Process for recovering nitrate from octogen raffinate

Abstract

The invention discloses a process for recovering nitrate from octogen raffinate, and belongs to the technical field of waste liquid treatment and recovery, the process comprises the following steps: S1, introducing generated wastewater into a distillation pot, distilling the wastewater by using the distillation pot, and generating distillation raffinate after distillation; s2, pouring the distillation raffinate into a low-temperature evaporator, controlling the low-temperature evaporator to perform low-temperature evaporation on the distillation raffinate, removing redundant moisture in the distillation raffinate, and finally forming concentrated slurry from the distillation raffinate; and S3, removing the thick slurry, then adding a diluent, and then stirring the thick slurry to enable the diluent to be fully mixed in the thick slurry. According to the method, the low-temperature evaporator is used for continuously evaporating the distilled residual liquid, the internal moisture of the formed thick slurry is greatly reduced, the incineration operation cost is greatly reduced, and in view of unstable factors contained in the distillation residual liquid, in the process of concentrating the distillation residual liquid through low-temperature evaporation, the low-temperature evaporation concentration of the low-temperature residual liquid is realized, so that the low-temperature evaporation concentration of the low-temperature residual liquid is realized. The distillation residual liquid is always kept in a low-temperature state, so that the safety is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of waste liquid treatment and recovery, and in particular relates to a process for recovering nitrate from octogen residual liquid. Background Art

[0002] Wastewater treatment includes wastewater incineration, organic wastewater treatment or organic industrial wastewater treatment, also known as high-concentration organic wastewater treatment. There are three treatment methods: physical treatment, chemical treatment and biological treatment. Chemical treatment is generally combined with physical processes, also known as physicochemical treatment. Physical treatment refers to the use of physical or mechanical separation to treat wastewater. Common methods include: filtration, sedimentation, flotation, oil separation and centrifugation. Chemical treatment is a wastewater treatment method that separates and removes pollutants in dissolved or colloidal states in wastewater through chemical reactions and mass transfer, or converts them into harmless substances. Biological treatment is a wastewater treatment method that converts organic pollutants in wastewater in solution, colloidal and finely suspended states into stable and harmless substances through the metabolism of microorganisms.

[0003] The main components of Octogen residual liquid are ammonium nitrate, acetone, ethyl acetate, acetic acid, product by-products and trace residues of products. The wastewater contains unstable components and poses certain safety risks. The wastewater has the following characteristics: 1. It contains unstable components and poses certain safety risks; 2. It has high TDS, poor fluidity after concentration and easy precipitation of solids, which affects subsequent transportation and incineration, and the instrument connection port is easily blocked, causing instrument inaccuracy; 3. It has a high ammonia nitrogen / total nitrogen ratio and is easy to enter the condensate, increasing the difficulty of subsequent treatment. The current method of treating Octogen residual liquid is to distill the Octogen residual liquid and then put the distillation residue into the boiler for co-combustion. However, as the production capacity expands, the amount of distillation residue also increases, exceeding the processing capacity of the original boiler. While ensuring that the final treatment process of incineration remains unchanged, a process for recovering nitrate from Octogen residual liquid is needed. Summary of the Invention

[0004] The purpose of the present invention is to propose a process for recovering nitre from octogen residue in order to solve the problem that the existing method of treating octogen residue is to distill the octogen residue and then put the distillation residue into a boiler for co-combustion, but as the production capacity expands, the amount of distillation residue also increases, exceeding the processing capacity of the original boiler.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A process for recovering nitre from octogen residual liquid specifically comprises the following steps:

[0007] S1, introducing the generated wastewater into a distillation pot, using the distillation pot to distill the wastewater, and generating distillation residue after distillation;

[0008] S2, pouring the distillation residue into a low-temperature evaporator, controlling the low-temperature evaporator to evaporate the distillation residue at a low temperature to remove excess water in the distillation residue, and finally forming a concentrated slurry from the distillation residue;

[0009] S3, removing the concentrated slurry and then adding a diluent, and then stirring the concentrated slurry to allow the diluent to be fully mixed in the concentrated slurry;

[0010] S4, waiting for the concentrated slurry to cool down, at which time the ammonium nitrate in the concentrated slurry gradually crystallizes;

[0011] S5, pouring the concentrated slurry into a solid-liquid separator, and controlling the solid-liquid separator to separate the slurry and crystallized ammonium nitrate;

[0012] S6. Collect the separated slurry, take out the crystallized ammonium nitrate, place the ammonium nitrate on gauze, and then rinse the ammonium nitrate with clean water to dilute the diluent remaining on the surface of the ammonium nitrate. At the same time, non-salt organic matter attached to the surface of the ammonium nitrate will dissolve. Finally, the clean water used for rinsing will flow out through the gauze, and the clean water used to wash the ammonium nitrate is collected in a container;

