Radioactive organic-nitrate slurry treatment system

Abstract

The utility model provides a radioactive organic-nitrate slurry treatment system. The treatment system comprises a steam reforming reaction device, a carbon reduction reforming reaction device and a filtering device. The treatment method comprises the following steps: S1, in the steam reforming reaction device pre-filled with a first solid, performing a first reaction on radioactive organic-nitrate slurry, a first additive and a first oxidant; s2, performing a second reaction on a reaction product of the first reaction, a second additive and a second oxidant in the carbon reduction reforming reaction device pre-filled with a second solid; and S3, in the filtering device, filtering a reaction product of the second reaction. The radioactive organic nitrate slurry treatment device can realize safe and efficient treatment and final safe disposal of radioactive organic nitrate slurry.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of radioactive organic-nitrate slurry processing systems. BACKGROUND

[0002] The wastewater generated in each link of nuclear industry system production and operation contains nitrate waste, which has the characteristics of radioactive pollution, high organic matter and high salinity, and is very difficult to handle and dispose. Currently, the main methods for removing nitrate include catalytic denitrification, electrodialysis, reverse osmosis, biological denitrification and ion exchange. In actual processing, the effect cannot meet the satisfactory effect. It is even more difficult to treat nitrate waste with radioactive pollution, high organic matter and high salinity. Radioactive organic nitrate slurry generated in nuclear industry production and operation is one of them.

[0003] The traditional method for treating radioactive slurry (complex composition) is cement solidification, vacuum microwave drying technology and glass solidification. However, there are many challenges in the traditional technology for treating slurry containing organic matter, nitrate and high salinity. For example, the presence of nitrate increases the diffusion and migration of radioactive nuclides, and the presence of organic components makes it impossible to achieve long-term stable fixation of nuclides in the product after cement solidification. Organic components and nitrate cannot be completely destroyed, which makes it impossible to perform glass solidification or other processing. UTILITY MODEL CONTENT

[0004] The technical problem to be solved by the utility model is to overcome the defects in the prior art that the presence of nitrate increases the diffusion and migration of radioactive nuclides, and the presence of organic components makes it impossible to achieve long-term stable fixation of nuclides in the product after cement solidification, and to provide a radioactive organic-nitrate slurry processing system. The utility model can realize safe and efficient treatment and final safe disposal of radioactive organic nitrate slurry.

[0005] The utility model solves the above technical problems by the following technical solutions:

[0006] The utility model provides a kind of radioactive organic-nitrate slurry processing system, it includes steam reforming reaction device, carbon reduction reforming reaction device and filter device;

[0007] The steam reforming reaction device is provided with a first slag discharge port, a first additive inlet, a first feed inlet, a first oxidizing agent inlet and a first discharge port;The position of the first discharge port is higher than the first additive inlet, the first feed inlet and the first oxidizing agent inlet;

[0008] The carbon reduction reforming reaction device is provided with a second slag discharge port, a second additive inlet, a second feed inlet, a second oxidizing agent inlet and a second discharge port; the second discharge port is located higher than the second additive inlet, the second feed inlet and the second oxidizing agent inlet; the first discharge port is connected with the second feed inlet.

[0009] The filtering device is provided with a third feed inlet and a third discharge port; the second discharge port is connected with the third feed inlet.

[0010] In the utility model, the steam reforming reaction device can be a fluidized bed reactor.

[0011] In the utility model, the steam reforming reaction device can include integrally formed first fixed section and first expansion section, first expansion section is located above first fixed section. The first fixed section is solid bed containing first solid. The whole first fixed section can be inverted circular platform shape. The first discharge port can be arranged on the first fixed section. The first expansion section is partially filled with first solid. The whole first expansion section can be cylindrical. The first additive inlet, the first feed inlet, the first oxidizing agent inlet and the first discharge port can be arranged on the first expansion section.

[0012] In the utility model, according to convention, the position of the first discharge port can be lower than the first additive inlet, the first feed inlet and the first oxidizing agent inlet.

[0013] In the utility model, the top of the steam reforming reaction device is provided with a cyclone separator, the cyclone separator includes a wind scoop and a reflux tube, the air outlet of the wind scoop is the first discharge port, and the reflux tube is inserted into the steam reforming reaction device.

[0014] In the utility model, the mud storage tank can be connected with the first feed inlet. A feed pump can be arranged between the mud storage tank and the first feed inlet. A temporary storage tank can also be arranged between the mud storage tank and the feed pump. The feed pump can be a peristaltic pump.

[0015] In the utility model, the first additive feed tank can be connected with the first additive inlet.

