A process device for producing diammonium phosphate by using residual acid

Abstract

The application discloses a kind of process devices for producing diammonium phosphate by using raffinate acid.The device of the application comprises a settling agent preparation system, including a raw material container of the settling agent, a preparation tank of the settling agent connected with the raw material container and a metering pump connected with the preparation tank;A mixed settling system, including an input port of raffinate acid, a raffinate acid A tank connected with the input port, the raffinate acid A tank is provided with a rotary harrow mechanism, and a settling agent pipeline connected with the preparation tank;A slagging and separating system, including a slagging pump connected with the raffinate acid A tank and a raffinate acid B tank connected with the slagging pump, the raffinate acid B tank is connected with a raffinate acid low-layer slag filter pressing system;A clear liquid delivery system, including a pressure acid pump connected with the raffinate acid A tank and a clear liquid storage acid tank connected with the pressure acid pump;A neutralization reaction and granulation system, including a pipe reaction groove connected with the clear liquid storage acid tank, a tubular reactor connected with the pipe reaction groove, and a granulator connected with the tubular reactor;A finished product processing system, including a processing unit connected with the granulator.

Description

Technical Field

[0001] This application relates to the field of phosphating technology, and more particularly to a process apparatus for producing diammonium phosphate using residual raffinate. Background Technology

[0002] In the industrial production of diammonium phosphate, wet-process phosphoric acid is one of the main raw materials. During the extraction process, wet-process phosphoric acid generates a large amount of raffinate acid, which contains a certain amount of available phosphorus and has potential reuse value. Some companies are attempting to use raffinate acid as a phosphorus source in the production of diammonium phosphate in order to reduce costs and improve resource utilization efficiency.

[0003] However, existing processes have certain limitations when treating residual raffinate for diammonium phosphate (DAP) production. Especially when producing high-concentration DAP (such as 64% DAP), the high impurity content and unstable phosphoric acid concentration in the residual raffinate make it difficult to meet the raw material requirements of conventional processes such as spray granulation. This results in the inability to effectively utilize P2O5 in the residual raffinate, thus limiting its application in high-end phosphate fertilizer production. Utility Model Content

[0004] This application provides a process apparatus for producing diammonium phosphate using residual raffinate. The technical solution of this application is described below: This application provides a process apparatus for producing diammonium phosphate using raffinate, characterized in that it includes: A settling agent preparation system includes a raw material container (1) for settling agent, a settling agent preparation tank (2) connected to the raw material container, and a metering pump (3) connected to the preparation tank. Mixed sedimentation system: including an inlet (4) for residual raffinate, a residual raffinate A tank (6) connected to the inlet, the residual raffinate A tank being equipped with a rake mechanism, and a sedimentation agent pipeline (5) connected to the preparation tank. Sludge removal and separation system: including a sludge removal pump (7) connected to the residual acid A tank and a residual acid B tank (8) connected to the sludge removal pump, wherein the residual acid B tank is connected to the residual acid low layer sludge pressure filter system (9). Clarified liquid delivery system: includes a pressure pump (10) connected to the residual acid A tank and a clear liquid storage tank (11) connected to the pressure pump. Neutralization reaction and granulation system: including a tubular inverter (12) connected to the clear acid storage tank, a tubular reactor (13) connected to the tubular inverter, and a granulator (14) connected to the tubular reactor; Finished product processing system: including a processing unit (15) connected to the granulator for drying, washing, wrapping and finished product output.

[0005] Optionally, the clear liquid storage tank (11) is equipped with a liquid level monitoring device for real-time monitoring of the liquid level changes of the clear liquid.

[0006] Optionally, an automatic regulating valve is provided between the slag pump (7) and the residual acid tank B (8).

[0007] Optionally, the settling tank is a storage tank equipped with a rotating rake device. When the residual acid level submerges the rake arm, the rotating rake motor is activated to promote the settling reaction.

[0008] Optionally, the metering pump (3) of the settling agent preparation system is an adjustable speed metering pump.

[0009] Optionally, the settling agent pipeline (5) of the mixed settling system is equipped with a flow control valve for adjusting the mixing ratio of settling agent and residual acid.

[0010] Optionally, the tubular reactor (13) is a multi-tube reactor.

[0011] Optionally, the processing unit (15) of the finished product processing system includes a dryer, a screening device, a washing device, and a packaging device.

