businesses and creating numerous environmental and safety risks. Sorting and comprehensively utilizing industrial solid waste salt will not only recycle industrial raw materials like sodium chloride and sodium sulfate, but will also significantly reduce the landfill load for hazardous waste salt and mitigate the risk of secondary environmental pollution, a significant advancement in its significance.

[0003] Given that the refined sodium chloride and sodium sulfate recovered as resources are mainly used in the chlor-alkali, glass, and papermaking industries, refined salt users have strict requirements on the content of organic pollutants in the recycled sodium chloride and sodium sulfate crystals. For sodium chloride used in the chlor-alkali industry, although the industry standard QB / T5270-2018 does not clearly stipulate the content of organic pollutants, chlor-alkali manufacturers generally require that the total organic carbon (TOC) content in refined sodium chloride be less than 30 mg / kg in order to protect ion membrane equipment from organic contamination, and the lower the TOC content, the better. Therefore, in order to achieve the maximum resource utilization of industrial solid waste salt, the organic pollutants in the industrial solid waste salt must first be removed.

[0004] High-temperature incineration above 900°C is an effective method to remove organic pollutants from industrial waste salt. It can completely decompose organic pollutants. However, during the high-temperature incineration process, solid waste salt will melt and form sticky walls and lumps, which will make the equipment unable to operate continuously and stably. Secondly, the high-temperature operation leads to high energy consumption and high operating costs, making it difficult to promote and apply.

[0005] High-temperature carbonization is the process of carbonizing organic pollutants at 500-600℃ under oxygen-deficient conditions. Compared with high-temperature incineration, it greatly reduces energy consumption. However, there are three difficulties in high-temperature carbonization: (1) During the high-temperature carbonization process, solid waste salt is prone to wall formation, resulting in the inability of the equipment to operate continuously and stably; (2) During the high-temperature carbonization process, solid waste salt is prone to agglomeration and clustering. After agglomeration, heat conduction is slow, and the internal temperature of the agglomerate / block cannot reach the temperature required for complete carbonization of organic pollutants, resulting in poor organic pollutant removal effect and difficulty in effectively reducing TOC in solid waste salt to below 30mg / kg; (3) During the high-temperature carbonization process, high-molecular organic pollutants are vaporized by heat, causing serious air pollution, and the organic waste gas formed by vaporization is very likely to cause safety accidents such as "flash explosion"; (4) The organic waste gas formed by the vaporization of high-molecular organic pollutants is very likely to condense on the inner wall of the equipment and the inner wall of the gas transmission pipeline, causing pipeline blockage and the inability of the equipment to operate continuously and stably. Summary of the Invention

[0006] In response to the above-mentioned technical problems, the present invention provides a method for removing organic pollutants from industrial waste salt, which can not only effectively reduce the total organic carbon (TOC) of industrial solid waste salt to below 30 mg / kg, but also avoid problems such as sticking to the wall, clogging, agglomeration / clumping of solid waste salt and large molecular organic pollutants during the thermal desorption process, ensuring that the device can operate continuously and stably, while solving the problem of atmospheric pollution and reducing energy consumption.

[0007] The present invention provides a method for removing organic pollutants from industrial waste salt, which comprises a mixing device, a drying device, a thermal desorption device, a screening device, a cooling device, a condenser, and an incinerator. The industrial waste salt passes through the mixing device, the drying device, the thermal desorption device, the screening device, and the cooling device in sequence, ultimately obtaining low-TOC waste salt. The dry tail gas generated by the drying device is condensed to remove water and then enters the incinerator as a supplement to the combustion-supporting air, thereby solving the pollution problem of the dry tail gas. The condensed water discharged from the condenser is low-concentration biodegradable wastewater and is further discharged after biochemical treatment. The organic gas discharged from the thermal desorption device enters the incinerator for incineration, and the high-temperature flue gas generated by the incineration enters the partition wall of the thermal desorption device to heat the waste salt. The flue gas, after heat exchange once, enters the partition wall of the drying device again to heat the waste salt from the mixing device before being discharged into the air.