[0016] In the utility model, the oxygen supply system and the steam boiler can be connected with the first oxidizing agent inlet.

[0017] In the utility model, the first discharge port can be provided with an oxygen monitor and a hydrogen monitor.

[0018] In the utility model, the carbon reduction reforming reaction device can be a fluidized bed reactor.

[0019] The carbon reduction reforming reaction device can include a second fixed section and a second enlarged section which are integrally formed, and the second enlarged section is located above the second fixed section. The second fixed section is a solid bed containing second solids. The overall second fixed section can be in the shape of an inverted circular truncated cone. The second slag outlet can be provided on the second fixed section. The second enlarged section is partially filled with second solids. The overall second enlarged section can be in the shape of a cylinder. The second additive inlet, the second feed inlet, the second oxidizing agent inlet and the second discharge outlet can be provided on the second enlarged section.

[0020] According to the conventional, the position of the second slag outlet can be lower than the second additive inlet, the second feed inlet and the second oxidizing agent inlet.

[0021] The second additive feed tank can be connected to the second additive inlet.

[0022] The oxygen supply system can be connected to the second oxidizing agent inlet.

[0023] The second discharge outlet can be provided with an oxygen monitor.

[0024] The filter device can include a pulse bag filter, an activated carbon adsorber and a high-efficiency filter which are connected in sequence. The third slag outlet and the third feed inlet are provided on the pulse bag filter, and the third discharge outlet is the discharge outlet of the high-efficiency filter. The pulse bag filter can be a vertical container. A vacuum ejector can be arranged on the connecting pipeline of the pulse bag filter and the activated carbon adsorber. A gas monitor can be arranged on the outlet of the vacuum ejector. A heater can be arranged outside the pulse bag filter. A gas monitor can be arranged on the outlet of the pulse bag filter.

[0025] The filter device can also be provided with a third slag outlet. The position of the third slag outlet can be lower than the third feed inlet. The first slag outlet and the second slag outlet can be connected to the feed inlet of the solid waste collection tank. The third slag outlet can be connected to the feed inlet of the solid waste collection tank.

[0026] The third discharge outlet can be connected to an exhaust fan. The air outlet of the exhaust fan can be provided with a continuous discharge monitor.

[0027] A cooler can be arranged on the pipeline connecting the second discharge outlet and the third feed inlet.

[0028] The utility model provides a kind of processing method of radioactive organic-nitrate slurry, it uses the processing system of radioactive organic-nitrate slurry as described above, including the following steps:

[0029] S1, in the vapor reforming reaction device preloaded with a first solid, a radioactive organic-nitrate slurry, a first additive, and a first oxidant are subjected to a first reaction; the first additive includes a mineralization additive, a metal catalyst, and a reducing agent; the first oxidant includes steam and oxygen;

[0030] S2, in the carbon reduction reforming reaction device preloaded with a second solid, a reaction product of the first reaction, a second additive, and a second oxidant are subjected to a second reaction; the second additive includes calcium carbonate; the second oxidant includes oxygen;

[0031] S3, in the filtering device, a reaction product of the second reaction is filtered.

[0032] In the present application, in step S1, the first solid can be a mineralization additive, such as clay.

[0033] In the present application, in step S1, the radioactive organic-nitrate slurry can include a radioactive heavy metal salt, an organic matter, and a nitrate salt. The radioactive heavy metal salt includes a uranium salt. The organic matter can include waste oil or waste organic solvent. The nitrate salt can include sodium nitrate. The radioactive organic-nitrate slurry can also include at least one of a nitrite salt, a chloride salt, a calcium salt, and a magnesium salt.

[0034] In the present application, in step S1, the feed flow rate of the radioactive organic-nitrate slurry can be 10-100 kg / h.

[0035] In the present application, in step S1, the mineralization additive can be clay.

[0036] In the present application, in step S1, the feed flow rate of the mineralization additive can be 5-20 kg / h.

[0037] In the present application, in step S1, the metal catalyst can be iron oxide.

[0038] In the present application, in step S1, the feed flow rate of the metal catalyst can be 5-30 kg / h.

[0039] In the present application, in step S1, the reducing agent can be carbon.

[0040] In the present application, in step S1, the feed flow rate of the reducing agent can be 10-50 kg / h.

[0041] In the present application, in step S1, the feed flow rate of the steam can be 20-200 kg / h, such as 100 kg / h.

[0042] In the step S1, the pressure of the steam can be no more than 15 psig.

[0043] In the step S1, the temperature of the steam can be 600 DEG C.