[0012] Optionally, the residual acid tank A (6) is equipped with a temperature control device to maintain the temperature of the residual acid within a set range.

[0013] Optionally, the slag pump (7) is connected to the residual acid tank B (8) via a hose.

[0014] As can be seen from the above technical solutions, this application has the following advantages: 1. By introducing a structure with a rotating rake device into the settling tank, the mixing and settling reaction of the residual acid and the settling agent can be effectively promoted, resulting in faster stratification of the clarified liquid and the acid residue, and a significantly improved stratification efficiency. The clarity of the clarified liquid reaches a high level, and the acid residue is treated effectively, exhibiting fluidity and a loose state, thus reducing the risk of pipeline blockage.

[0015] 2. The clarified liquid delivery system employs a combination of a pressure pump and a liquid level monitoring device, ensuring a stable and efficient delivery process. Simultaneously, the pressure pump precisely controls the delivery flow rate, effectively preventing issues of excess or insufficient liquid, ensuring that the P2O5 mass fraction remains stable at a high level during subsequent reactions, thus guaranteeing the quality of diammonium phosphate.

[0016] 3. The design of the tubular reactor and granulator can effectively control the reaction temperature and pressure, achieving a precise neutralization reaction. By optimizing the N / P mass ratio, reaction temperature, and granulation temperature, the reaction conversion rate and particle quality of diammonium phosphate can be improved, ensuring product stability and consistency.

[0017] 4. Through optimized sedimentation, separation, and reaction systems, this device improves resource utilization and reduces waste generation. Furthermore, environmentally friendly processes such as airflow encapsulation technology can be used during granulation and finished product processing to further reduce environmental pollution and resource waste. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart of an embodiment of the method provided in this application; Figure 2 This is a schematic diagram of an embodiment of the device provided in this application. Detailed Implementation

[0019] In this application, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and other terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to describe the relative positional relationship between the components or parts and do not specifically limit the specific installation orientation of each component or part.

[0020] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0021] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0022] Furthermore, the structures, proportions, sizes, etc., drawn in the accompanying drawings of this application are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modification to the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects and purposes that this application can produce, should still fall within the scope of the technical content disclosed in this application.

[0023] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] See Figure 1 This application first provides a process for producing diammonium phosphate using residual raffinate, comprising: S101. Mix flocculants SDCJ-1 and SDCJ-2 at a mass ratio of 8:1, and stir in a 10m³ flocculant preparation tank for 1 to 2 hours to obtain a mixed flocculant. First, take flocculants SDCJ-1 and SDCJ-2 and mix them at a mass ratio of 8:1. SDCJ-1 is a white granular dry powder with good water solubility, which can effectively participate in the sedimentation reaction; while SDCJ-2 is a light yellow to brownish-yellow viscous liquid with strong solubility, which can help the flocculant better combine with impurities in the residual acid. In a 10m³ flocculant preparation tank, add the two flocculants according to the specified ratio, and then start the stirring device of the preparation tank for 1 to 2 hours to uniformly stir, so that the two flocculants are completely mixed, and the required mixed flocculant is obtained.

[0025] S102. The residual acid is transported to a settling tank with a rake arm, the mixed settling agent is added, and the mixture is stirred and settling at 80°C for 2 hours to obtain a clear liquid in the upper layer and a sludge acid in the lower layer, wherein the P2O5 mass fraction of the clear liquid is not less than 44% and the viscosity of the sludge acid is less than 3500 mPa·s. The obtained mixed settling agent is piped to the settling tank of the residual raffinate. At this point, the residual raffinate is extracted from the byproducts of the PPA unit and fed into the settling tank (equipped with a rotary rake agitator to effectively promote the settling reaction). The temperature inside the settling tank is controlled at 80°C, the mixed settling agent is added, and the rake agitator is activated. By maintaining the temperature at 80°C and stirring for 2 hours, the settling agent reacts with the impurities in the residual raffinate. After this settling process, a clear liquid is obtained on top and a sludge acid layer on the bottom. The mass fraction of P2O5 in the clear liquid is not less than 44%, while the viscosity of the sludge acid is controlled below 3500 mPa·s to ensure good fluidity for subsequent processing.

[0026] S103. The clarified liquid is transported to an acid storage tank for storage, and the sludge acid is transported to a spare tank; After the sedimentation reaction is complete, the clarified liquid is automatically transferred to an acid storage tank for later use. The sludge acid is then transferred to a spare tank via a sludge pump for further processing or consumption. The clarified liquid is stored in the acid storage tank for further processing and utilization in subsequent processes.

