A flash treatment system and method for recycling multi-component mercury-containing hazardous solid waste resources

Abstract

The invention discloses a flash evaporation treatment system for resource recovery of multi-component mercury-containing hazardous solid waste, which comprises an enrichment and reduction device, a crushing device, an electrode oxidation pretreatment device, a low-temperature flash evaporation device, a micron heat filter, a refrigerant extreme cold separation treatment device, and a dynamic membrane separation recovery treatment device, which are connected in sequence; the low-temperature flash evaporation device is also connected to a discharging device, and the refrigerant extreme cold separation treatment device is connected to a mercury deep treatment adsorption capture device and a nano-scale microporous tail gas filter in sequence through a vacuum pump; the waste discharge ports of the fillers of the mercury deep treatment adsorption capture device and the nano-scale microporous tail gas filter are both connected to the crushing device, and the waste discharge port of the dynamic membrane separation recovery treatment device is connected to the enrichment and reduction device; the waste discharge port of the micron heat filter is connected to the low-temperature flash evaporation device; mercury-containing hazardous solid waste realizes mercury resource recovery and solid waste treatment through this system.

Description

Technical Field

[0001] The present invention belongs to the field of environmental protection and resource recovery, and relates to the harmless treatment and resource recovery of mercury-containing polluted waste, arsenic-containing polluted waste, and organic-containing polluted waste, and specifically to a flash evaporation treatment system and method for resource recovery of multi-component mercury-containing hazardous solid waste. Background Art

[0002] In recent years, with the continuous development of industrial production, environmental pollution has become increasingly serious. The accumulation, migration and transformation of solid waste pollutants in the environment have seriously endangered the ecological environment and human health. For example, municipal sludge, industrial water treatment sludge, urban domestic garbage, sludge generated during oil and gas field exploitation, smelting waste slag, tailings slag, etc. In addition, with the rapid advancement of urbanization in my country, a large number of heavily polluting enterprises have been closed, and the remaining untreated site pollution has become one of the focuses of current domestic and foreign technical research and treatment.

[0003] Mercury is one of the most toxic heavy metal pollutants, but unlike other heavy metals, it is volatile. In 2013, the world reached a legally binding international convention specifically involving mercury - the Minamata Convention, which officially came into force on August 16, 2017, and became the highest level of international law, just like the Stockholm Convention on Persistent Organic Pollutants. my country is the world's largest producer, user and emitter of mercury, and my country's environmental mercury pollution problem is very prominent, and most of it is mercury and organic compound pollution. Even in many places, due to the existence of compound pollution, there are more serious methylmercury pollution problems. Therefore, low-cost, synergistic removal of mercury and organic multi-pollution and synergistic purification of the mixed secondary pollution "water, gas, and slag" generated during the treatment process have become practical problems that technicians in this field need to solve urgently.

[0004] The invention patent for a thermal desorption system and method for treating mercury-contaminated soil with publication number CN106424113A only considers a single mercury pollution source from the thermal desorption unit to the exhaust gas purification system, and does not consider other possible pollution factors such as petroleum hydrocarbons, hydrogen sulfide, ammonia nitrogen, etc. In addition, pollutants such as light hydrocarbons will cause safety hazards such as explosion in the presence of air, so it is not suitable for thermal desorption treatment of multiple pollutants containing mercury and organic substances.

[0005] The invention patent for indirect thermal analysis equipment with publication number CN101780467A and the invention patent for a skid-mounted soil thermal separation equipment with publication number CN104815842A do not use a vacuum method and require high temperatures to perform thermal analysis on pollutants, so the operating cost is high.

[0006] Although the invention patent of an indirect thermal desorption remediation system for treating mercury-containing solid waste and soil with publication number CN208626924U and the invention patent of an indirect thermal desorption remediation system and method for treating mercury-containing solid waste and soil with publication number CN109045898A both adopt a closed mode, continuous treatment cannot achieve high vacuum, so the treatment temperature needs to reach a high temperature of 400°C or even 800°C, which also has high operating costs. In addition, high temperature will greatly reduce the service life of the ceramic membrane heat filter. The exhaust gas treatment process of this process is complicated, and no comprehensive treatment plan is proposed for the multi-component mixed exhaust gas. At the same time, the exhaust gas purification method will cause a large amount of sewage to be generated, so a complex water treatment process is added to the patent.