[0008] The object of the present invention is to provide a method for removing organic pollutants from industrial waste salt, the method comprising the steps of:

[0009] (1) A certain mass of industrial solid waste salt is fed into a mixing device and sodium hypochlorite is added to react;

[0010] (2) The waste salt after the reaction in the mixing device enters the drying device, and metal balls are added to the drying device; the operating temperature of the drying device is 80-100°C, and the residence time is 0.5-2 hours; the dry tail gas enters the condenser;

[0011] (3) The industrial solid waste salt after drying in step (2) enters a thermal desorption device, where the waste salt is heated to 550-650°C for 2-4 hours, and the vaporized organic waste gas enters an incinerator; the waste salt from which organic pollutants have been removed enters a screening device;

[0012] (4) The waste salt after the organic pollutants are removed by the thermal desorption device in step (3) enters the screening device to separate the metal balls and the waste salt. The separated metal balls are transported to the drying device for recycling; the separated waste salt enters the cooling device for subsequent treatment.

[0013] In one embodiment, the amount of sodium hypochlorite added in step (1) is 1 to 6% (mass fraction) of the amount of industrial solid waste salt used.

[0014] In one embodiment, the reaction time of step (1) is 1-2 hours.

[0015] In one embodiment, the content of organic pollutants in the industrial solid waste salt in step (1) is 1200 mg / kg to 48900 mg / kg.

[0016] In one embodiment, the metal ball in step (2) is a titanium metal ball.

[0017] In one embodiment, the metal balls in step (2) are titanium balls, the diameter of the titanium balls is 20-100 mm, and the amount of the titanium balls added is 20-40% of the mass of the industrial solid waste salt.

[0018] In one embodiment, the dried tail gas in step (2) enters a condenser, is cooled to 30-50°C by cooling water, and then enters an incinerator to supplement combustion air. The wastewater discharged from the condenser enters a subsequent sewage biochemical treatment system.

[0019] In one embodiment, the vaporized and volatilized organic waste gas in step (3) enters the incinerator and is mixed with the natural gas and combustion-supporting air in the incinerator and directly burned. The air is heated to 850-950°C and then the thermal desorption device and the drying device are heated in sequence. The flue gas temperature after heating and utilization is reduced to below 150°C and then discharged into the air.

[0020] In one embodiment, the function of the mixing device described in step (1) is to continuously and thoroughly mix the industrial solid waste salt and sodium hypochlorite and retain the reaction for a period of time, so that the macromolecular organic pollutants in the waste salt are oxidized and degraded into small molecular organic matter; the industrial solid waste salt enters the mixing device from the first interface of the mixing device, the sodium hypochlorite enters the mixing device from the second interface of the mixing device, and the third interface of the mixing device is connected to the first interface of the drying device; the industrial solid waste salt enters the drying device from the first interface of the drying device; the mixing device is provided with a stirring mixing tank.

[0021] In one embodiment, the drying operation of the drying device in step (2) utilizes the high-temperature flue gas from the thermal desorption device to heat the waste salt to remove moisture from the industrial solid waste salt, while increasing the temperature to accelerate the oxidative degradation rate of sodium hypochlorite.

[0022] In one embodiment, the first interface of the drying device in step (2) is connected to the mixing device; the second interface is connected to the thermal desorption device, and the second interface is used to transport solid waste salt; the third interface is connected to the thermal desorption device, and the third interface is used to transport high-temperature flue gas; the fourth interface is connected to the second interface of the screening device, and is used to transport metal balls; and the fifth interface is connected to the condenser, and is used to transport dry exhaust gas.

[0023] In one embodiment, the drying device in step (2) is a rotary kiln or a rake dryer, the operating temperature of the drying device is 80-100° C., and the residence time is 0.5-2 hours.

[0024] In one embodiment, the function of the thermal desorption device is to use high-temperature flue gas to heat the waste salt, causing the degraded small molecular organic pollutants in the waste salt to vaporize and volatilize, thereby removing the organic pollutants in the solid waste salt; the first interface of the thermal desorption device is connected to the second interface of the drying device, and the solid waste salt and titanium metal balls from the drying device enter the thermal desorption device through the first interface of the thermal desorption device; the second interface of the thermal desorption device is connected to the first interface of the screening device, and the waste salt after thermal desorption is discharged through the second interface of the thermal desorption device and enters the screening device; the third interface of the thermal desorption device is connected to the incinerator, and the high-temperature flue gas from the incinerator enters the thermal desorption device through the third interface of the thermal desorption device and heats the solid waste salt; the fourth interface of the thermal desorption device is connected to the third interface of the drying device, and the hot air after heating the solid waste salt enters the drying device through the fourth interface. The fifth interface of the thermal desorption device is connected to the first interface of the incinerator for conveying organic waste gas.