[0013] S7, collect the ammonium nitrate after cleaning, then it is carried out drying, and finally utilize plastic packaging bag that the dried ammonium nitrate is collected;

[0014] S8, pouring the clean water used to wash the ammonium nitrate and the separated slurry into a container, and then introducing the mixed liquid into a distillation tower for distillation to reduce the water content in the mixed liquid;

[0015] S9. Collect the remaining mixed liquid, pour the mixed liquid into a reactor for heating, then add activated carbon into the reactor, the activated carbon absorbs the diluent in the mixed liquid, finally take out the activated carbon to recover the diluent, and put the remaining waste liquid into a boiler for incineration.

[0016] As a further description of the above technical solution:

[0017] In S1, the temperature of the distillation pot is controlled to be 100-120° C., the distillation time is controlled to be 2-3 hours, and the distillation residue produced after distillation has the following components: 25%-30% organic matter, salt, and 70%-75% water.

[0018] As a further description of the above technical solution:

[0019] In S2, after the distillation residue is evaporated using a low-temperature evaporator, 20%-25% of the water in the distillation residue remains. The distillation residue itself contains energetic materials. The use of low-temperature evaporation can effectively avoid safety risks and greatly improve safety compared to conventional evaporation and concentration methods. In addition, controlling the proportion of residual water in the distillation residue is also one of the key factors for safe recovery.

[0020] As a further description of the above technical solution:

[0021] In said S3, the additives include the following substances: organic solvents such as methanol, ethanol, and acetic acid. The addition ratio of methanol, ethanol, and acetic acid is 2:2:1, and the content of methanol, ethanol, and acetic acid accounts for 5-15% of the total content of the concentrated slurry.

[0022] As a further description of the above technical solution:

[0023] In S3, the concentrated slurry is stirred by a stirrer, the rotation speed of the stirrer is controlled to be 300-500 rpm, and the stirring time is controlled to be 3-5 min.

[0024] As a further description of the above technical solution:

[0025] In S6, the ammonium nitrate is rinsed with clean water for 2-4 minutes. During the rinsing process, the gauze is shaken to adjust the position of the ammonium nitrate so that the ammonium nitrate can be fully rinsed and the diluent attached to the surface can be rinsed away.

[0026] As a further description of the above technical solution:

[0027] In S7, the ammonium nitrate is dried by air drying in a drying machine for 10-15 minutes.

[0028] As a further description of the above technical solution:

[0029] In S8, the excess water in the mixed liquid is evaporated by distillation, and the diluent is also evaporated and collected under the action of distillation, so as to achieve the purpose of recovering the diluent, and only 20% of the mixed liquid remains.

[0030] As a further description of the above technical solution:

[0031] In S9, the indirect heating inside the reactor is controlled to ensure that the temperature inside the reactor is controlled at 50-60° C. After the activated carbon is added, it is left in the mixed liquid for 24-48 hours.

[0032] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0033] 1. In the present invention, the residual liquid after distillation is further evaporated by a low-temperature evaporator, and the concentrated slurry formed greatly reduces the internal moisture, greatly reducing the incineration operation cost. In view of the unstable factors contained in the distillation residual liquid, the present invention uses low-temperature evaporation to concentrate the distillation residual liquid, and always keeps the distillation residual liquid at a low temperature, which greatly improves safety.

[0034] 2. In the present invention, the diluent in the mixed liquid is recovered for the first time by distillation, and then the residual diluent is recovered for the second time by activated carbon. The double recovery method is used to recover the diluent to a great extent, saving the waste liquid treatment cost. DETAILED DESCRIPTION

[0035] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0036] Example 1

[0037] The present invention provides a technical solution: a process for recovering nitre from octogen residual liquid, characterized in that it specifically comprises the following steps:

[0038] S1. introducing the generated wastewater into a distillation pot, distilling the wastewater using the distillation pot to produce a distillation residue after distillation, controlling the temperature of the distillation pot to 100° C., controlling the distillation time to 2 hours, and the distillation residue produced after distillation has the following components: 25% organic matter, salt, and 70% water;

[0039] S2. Pour the distillation residue into a low-temperature evaporator, control the low-temperature evaporator to evaporate the distillation residue at a low temperature, remove excess water in the distillation residue, and finally form a concentrated slurry with the distillation residue. After the distillation residue is evaporated by the low-temperature evaporator, 20% of the water in the distillation residue remains;