[0027] S104. The clarified liquid is reacted with liquid ammonia in a tubular reactor at a reaction temperature of 110–135°C and a pressure of 0.3 MPa, with the degree of neutralization controlled at 1.5–1.7, to obtain an ammonium phosphate slurry, wherein the slurry has a moisture content of less than 10%. The clarified phosphoric acid solution is transported to a tubular reactor via a tubular inverter. In this reactor, the solution reacts with liquid ammonia to produce an ammonium phosphate slurry. To ensure a smooth reaction, the reaction temperature is controlled between 110°C and 135°C, and the pressure is maintained at 0.3 MPa. The amount of ammonia added is adjusted according to the quality of the phosphoric acid solution and the required degree of neutralization, based on the reaction requirements. By precisely controlling the degree of neutralization between 1.5 and 1.7, complete reaction between phosphoric acid and ammonia is ensured, while the moisture content of the slurry is kept below 10%, ensuring a high concentration and high quality slurry.

[0028] S105. The ammonium phosphate slurry is fed into a granulator, the water content is controlled at 1.8-3.5%, the granulation temperature is 85-95℃, the N / P mass ratio is adjusted to 1.8:1, and after drying, sieving, washing and coating, a 64% diammonium phosphate product is obtained.

[0029] The resulting diammonium phosphate slurry is conveyed to a granulator. In the granulator, operators must strictly control the slurry's water content between 1.8% and 3.5%, and adjust the granulation temperature between 85℃ and 95℃. Furthermore, the N / P mass ratio of the slurry needs to be adjusted to 1.8:1 to ensure the final product has the optimal nutrient ratio. During this process, the slurry undergoes drying, sieving, washing, and coating processes to ultimately obtain a high-quality 64% diammonium phosphate product. The entire process ensures stable quality, rounded particles, and dust-free production of the diammonium phosphate product, meeting relevant standard requirements.

[0030] Through this embodiment, the present invention can effectively convert residual acid into a high-concentration diammonium phosphate product. Strict temperature control, stirring, and reaction condition control in each process step ensure the quality of the product at every stage. Simultaneously, the optimization of the sedimentation reaction and the separation of the clarified liquid and sludge acid not only effectively improve raw material utilization but also reduce environmental pollution, demonstrating significant economic and environmental benefits.

[0031] In an optional embodiment, the main component of SDCJ-1 is C3. x H5 x N x O x Cl x It is a white granular dry powder, soluble in water, and partially soluble in methanol and glycerol.

[0032] In this embodiment, the main component of SDCJ-1 is C3. x H5x N x O x Cl x It is a white granular dry powder that is effectively soluble in water and partially soluble in methanol and glycerol. As a flocculant, SDCJ-1 reacts with impurities in the raffinate, promoting their coagulation and sedimentation, thus purifying the raffinate solution and reducing the viscosity of the sludge acid. Due to its good solubility, SDCJ-1 can be uniformly mixed with other components (such as SDCJ-2) during the mixing process, ensuring the stability and efficiency of the sedimentation effect. Furthermore, the granular powder form of SDCJ-1 facilitates storage, transportation, and use.

[0033] In an optional embodiment, the main component of the SDCJ-2 is C. x H x O x S x It is a light yellow to brownish-yellow viscous liquid with a pungent odor, and is soluble in water and ethanol.

[0034] In this embodiment, the main component of SDCJ-2 is C. x H x O x S x It is a light yellow to brownish-yellow viscous liquid with a pungent odor, soluble in water and ethanol. SDCJ-2, used as a flocculant in conjunction with SDCJ-1, enhances the sedimentation effect. Due to its strong solubility, SDCJ-2 can effectively react with impurities in the residual raffinate upon dissolution, promoting the coagulation and sedimentation of these impurities. Furthermore, the pungent odor of SDCJ-2 requires special attention to ventilation and safety precautions during use, but it effectively improves the speed and quality of the sedimentation process. The ratio of SDCJ-2 to SDCJ-1 has been optimized experimentally to ensure safety and stability during use without compromising effectiveness.

[0035] In an optional embodiment, the settling tank is a storage tank with a rotating rake device, wherein the rotating rake motor is activated to promote the settling reaction when the residual acid level submerges the rake arm.

