Toluene solvent recovery method in chlorine-containing triaminotrinitrobenzene production

Abstract

The invention relates to a toluene solvent recovery method in chlorine-containing triaminotrinitrobenzene production. The method comprises the following steps: washing mother liquor obtained after TATB production with water, wherein the content of removed inorganic chlorine is less than or equal to 2.15 mg / kg; carrying out activated carbon and molecular sieve adsorption operation on the washed feed liquid, wherein the content of removed organic chlorine is less than or equal to 4.95 g / kg; pumping the material adsorbed by the molecular sieve into a reduced-pressure vacuum continuous rectifying tower to separate methylbenzene from solute; connecting a tower kettle material stream to a filter to filter out solid from residual liquid obtained from the tower kettle of the rectifying tower, and enabling filtrate to flow back to the vacuum tower again through a circulating pump; and the high-purity toluene solvent obtained at the top of the rectifying tower is recycled and continuously used. According to the recovery method provided by the invention, an intermittent feeding mode is adopted, so that the purity of the recovered solvent can be effectively improved. And the dechlorination efficiency reaches 78-80%. And meanwhile, the solvent is recovered in a vacuum distillation manner, so that the energy consumption required by solvent recovery can be reduced, and the requirements of energy conservation and consumption reduction are met.

Description

Technical Field

[0001] This invention relates to solvent recovery technology in the production of energetic materials, specifically to a toluene solvent recovery process in the production of triaminotrinitrobenzene (TATB), belonging to the field of separation technology; specifically, it relates to a method for toluene solvent recovery in the production of chlorinated triaminotrinitrobenzene. Background Technology

[0002] Triaminotrinitrobenzene (TATB) possesses low sensitivity, high thermal stability, and high explosive energy, making it ideal for manufacturing nuclear weapons and munitions. Related data shows that toluene is widely used as a key solvent in the TATB production process. Early studies confirmed that toluene solvent accounts for more than 30% of the production cost; therefore, solvent recycling can significantly reduce costs, achieve resource reuse, and ensure environmental safety.

[0003] Existing technologies, such as patent CN118637973A, describe a toluene recovery method. First, the toluene is dehydrated using the hygroscopic properties of calcium oxide. Then, the recovered toluene is further purified through distillation to obtain high-purity, low-moisture toluene. However, the production process involves reaction byproducts containing organic chlorines such as chlorobenzenes and inorganic chlorides such as ammonium chloride, resulting in a high chlorine content in the recovered toluene solvent. If traditional solvent recovery methods are used, chloride ions under atmospheric pressure and high-temperature distillation conditions can easily cause corrosion to the distillation column, trays, and related heat exchange equipment, increasing the cost of periodic equipment replacement. Furthermore, organic chlorines can form azeotropes with other substances, reducing the yield of TATB and the purity of the recovered solvent.

[0004] Most existing dechlorination technologies use dechlorinating agents. Patent CN120132816A describes a low-temperature liquid-phase molecular sieve dechlorinating agent and its preparation method. The studied low-temperature liquid-phase molecular sieve dechlorinating agent uses phosphorus-modified fine-crystal molecular sieves, phytic acid-modified polyhydroxy polymer complexed metal ions, active silicon-coated nano-ceramic powder, and oligoglycerol as raw materials to prepare a low-temperature liquid-phase molecular sieve dechlorinating agent with high chlorine penetration capacity, high radial crushing resistance, and low abrasion rate. The liquid-phase dechlorinating agent prepared by this patent has a measured chlorine penetration capacity of 39.8–43.6% and a radial crushing resistance of 134–148 N·cm. -1 The wear rate is 0.82-1.12%. However, the dechlorinating agent in this penetrating chlorine capacity can only remove inorganic chlorine such as hydrogen chloride and ammonium chloride, and its effect on removing organic chlorine is not good. The toluene mother liquor involved in this invention contains a high content of organic chlorine, so it is not suitable for the dechlorination stage in the toluene recovery system.