[0007] The invention patent for the thermal desorption and remediation equipment and method for contaminated soil with publication number CN107096790A only considers the thermal decomposition treatment method of organic pollutants, but does not consider the treatment of mercury-containing multi-element tail gas and mercury resource recovery.

[0008] Although the invention patent with publication number CN110586621A, a complete set of highly efficient treatment equipment and method for mercury-containing or organically contaminated solid waste, involves the disposal of multiple mercury-containing wastes, it does not adopt vacuum pyrolysis.

[0009] Although the invention patent with publication number CN109226225A, a novel modular sequential batch vacuum extraction thermal desorption treatment system and method, also adopts a vacuum method, it does not take into account the comprehensive treatment of multiple secondary pollution caused by multiple pollutants, such as "water, air, and dust", and does not consider that dust removal will cause blockage of the subsequent exhaust gas treatment system. At the same time, the use of high-temperature treatment methods results in high operating costs. In summary, this patent is not suitable for actual projects.

[0010] The invention patent with publication number CN104532018A, a method for recovering mercury from multi-component mercury-containing hazardous solid waste through high-temperature rotary roasting, treats multi-component mercury-containing hazardous waste, but uses high temperature and complex tail gas treatment processes, which will increase operating costs. In addition, it does not consider the safety risks of mixing hydrocarbons with air.

[0011] Traditional thermal desorption technology is only applicable to the treatment of a single mercury pollution source. From the current patent technology and related academic research journals, there are no reports on methods or technologies for high vacuum low temperature flash distillation treatment of multiple mercury-containing hazardous solid wastes and resource recovery. Therefore, considering safety, environmental protection and cost, it is imperative to develop a method or treatment system for distillation treatment of multiple hazardous solid wastes and resource recovery for the development of mercury pollution control in China and the fulfillment of the international mercury convention. Summary of the invention

[0012] The purpose of the present invention is to overcome the shortcomings of traditional methods for treating multiple hazardous wastes, such as explosive safety problems, secondary environmental pollution problems, toxic and harmful gas escape problems, difficulty in resource recovery, and high treatment costs, and to provide a flash evaporation treatment system for multiple mercury-containing hazardous solid wastes and resource recovery.

[0013] The technical solution of the present invention is as follows:

[0014] A flash evaporation treatment system for resource recovery of multi-component mercury-containing hazardous solid wastes comprises an enrichment and reduction device, a crushing device, an electrode oxidation pretreatment device, a low-temperature flash evaporation device, a micron heat filter, a refrigerant extreme cold separation treatment device, and a dynamic membrane separation recovery treatment device, which are connected in sequence; the low-temperature flash evaporation device is also connected to a discharge device, and the refrigerant extreme cold separation treatment device is connected in sequence to a mercury deep treatment adsorption capture device and a nano-scale microporous tail gas filter through a vacuum pump; the waste discharge ports of the fillers of the mercury deep treatment adsorption capture device and the nano-scale microporous tail gas filter are both connected to the crushing device, and the waste discharge port of the dynamic membrane separation recovery treatment device is connected to the enrichment and reduction device; the waste discharge port of the micron heat filter is connected to the low-temperature flash evaporation device.

[0015] The processing method includes the following steps:

[0016] a) Utilize enrichment and reduction equipment to capture and fix mercury pollutants in solid substances by adding capture agents and stabilizers to mercury-containing hazardous wastes with high water content, and then dehydrate them to fully reduce their water content, thereby increasing the content of pollutants in solid conditions and forming multi-component mercury-containing hazardous solid wastes; improve treatment efficiency and reduce treatment costs.