[0036] In this embodiment, the settling tank is a storage tank equipped with a rotating rake device, which can better promote the mixing between the raffinate and the settling agent. Inside the settling tank, a rotating rake device is installed. When the raffinate level submerges the rake arm, the rotating rake motor is activated to perform stirring and agitation, promoting the completion of the settling process. The function of the rotating rake device is to increase the stirring intensity and uniformity, ensuring sufficient contact between the settling agent and impurities in the raffinate, thereby accelerating the settling of impurities. By activating the rotating rake motor, the stirring time and speed can be precisely controlled, ensuring the efficiency and quality of the settling reaction. Furthermore, the design of the rotating rake device can avoid over-stirring, thus preventing excessive reaction between the raffinate and the settling agent.

[0037] In an optional embodiment, the amount of the mixed settling agent added is 0.5% to 1.5% of the mass of the residual acid.

[0038] In this embodiment, the dosage of the mixed flocculant is 0.5% to 1.5% of the mass of the residual acid. Through experimental optimization, it was found that this dosage range ensures the optimal balance of sedimentation effect. Adding too much flocculant will increase production costs, while adding too little may lead to unsatisfactory sedimentation effect, resulting in unstable P2O5 mass fraction in the clarified liquid or excessively high viscosity of the sludge acid. Therefore, controlling the dosage of flocculant within this range can ensure efficient sedimentation and make the clarified liquid meet the specified quality standards, thereby providing high-quality raw materials for the subsequent production of ammonium phosphate slurry.

[0039] In an optional embodiment, the clarification rate of the clear liquid obtained after sedimentation is not less than 75%, and the sludge acid does not show obvious drying after standing for 19 hours.

[0040] In this embodiment, the clarification rate of the clarified liquid obtained after sedimentation is not less than 75%, and the sludge acid shows no obvious drying phenomenon after standing for 19 hours. This embodiment shows that the use of a sedimentation agent can effectively promote the sedimentation of impurities in the residual acid, obtaining a clear clarified liquid. The clarification rate of the clarified liquid ensures that its P2O5 mass fraction reaches more than 45%, thus providing high-quality raw materials for the subsequent production of diammonium phosphate. At the same time, the fluidity of the sludge acid is guaranteed, and no obvious drying phenomenon is observed after standing for 19 hours. The fluidity of the sludge acid is of great significance for subsequent processing and utilization; therefore, ensuring good fluidity of the sludge acid is one of the key objectives in the sedimentation process.

[0041] In an optional embodiment, phosphoric acid is added to adjust the acidity of the clarified liquid before reacting it with liquid ammonia, so that the mass fraction of P2O5 in the clarified liquid is stabilized at above 45%.

[0042] In this embodiment, phosphoric acid is added to adjust the acidity before reacting the clarified liquid with liquid ammonia, so that the P2O5 mass fraction of the clarified liquid is stabilized above 45%. The P2O5 mass fraction of the clarified liquid is one of the key factors affecting the quality of the diammonium phosphate slurry. By adjusting the acidity, the P2O5 concentration of the clarified liquid can be further increased and stabilized above 45%, thereby ensuring the quality and yield of the diammonium phosphate product. In addition, the addition of phosphoric acid can effectively adjust the acidity before the clarified liquid enters the tubular reactor, making the reaction process more controllable, improving reaction efficiency, and reducing the impact on subsequent operations.

[0043] As can be seen from the detailed description of the above optional embodiments, the present invention, by rationally controlling the type, dosage, and reaction conditions of the flocculant, can not only improve the sedimentation effect of residual acid and ensure the quality of the clarified liquid, but also optimize each step in the diammonium phosphate production process. Each optional embodiment further refines the process operation in different aspects, improving the stability and efficiency of the production process, and has significant industrial application value.

[0044] To further verify the application effect of this invention in actual production, several typical production cases are provided below. These cases demonstrate the specific effects achieved by using the process method of this invention in actual production under different operating conditions, especially its excellent performance in the treatment of residual acid, separation of clarified liquid and sludge acid, and improvement of sludge acid flowability.