[0005] In traditional solvent recovery methods, batch distillation can optimize the separation of different components by adjusting parameters such as reflux ratio, temperature, and time. However, continuous feeding requires a stable feed composition and is less adaptable to industrial waste solvents containing impurities or with fluctuating concentrations. Batch feeding allows for precise control of the feed rate and timing based on subsequent processing steps, which is beneficial for stabilizing the entire recovery process and improving separation efficiency. Furthermore, for toluene solvent systems, batch feeding results in smaller batch sizes, making the risks more manageable. In addition, atmospheric pressure operation requires high temperatures, which accelerates tower corrosion and shortens equipment lifespan. High temperatures may also cause partial decomposition of certain substances in the waste liquid, increasing production safety risks. Therefore, there is a need to develop a toluene solvent recovery method for TATB production that features low chlorine content, high solvent recovery efficiency, and high safety. Summary of the Invention

[0006] The purpose of this invention is to provide a method for recovering toluene solvent in the production of chlorinated triaminotrinitrobenzene (TATB). The recovery method can separate toluene from other substances and effectively reduce the chlorine content to obtain high-purity toluene solvent.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] A method for recovering toluene solvent in the production of chlorinated triaminotrinitrobenzene; characterized by comprising the following steps:

[0009] (1) As shown in the following chemical equation, inorganic chlorine in the raw material usually exists in the form of ammonium chloride, which can be dissolved and separated by washing with water. The mother liquor after TATB production is first washed with water to remove inorganic chlorine content ≤2.15mg / kg;

[0010] NH4Cl≒NH4 + +Cl -

[0011] NH4 + +H₂O≒NH₃·H₂O+H +

[0012] (2) Activated carbon has a large specific surface area and adsorption capacity, and can adsorb organochlorine compounds. Molecular sieves selectively adsorb organochlorine compounds through their pore structure. The washed feed solution was subjected to adsorption operations with activated carbon and molecular sieves, and the organochlorine content was removed by ≤4.95g / kg;

[0013] (3) The material adsorbed by the molecular sieve is pumped into a vacuum continuous distillation column for the separation of toluene and solute. By reducing the pressure, the boiling point of toluene is lowered, causing it to volatilize at a lower temperature, thereby separating it from the solute. By controlling the temperature at the top and bottom of the column, the effective separation of toluene and solute can be achieved.

[0014] (4) Connect the material stream in the bottom of the column to a filter to filter out the solids. The filters are connected in parallel, with one on and one on standby. When the pressure drop across the two ends reaches the upper limit of the allowable pressure drop of the filter, the filter is replaced. The filtrate is returned to the vacuum column via a circulation pump. High-purity toluene solvent is obtained at the top of the column.

[0015] In step (1), deionized water is used to wash the mother liquor, and the process is repeated 3 to 4 times; the volume ratio of deionized water to mother liquor is 1.9 to 2.1:1; the washing temperature is 80 to 85°C; and the washing time is 20 to 30 minutes.

[0016] In step (2), activated carbon adsorption is performed under normal pressure; the operating temperature is 40-45℃; a dechlorination tank is used, the stirring speed of the dechlorination tank is 300-400 rpm, and the adsorption residence time is 3-4 h.

[0017] In step (2), the activated carbon used is 80-100 mesh, and the amount of activated carbon added is 15-25 mg / g of mother liquor.

[0018] In step (2), the molecular sieve adsorption operation adopts the fixed bed adsorption method, using Hβ type molecular sieve adsorbent as dechlorinating agent to remove organic chlorine. The Hβ type molecular sieve loading amount is 20-30 mg / g mother liquor, and it is activated by gradient heating at 110-120℃, 230-240℃, 350-360℃ and 470-480℃, for 2-3 hours at each temperature, with a heating rate of 25-30℃ / min, and the molecular sieve adsorption residence time is 1-2 hours.

[0019] In step (3), the distillation operation is a batch operation, and the reduced pressure distillation is carried out in a vacuum distillation column. The number of distillation column plates is set to 5 to 10, the column pressure is set to 0.03 to 0.05 MPa, the reflux ratio is set to 1.5 to 2.5, the column bottom temperature is set to 65 to 85°C, and the column top temperature is set to 50 to 70°C.

[0020] In step (4), two filters are connected and operate in parallel at an operating pressure of 0.2–0.3 MPa. The filters use ceramic precision membranes with a pore size of 0.1–0.5 μm. A differential pressure gauge is connected to the filters; when the pressure drop across the filters reaches the upper limit of the allowable pressure drop, the filters can be replaced.

[0021] The mother liquor comprises: 94-96% toluene, 2%-3% 1,3,5-trichloro-2,4,6-trinitrobenzene (TCTNB), 2%-3% 1,3,5-trichloro-2,6-dinitrobenzene (TCDNB) and byproducts such as ammonium chloride, and 0.02% water. The inorganic chlorine content is 9-11 g / kg, and the organic chlorine content is 19.5-23.1 g / kg.