[0040] S3. Remove the concentrated slurry and then add a diluent, then stir the concentrated slurry to allow the diluent to be fully mixed in the concentrated slurry, the additives include the following substances: methanol, ethanol, acetic acid and other organic solvents, the addition ratio of methanol, ethanol and acetic acid is 2:2:1, and the content of methanol, ethanol and acetic acid accounts for 5% of the total content of the concentrated slurry. Use a stirrer to stir the concentrated slurry, control the stirrer speed to 300 rpm, and control the stirring time to 3 minutes;

[0041] S4, waiting for the concentrated slurry to cool down, at which time the ammonium nitrate in the concentrated slurry gradually crystallizes;

[0042] S5, pouring the concentrated slurry into a solid-liquid separator, and controlling the solid-liquid separator to separate the slurry and crystallized ammonium nitrate;

[0043] S6. Collect the separated slurry and take out the crystallized ammonium nitrate. Place the ammonium nitrate on gauze, then rinse the ammonium nitrate with clean water to dilute the diluent remaining on the surface of the ammonium nitrate. At the same time, non-salt organic matter attached to the surface of the ammonium nitrate will dissolve. Finally, the clean water used for rinsing will flow out through the gauze. Use a container to collect the clean water used to wash the ammonium nitrate, and rinse the ammonium nitrate with clean water for 2 minutes. During the rinsing process, shake the gauze to adjust the position of the ammonium nitrate so that the ammonium nitrate can be fully rinsed and the diluent attached to the surface can be rinsed clean.

[0044] S7, collect the ammonium nitrate after cleaning, then it is carried out drying, finally utilize plastic packaging bag that dried ammonium nitrate is collected, utilize drying machine to carry out air drying to ammonium nitrate, and drying time is 10min;

[0045] S8, pouring the clean water used to wash the ammonium nitrate and the separated slurry into a container, then introducing the mixed liquid into a distillation tower for distillation to reduce the water content in the mixed liquid, and using distillation to evaporate the excess water in the mixed liquid. The diluent is also evaporated and collected under the action of distillation, thereby achieving the purpose of recovering the diluent, and only 20% of the mixed liquid remains;

[0046] S9. Collect the remaining mixed liquid, pour the mixed liquid into the reactor for heating, then add activated carbon into the reactor, the activated carbon absorbs the diluent in the mixed liquid, finally take out the activated carbon to recover the diluent, and put the remaining waste liquid into the boiler for incineration, control the indirect heating inside the reactor, ensure that the temperature in the reactor is controlled at 50°C, and leave the activated carbon in the mixed liquid for 24 hours after addition.

[0047] Example 2

[0048] The present invention provides a technical solution: a process for recovering nitre from octogen residual liquid, characterized in that it specifically comprises the following steps:

[0049] S1. introducing the generated wastewater into a distillation pot, distilling the wastewater using the distillation pot to produce a distillation residue after distillation, controlling the temperature of the distillation pot to 110° C., controlling the distillation time to 2.5 hours, and the distillation residue produced after distillation has the following components: 28% organic matter, salt, and 73% water;

[0050] S2. Pour the distillation residue into a low-temperature evaporator, control the low-temperature evaporator to evaporate the distillation residue at a low temperature, remove excess water in the distillation residue, and finally form a concentrated slurry with the distillation residue. After the distillation residue is evaporated by the low-temperature evaporator, the water content in the distillation residue is 23%;

[0051] S3. The concentrated slurry is removed and a diluent is added, and the concentrated slurry is subsequently stirred to allow the diluent to be fully mixed in the concentrated slurry, wherein the additives include the following substances: organic solvents such as methanol, ethanol, and acetic acid, and the addition ratio of methanol, ethanol, and acetic acid is 2:2:1. The content of methanol, ethanol, and acetic acid accounts for 10% of the total content of the concentrated slurry. The concentrated slurry is stirred using a stirrer, and the stirrer speed is controlled to be 400 rpm, and the stirring time is controlled to be 4 minutes;

[0052] S4, waiting for the concentrated slurry to cool down, at which time the ammonium nitrate in the concentrated slurry gradually crystallizes;

[0053] S5, pouring the concentrated slurry into a solid-liquid separator, and controlling the solid-liquid separator to separate the slurry and crystallized ammonium nitrate;

[0054] S6. Collect the separated slurry and take out the crystallized ammonium nitrate. Place the ammonium nitrate on gauze, then rinse the ammonium nitrate with clean water to dilute the diluent remaining on the surface of the ammonium nitrate. At the same time, non-salt organic matter attached to the surface of the ammonium nitrate will dissolve. Finally, the clean water used for rinsing will flow out through the gauze. Use a container to collect the clean water used to wash the ammonium nitrate, and rinse the ammonium nitrate with clean water for 3 minutes. During the rinsing process, shake the gauze to adjust the position of the ammonium nitrate so that the ammonium nitrate can be fully rinsed and the diluent attached to the surface can be rinsed clean.