[0045] Example 1: According to actual production case 1, at a temperature of 65℃, the P2O5 content of the raffinate acid was 44%, the solids content was 10%, and the viscosity was 4366.0 Pa·s. By adding 1‰ of a flocculant to this raffinate acid and after 2 hours of stirring and sedimentation, clarification and stratification were successfully achieved. The resulting clear liquid had a P2O5 content of 44% and a solids content of 0.9%. The viscosity of the sludge acid decreased to 2989.1 Pa·s, and the sludge acid exhibited fluidity and a loose state, effectively improving pipeline flow and preventing blockage. This case demonstrates the high efficiency of the sedimentation process under specific conditions.

[0046] Example 2: According to actual production case 2, at a temperature of 75℃, the P2O5 content of the residual acid was 45%, the solids content was 11%, and the viscosity was 4532.6 Pa·s. After adding 1‰ of a flocculant, and after 2 hours of settling, the P2O5 content of the clarified liquid was 45%, the solids content was 0.85%, and the viscosity of the sludge acid decreased to 3001.2 Pa·s. The sludge acid still retained its fluidity and was loosely structured, greatly improving pipeline flowability and avoiding the common problem of sediment clogging. This case verified the influence of flocculant dosage and temperature on the quality of the clarified liquid and demonstrated the stability of this technology under different conditions.

[0047] Example 3: In actual production case 3, the temperature was set at 55℃, the residual acid had a P2O5 content of 45%, a solids content of 12.6%, and a viscosity of 4766.4 Pa·s. After adding 1.1‰ flocculant and after 2 hours of stirring and settling, the P2O5 content of the clarified liquid remained at 45%, the solids content was 0.95%, and the viscosity of the sludge acid decreased to 3022.2 Pa·s. The settled sludge acid exhibited good fluidity and no obvious drying phenomenon, significantly improving the efficiency of subsequent operations and avoiding pipeline blockage.

[0048] Example 4: In actual production case 4, the temperature was 85℃, the P2O5 content of the residual acid was 45%, the solids content was 11.3%, and the viscosity was 4712.4 Pa·s. After adding 1.1‰ of a settling agent and settling for 2 hours, the P2O5 mass fraction of the clarified liquid was 45%, the solids content was 0.92%, and the viscosity of the sludge acid was 3004.0 Pa·s. This case further verifies the stability of the settling process at higher temperatures. The settled sludge acid exhibits ideal fluidity and is not prone to clumping, effectively improving the fluidity of subsequent pipelines.

[0049] These practical production cases demonstrate that the sedimentation process can effectively achieve stratification of the clarified liquid and the slag acid under different temperature, P2O5 concentration, and solid content conditions, and significantly improve the fluidity of the slag acid, avoiding common pipeline blockage problems. Furthermore, the P2O5 mass fraction of the clarified liquid remains above 45%, proving the stability and efficiency of the process and providing a reliable raw material for the production of 64% diammonium phosphate.

[0050] See Figure 2 This application also provides a process apparatus for producing diammonium phosphate using raffinate, comprising: A settling agent preparation system includes a raw material container 1 for the settling agent, a settling agent preparation tank 2 connected to the raw material container, and a metering pump 3 connected to the preparation tank. Mixed sedimentation system: including an inlet 4 for residual raffinate, a residual raffinate A tank 6 connected to the inlet, the residual raffinate A tank being equipped with a rake mechanism, and a sedimentation agent pipeline 5 connected to the preparation tank; Sludge Discharge and Separation System: Includes a sludge discharge pump 7 connected to the residual acid A tank and a residual acid B tank 8 connected to the sludge discharge pump, wherein the residual acid B tank is connected to the residual acid low-layer sludge pressure filter system 9; The clear liquid delivery system includes a pressure acid pump 10 connected to the residual acid A tank and a clear liquid storage tank 11 connected to the pressure acid pump; Neutralization reaction and granulation system: including a tubular reverse tank 12 connected to the clear acid storage tank, a tubular reactor 13 connected to the tubular reverse tank, and a granulator 14 connected to the tubular reactor; Finished product processing system: includes a processing unit 14 connected to the granulator, used for drying, washing, packaging and finished product output.

[0051] This embodiment provides a process apparatus for producing diammonium phosphate using residual raffinate. This apparatus, according to the technical solution of this invention, achieves effective treatment of residual raffinate and production of diammonium phosphate. Through the coordinated operation of multiple systems, the apparatus optimizes various stages such as sedimentation, separation, clarified liquid transportation, reaction, and granulation, thereby improving production efficiency and product quality. The various parts of the apparatus are described in detail below: Flocculant preparation system: The settling agent preparation system of this device includes a raw material container 1 for the settling agent, a settling agent preparation tank 2, and a metering pump 3 connected to it. The raw material container 1 is used to store the required settling agent raw materials (such as SDCJ-1 and SDCJ-2), while the preparation tank 2 mixes the two settling agents in a certain ratio (e.g., 8:1). The preparation tank 2 is connected to the metering pump 3, and the precise control of the metering pump 3 ensures that the dosage of the mixed settling agent is accurate and can meet the settling requirements of residual raffinate.