[0017] b) Send the multi-component mercury-containing hazardous solid waste into a crushing device, fully crush it into 0.5cm-5cm particles, and send it to the next unit;

[0018] c) The crushed multi-component mercury-containing hazardous solid waste is sent to the electrode oxidation pretreatment device, and solid salt containing 1%-5% of the total amount of hazardous solid waste is added, and the mixture is stirred continuously for 30min-90min to enhance the conversion of mercury-containing compounds. At the same time, some functional groups of pollutants are electrochemically active. Through the forced action of the electric field, the functional group structure changes, thereby changing its chemical properties. The electrochemical method of electrode oxidation degrades organic matter such as petroleum hydrocarbons into carbon dioxide, water and other inorganic salts, hydrogen sulfide is oxidized into sulfate, ammonia nitrogen and nitrogen oxides are converted into nitrates, and mercury and its mercury compounds are converted into mercuric oxide; the subsequent flash evaporation efficiency is improved.

[0019] d) sending the multi-component mercury-containing hazardous solid waste after electrode oxidation pretreatment to a low-temperature flash evaporation device with an absolute pressure of 30mbar-300mbar from the extracted air, and then starting heating to keep the absolute pressure constant. Using the principle of vacuum heating, the heating temperature is 150°C-450°C, and the heating time is 0.5h-3h, so that the mercury-containing hazardous solid waste formed in step c is evaporated and extracted under a vacuum environment to form mercury-containing vapor, water vapor and dust, and then enter the next micron heat filter; and the clean solid waste remaining after evaporation extraction is collected centrally through a discharging device and recycled through hot clean slag;

[0020] e) In the micron heat filter, the principle of suction is adopted to remove dust and filter the mercury-containing vapor and water vapor produced in step d. After dust removal and filtration, the clean mercury-containing vapor and water vapor are formed and enter the next refrigerant extreme cold separation treatment equipment; and the filtered dust is recovered to the low-temperature flash evaporation device for further treatment to achieve dust-free treatment.

[0021] f) In the refrigerant extreme cold separation treatment equipment, the temperature is controlled at 20℃-50℃, and the clean mercury-containing vapor and water vapor are condensed and recovered to form liquid mercury and mercury-containing wastewater, which enter the next dynamic membrane separation and recovery treatment device for treatment; the other part of the mercury-containing waste gas that cannot be condensed enters the next mercury deep treatment adsorption capture device through a vacuum pump for deep treatment;

[0022] g1) Liquid mercury and mercury-containing wastewater are recovered in a dynamic membrane separation and recovery treatment device, and then an irregular dynamic membrane is used to form a filtration layer with a thickness of 3-5 cm and a dense pore size of 3-50,000 meshes in an irregular shape under negative pressure, thereby performing microfiltration-level precision filtration on the mercury-containing wastewater; the mercury-containing wastewater is purified and the residual mercury is filtered out; and the treated irregular dynamic membrane carries the filtered residual mercury and returns it to the enrichment and reduction device through the waste outlet for reprocessing; the recovered liquid mercury can be reused industrially, and the water resources after the purification of the mercury-containing wastewater can also be reused or discharged;

[0023] g2) The part of the mercury-containing waste gas that cannot be condensed is adsorbed in the mercury deep treatment adsorption and capture device by the activated carbon or resin filler with mercury removal function; finally, the exhaust gas is deeply filtered through the nano-scale microporous exhaust filter to form environmentally friendly exhaust gas for discharge; and after the fillers in the mercury deep treatment adsorption and capture device and the nano-scale microporous exhaust filter are saturated after long-term operation, the dust intercepted by the saturated fillers and the nano-scale microporous exhaust filter is recovered to the crushing device through the waste outlet for recycling treatment;

[0024] In step c, the electrode oxidation pretreatment device uses a catalytic oxidation electrode which is any one of a metal oxide electrode, a metal carbide electrode, a carbon-based electrode, and a stainless steel electrode, or a mixture of two of them.

[0025] In step c, the solid salt added to the electrode oxidation pretreatment device is any one of sodium hydroxide, sodium carbonate, sodium chloride, and sodium sulfate, or a mixture of two or more thereof.