[0044] In the step S1, the feed flow rate of the oxygen can be 10-200 Nm 3 / h, for example, 50 Nm 3 / h.

[0045] In the step S1, the pressure of the first reaction can be -9.9-0 kPa, preferably -4.98-0 kPa, for example, -2 kPa.

[0046] In the step S1, the temperature of the first reaction can be 600-800 DEG C, for example, 750 DEG C.

[0047] In the step S1, the residence time of the first reaction can be 2 s.

[0048] In the step S2, the second solid can be calcium carbonate.

[0049] In the step S2, the feed flow rate of the reaction product of the first reaction can be 200-2000 Nm 3 / h, for example, 550 Nm 3 / h.

[0050] In the step S2, the feed flow rate of the calcium carbonate can be 5-20 kg / h, for example, 10 kg / h.

[0051] In the step S2, the feed flow rate of the oxygen can be 10-200 Nm 3 / h, for example, 60 Nm 3 / h.

[0052] In the step S2, the pressure of the second reaction can be -9.9-0 kPa, for example, -5 kPa.

[0053] In the step S2, the temperature of the second reaction can be 800-1100 DEG C, for example, 1000 DEG C.

[0054] In the step S2, the residence time of the second reaction can be 2 s.

[0055] In the step S3, before filtration, the reaction product of the second reaction can be cooled to 180-250 DEG C.

[0056] In the utility model, the "pressure" all indicates the pressure if not doing the special explanation.

[0057] The utility model discloses the positive progress effect lies in:

[0058] (1) in the utility model, waste material, superheated steam and related additive are introduced into the steam reforming reaction device, liquid is heated and evaporated, organic matter is reformed and decomposed, and active chemical substances in waste feed are completely converted into stable mineralization products, which almost contain all radioactive nuclides and heavy metals.

[0059] (2) in the utility model, fluidized bed design is adopted, and the steam reforming reaction device provides a large surface area to make waste fully and effectively react, effectively treat and fix radioactive waste liquid, sludge containing high-concentration sodium, aluminum, nitrate, nitrite, nitric acid, hydroxide and sulfate, and a large amount of radioactive nuclides, chlorides, fluorides, phosphates, heavy metals and other inorganic elements.

[0060] (3) in the utility model, the reducing additive can directly reduce nitric acid, nitrate and nitrite in the reforming reaction device into nitrogen gas, and the addition of clay or other inorganic co-reactants in waste feed or fluidized bed can convert radioactive nuclides, alkali metals, sulfate, chlorides, fluorides, phosphates and non-volatile heavy metals into fixed mineralization product. BRIEF DESCRIPTION OF DRAWINGS

[0061] Figure 1 It is the processing system schematic diagram of radioactive organic-nitrate slurry in example 1.

[0062] The first additive feed tank 1, the feed pump 2, the steam reforming reaction device 3, the first solid 30, the first fixed section 31, the first expansion section 32, the air funnel 301, the backflow pipe 302, the second additive feed tank 4, the carbon reduction reforming reaction device 5, the second solid 50, the second fixed section 51, the second expansion section 52, the cooler 53, the pulse bag filter 6, the vacuum ejector 61, the activated carbon adsorber 7, the high-efficiency filter 8, the exhaust fan 9 and the solid waste collection tank 10 are shown in the figure. DETAILED DESCRIPTION

[0063] The utility model will be described in detail below with a preferred embodiment and in conjunction with the drawings.

[0064] In the embodiment, the main components and the basic conditions of the materials are as follows:

[0065] Slurry tank: Radioactive organic nitrate slurry is metered from the slurry tank (storage tank, waste tank truck, or shipping container) directly into the steam reforming reactor 3. On-line quality and density measurements of the incoming slurry can be made during slurry transfer. The required co-reactants and reducing agents are then calculated by the control system algorithm based on the on-line measurement readings. Frequent sampling and analysis of samples is not required prior to processing the slurry. During the processing, the rate of co-reactant addition can be varied to optimize the use of additives, while eliminating the need to pre-mix the additives with the slurry. Sampling of each major slurry type can be performed to determine the optimum type of co-reactants and additives, and the additive calculation ranges can be pre-set.

[0066] Radioactive organic nitrate slurry: Waste generated from the uranium purification process in the nuclear chemical industry, the major chemical components are sodium nitrate, other nitrates and nitrites, the secondary chemical components are inorganics, sulfates, chlorides, and calcium containing compounds, the major organic waste is spent oil, spent organic solvents, and the secondary waste is heavy metals (uranium and magnesium, etc.).