[0022] The mother liquor after washing consists of: 94-96% toluene, 2%-3% 1,3,5-trichloro-2,4,6-trinitrobenzene (TCTNB), 2%-3% byproducts such as 1,3,5-trichloro-2,6-dinitrobenzene (TCDNB), and 0.02% water. The inorganic chlorine content is 1.97-2.15 mg / kg, and the organic chlorine content is 19.5-23.1 g / kg.

[0023] The mother liquor after adsorption and dechlorination consists of: 97-98% toluene, 2%-3% byproducts, and 0.02% water. The inorganic chlorine content is 1.96-2.15 mg / kg, and the organic chlorine content is 3.97-4.95 g / kg.

[0024] The recovery method provided by this invention employs an intermittent feeding approach, treating the mother liquor through a combination of dechlorination and vacuum distillation, which effectively improves the purity of the recovered solvent. The initial dechlorination operation reduces the risk of equipment corrosion due to excessive chlorine content and effectively avoids the problem of impure separation products caused by the presence of chlorine, achieving a dechlorination efficiency of 78-80%. Simultaneously, solvent recovery via vacuum distillation reduces the energy consumption required for solvent recovery, meeting the needs of energy conservation and emission reduction. Attached Figure Description

[0025] Figure 1 Flowchart of toluene solvent recovery process in the production of chlorinated triaminotrinitrobenzene Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0027] This patented invention adopts Figure 1 The process flow apparatus mainly includes a water washing tank, an activated carbon adsorption dechlorination tank, a molecular sieve adsorption dechlorination tank, a centrifugal pump, a vacuum distillation column, and filters that can be operated in parallel on pipelines, all connected in sequence.

[0028] This patented invention performs intermittent vacuum distillation on the dechlorinated material. Toluene is separated from the top of the distillation column, and a solid-liquid mixture is collected from the bottom of the distillation column. The solid in the mixture can be filtered out by a filter, and the liquid is returned to the vacuum distillation column, which can achieve the purpose of reducing the operating temperature and improving the toluene recovery rate.

[0029] 1) The mother liquor is dissolved and separated in water washing tank 1 to remove inorganic chlorine;

[0030] 2) The mother liquor is dechlorinated by activated carbon adsorption in dechlorination tank 2 and molecular sieve adsorption in dechlorination tank 3 to remove organic chlorine;

[0031] 3) The dechlorinated mother liquor is sent to the solvent recovery tower 5 via centrifugal pump 4, and is operated by intermittent feeding and vacuum distillation. Qualified toluene solvent is collected from the top of the distillation tower, and a solid-liquid mixture is obtained from the bottom of the tower.

[0032] 4) Two filters are connected in parallel to the column bottom, one operating and one on standby. Differential pressure gauges are connected to both sides of the filters, and the operation of the filters is controlled by valves. When the pressure drop across the two ends reaches the upper limit of the filter's allowable pressure drop, the filter can be replaced, and the filtrate is returned to the vacuum distillation column via a circulation pump. See the attached diagram. After the separation process of this patent, toluene solvent of the following purity can be obtained from the top of the distillation column for reuse:

[0033] Toluene purity ≥ 99.97%, water ≤ 0.02%

[0034] Example 1

[0035] The toluene mother liquor composition is as follows: toluene 94.2%, 1,3,5-trichloro-2,4,6-trinitrobenzene (TCTNB) 2.8%, byproducts such as 1,3,5-trichloro-2,6-dinitrobenzene (TCDNB) 3%, water 0.02%, and the remainder being impurities. The inorganic chlorine content is 11 g / kg, and the organic chlorine content is 23.1 g / kg.

[0036] 1) The material containing toluene, TCTNB, byproducts, and water was first fed into washing tank 1 and washed with deionized water to remove inorganic chlorine. The single material processing volume was 500 mL. The volume ratio of deionized water to mother liquor was 1.9:1, the washing temperature was 80℃, the washing time was 20 min, and the washing process was repeated 3 times. After treatment, the inorganic chlorine content in the material was reduced to 2.15 mg / kg.