[0025] In one embodiment, the thermal desorption device is a partition-heated rotary kiln, in which the hot air and the solid waste salt are heated by the partition; the operating temperature of the thermal desorption device is 550-650° C., and the residence time is 2-4 hours.

[0026] In one embodiment, the screening device functions to separate titanium balls from waste salt, allowing the titanium balls to be recycled. The first interface of the screening device is connected to the second interface of the thermal desorption device, transporting waste salt and titanium balls from the thermal desorption device. The second interface of the screening device is connected to the fourth interface of the drying device, for transporting recycled titanium balls. The third interface of the screening device is connected to the first interface of the cooling device, for transporting waste salt.

[0027] In one embodiment, the thermal desorption device is a vibrating screen or a rotary screen, and the diameter of the screen holes is less than 20 mm.

[0028] In one embodiment, the function of the cooling device is to reduce the temperature of the solid waste salt by circulating cooling water; the first interface of the cooling system is connected to the third interface of the screening device, and the solid waste salt after separation of the titanium metal balls enters the cooling device from the first interface and is discharged from the second outlet of the cooling device after cooling.

[0029] In one embodiment, the cooling device is a rotary kiln or a jacketed auger.

[0030] In one embodiment, the function of the incinerator is to incinerate the organic waste gas from the thermal desorption device, eliminate the atmospheric pollution of the organic waste gas, and obtain high-temperature flue gas at the same time; the first interface of the incinerator is connected to the fifth interface of the thermal desorption device, which is used to transport the organic waste gas from the thermal desorption device; the second interface of the incinerator is connected to natural gas and combustion-supporting air, and the organic waste gas and natural gas are used as combustion heat sources, which are mixed with the combustion-supporting air and directly burned. After the air is heated to 850-950°C, it leaves the incinerator from the third interface of the incinerator and enters the thermal desorption device through the third interface of the thermal desorption device.

[0031] In one embodiment, the function of the condenser is to cool the exhaust gas to 30-50°C by cooling water so that the moisture in the dry exhaust gas is condensed and precipitated, thereby reducing the moisture content in the dry exhaust gas; the first interface of the condenser is connected to the fifth interface of the drying device for conveying the dry exhaust gas; the second interface of the condenser is connected to the second interface of the incinerator for replenishing combustion air; the third interface of the condenser is used to convey the condensed wastewater, and the wastewater is sent to the sewage biochemical treatment system for separate treatment.

[0032] In one embodiment, the condenser is a plate or shell and tube heat exchanger.

[0033] The second object of the present invention is to provide an application of the above-mentioned method for removing organic pollutants from industrial waste salt in the treatment of industrial solid waste salt.

[0034] The technical advantages of the present invention are:

[0035] (1) The present invention adds a strong oxidant, sodium hypochlorite, to degrade organic pollutants in industrial waste salt, forming small molecular organic matter that is more easily vaporized by heat, which lays a good foundation for the subsequent high-temperature removal of organic pollutants;

[0036] (2) During the high-temperature desorption process, the organic waste gas formed by the vaporization of small molecular organic matter is not easy to condense on the metal surface of equipment and pipelines due to its low boiling point, which is more conducive to the transportation and incineration of organic waste gas;

[0037] (3) All organic waste gas generated by high-temperature desorption is incinerated, which not only eliminates the atmospheric pollution problem of organic waste gas, but also saves natural gas consumption, reduces the energy consumption of waste salt resource operation, and reduces operating costs;

[0038] (4) During the operation of the waste salt drying and thermal desorption device, recyclable heat-resistant and corrosion-resistant titanium alloy metal balls are added to effectively prevent the waste salt from forming walls or agglomerating by relying on the impact, shearing and grinding effects of the metal balls;

[0039] (5) The dry exhaust gas after the water is condensed and precipitated by the condenser is used as combustion air, and the insufficient part is supplemented by fresh air, eliminating the atmospheric pollution problem of the exhaust gas of the drying device.