[0067] Steam reforming reactor 3: Made of high temperature alloy, designed and fabricated in accordance with ASME Pressure Vessel Code, Section VIII, Division 2, to withstand pressure surges from upsets or abnormal conditions.

[0068] Carbon reduction reforming reactor 5: Composed of an alloy shell with an internal refractory lining. The reactor is designed and fabricated in accordance with ASME Pressure Vessel Code, Section VIII, Division 2, to withstand pressure surges from upsets or abnormal conditions.

[0069] Solid waste treatment system: Used to further treat the solid waste received in the solid waste collection tank 10, two major treatment routes can be provided: first, non-single final waste form, the granular solids are placed in bulk containers as free-flowing solids for disposal or storage; second, single final waste form, the granular product solids are mixed with a cement-like binder, the slurry is placed in bulk containers, and the solid and binder mixture forms a monolithic solid with compressive strength exceeding 500 psi.

[0070] Water supply system: Used to supply cooling water, an automatic solenoid isolation valve can be installed on the water supply line to enable quick water shut-off in the event of automatic process shutdown initiation.

[0071] Data monitoring and acquisition system: Provides a computerized human-machine interface for all aspects of the process. The system provides full remote operation of all systems in the radioactive and contaminated areas, as well as auxiliary and utility services interfacing with the thermal treatment. Multiple levels of alarm functions, interlocks, and automatic control functions are provided. The system is located in a dedicated control room where operators continuously monitor the process and facility operations. The control room provides remote closed-circuit television monitors, CEMS, and radiological monitoring readouts.

[0072] Motor control center: Provides a protective switchgear cabinet, outdoor transformer for the motor control center and uninterruptible power supply (UPS), safety distribution of power, and control of all electrical equipment. The UPS is designed to provide 20 minutes of continuous data monitoring and acquisition operation of all instruments, controls, and valves to prevent a total loss of power to the facility. An optional backup generator can be provided to maintain the ventilation system operating in the event of a total loss of normal power to the facility. All thermal and process operations can be safely ensured in less than one minute in the event of a total loss of power. The motor control center buses are separated and electrical loads are arranged to ensure that redundant blowers shut down on different buses.

[0073] Steam boiler: Used to produce steam, which is supplied to the steam boiler by the demineralized water supply system.

[0074] Instrument air supply system: If instrument air is not available at the system installation location, two redundant air compressors and dryers provide instrument air. The instrument air supply system is used to power remote actuated valves and to operate power tools during maintenance. The system also provides air to maintenance personnel for breathing and cooling when access to maintenance in potentially contaminated areas is required. The breathing air system provides adsorbers, filters, and controls to ensure personnel safety. Compressed service air is required to provide motive air to process eductors. The heating, ventilation, and air conditioning system provides temperature control and plant ventilation in accessible areas of the process facility.

[0075] Nitrogen supply system: Located outdoors. Nitrogen gas is used as a purge gas for instrumentation during the operation of the process system for the treatment of radioactive organic nitrate sludge to prevent moisture buildup in the process pressure transmitter sensing lines and to purge and / or cool the waste feed eductor and waste packaging system seals. Nitrogen is also used to transfer dry solids to prevent excessive buildup of moisture-induced clumping. The nitrogen supply system provides normal nitrogen gas requirements through a liquid nitrogen supply tank and vaporizer. The nitrogen supply system also provides a continuous supply of purge nitrogen gas in the event of a loss of power to the facility. Nitrogen is used to purge all equipment during shutdown operations, whenever possible, in less than one minute, even in the event of a total loss of power to the facility.

[0076] Oxygen supply system: provides gaseous oxygen feed to the liquid oxygen tank and vaporizer located outdoors. It is fed separately to the steam reforming reaction device 3 and the carbon reduction reforming reaction device 5 through a gas distributor. The oxygen supply system is composed of qualified and specially cleaned stainless steel parts and automatic isolation valves.

[0077] Example 1

[0078] A system for treating radioactive organic-nitrate slurry, such as Figure 1 , comprising a steam reforming reaction device 3, a carbon reduction reforming reaction device 5 and a filtering device;

[0079] The steam reforming reaction device 3 is provided with a first slag discharge port, a first additive inlet, a first feed inlet, a first oxidant inlet and a first discharge port; the position of the first slag discharge port is lower than that of the first additive inlet, the first feed inlet and the first oxidant inlet; the position of the first discharge port is higher than that of the first additive inlet, the first feed inlet and the first oxidant inlet;

[0080] The carbon reduction reforming reaction device 5 is provided with a second slag discharge port, a second additive inlet, a second feed inlet, a second oxidant inlet and a second discharge port; the position of the second slag discharge port is lower than that of the second additive inlet, the second feed inlet and the second oxidant inlet; the position of the second discharge port is higher than that of the second additive inlet, the second feed inlet and the second oxidant inlet; the first discharge port is connected with the second feed inlet;

[0081] The filtering device is provided with a third slag discharge port, a third feed inlet and a third discharge port; the position of the third slag discharge port is lower than that of the third feed inlet; the second discharge port is connected with the third feed inlet.