[0052] Hybrid Settlement System: The mixed settling system includes an inlet 4 for residual raffinate and a connected residual raffinate tank A 6. Tank A 6 is equipped with a rake mechanism to promote uniform mixing of the residual raffinate and the settling agent. This rake mechanism maintains a certain stirring speed after the residual raffinate and settling agent are mixed, effectively improving the efficiency of the settling reaction. During the settling process, the settling agent, through mixing with the residual raffinate, helps to coagulate and settle impurities and solid particles in the residual raffinate to the bottom of the tank. The function of this system is to ensure that the mixed settling agent can fully exert its settling effect, resulting in clear stratification of the clarified liquid and the acid residue.

[0053] Slag removal and separation system: After the settling reaction in tank A of residual acid is completed, the clear liquid and the residual acid sludge separate into layers. The sludge removal and separation system includes a sludge removal pump 7 connected to tank A of residual acid and a tank B of residual acid connected to the sludge removal pump 7. The sludge removal pump 7 is responsible for transferring the settled residual acid sludge from tank A to tank B for subsequent processing. Tank B of residual acid is further connected to a low-layer sludge pressure filtration system 9 of residual acid, which is used to remove residual solid particles and improve the treatment efficiency of the residual acid sludge. After being treated by the pressure filtration system, the residual acid sludge achieves good fluidity, avoiding pipeline blockage and equipment damage.

[0054] Clear liquid delivery system: The clarified liquid is pumped from the residual acid A tank to the clarified liquid storage tank 11 via the acid pump 10. The clarified liquid storage tank 11 is used to store the clarified liquid after sedimentation and stratification, ensuring its stable supply in subsequent processes. By properly storing and adjusting the P2O5 content in the clarified liquid, this device can maintain a stable clarified liquid quality, providing the necessary raw materials for subsequent reaction processes.

[0055] Neutralization reaction and granulation system: The neutralization reaction and granulation system includes a tubular reactor 12, a tubular reactor 13, and a granulator 14 connected to the tubular reactor. In this system, the clarified liquid and liquid ammonia react in the tubular reactor 13 to produce an ammonium phosphate slurry. The reaction temperature is controlled between 110°C and 135°C, the pressure is approximately 0.3 MPa, and the degree of neutralization during the reaction is controlled between 1.5 and 1.7 to ensure the quality of the slurry. The resulting ammonium phosphate slurry is processed by the granulator 14, which controls the water content between 1.8% and 3.5% to ensure uniform granulation of the slurry and obtain diammonium phosphate particles of appropriate size.

[0056] Finished product processing system: The finished product processing system includes a processing unit connected to the granulator, used for further drying, sieving, washing, and coating of diammonium phosphate granules to ensure the final product meets the required quality standards. After this series of processes, the final diammonium phosphate granules are of stable quality and meet market demands.

[0057] This device can be applied in actual production processes to ensure that the produced diammonium phosphate has high purity and good physical properties. For example, in actual production, this device can effectively improve pipeline flowability and avoid pipeline blockage caused by excessively high viscosity of the slag acid during production. In addition, the sedimentation system can effectively remove impurities from the residual acid, ensuring high-quality clear liquid is obtained during the production process, thereby guaranteeing the smooth progress of subsequent neutralization reactions.

[0058] In an optional embodiment, the clear liquid storage tank 11 is equipped with a liquid level monitoring device for real-time monitoring of the liquid level changes of the clear liquid.

[0059] In this embodiment, the clarified acid storage tank 11 is equipped with a liquid level monitoring device for real-time monitoring of the clarified acid level changes. The liquid level monitoring device can accurately measure the clarified acid level and feed the data back to the control system in real time. By monitoring changes in the clarified acid level, the production process can be adjusted and optimized in a timely manner, ensuring a stable supply of clarified acid and avoiding insufficient or excessive supply, thereby improving the stability and safety of the process. For example, when the liquid level is too low, the control system can automatically initiate a clarified acid replenishment operation to maintain the continuity of the process and prevent equipment damage or production interruption.