[0040] (6) The present invention fully utilizes the heat in the high-temperature flue gas discharged from the incinerator, improves the thermal energy utilization rate, and reduces the cost of industrial waste salt treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Schematic diagram of the device for removing organic pollutants from industrial waste salt according to the present invention. DETAILED DESCRIPTION

[0042] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0043] The present invention relates to a device for removing organic pollutants from industrial waste salt. Figure 1As shown, the device includes a mixing device, a drying device, a rotary kiln, a thermal desorption device, a screening device, a cooling device, a condenser, and an incinerator; wherein the mixing device, drying device, thermal desorption device, screening device, and cooling device are connected in sequence; solid waste salt enters the mixing device from the first interface of the mixing device, sodium hypochlorite enters the mixing device from the second interface of the mixing device, and the third interface of the mixing device is connected to the first interface of the drying device. Solid waste salt enters the drying device from the first interface of the drying device; the first interface of the drying device is connected to the mixing device; the second interface is connected to the thermal desorption device, and the second interface is used to transport solid waste salt; the third interface is connected to the thermal desorption device, and the third interface is used to transport high-temperature flue gas; the fourth interface is connected to the second interface of the screening device, and is used to transport titanium metal balls; the fifth interface is connected to the condenser, and is used to transport dry exhaust gas.

[0044] The first interface of the thermal desorption device is connected to the second interface of the drying device. The solid waste salt and titanium metal balls from the drying device enter the thermal desorption device through the first interface of the thermal desorption device. The second interface of the thermal desorption device is connected to the first interface of the screening device. The waste salt after thermal desorption is discharged through the second interface of the thermal desorption device and enters the screening device. The third interface of the thermal desorption device is connected to the incinerator. The high-temperature flue gas from the incinerator enters the thermal desorption device through the third interface of the thermal desorption device and heats the solid waste salt. The fourth interface of the thermal desorption device is connected to the third interface of the drying device. The hot air after heating the solid waste salt enters the drying device through the fourth interface. The fifth interface of the thermal desorption device is connected to the first interface of the incinerator to transport organic waste gas.

[0045] The first interface of the screening device is connected to the second interface of the thermal desorption device to transport waste salt and titanium metal balls from the thermal desorption device; the second interface of the screening device is connected to the fourth interface of the drying device to transport recycled titanium metal balls; the third interface of the screening device is connected to the first interface of the cooling device to transport waste salt.

[0046] The first interface of the cooling system is connected to the third interface of the screening device. The solid waste salt after separation of the titanium metal balls enters the cooling device from the first interface and is discharged from the second outlet of the cooling device after cooling.

[0047] The first interface of the incinerator is connected to the fifth interface of the thermal desorption device, which is used to transport the organic waste gas from the thermal desorption device; the second interface of the incinerator is connected to natural gas and combustion-supporting air. The organic waste gas and natural gas are used as combustion heat sources, which are mixed with the combustion-supporting air and directly burned. After the air is heated to 850-950℃, it leaves the incinerator from the third interface of the incinerator and enters the thermal desorption device through the third interface of the thermal desorption device.

[0048] The first interface of the condenser is connected to the fifth interface of the drying device for transporting dry exhaust gas; the second interface of the condenser is connected to the second interface of the incinerator for replenishing combustion air; the third interface of the condenser is used to transport condensed wastewater, which is sent to the sewage biochemical treatment system for separate treatment.

[0049] Example 1

[0050] A solid waste salt having a COD content of 1200 mg / kg is prepared by using a method for removing organic pollutants from industrial waste salt according to the present invention, comprising the following steps:

[0051] (1) A certain mass of industrial solid waste salt is fed into a mixing device, and sodium hypochlorite is added at a concentration of 1% by mass of the waste salt, mixed evenly, and then allowed to react for 1 hour;

[0052] (2) The waste salt from the reaction in the mixing device enters the rotary kiln of the drying device, and titanium metal balls with a diameter of 80 mm, which are 20% of the waste salt mass, are added at the same time. The operating temperature of the drying device is 80°C, and the residence time is 2 hours; the dried waste salt enters the thermal desorption device, and the dry tail gas enters the condenser; after being cooled to 30°C by cooling water, it enters the incinerator to supplement the combustion air, and the wastewater discharged from the condenser enters the subsequent sewage biochemical treatment system;

[0053] (3) The dried industrial solid waste salt enters the thermal desorption device, where the waste salt is heated to 550°C and stays for 2 hours. The waste salt with organic pollutants removed enters the screening device, and the vaporized organic waste gas enters the incinerator; in the incinerator, it is mixed with natural gas and combustion air and directly burned. After the temperature of the incinerator is heated to 900°C, the high-temperature gas heats the thermal desorption device and the drying device in sequence along the high-temperature flue gas partition wall. After the air is heated to 900°C, the thermal desorption device and the drying device are heated in sequence along the partition wall. After the flue gas temperature after heating and utilization drops to below 150°C, it is discharged into the air;

[0054] (4) The waste salt after the organic pollutants are removed by the thermal desorption device enters the screening device to separate the titanium metal balls and the waste salt, and the titanium metal balls are transported to the drying device for recycling; the separated waste salt enters the cooling device to obtain the waste salt after the organic pollutants are removed.