[0026] In step e, the micron heat filter has a pore size of 1 μm-50 μm, and the temperature of the micron heat filter is consistent with the temperature of the low-temperature flash evaporation device to avoid condensation of water vapor and the like, which may cause blockage.

[0027] In step g1, the membrane used in the dynamic membrane separation and recovery treatment device is an irregular dynamic ecological membrane, which is compositely modified from different fiber materials such as plant fiber and inorganic mineral fiber.

[0028] Compared with the prior art, the present invention has obvious economic and social benefits, and the specific advantages are:

[0029] The electrode oxidation pretreatment device can degrade organic matter such as petroleum hydrocarbons into carbon dioxide, water and other inorganic salts, oxidize hydrogen sulfide into sulfate, convert ammonia nitrogen and nitrogen oxides into nitrates, and convert mercury and its mercury compounds into mercuric oxide. It reduces the subsequent desulfurization and denitrification, hydrogen sulfide, dioxin and other organic pollutant tail gas treatment processes, greatly reduces operating costs, and unifies the mercury form for subsequent low-temperature flash evaporation treatment;

[0030] The whole treatment process uses a batch-type closed device to completely suppress the escape of harmful and toxic gases;

[0031] The multi-component hazardous waste materials can be treated to the maximum extent at low temperature by passing through the low-temperature flash evaporation device, which is conducive to the subsequent resource recovery and greatly reduces the operating cost. At the same time, under vacuum and oxygen-free conditions, there will be no explosion due to the contact between hydrocarbons and oxygen, which greatly reduces the hidden dangers of production safety;

[0032] The use of low-temperature flash evaporation can greatly reduce the amount of exhaust gas generated. The use of a hot filter can significantly reduce the generation of dust in the exhaust gas without causing blockage in the exhaust gas pipeline. In addition, the entire exhaust gas purification system is simple.

[0033] The tail gas purification unit in the present invention does not involve water consumption, thereby avoiding the pollution and waste of water resources.

[0034] The present invention can treat multiple hazardous wastes, such as mercury and various mercury compounds, arsenic and various arsenic compounds, and volatile and semi-volatile organic pollutants such as petroleum hydrocarbons. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic diagram of the structure of the present invention

[0036] 1-enrichment and reduction device, 2-crushing device, 3-electrode oxidation pretreatment device, 4-low-temperature flash evaporation device, 5-micron hot filter, 6-refrigerant extreme cold separation treatment equipment, 7-dynamic membrane separation and recovery treatment device, 8-vacuum pump, 9-mercury deep treatment adsorption and capture device, 10-nanometer microporous exhaust gas filter, 11-discharging device. DETAILED DESCRIPTION

[0037] like Figure 1 As shown, a flash treatment system for resource recovery of multi-component mercury-containing hazardous solid waste is characterized in that it includes an enrichment and reduction device 1, a crushing device 2, an electrode oxidation pretreatment device 3, a low-temperature flash evaporation device 4, a micron heat filter 5, a refrigerant extreme cold separation treatment equipment 6, and a dynamic membrane separation recovery treatment device 7 which are connected in sequence; the low-temperature flash evaporation device 4 is also connected to a discharge device 11, and the refrigerant extreme cold separation treatment equipment 6 is connected to a mercury deep treatment adsorption capture device 9 and a nano-scale microporous tail gas filter 10 in sequence through a vacuum pump 8; the filler waste discharge ports of the mercury deep treatment adsorption capture device 9 and the nano-scale microporous tail gas filter 10 are both connected to the crushing device 2, and the waste discharge port of the dynamic membrane separation recovery treatment device 7 is connected to the enrichment and reduction device 1; the waste discharge port of the micron heat filter 5 is connected to the low-temperature flash evaporation device 4.