[0082] In this embodiment, the steam reforming reaction device 3 is a fluidized bed reactor, which is divided into two parts. The lower part is a first fixed section 31, i.e. a solid bed containing first solids 30, which is in the shape of an inverted circular truncated cone; the upper part is a first enlarged section 32, which is in the shape of a cylinder and is partially filled with the first solids 30, forming a larger-diameter separation space, the first enlarged section 32 reduces the gas velocity and causes the solid particles to separate from the rising gas. Most of the particles sucked into the fluidized gas fall to the bed by gravity. The first slag discharge port is arranged on the first fixed section 31. The first additive inlet, the first feed inlet, the first oxidant inlet and the first discharge port are arranged on the first enlarged section 32.

[0083] In this embodiment, the top of the steam reforming reactor 3 is provided with a cyclone separator, which includes a dust hopper 301 and a return pipe 302. In this case, the air outlet of the dust hopper 301 is the first discharge port, and the return pipe 302 can be inserted into the first solid 30. The cyclone separator can effectively remove most of the fine particles entrained in the fluidized gas. The return pipe 302 can make the solid particles fall back to the steam reforming reactor 3. The process gas of the steam reforming reactor 3 mainly consists of water vapor, carbon dioxide, hydrogen, carbon monoxide and nitrogen, and also contains trace amounts of volatile organic compounds and acidic gases, as well as some solid products and carbon particles.

[0084] In this embodiment, the slurry tank is connected to the first feed port, and a feed pump 2 is provided between the slurry tank and the first feed port. In this embodiment, a temporary storage tank is also provided between the slurry tank and the feed pump 2 to provide a larger storage capacity to minimize the frequency of waste transfer from the facility. In this embodiment, the feed pump 2 uses a peristaltic pump, as they require minimal maintenance and only involve hose replacement. In other embodiments, a screw pump can also be used for larger systems.

[0085] In this embodiment, the first additive feed tank 1 is connected to the first additive inlet, and the first additive feed tank 1 contains mineralization additives, metal catalysts and reducing agents. In this embodiment, the mineralization additives and reducing agents are provided by two loss-in-weight feeders with airlocks, and the metal catalysts and other additives are provided by a hopper with a remote isolation valve. The outlets of the two feeders and the hopper are connected to the first additive feed tank, and then enter the steam reforming reactor 3 at a height close to the center of the first solid 30 through a common solid conveying pipeline. During this process, a small amount of nitrogen can be used for purging to keep the pipeline unobstructed. In this embodiment, clay is used as the mineralization additive to convert accumulated product solids into completely immobilized insoluble products, which are removed semi-continuously from the first slagging port. Iron oxide is used as the metal catalyst, which is directly introduced through the first additive inlet during operation. Carbon is added semi-continuously in the steam reforming reactor 3 as a reducing agent to provide carbon for the reforming reaction and energy for the reforming reaction.

[0086] In this embodiment, the oxygen supply system and the steam boiler are connected to the first oxidant inlet. The radioactive organic nitrate slurry is injected by the feed pump 2 into the bottom of the first solids 30, i.e. above the first oxidant inlet. The water in the slurry is instantaneously vaporized and superheated upon contact with the high temperature first solids 30 to the bed temperature. As the water in the slurry vaporizes, the dry slurry solids are rapidly heated to the reaction temperature. The organic material in the slurry is volatilized and pyrolyzed upon contact with the hot bed solids. The volatile organic materials undergo steam reforming in the bed and are converted to nitrogen gas upon contact with the reducing agent on the bed. The inorganic constituents, such as alkali metals, non-volatile heavy metals, radionuclides, S, Cl, F, P, etc., combine with the co-reactants, such as clay, to form stable, high melting point, crystalline minerals, which become the final solid product. The superheated steam, residual acid gases, powdered product particles and some carbon powder are carried out of the first solids 30 by the fluidized and reaction product gases flowing upward.