[0055] S7, collect the ammonium nitrate after cleaning, then it is carried out drying, finally utilize plastic packaging bag that dried ammonium nitrate is collected, utilize drying machine to carry out blowing drying to ammonium nitrate, and drying time is 13min;

[0056] S8, pouring the clean water used to wash the ammonium nitrate and the separated slurry into a container, then introducing the mixed liquid into a distillation tower for distillation to reduce the water content in the mixed liquid, and using distillation to evaporate the excess water in the mixed liquid. The diluent is also evaporated and collected under the action of distillation, thereby achieving the purpose of recovering the diluent, and only 20% of the mixed liquid remains;

[0057] S9. Collect the remaining mixed liquid, pour the mixed liquid into the reactor for heating, then add activated carbon into the reactor, the activated carbon absorbs the diluent in the mixed liquid, finally take out the activated carbon to recover the diluent, and put the remaining waste liquid into the boiler for incineration, control the indirect heating inside the reactor, ensure that the temperature in the reactor is controlled at 55°C, and leave the activated carbon in the mixed liquid for 36 hours after addition.

[0058] Example 3

[0059] The present invention provides a technical solution: a process for recovering nitre from octogen residual liquid, characterized in that it specifically comprises the following steps:

[0060] S1. introducing the generated wastewater into a distillation pot, distilling the wastewater in the distillation pot to produce a distillation residue after distillation, controlling the temperature of the distillation pot to 120° C. and the distillation time to 3 hours, wherein the distillation residue produced after distillation has the following composition: 30% organic matter, salt, and 75% water;

[0061] S2. Pour the distillation residue into a low-temperature evaporator, control the low-temperature evaporator to evaporate the distillation residue at a low temperature, remove excess water in the distillation residue, and finally form a concentrated slurry with the distillation residue. After the distillation residue is evaporated by the low-temperature evaporator, the water content in the distillation residue is 25%;

[0062] S3. The concentrated slurry is removed and a diluent is added, and the concentrated slurry is then stirred to allow the diluent to be fully mixed in the concentrated slurry. The additives include the following substances: organic solvents such as methanol, ethanol, and acetic acid. The addition ratio of methanol, ethanol, and acetic acid is 2:2:1. The content of methanol, ethanol, and acetic acid accounts for 15% of the total content of the concentrated slurry. The concentrated slurry is stirred using a stirrer, and the stirrer speed is controlled to be 500 rpm and the stirring time is controlled to be 5 minutes.

[0063] S4, waiting for the concentrated slurry to cool down, at which time the ammonium nitrate in the concentrated slurry gradually crystallizes;

[0064] S5, pouring the concentrated slurry into a solid-liquid separator, and controlling the solid-liquid separator to separate the slurry and crystallized ammonium nitrate;

[0065] S6. Collect the separated slurry and take out the crystallized ammonium nitrate. Place the ammonium nitrate on gauze, then rinse the ammonium nitrate with clean water to dilute the diluent remaining on the surface of the ammonium nitrate. At the same time, non-salt organic matter attached to the surface of the ammonium nitrate will dissolve. Finally, the clean water used for rinsing will flow out through the gauze. Use a container to collect the clean water used to wash the ammonium nitrate, and rinse the ammonium nitrate with clean water for 4 minutes. During the rinsing process, shake the gauze to adjust the position of the ammonium nitrate so that the ammonium nitrate can be fully rinsed and the diluent attached to the surface can be rinsed clean.

[0066] S7, collect the ammonium nitrate after cleaning, then it is carried out drying, finally utilize plastic packaging bag that dried ammonium nitrate is collected, utilize drying machine to carry out air drying to ammonium nitrate, and drying time is 15min;

[0067] S8, pouring the clean water used to wash the ammonium nitrate and the separated slurry into a container, then introducing the mixed liquid into a distillation tower for distillation to reduce the water content in the mixed liquid, and using distillation to evaporate the excess water in the mixed liquid. The diluent is also evaporated and collected under the action of distillation, thereby achieving the purpose of recovering the diluent, and only 20% of the mixed liquid remains;

[0068] S9. Collect the remaining mixed liquid, pour the mixed liquid into the reactor for heating, then add activated carbon into the reactor, the activated carbon absorbs the diluent in the mixed liquid, finally take out the activated carbon to recover the diluent, and put the remaining waste liquid into the boiler for incineration, control the indirect heating inside the reactor, ensure that the temperature in the reactor is controlled at 60°C, and leave the activated carbon in the mixed liquid for 48 hours after addition.