[0038] The method for recycling and treating multi-component mercury-containing hazardous solid waste resources by the above-mentioned flash treatment system comprises the following steps:

[0039] a) Using the enrichment and reduction device 1, for mercury-containing hazardous waste with a high water content, by adding a capture agent and a stabilizer, the mercury pollutants are captured and fixed in the solid matter, and then dehydrated to fully reduce its water content, thereby increasing the content of pollutants in the solid state to form multi-component mercury-containing hazardous solid waste;

[0040] b) feeding the multi-component mercury-containing hazardous solid waste into the crushing device 2, where it is fully crushed and fed into the next unit;

[0041] c) The crushed multi-component mercury-containing hazardous solid waste is sent to the electrode oxidation pretreatment device 3, and solid salt containing 1%-5% of the total amount of hazardous solid waste is added, and the mixture is stirred continuously for 30min-90min to enhance the conversion of mercury-containing compounds. At the same time, some functional groups of the pollutants are electrochemically active. Through the forced action of the electric field, the functional group structure changes, thereby changing its chemical properties. The electrochemical method of electrode oxidation degrades organic matter such as petroleum hydrocarbons into carbon dioxide, water and other inorganic salts, oxidizes hydrogen sulfide into sulfate, converts ammonia nitrogen and nitrogen oxides into nitrates, and converts mercury and its mercury compounds into mercuric oxide;

[0042] d) sending the multi-component mercury-containing hazardous solid waste after electrode oxidation pretreatment to a low-temperature flash evaporation device 4 from which air is extracted and the absolute pressure is between 30mbar and 300mbar, and then starting heating to keep the absolute pressure constant. Using the principle of vacuum heating, the heating temperature is 150°C-450°C and the heating time is 0.5h-3h, so that the mercury-containing hazardous solid waste formed in step c is evaporated and extracted under a vacuum environment to form mercury-containing vapor, water vapor and dust, which then enter the next micron heat filter 5; and the clean solid waste remaining after evaporation and extraction is collected centrally through the discharging device 11;

[0043] e) In the micron hot filter 5, the mercury-containing vapor and water vapor generated in step d are dust-filtered by the principle of suction. After dust-filtering and filtration, the clean mercury-containing vapor and water vapor enter the next refrigerant extreme cold separation treatment equipment 6; and the filtered dust is recovered to the low-temperature flash evaporation device 4 for further treatment;

[0044] f) In the refrigerant extreme cold separation treatment device 6, the temperature is controlled at 20°C-50°C, and the clean mercury-containing vapor and water vapor are condensed and recovered to form liquid mercury and mercury-containing wastewater, which enter the next dynamic membrane separation recovery treatment device 7 for treatment; and the other part of the mercury-containing waste gas that cannot be condensed enters the next mercury deep treatment adsorption capture device (9) through the vacuum pump 8 for deep treatment;

[0045] g1) Liquid mercury and mercury-containing wastewater are separated and recovered in the dynamic membrane separation and recovery treatment device 7, and then an irregular dynamic membrane is used to form a filter layer with a thickness of 3-5 cm and a dense pore of 30,000-50,000 meshes in an irregular shape under negative pressure, so as to perform microfiltration-level precision filtration on the mercury-containing wastewater; the mercury-containing wastewater is purified and the residual mercury is filtered out; and the treated irregular dynamic membrane carries the filtered residual mercury and returns it to the enrichment and reduction device 1 through the waste outlet for further treatment;

[0046] g2) The part of the mercury-containing waste gas that cannot be condensed is adsorbed in the mercury deep treatment adsorption and capture device 9 by the activated carbon or resin filler with mercury removal function; finally, the tail gas is deeply filtered through the nano-scale microporous tail gas filter 10, so as to form environmentally friendly tail gas for discharge; and after the fillers in the mercury deep treatment adsorption and capture device 9 and the nano-scale microporous tail gas filter 10 are saturated after long-term operation, the saturated fillers and the dust intercepted by the nano-scale microporous tail gas filter 10 are recovered to the crushing device 2 through their respective waste outlets for recycling treatment;

[0047] The above-mentioned electrode oxidation pretreatment device 3 uses a catalytic oxidation electrode that is any one of a metal oxide electrode, a metal carbide electrode, a carbon-based electrode, and a stainless steel electrode, or a mixture of two of them; the solid salt added to the electrode oxidation pretreatment device 3 is any one of sodium hydroxide, sodium carbonate, sodium chloride, and sodium sulfate, or a mixture of two or more of them.