[0055] Table 1 Comparison of implementation effects of different operation methods

[0056]

[0057] Note: The agglomeration and wall adhesion thickness are the test data after 72 hours of continuous operation.

[0058] Example 2

[0059] A solid waste salt having a COD content of 8560 mg / kg is prepared by using a method for removing organic pollutants from industrial waste salt according to the present invention, comprising the following steps:

[0060] (1) A certain mass of industrial solid waste salt is fed into a mixing device, and sodium hypochlorite is added at a mass ratio of 2% of the waste salt mass. After mixing evenly, the mixture is allowed to react for 1.5 hours.

[0061] (2) The waste salt from the mixing device enters the rotary kiln of the drying device, and titanium metal balls with a diameter of 600 mm, which are 30% of the waste salt mass, are added at the same time. The operating temperature of the drying device is 90°C and the residence time is 1 hour. The dried waste salt enters the thermal desorption device, and the dry tail gas enters the condenser. After being cooled to 30°C by cooling water, it enters the incinerator to supplement the combustion air. The wastewater discharged from the condenser enters the subsequent sewage biochemical treatment system.

[0062] (3) The dried industrial solid waste salt enters the thermal desorption device, where the waste salt is heated to 630°C and stays for 2.5 hours. The waste salt with organic pollutants removed enters the screening device, and the vaporized organic waste gas enters the incinerator; the organic waste gas is mixed with natural gas and combustion air in the incinerator and directly burned. After the air is heated to 850°C, the thermal desorption device and the drying device are heated in sequence. After the flue gas temperature is reduced to below 150°C after heating and utilization, it is discharged into the air;

[0063] (4) The waste salt after the organic pollutants are removed by the thermal desorption device enters the screening device to separate the titanium metal balls and the waste salt, and the titanium metal balls are transported to the drying device for recycling; the separated waste salt enters the cooling device to obtain the waste salt after the organic pollutants are removed.

[0064] Table 2 Comparison of implementation effects of different operation methods

[0065]

[0066] Note: The agglomeration and wall adhesion thickness are the test data after 72 hours of continuous operation.

[0067] Example 3

[0068] A solid waste salt having a COD content of 48900 mg / kg is prepared by using a method for removing organic pollutants from industrial waste salt according to the present invention, comprising the following steps:

[0069] (1) A certain mass of industrial solid waste salt is fed into a mixing device, and sodium hypochlorite is added at a concentration of 6% by mass of the waste salt, mixed evenly, and then allowed to react for 1 hour;

[0070] (2) The waste salt from the mixing device enters the rotary kiln of the drying device, and titanium metal balls (mixing balls) with a diameter of 20-100 mm and a weight of 40% of the waste salt are added at the same time. The operating temperature of the drying device is 100°C and the residence time is 0.5 hours. The dried waste salt enters the thermal desorption device, and the dry tail gas enters the condenser. After being cooled to 30°C by cooling water, it enters the incinerator to supplement the combustion air. The waste water discharged from the condenser enters the subsequent sewage biochemical treatment system.

[0071] (3) The dried industrial solid waste salt enters the thermal desorption device, where the waste salt is heated to 650°C and stays for 4 hours. The waste salt with organic pollutants removed enters the screening device, and the vaporized organic waste gas enters the incinerator; the organic waste gas is mixed with natural gas and combustion air in the incinerator and directly burned. After the air is heated to 950°C, the thermal desorption device and the drying device are heated in sequence. After the flue gas temperature is reduced to below 150°C after heating and utilization, it is discharged into the air;

[0072] (4) The waste salt after the organic pollutants are removed by the thermal desorption device enters the screening device to separate the titanium metal balls and the waste salt, and the titanium metal balls are transported to the drying device for recycling; the separated waste salt enters the cooling device to obtain the waste salt after the organic pollutants are removed.

[0073] Table 3 Comparison of implementation effects of different operation methods

[0074]

[0075] Note: The agglomeration and wall adhesion thickness are the test data after 72 hours of continuous operation.