[0069] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A process for recovering nitre from octogen residual liquid, characterized in that: The specific steps include: S1, introducing the generated wastewater into a distillation pot, using the distillation pot to distill the wastewater, and generating distillation residue after distillation; S2, pouring the distillation residue into a low-temperature evaporator, controlling the low-temperature evaporator to evaporate the distillation residue at a low temperature to remove excess water in the distillation residue, and finally forming a concentrated slurry from the distillation residue; S3, removing the concentrated slurry and then adding a diluent, and then stirring the concentrated slurry to allow the diluent to be fully mixed in the concentrated slurry; S4, waiting for the concentrated slurry to cool down, at which time the ammonium nitrate in the concentrated slurry gradually crystallizes; S5, pouring the concentrated slurry into a solid-liquid separator, and controlling the solid-liquid separator to separate the slurry and crystallized ammonium nitrate; S6. Collect the separated slurry, take out the crystallized ammonium nitrate, place the ammonium nitrate on gauze, and then rinse the ammonium nitrate with clean water to dilute the diluent remaining on the surface of the ammonium nitrate. At the same time, non-salt organic matter attached to the surface of the ammonium nitrate will dissolve. Finally, the clean water used for rinsing will flow out through the gauze, and the clean water used to wash the ammonium nitrate is collected in a container; S7, collect the ammonium nitrate after cleaning, then it is carried out drying, and finally utilize plastic packaging bag that the dried ammonium nitrate is collected; S8, pouring the clean water used to wash the ammonium nitrate and the separated slurry into a container, and then introducing the mixed liquid into a distillation tower for distillation to reduce the water content in the mixed liquid; S9. Collect the remaining mixed liquid, pour the mixed liquid into a reactor for heating, then add activated carbon into the reactor, the activated carbon absorbs the diluent in the mixed liquid, finally take out the activated carbon to recover the diluent, and put the remaining waste liquid into a boiler for incineration.

2. A process for recovering nitre from octogen residual liquid according to claim 1, characterized in that: In S1, the temperature of the distillation pot is controlled to be 100° C.-120° C., the distillation time is controlled to be 2-3 hours, and the distillation residue produced after distillation has the following components: 25%-30% organic matter, salt, and 70%-75% water.

3. A process for recovering nitre from octogen residual liquid according to claim 1, characterized in that: In S2, after the distillation residue is evaporated using a low-temperature evaporator, 20%-25% of the water in the distillation residue remains. The distillation residue itself contains energetic materials. The use of low-temperature evaporation can effectively avoid safety risks and greatly improve safety compared to conventional evaporation and concentration methods. In addition, controlling the proportion of residual water in the distillation residue is also one of the key factors for safe recovery.

4. A process for recovering nitre from octogen residual liquid according to claim 1, characterized in that: In said S3, the additives include the following substances: organic solvents such as methanol, ethanol, and acetic acid. The addition ratio of methanol, ethanol, and acetic acid is 2:2:1, and the content of methanol, ethanol, and acetic acid accounts for 5-15% of the total content of the concentrated slurry.

5. A process for recovering nitre from octogen residual liquid according to claim 1, characterized in that: In S3, the concentrated slurry is stirred by a stirrer, the rotation speed of the stirrer is controlled to be 300-500 rpm, and the stirring time is controlled to be 3-5 min.

6. A process for recovering nitre from octogen residual liquid according to claim 1, characterized in that: In S6, the ammonium nitrate is rinsed with clean water for 2-4 minutes. During the rinsing process, the gauze is shaken to adjust the position of the ammonium nitrate so that the ammonium nitrate can be fully rinsed and the diluent attached to the surface can be rinsed away.

7. A process for recovering nitre from octogen residual liquid according to claim 1, characterized in that: In S7, the ammonium nitrate is dried by air drying in a drying machine for 10-15 minutes.

8. A process for recovering nitre from octogen residual liquid according to claim 1, characterized in that: In S8, the excess water in the mixed liquid is evaporated by distillation, and the diluent is also evaporated and collected under the action of distillation, so as to achieve the purpose of recovering the diluent, and only 20% of the mixed liquid remains.

9. A process for recovering nitre from octogen residual liquid according to claim 1, characterized in that: In S9, the indirect heating inside the reactor is controlled to ensure that the temperature inside the reactor is controlled at 50-60° C. After the activated carbon is added, it is left in the mixed liquid for 24-48 hours.