[0048] The micron heat filter (5) has a pore size of 1 μm-50 μm, and the temperature of the micron heat filter is consistent with the temperature of the low-temperature flash evaporation device.

[0049] The membrane used in the above-mentioned dynamic membrane separation recovery treatment device (7) is an irregular dynamic ecological membrane, which is compositely modified from different fiber materials such as plant fiber, inorganic mineral fiber, etc.

[0050] Example 1

[0051] The waste demercuration adsorbent generated during the exploitation of oil and gas fields is disposed of, and its mercury element weight content accounts for 4% (in the form of elemental mercury and mercuric sulfide), and the weight content of petroleum hydrocarbons accounts for 0.3%; first, it is concentrated in an enrichment and reduction device 1, and a capture agent and a stabilizer are added to capture and fix the mercury pollutants in the solid matter, and then it is dehydrated to form a multi-component mercury-containing hazardous solid waste; then it is sent to a crushing device 2 for crushing, and the crushing particle size is 5cm, and enters an electrode oxidation pretreatment device 3 for boron-doped diamond electrodes, and sodium hydroxide containing 1% of the total amount of hazardous solid waste is added, and it is continuously stirred for 60min. This step degrades organic matter such as petroleum hydrocarbons into carbon dioxide, water and other inorganic salts, oxidizes sulfur ions into sulfates, and at the same time, mercury sulfide and part of its elemental mercury are completely converted into mercuric oxide; a low-temperature flash evaporation device 4 is used for disposal, and air is first evacuated from the device to make the absolute pressure reach 50mbar, and then heating is started, and the absolute pressure is always kept constant, wherein the heating temperature is 390℃ and the heating time is 2h. The mixed vapor generated during the flash evaporation process is subjected to dust removal and filtration by a micron heat filter 5 with a pore size of 50 μm. The temperature of the micron heat filter 5 is consistent with the temperature of the low-temperature flash evaporation device 4. The water vapor and mercury vapor are condensed at 25°C by a refrigerant extreme cold separation treatment device 6, and liquid mercury is preliminarily recovered by a dynamic membrane separation recovery treatment device 7. Then, the mercury-containing wastewater is treated according to the dynamic membrane separation technology; the other part of the mercury-containing waste gas that cannot be condensed in the refrigerant extreme cold separation treatment device 6 enters the mercury removal adsorption tower as a mercury deep treatment adsorption capture device 9 through a vacuum pump 8 to deeply recover the residual mercury in the mercury-containing tail gas, and finally a nano-scale microporous tail gas filter 10 with a pore size of 50 nm is used to deeply purify the tail gas. The treatment effect is shown in Table 1.

[0052] Table 1. Effect of treating waste mercury removal agents in oil and gas fields

[0053]

[0054] Example 2

[0055] The waste low-mercury catalyst from the polyvinyl chloride catalytic conversion section is disposed of, and its mercury content by weight is 1.2% (in the form of mercuric chloride and mercurous chloride); first, it is concentrated in the enrichment and reduction device 1, and a capture agent and a stabilizer are added to capture and fix the mercury pollutants in the solid matter, and then it is dehydrated to form a multi-component mercury-containing hazardous solid waste; then it is sent to the crushing device 2 for crushing, and the crushing particle size is 2cm, and enters the electrode oxidation pretreatment device of the metal oxide electrode, and sodium chloride containing 5% of the total amount of hazardous solid waste is added, and it is continuously stirred for 45 minutes. This step converts mercuric chloride and mercurous chloride into mercuric oxide. A low-temperature flash evaporation device is used for disposal. The air in the device is first evacuated to make the absolute pressure reach 100mbar, and then heating is started, and the absolute pressure is always kept constant, wherein the heating temperature is 380℃ and the heating time is 1.5h. The mixed vapor generated during the flash evaporation process is dust-filtered by a micron hot filter with a pore size of 25 μm. The temperature of the micron hot filter is consistent with the temperature of the low-temperature flash evaporation device. The water vapor and mercury vapor are condensed and initially recovered at 35°C by using a refrigerant extreme cold separation treatment device. Liquid mercury is initially recovered by using a dynamic membrane separation recovery treatment device, and then the mercury-containing wastewater is treated according to the dynamic membrane separation technology; the other part of the mercury-containing waste gas that cannot be condensed in the refrigerant extreme cold separation treatment device 6 is deeply recovered by using a demercuration adsorption tower through a vacuum pump 8. Finally, a nano-scale microporous tail gas filter 10 with a pore size of 50 nm is used to deeply purify the tail gas. The treatment effect is shown in Table 2.