[0076] The above embodiments are merely preferred embodiments for the purpose of fully illustrating the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are within the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

Claims

1. A method for removing organic pollutants from industrial waste salt, characterized in that: The method comprises the following steps: (1) A certain mass of industrial solid waste salt is fed into a mixing device, and sodium hypochlorite is added to react for 1 to 2 hours. The amount of sodium hypochlorite added is 1 to 6% of the amount of industrial solid waste salt. The content of organic pollutants in the industrial solid waste salt is 1200 mg / kg to 48900 mg / kg. (2) The waste salt after the reaction in the mixing device enters the drying device, and metal balls are added to the drying device. The metal balls are titanium balls with a diameter of 20-100 mm, and the addition amount of the titanium balls is 20-40% of the mass of the industrial solid waste salt; the operating temperature of the drying device is 80-100 ° C, and the residence time is 0.5-2 hours; the dry tail gas enters the condenser; (3) The industrial solid waste salt after drying in step (2) enters a thermal desorption device, where the waste salt is heated to 550-650°C for 2-4 hours, and the vaporized organic waste gas enters an incinerator; the waste salt from which organic pollutants have been removed enters a screening device; (4) The waste salt after the organic pollutants are removed by the thermal desorption device in step (3) enters the screening device to separate the metal balls and the waste salt. The separated metal balls are transported to the drying device for recycling; the separated waste salt enters the cooling device for subsequent treatment; The function of the mixing device is to continuously mix industrial solid waste salt and sodium hypochlorite and retain the reaction for a period of time, so that the macromolecular organic pollutants in the waste salt are oxidized and degraded into small molecular organic matter; the industrial solid waste salt enters the mixing device from the first interface of the mixing device, and the sodium hypochlorite enters the mixing device from the second interface of the mixing device. The third interface of the mixing device is connected to the first interface of the drying device; the industrial solid waste salt enters the drying device from the first interface of the drying device; the mixing device is provided with a stirring mixing tank; The drying device is a rotary kiln or a rake dryer, and the operating temperature of the drying device is 80-100°C, and the residence time is 0.5-2 hours. The first interface of the drying device is connected to the mixing device; the second interface is connected to the thermal desorption device, and the second interface is used to transport solid waste salt; the third interface is connected to the thermal desorption device, and the third interface is used to transport high-temperature flue gas; the fourth interface is connected to the second interface of the screening device, and is used to transport metal balls; and the fifth interface is connected to the condenser, and is used to transport dry exhaust gas. The function of the condenser is to cool the exhaust gas to 30-50°C by cooling water, thereby condensing and precipitating the moisture in the dry exhaust gas. The first interface of the condenser is connected to the fifth interface of the drying device for conveying the dry exhaust gas. The second interface of the condenser is connected to the second interface of the incinerator for replenishing combustion air. The third interface of the condenser is used to convey the condensed wastewater, which is then sent to the sewage biochemical treatment system for separate treatment. The thermal desorption device is a partition-heating rotary kiln. In the thermal desorption device, the partition between hot air and solid waste salt is heated; the operating temperature of the thermal desorption device is 550-650°C, and the residence time is 2-4 hours; the second interface of the thermal desorption device is connected to the first interface of the screening device, and the waste salt after thermal desorption is discharged through the second interface of the thermal desorption device and enters the screening device; the third interface of the thermal desorption device is connected to the incinerator, and the high-temperature flue gas from the incinerator enters the thermal desorption device through the third interface of the thermal desorption device and heats the solid waste salt; the fourth interface of the thermal desorption device is connected to the third interface of the drying device, and the hot air after heating the solid waste salt enters the drying device through the fourth interface; the fifth interface of the thermal desorption device is connected to the first interface of the incinerator for conveying organic waste gas; The function of the incinerator is to incinerate the organic waste gas from the thermal desorption device, eliminate the atmospheric pollution of the organic waste gas, and obtain high-temperature flue gas at the same time; the first interface of the incinerator is connected to the fifth interface of the thermal desorption device, which is used to transport the organic waste gas from the thermal desorption device; the second interface of the incinerator is connected to natural gas and combustion-supporting air. The organic waste gas and natural gas are used as combustion heat sources, which are mixed with the combustion-supporting air and directly burned. After the air is heated to 850~950℃, it leaves the incinerator from the third interface of the incinerator and enters the thermal desorption device through the third interface of the thermal desorption device.

2. Application of the method according to claim 1 in the treatment of industrial solid waste salt.

3. The use according to claim 2, characterized in that It can avoid the problems of solid waste salt and large molecular organic pollutants sticking to the wall, clogging and agglomeration during the thermal desorption process.

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