[0087] In this embodiment, the oxygen monitor and the hydrogen monitor are installed at the first discharge outlet. For the purpose of process control, the steam reforming reactor 3 monitors the process gases at the first discharge outlet, including the on-line display of oxygen and hydrogen. The hydrogen monitor is used to control the level of reducing agent in the steam reforming reactor 3. The conversion of nitric acid, nitrate and nitrite to nitrogen is directly proportional to the level of hydrogen generated in the steam reforming reactor 3. If the hydrogen level exceeds the desired level (15 vol%), the amount of carbon added should be reduced. If the hydrogen level is below the desired level (15 vol%), the rate of carbon addition should be increased. If the oxygen content in the first discharge outlet increases to more than 2 vol%, the entire process system needs to be shut down, at which time, the oxygen, steam and waste are isolated in the steam reforming reactor 3, and the nitrogen supply system is used to perform a nitrogen purge of the entire system. During the nitrogen purge, nitrogen is introduced from the first additive inlet and / or the first discharge outlet and is removed from the first discharge outlet.

[0088] In this embodiment, the carbon reduction reforming reactor 5 is a fluidized bed reactor, which is divided into two parts. The lower part is the second fixed section 51, i.e. the solid bed containing the second solids 50, which is in the shape of an inverted circular truncated cone. The upper part is the second expanded section 52, which is in the shape of a cylinder and is partially filled with the second solids 50 to form a larger diameter separation space, which reduces the gas velocity and allows the solid particles to separate from the rising gas. Most of the particles that are drawn into the fluidized gas fall back to the bed by gravity. The second discharge outlet is provided on the second fixed section 51. The second additive inlet, the second feed inlet, the second oxidant inlet and the second discharge outlet are provided on the second expanded section 52.

[0089] In this embodiment, the second additive feed tank 4 is connected to the second additive inlet, and the second additive feed tank 4 contains calcium carbonate. In this embodiment, the calcium carbonate is provided by a hopper with a fill / close valve at the top and a solids dump valve at the bottom, and the solids dump valve of the hopper is connected to a solids feed line into the carbon reduction reforming reactor 5, which is purged with a small amount of air to keep the line open during feeding.

[0090] In this embodiment, the oxygen supply system is connected to the second oxidant inlet. In this embodiment, the carbon reduction reforming reactor 5 is positioned downstream of the steam reforming reactor 3 and is fluidized by the gas from the first outlet and the incoming oxygen. Fine solid particles eluted from the steam reforming reactor 3 also enter the carbon reduction reforming reactor 5 along with the process gas, and the carbon is converted to carbon dioxide, reducing the carbon fines in the eluted solids; trace amounts of acidic gases produced in the steam reforming reactor 3 are removed by reaction with the calcium bed particles composed of the second solids 50 of the carbon reduction reforming reactor 5, producing mineralized calcium compounds; and residual volatile organic compounds, carbon monoxide, and hydrogen are oxidized to carbon dioxide and water vapor.

[0091] In this embodiment, an oxygen monitor is installed at the second outlet. The oxygen monitor controls the output of oxygen to the carbon reduction reforming reactor 5. The excess oxygen concentration level is set during the process operation, and then automatically controlled during operation. The normal excess oxygen content of the tail gas from the carbon reduction reforming reactor 5 is 2% to 8% by volume of free oxygen volume.

[0092] In this embodiment, a cooler 53 is provided in the pipeline connecting the second outlet of the carbon reduction reforming reactor 5 to the third inlet, for cooling the hot off-gas from the second outlet of the carbon reduction reforming reactor 5. The cooler 53 is provided with cooling nozzles for cooling the hot off-gas in the pipeline, and the cooling nozzles are connected to a water supply system. The cooling water and atomizing air sprayed by the cooler 53 are controlled as required to maintain the temperature of the downstream filtration device within the required operating range.

[0093] In this embodiment, a filtration device is installed downstream of the carbon reduction reforming reactor 5, including a pulse bag filter 6, an activated carbon adsorber 7, and a high efficiency particulate air (HEPA) filter 8 connected in sequence, a third discharge port and a third inlet are provided on the pulse bag filter 6, a third outlet is the outlet of the HEPA filter 8, and the third outlet is connected to an exhaust fan 9. In this embodiment, the pulse bag filter 6 is a vertical vessel, and the purpose is to remove and collect fine solid particles eluted from the carbon reduction reforming reactor 5. In this embodiment, an electric heater is provided on the outside of the pulse bag filter 6 to maintain the temperature of the filter elements and the vessel therein above the dew point of the gas to prevent moisture condensation on the filter medium during start-up and shutdown.