[0037] 2) The upper organic phase is fed into a dechlorination tank to remove organochlorine. First, 80-100 mesh activated carbon is used for adsorption in activated carbon dechlorination tank 2. The activated carbon dosage is 15 mg / g of mother liquor, the operating pressure is atmospheric pressure, the operating temperature is 40℃, the stirring speed is 300 rpm, and the adsorption residence time is 3 h. Then, activated Hβ-type molecular sieves are used in molecular sieve dechlorination tank 3 for adsorption. The molecular sieves are activated by gradient heating at 110–120℃, 230–240℃, 350–360℃, and 470–480℃, for 2 hours at each temperature, with a heating rate of 30℃ / min. The molecular sieve loading is 20 mg / g of mother liquor, and the adsorption residence time is 1 h. After treatment, the organochlorine content in the material is reduced to 4.95 g / kg.

[0038] After the dechlorination process, the material composition was: toluene 96.9%, TCTNB and byproducts 3.0%, water 0.02%, and the remainder being impurities. The inorganic chlorine content was 2.15 mg / kg, and the organic chlorine content was 4.95 g / kg.

[0039] 3) The dechlorinated material is pumped into the solvent recovery tower 5 using centrifugal pump 4, employing intermittent feeding and vacuum distillation, with a single feed rate of 500 mL. The distillation tower has 8 trays, with feed introduced at the 4th tray. The tower pressure is set to 0.05 MPa, and the reflux ratio is set to 2.5. The reboiler temperature is set to 85℃, and the top temperature is set to 70℃. Toluene is separated at the top of the tower at a volumetric flow rate of 472 mL, while other substances are separated at the bottom, with a toluene volumetric flow rate of 38 mL. The top product is collected to obtain toluene solvent with a purity of 99.97%.

[0040] 4) Two parallel Y-type filters are connected to the bottom of the tower, using ceramic precision filter membranes with a pore size of 0.5μm and an operating pressure of 0.2MPa. When ΔP1 = 10kPa, valves a and b are closed, valves c and d are opened, and filter 1 is replaced simultaneously. When ΔP2 = 10kPa, valves c and d are closed, valves a and b are opened, and filter 2 is replaced simultaneously. After the solids are filtered out, the remaining liquid is returned to the pressure reducing tower.

[0041] Example 2

[0042] The toluene mother liquor composition is as follows: 95% toluene, 2.5% 1,3,5-trichloro-2,4,6-trinitrobenzene (TCTNB), 2.5% byproducts such as 1,3,5-trichloro-2,6-dinitrobenzene (TCDNB), 0.02% water, and the remainder being impurities. The inorganic chlorine content is 10.2 g / kg, and the organic chlorine content is 20.8 g / kg.

[0043] 1) The material containing toluene, TCTNB, byproducts, and water was first fed into washing tank 1 and washed with deionized water to remove inorganic chlorine. The single material processing volume was 500 mL. The volume ratio of deionized water to mother liquor was 2.1:1, the washing temperature was 85℃, the washing time was 30 min, and the washing process was repeated 3 times. After treatment, the inorganic chlorine content in the material was reduced to 1.96 mg / kg.

[0044] 2) The upper organic phase is fed into a dechlorination tank to remove organochlorine. First, 80-100 mesh activated carbon is used for adsorption in activated carbon dechlorination tank 2. The activated carbon dosage is 20 mg / g of mother liquor, the operating pressure is atmospheric pressure, the operating temperature is 45℃, the stirring speed is 400 rpm, and the adsorption residence time is 3.5 h. Then, activated Hβ-type molecular sieves are used in molecular sieve dechlorination tank 3 for adsorption. The molecular sieves are activated by gradient heating at 110–120℃, 230–240℃, 350–360℃, and 470–480℃, for 3 hours at each temperature, with a heating rate of 25℃ / min. The molecular sieve loading is 25 mg / g of mother liquor, and the adsorption residence time is 1.5 h. After treatment, the organochlorine content in the material is reduced to 3.97 g / kg.

[0045] After the dechlorination process, the material composition was: 97.9% toluene, 2.1% TCTNB and byproducts, 0.02% water, and the remainder being impurities. The inorganic chlorine content was 1.96 mg / kg, and the organic chlorine content was 3.97 g / kg.

[0046] 3) The dechlorinated material is pumped into solvent recovery tower 5 using a centrifugal pump. Intermittent feeding and vacuum distillation are employed, with a single feed rate of 500 mL. The distillation tower has 10 trays, with feed introduced at the 7th tray. The tower pressure is set to 0.04 MPa, and the reflux ratio to 1.5. The reboiler temperature is set to 77℃, and the top temperature is set to 62℃. Toluene is separated at the top of the tower at a flow rate of 481 mL, while other substances are separated at the bottom, with a toluene flow rate of 19 mL. The top product is collected to obtain toluene solvent with a purity of 99.99%.