[0060] In an optional embodiment, an automatic regulating valve is provided between the slag pump 7 and the residual acid tank B 8.

[0061] In this embodiment, an automatic regulating valve is provided between the slag pump 7 and the residual acid tank B 8. The purpose of this automatic regulating valve is to automatically adjust the operating state of the slag pump according to the needs of the reaction process. Specifically, the automatic regulating valve can automatically control the operating speed of the slag pump and the amount of residual acid transported based on the flow rate, pressure, and production requirements of the residual acid. For example, when the residual acid flow rate is high, the automatic regulating valve can reduce the workload of the slag pump to prevent the residual acid from flowing into tank B too quickly; when the residual acid flow rate is low, the automatic regulating valve will increase the pump's operating speed to ensure that the residual acid in tank B is transferred in a timely manner and maintains a stable production state. This function helps optimize the production process and improve production efficiency and product quality.

[0062] In an optional embodiment, the metering pump 3 of the settling agent preparation system is an adjustable speed metering pump.

[0063] In an optional embodiment, the settling agent pipeline 5 of the mixed settling system is equipped with a flow control valve for adjusting the mixing ratio of settling agent and residual acid.

[0064] In an optional embodiment, the tubular reactor 13 is a multi-tube reactor.

[0065] In an optional embodiment, the processing unit 14 of the finished product processing system includes a dryer, a screening device, a washing device, and a packaging device.

[0066] In an optional embodiment, the residual acid tank A 6 is equipped with a temperature control device to maintain the temperature of the residual acid within a set range.

[0067] In an optional embodiment, the slag pump 7 is connected to the residual acid tank B 8 via a hose.

[0068] It should be noted that the above description of the disclosed embodiments enables those skilled in the art to implement or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A process apparatus for producing diammonium phosphate using residual raffinate, characterized in that, include: Settling agent preparation system: includes a raw material container (1) for settling agent, a settling agent preparation tank (2) connected to the raw material container, and a metering pump (3) connected to the preparation tank. Mixed sedimentation system: including an inlet (4) for residual raffinate, a residual raffinate A tank (6) connected to the inlet, the residual raffinate A tank being equipped with a rake mechanism, and a sedimentation agent pipeline (5) connected to the preparation tank. Sludge removal and separation system: including a sludge removal pump (7) connected to the residual acid A tank and a residual acid B tank (8) connected to the sludge removal pump, wherein the residual acid B tank is connected to the residual acid low layer sludge pressure filter system (9). Clarified liquid delivery system: includes a pressure pump (10) connected to the residual acid A tank and a clear liquid storage tank (11) connected to the pressure pump. Neutralization reaction and granulation system: including a tubular inverter (12) connected to the clear acid storage tank, a tubular reactor (13) connected to the tubular inverter, and a granulator (14) connected to the tubular reactor; Finished product processing system: includes a processing unit (15) connected to the granulator for drying, washing, wrapping and finished product output.

2. The process apparatus according to claim 1, characterized in that, The acid storage tank (11) is equipped with a liquid level monitoring device for real-time monitoring of liquid level changes.

3. The process apparatus according to claim 1, characterized in that, An automatic regulating valve is provided between the slag pump (7) and the residual acid tank B (8).

4. The process apparatus according to claim 1, characterized in that, The settling tank is a storage tank equipped with a rotating rake device. When the residual acid level submerges the rake arm, the rotating rake motor is activated to promote the settling reaction.

5. The process apparatus according to claim 1, characterized in that, The metering pump (3) of the settling agent preparation system is an adjustable speed metering pump.

6. The process apparatus according to claim 1, characterized in that, The settling agent pipeline (5) of the mixed settling system is equipped with a flow control valve to adjust the mixing ratio of settling agent and residual acid.

7. The process apparatus according to claim 1, characterized in that, The tubular reactor (13) is a multi-tube reactor.

8. The process apparatus according to claim 1, characterized in that, The processing unit (15) of the finished product processing system includes a dryer, a screening device, a washing device, and a packaging device.

9. The process apparatus according to claim 1, characterized in that, The residual acid tank A (6) is equipped with a temperature control device to maintain the temperature of the residual acid within a set range.

10. The process apparatus according to claim 1, characterized in that, The slag pump (7) is connected to the residual acid tank B (8) via a hose.

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