[0094] In this embodiment, a vacuum ejector 61 is provided between the pulse bag filter 6 and the activated carbon adsorber 7. The exhaust gas filtered by the pulse bag filter 6 will pass through the vacuum ejector 61. The exhaust fan 9 provides negative pressure for the vacuum ejector 61 to maintain the separation space of the pulse bag filter 6, the carbon reforming reaction device 5, and the steam reforming reaction device 3 in a negative pressure state. In this embodiment, a gas monitor is installed at the outlet of the pulse bag filter 6 and the vacuum ejector 61 to monitor the flow of total exhaust gas such as H2O, O2, N2, CO, CO2, total hydrocarbon (THC), HCl, and NOx.

[0095] In this embodiment, the high-efficiency filter 8 is provided with multiple groups of backup components to allow replacement of the components, so that the process system can remain in an online operation state. In this embodiment, the exhaust fan 9 provides airflow throughout the facility and controls the negative pressure level in various equipment areas. The mixed ventilation airflow and clean, cooled process exhaust gas pass through the exhaust stack to obtain the permitted and permitted emissions. In this embodiment, the outlet of the exhaust fan 9 is provided with a continuous emission monitoring instrument (CEMS) for monitoring the emission of process tail gas, recording data such as total hydrocarbon (THC), H2O, O2, N2, CO, CO2, HCl, SOx, and NOx for analysis and record keeping.

[0096] In this embodiment, the first, second, and third slag outlets are connected to the feed inlet of the solid waste collection tank 10. The discharged waste is collected in the solid waste collection tank 10 for further treatment by the solid waste treatment system.

[0097] Embodiment 2

[0098] A method for treating radioactive organic nitrate slurry, which uses the radioactive organic nitrate slurry treatment system in Embodiment 1, comprising the following steps:

[0099] S1, in the steam reforming reaction device 3 pre-packed with clay, the radioactive organic-nitrate slurry, the first additive composed of clay, iron oxide, and carbon, and the first oxidizing agent composed of steam and oxygen are reacted to generate synthesis gas; the reaction pressure is -2 kPa, the temperature is 750°C, the residence time is 2 s, the feed flow rate of the radioactive organic-nitrate slurry is 80 L / h, about 87 kg / h, the flow rate of the clay is 5 kg / h, the flow rate of the iron oxide is 5 kg / h, the flow rate of the carbon is 10 kg / h, the flow rate of the steam is 100 kg / h, and the flow rate of the oxygen is 50 Nm 3 / h;

[0100] S2, in the carbon reduction reforming reaction device 5 pre-packed with calcium carbonate, the reaction product of step S1, the second additive calcium carbonate, and the second oxidizing agent oxygen are reacted; the reaction pressure is -5 kPa, the temperature is 1000°C, the residence time is 2 s, and the feed flow rate of the synthesis gas is 550 Nm3 The feed flow rate of calcium carbonate was 10 kg / h, and the feed flow rate of oxygen was 60 Nm 3 / h.

[0101] S3, the tail gas after the reaction is cooled to 180-250℃ by a cooler 53, and then discharged after passing through a pulse bag filter 6, an activated carbon adsorber 7 and a high efficiency filter 8 in sequence; the solid waste generated in the steam reforming reaction device 3, the carbon reduction reforming reaction device 5 and the pulse bag filter 6 is collected into a solid waste collection tank 10.

[0102] In this embodiment, the radioactive organic-nitrate slurry contains inorganic substances (including nitrate about 70wt%, nitrite about 25wt%, nitric acid 2.5wt%, hydroxide 2wt% and sulfate 0.5wt%, wherein the uranium content is 10mg / L) and COD 2 million mg / L, and the volume content of solid particles of the radioactive organic-nitrate slurry is less than 10%.

[0103] In this embodiment, the discharged tail gas contains oxygen 5vt%, water 36vt%, carbon dioxide 10vt%, nitrogen 49vt%, sulfur dioxide ≤50mg / Nm 3 , nitrogen oxides ≤100mg / Nm 3 , solid particles ≤10mg / Nm 3 .

[0104] In this embodiment, the discharged solid residue contains sodium-aluminum-silicate (Na, K, Al, S, Cl, F, P, heavy metals and radionuclides combined into water-insoluble compounds) 96vt%, sulfate 1vt%, carbonate 3vt%.

Claims

1. A system for the treatment of radioactive organo-nitrate sludge, characterized in that, It comprises a steam reforming reaction device (3), a carbon reduction reforming reaction device (5) and a filtering device; The steam reforming reaction device (3) is provided with a first slag discharge port, a first additive inlet, a first feed inlet, a first oxidant inlet and a first discharge port; the position of the first discharge port is higher than that of the first additive inlet, the first feed inlet and the first oxidant inlet; The carbon reduction reforming reaction device (5) is provided with a second slag discharge port, a second additive inlet, a second feed inlet, a second oxidant inlet and a second discharge port; the position of the second discharge port is higher than that of the second additive inlet, the second feed inlet and the second oxidant inlet; the first discharge port is connected with the second feed inlet; The filtering device is provided with a third feed inlet and a third discharge port; the second discharge port is connected with the third feed inlet.