[0047] 4) Two parallel T-type filters are connected to the bottom of the tower, using ceramic precision filter membranes with a pore size of 0.35μm and an operating pressure of 0.3MPa. When ΔP1 = 18kPa, close valves a and b, open valves c and d, and replace filter 1 simultaneously. When ΔP2 = 18kPa, close valves c and d, open valves a and b, and replace filter 2 simultaneously. After filtering out the solids, the remaining liquid is returned to the pressure reducing tower.

[0048] Example 3

[0049] The toluene mother liquor composition is as follows: 96% toluene, 2% 1,3,5-trichloro-2,4,6-trinitrobenzene (TCTNB), 2% byproducts such as 1,3,5-trichloro-2,6-dinitrobenzene (TCDNB), 0.02% water, and the remainder being impurities. The inorganic chlorine content is 9 g / kg, and the organic chlorine content is 19.5 g / kg.

[0050] 1) The material containing toluene, TCTNB, byproducts, and water was first fed into washing tank 1 and washed with deionized water to remove inorganic chlorine. The single material processing volume was 500 mL. The volume ratio of deionized water to mother liquor was 2:1, the washing temperature was 83℃, the washing time was 26 min, and the washing process was repeated 4 times. After treatment, the inorganic chlorine content in the material was reduced to 2.01 mg / kg.

[0051] 2) The upper organic phase is fed into a dechlorination tank to remove organochlorine. First, 80-100 mesh activated carbon is used for adsorption in activated carbon dechlorination tank 2. The activated carbon dosage is 25 mg / g of mother liquor, the operating pressure is atmospheric pressure, the operating temperature is 42℃, the stirring speed is 350 rpm, and the adsorption residence time is 4 h. Then, activated Hβ-type molecular sieves are used in molecular sieve dechlorination tank 3 for adsorption. The molecular sieves are activated by gradient heating at 110–120℃, 230–240℃, 350–360℃, and 470–480℃, for 2.5 hours at each temperature, with a heating rate of 28℃ / min. The molecular sieve loading is 30 mg / g of mother liquor, and the adsorption residence time is 2 h. After treatment, the organochlorine content in the material is reduced to 3.87 g / kg.

[0052] After the dechlorination process, the material composition was: toluene 97.1%, TCTNB and byproducts 2.9%, water 0.02%, and the remainder being impurities. The inorganic chlorine content was 2.01 mg / kg, and the organic chlorine content was 4.87 g / kg.

[0053] 3) The dechlorinated material is pumped into solvent recovery tower 5 using a centrifugal pump. Intermittent feeding and vacuum distillation are employed, with a single feed rate of 500 mL. The distillation tower has 10 trays, with feed introduced at the 5th tray. The tower pressure is set to 0.03 MPa, and the reflux ratio is set to 2. The reboiler temperature is set to 65℃, and the top temperature is set to 50℃. Toluene is separated at the top of the tower at a flow rate of 482 mL, while other substances are separated at the bottom, with a toluene flow rate of 18 mL. The top product is collected to obtain toluene solvent with a purity of 99.98%.

[0054] 4) Two parallel basket filters are connected to the bottom of the tower, using ceramic precision filter membranes with a pore size of 0.1 μm and an operating pressure of 0.25 MPa. When ΔP1 = 15 kPa, close valves a and b, open valves c and d, and replace filter 1 simultaneously. When ΔP2 = 15 kPa, close valves c and d, open valves a and b, and replace filter 2 simultaneously. After filtering out the solids, the remaining liquid is returned to the pressure reducing tower.

[0055] In Examples 1-3 above, the dechlorination efficiency was all above 78%, and the purity of the toluene solvent obtained from the top of the reduced pressure column was all above 99.7%. This indicates that the dechlorination and separation processes involved in this invention can achieve high-purity and effective recovery of toluene solvent while ensuring reduced energy consumption. By comparison, the conditions described in Example 2 are the optimal conditions for the dechlorination and separation processes. In Example 1, insufficient adsorbent dosage would cause the adsorbent to quickly become saturated, rapidly depleting its effective adsorption capacity. In Example 3, excessive adsorbent dosage might over-adsorb water molecules or other small molecules, occupying the pores and thus reducing the adsorption capacity for the target organochlorine. Similarly, the feed method and other column parameter settings in Example 2 achieve the best recovery effect of the toluene solvent at the top of the column, resulting in higher recovery efficiency and higher purity.