[0056] Table 2. Effect of treating waste low mercury catalyst

[0057]

[0058] Example 3

[0059] The multi-contaminated site containing mercury and polychlorinated biphenyls is disposed of, and the weight content of mercury element accounts for 0.53% (mainly elemental mercury and containing mercuric oxide), and the weight content of polychlorinated biphenyls accounts for 0.6172%; first, it is concentrated in the enrichment and reduction device 1, and a capture agent and a stabilizer are added to capture and fix the mercury pollutants in the solid matter, and then it is dehydrated to form multi-mercury-containing hazardous solid waste; then it is sent to the crushing device 2 for crushing, the crushing particle size is 2cm, and enters the titanium carbide electrode oxidation pretreatment device, and sodium sulfate containing 3% of the total amount of hazardous solid waste is added, and it is continuously stirred for 90 minutes. This step degrades organic matter such as polychlorinated biphenyls into carbon dioxide, water and other inorganic salts, and at the same time, all other mercury forms such as elemental mercury and its mercuric oxide are converted into mercuric oxide. A low-temperature flash evaporation device is used for disposal. The air in the device is first evacuated to make the absolute pressure reach 200mbar, and then heating is started, and the absolute pressure is always kept constant, wherein the heating temperature is 410℃ and the heating time is 1h. The mixed vapor generated during the flash evaporation process is filtered by a micron hot filter with a pore size of 5 μm. The temperature of the micron hot filter is consistent with the temperature of the low-temperature flash evaporation device. The water vapor and mercury vapor are condensed and initially recovered at 40°C by using a refrigerant extreme cold separation treatment device. Liquid mercury is initially recovered by using a dynamic membrane separation recovery treatment device, and then the mercury-containing wastewater is treated according to the dynamic membrane separation technology; the other part of the mercury-containing waste gas that cannot be condensed in the refrigerant extreme cold separation treatment device 6 is deeply recovered by a demercuration adsorption tower through a vacuum pump 8. Finally, a nano-scale microporous tail gas filter 10 with a pore size of 30 nm is used to deeply purify the tail gas. The treatment effect is shown in Table 3.

[0060] Table 3. Effects of sequential treatment of multi-component hazardous wastes containing mercury and PCBs

[0061]