2. The system for treatment of radioactive organo-nitrate sludge according to claim 1, characterized in that, The position of the first slag discharge port is lower than that of the first additive inlet, the first feed inlet and the first oxidant inlet; A first additive feed tank (1) is connected with the first additive inlet; An oxygen supply system and a steam boiler are connected with the first oxidant inlet; The first discharge port is provided with an oxygen monitor and a hydrogen monitor.

3. The radioactive organo-nitrate sludge treatment system of claim 1, wherein, A cyclone separator is arranged at the top of the steam reforming reaction device (3), which comprises a wind scoop (301) and a backflow pipe (302); the air outlet of the wind scoop (301) is the first discharge port, and the backflow pipe (302) penetrates into the steam reforming reaction device (3); A mud storage tank is connected with the first feed inlet; a feed pump (2) is arranged between the mud storage tank and the first feed inlet; a temporary storage tank is further arranged between the mud storage tank and the feed pump (2); the feed pump (2) is a peristaltic pump; The steam reforming reaction device (3) is a fluidized bed reactor.

4. The radioactive organo-nitrate salt slurry treatment system of claim 1, wherein, The steam reforming reaction device (3) comprises a first fixed section (31) and a first enlarged section (32) which are integrally formed; the first enlarged section (32) is located above the first fixed section (31); the first fixed section (31) has an overall inverted circular truncated cone shape; the first slag discharge port is arranged on the first fixed section (31); the first enlarged section (32) has an overall cylindrical shape; the first additive inlet, the first feed inlet, the first oxidant inlet and the first discharge port can be arranged on the first enlarged section (32).

5. The radioactive organo-nitrate sludge treatment system of claim 1, wherein, The position of the second slag discharge port can be lower than that of the second additive inlet, the second feed inlet and the second oxidant inlet; A second additive feed tank can be connected with the second additive inlet; An oxygen supply system can be connected with the second oxidant inlet; The second discharge port can be provided with an oxygen monitor.

6. The radioactive organo-nitrate salt slurry treatment system of claim 1, wherein, The carbon reduction reforming reaction device (5) is a fluidized bed reactor; The carbon reduction reforming reaction device (5) comprises a second fixed section (51) and a second enlarged section (52) which are integrally formed; the second enlarged section (52) is located above the second fixed section (51).

7. The system for treatment of radioactive organo-nitrate sludge according to claim 6, characterized in that, The second fixed section (51) has an overall inverted circular truncated cone shape; The second slag discharge port is arranged on the second fixed section (51); The second fixed section (51) has an overall inverted circular truncated cone shape; The second enlarged section (52) is cylindrical as a whole; The second additive inlet, the second feed inlet, the second oxidizing agent inlet and the second discharge outlet are arranged on the second enlarged section (52).

8. The radioactive organo-nitrate salt slurry treatment system of claim 1, wherein, The filter device is also provided with a third slag discharge port; the position of the third slag discharge port is lower than that of the third feed inlet; the first slag discharge port and the second slag discharge port are connected with the feed inlet of the solid waste collecting tank (10); the third slag discharge port is connected with the feed inlet of the solid waste collecting tank (10); The filter device comprises a pulse bag filter (6), an activated carbon adsorber (7) and a high-efficiency filter (8) connected in sequence; the third slag discharge port and the third feed inlet are arranged on the pulse bag filter (6); and the third discharge outlet is the discharge outlet of the high-efficiency filter (8).

9. The system for treatment of radioactive organo-nitrate sludge according to claim 8, characterized in that, The pulse bag filter (6) is a vertical container; A vacuum ejector (61) is arranged on the connecting pipeline of the pulse bag filter (6) and the activated carbon adsorber (7); and a gas monitor is arranged on the outlet of the vacuum ejector (61); A heater is arranged outside the pulse bag filter (6). A gas monitor is arranged on the outlet of the pulse bag filter (6).

10. The radioactive organo-nitrate salt slurry treatment system of claim 1, wherein, The third discharge outlet is connected with an exhaust fan (9); and a continuous discharge monitor is arranged on the air outlet of the exhaust fan (9). A cooler (53) is arranged on the pipeline connecting the second discharge outlet and the third feed inlet.

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