[0056] The technical solutions disclosed and proposed in this invention can be implemented by those skilled in the art by appropriately modifying the conditions and routes, etc. Although the methods and preparation techniques of this invention have been described through preferred embodiments, those skilled in the art can obviously modify or recombine the methods and technical routes described herein without departing from the content, spirit, and scope of this invention to achieve the final preparation technique. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included within the spirit, scope, and content of this invention.

Claims

1. A method for recovering toluene solvent in the production of chlorinated triaminotrinitrobenzene; characterized in that, Includes the following steps: (1) The mother liquor after TATB production is first washed with water to remove inorganic chlorine content ≤2.15mg / kg; (2) The washed liquid was subjected to activated carbon and molecular sieve adsorption to remove organic chlorine content ≤4.95g / kg; (3) The material adsorbed by molecular sieve is pumped into a vacuum continuous distillation column for separation of toluene and solute; (4) The residue obtained from the bottom of the distillation column is connected to a filter to filter out the solids. The filters are connected in parallel, with one on and one on standby. When the pressure drop at both ends reaches the upper limit of the allowable pressure drop of the filter, the filter is replaced. The filtrate is returned to the vacuum column through a circulation pump. The toluene solvent obtained at the top of the distillation column is recovered and reused.

2. The method for recovering toluene solvent in the production of chlorinated triaminotrinitrobenzene as described in claim 1; characterized in that, In step (1), deionized water is used to wash the mother liquor, and the process is repeated 3 to 4 times; the volume ratio of deionized water to mother liquor is 1.9 to 2.1:1; the washing temperature is 80 to 85°C; and the washing time is 20 to 30 minutes.

3. The method for recovering toluene solvent in the production of chlorinated triaminotrinitrobenzene as described in claim 1; characterized in that, In step (2), the activated carbon adsorption operation is carried out at a normal pressure and a temperature of 40-45℃.

4. The method for recovering toluene solvent in the production of chlorinated triaminotrinitrobenzene as described in claim 1; characterized in that, In step (2), the activated carbon adsorption operation uses a dechlorination tank with a stirring speed of 300-400 rpm and an adsorption residence time of 3-4 h.

5. The method for recovering toluene solvent in the production of chlorinated triaminotrinitrobenzene as described in claim 1; characterized in that, In step (2), the activated carbon used is 80-100 mesh, and the amount of activated carbon added is 15-25 mg / g of mother liquor.

6. The method for recovering toluene solvent in the production of chlorinated triaminotrinitrobenzene as described in claim 1; characterized in that, In step (2), a fixed-bed adsorption method is used to remove organic chlorine by using Hβ-type molecular sieve adsorbent as dechlorinating agent. The Hβ-type molecular sieve loading amount is 20-30 mg / g of mother liquor. The molecular sieve is activated by gradient heating at 110-120℃, 230-240℃, 350-360℃ and 470-480℃ for 2-3 hours at each temperature, with a heating rate of 25-30℃ / min and a molecular sieve adsorption residence time of 1-2 hours.

7. The method for recovering toluene solvent in the production of chlorinated triaminotrinitrobenzene as described in claim 1; characterized in that, In step (3), the distillation operation is an intermittent operation, and the reduced pressure distillation is carried out in a vacuum distillation column.

8. The method for recovering toluene solvent in the production of chlorinated triaminotrinitrobenzene as described in claim 7; characterized in that, The number of trays in the distillation column is set to 5 to 10, the column pressure is set to 0.03 to 0.05 MPa, the reflux ratio is set to 1.5 to 2.5, the reboiler temperature is set to 65 to 85℃, and the top temperature is set to 50 to 70℃.

9. The method for recovering toluene solvent in the production of chlorinated triaminotrinitrobenzene as described in claim 1; characterized in that, In step (4), there are two filters connected in parallel, and the operating pressure is 0.2 to 0.3 MPa. The filters use ceramic precision filter membranes with a pore size of 0.1 to 0.5 μm.

10. The method for recovering toluene solvent in the production of chlorinated triaminotrinitrobenzene as described in claim 9; characterized in that, Connect the filter to a differential pressure gauge. Replace the working filter when the pressure drop due to the filter resistance reaches the upper limit of the allowable pressure drop.

Images