[0062] The above descriptions are only some of the preferred embodiments of the present invention and do not limit the present invention in any form. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for recycling and treating multi-component mercury-containing hazardous solid waste resources, characterized in that: Includes steps: a) using the enrichment and reduction device (1) to capture and fix the mercury pollutants in solid matter by adding capture agents and stabilizers to mercury-containing hazardous wastes with high water content, and then dehydrating the mercury pollutants to fully reduce their water content, thereby increasing the content of pollutants in solid conditions to form multi-component mercury-containing hazardous solid wastes; b) feeding the multi-component mercury-containing hazardous solid waste into a pulverizing device (2), where it is fully pulverized and fed into the next unit; c) feeding the crushed multi-component mercury-containing hazardous solid waste into an electrode oxidation pretreatment device (3), adding solid salt containing 1% to 5% of the total amount of the hazardous solid waste, stirring continuously for 30 minutes to 90 minutes, so as to enhance the conversion of mercury-containing compounds. At the same time, the electrochemical method of electrode oxidation degrades petroleum hydrocarbon organic matter into carbon dioxide, water and other inorganic salts, oxidizes hydrogen sulfide into sulfate, converts ammonia nitrogen and nitrogen oxides into nitrates, and converts mercury and its mercury compounds into mercuric oxide; d) sending the multi-component mercury-containing hazardous solid waste after electrode oxidation pretreatment to a low-temperature flash evaporation device (4) from which air is extracted and the absolute pressure is between 30mbar and 300mbar, and then starting heating to keep the absolute pressure constant. Using the principle of vacuum heating, the heating temperature is 150°C-450°C and the heating time is 0.5h-3h, so that the mercury-containing hazardous solid waste formed in step c is evaporated and extracted under a vacuum environment to form mercury-containing vapor, water vapor and dust, which then enter the next micron heat filter (5); and the clean solid waste remaining after evaporation and extraction is collected by a discharging device (11) and recycled through hot clean slag; e) In the micron heat filter (5), the mercury-containing vapor and water vapor generated in step d are dust-filtered by the suction principle, and the clean mercury-containing vapor and water vapor formed after dust-filtering enter the next refrigerant extreme cold separation treatment equipment (6); and the filtered dust is recovered to the low-temperature flash evaporation device (4) for further treatment; f) In the refrigerant extreme cold separation treatment equipment (6), the temperature is controlled at 20°C-50°C, and the clean mercury-containing vapor and water vapor are condensed and recovered to form liquid mercury and mercury-containing wastewater, which enter the next dynamic membrane separation recovery treatment device (7) for treatment; and the other part of the mercury-containing waste gas that cannot be condensed enters the next mercury deep treatment adsorption capture device (9) through a vacuum pump (8) for deep treatment; g1) Liquid mercury and mercury-containing wastewater are separated and recovered in a dynamic membrane separation and recovery treatment device (7) to recover liquid mercury, and then an irregular dynamic membrane is used to form a filter layer with a thickness of 3-5 cm and a dense pore size of 30,000-50,000 meshes in an irregular shape under negative pressure, thereby performing microfiltration-level precision filtration on the mercury-containing wastewater; the mercury-containing wastewater is purified and the residual mercury is filtered out; and the treated irregular dynamic membrane carries the filtered residual mercury and returns it to the enrichment and reduction device (1) through the waste outlet for further treatment; g2) The part of the mercury-containing waste gas that cannot be condensed is adsorbed in the mercury deep treatment adsorption and capture device (9) by the activated carbon or resin filler with mercury removal function; finally, the exhaust gas is deeply filtered through the nano-scale microporous exhaust gas filter (10), thereby forming exhaust gas that meets environmental protection standards for discharge; and after the fillers in the mercury deep treatment adsorption and capture device (9) and the nano-scale microporous exhaust gas filter (10) are saturated after long-term operation, the dust intercepted by the saturated fillers and the nano-scale microporous exhaust gas filter (10) is recovered to the crushing device (2) through their respective waste outlets for recycling treatment.

2. The method for recycling and treating multi-component mercury-containing hazardous solid waste resources according to claim 1, characterized in that: In step c, the electrode oxidation pretreatment device (3) uses a catalytic oxidation electrode which is any one of a metal oxide electrode, a metal carbide electrode, a carbon-based electrode, and a stainless steel electrode, or a mixture of two of them.

3. The method for recycling and treating multi-component mercury-containing hazardous solid waste resources according to claim 1, characterized in that: In step c, the solid salt added to the electrode oxidation pretreatment device (3) is any one of sodium hydroxide, sodium carbonate, sodium chloride, and sodium sulfate, or a mixture of two or more thereof.

4. The method for recycling and treating multi-component mercury-containing hazardous solid waste resources according to claim 1, characterized in that: In step e, the micron heat filter (5) has a pore size of 1 μm-50 μm, and the temperature of the micron heat filter is consistent with the temperature of the low-temperature flash evaporation device.

5. The method for recycling and treating multi-component mercury-containing hazardous solid waste resources according to claim 1, characterized in that: In step g1, the membrane used in the dynamic membrane separation recovery treatment device (7) is an irregular dynamic ecological membrane, which is formed by composite modification of different fiber materials such as plant fiber and inorganic mineral fiber.

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