A production process of nano-iron phosphate

Abstract

The present invention discloses a nano-ferric phosphate production process, comprising the following steps: using ammonium phosphate, phosphoric acid, ferrous sulfate, and hydrogen peroxide as raw materials, and using a three-stage diaphragm reactor, a microchannel reactor, and a three-stage microreactor as partial reaction equipment to prepare nano-ferric phosphate; wherein the three-stage diaphragm reactor includes a first-stage diaphragm reactor, a second-stage diaphragm reactor, and a third-stage diaphragm reactor that are connected in sequence; wherein the three-stage microreactor includes a first-stage microreactor, a second-stage microreactor, and a third-stage microreactor that are connected in sequence, a solid-liquid separation structure is provided between the first-stage microreactor and the second-stage microreactor, and a solid-liquid separation structure is provided between the second-stage microreactor and the third-stage microreactor; and the third-stage diaphragm reactor, the microchannel reactor, and the first-stage microreactor are connected in sequence. The present invention reduces the occupied space of the equipment.

Description

Technical Field

[0001] The invention belongs to the field of ferric phosphate production and relates to a nano ferric phosphate production process. Background Art

[0002] The existing technology involves adding ammonium phosphate at multiple points through holes in the bottom coil of a phosphoric acid mixing tank. After stirring for dozens of hours, ferrous phosphate is added through another coil at the bottom of the tank and stirring continues for several hours. Once the reaction is complete, hydrogen peroxide is added from the bottom of the tank. This tank consumes a lot of power, and stirring and mixing are long, making continuous production impossible. Summary of the Invention

[0003] The purpose of the present invention is to provide a nano-ferric phosphate production process, which solves the problems in the prior art of high power consumption of the stirring tank, long stirring and mixing time, and inability to produce continuously.

[0004] The technical solution adopted in the present invention is as follows:

[0005] A nano-ferric phosphate production process comprises the following steps: using ammonium phosphate, phosphoric acid, ferrous sulfate, and hydrogen peroxide as raw materials, and using a three-stage diaphragm reactor, a microchannel reactor, and a three-stage microreactor as partial reaction equipment to prepare nano-ferric phosphate;

[0006] The three-stage diaphragm reactor includes a first-stage diaphragm reactor, a second-stage diaphragm reactor, and a third-stage diaphragm reactor that are connected in sequence;

[0007] The three-stage microreactor includes a first-stage microreactor, a second-stage microreactor, and a third-stage microreactor connected in sequence, a solid-liquid separation structure is provided between the first-stage microreactor and the second-stage microreactor, and a solid-liquid separation structure is provided between the second-stage microreactor and the third-stage microreactor;

[0008] The third-stage diaphragm reactor, the microchannel reactor and the first-stage microreactor are connected in sequence.

[0009] The present invention is based on the existing nano-ferric phosphate production process, using ammonium phosphate, phosphoric acid, ferrous sulfate and hydrogen peroxide as raw materials. The principle and reaction process of preparing ferric phosphate from ammonium phosphate, phosphoric acid, ferrous sulfate and hydrogen peroxide are existing technologies. The present invention changes some reaction equipment used in the reaction process, replacing the existing stirring tank or reactor with a three-stage diaphragm reactor, a microchannel reactor and a three-stage microreactor, which not only shortens the mixing time of the various components but also reduces the space occupied by the equipment.

[0010] The three-stage diaphragm reactor, microchannel reactor and three-stage microreactor of the present invention all occupy a small area and are combined to replace the existing stirring tank. In addition, the reaction system formed by the three-stage diaphragm reactor, microchannel reactor and three-stage microreactor of the present invention enables the raw materials to undergo a mixing reaction in a closed channel, the reaction conditions can be precisely controlled, and the mixing speed and efficiency are greatly improved.

[0011] Furthermore, the nano-ferric phosphate production process comprises the following specific steps:

[0012] S1, ammonium phosphate and phosphoric acid are configured into a solution of a certain concentration and then pumped into a first-stage diaphragm reactor through different feeding ports for a first mixing reaction. After a period of time after the first mixing reaction, the solution is fed into a second-stage diaphragm reactor for a second mixing reaction. After a period of time after the second mixing reaction, the solution is fed into a third-stage diaphragm reactor to obtain a phosphorus-containing mixed solution;

[0013] S2, the phosphorus-containing mixed liquid enters the microchannel reactor connected to the third-stage diaphragm reactor through the third-stage diaphragm reactor, and at the same time, ferrous sulfate is pumped into the microchannel reactor to be fully mixed with the phosphorus-containing mixed liquid to obtain an intermediate mixed liquid;

[0014] S3, the intermediate mixed liquid, and hydrogen peroxide are simultaneously pumped into the first-stage microreactor for reaction; after reacting for a period of time in the first-stage microreactor, the reactants are filtered to obtain a precipitate and a filtrate; the filtrate enters a second-stage microreactor connected to the first-stage microreactor to continue the reaction; after reacting for a period of time in the second-stage microreactor, the reactants are filtered again to obtain a precipitate and a filtrate; the filtrate enters a third-stage microreactor connected to the second-stage microreactor to continue the reaction; and the precipitates obtained by the three filtrations are collected, washed, and dried to obtain ferric phosphate;

[0015] S4. Drying and calcining the iron phosphate to obtain nano iron phosphate.

[0016] The present invention limits the connection mode of each reaction device and the order of participating in the reaction, and also limits the feeding order of each raw material, so that the reaction efficiency is optimized.

[0017] The three-stage diaphragm reactor in the present invention is used for multi-stage mixing of ammonium phosphate and phosphoric acid. The diaphragm reactor generally adopts an existing membrane reactor. The advantages of the membrane reactor are relatively high conversion rate and yield of the reaction materials, short reaction time, easy control of reaction conditions, and relatively easy addition and mixing of the reaction materials. In order to prevent incomplete mixing of ammonium phosphate and phosphoric acid and the presence of a large amount of impurities after mixing, the present invention adopts a three-stage diaphragm reactor in which three diaphragm reactors are connected in sequence to replace the existing stirring tank, which can ensure that the ammonium phosphate and phosphoric acid are evenly mixed in a short time and the mixed liquid contains no or a small amount of impurities.

[0018] In the present invention, the phosphorus-containing mixed liquid after the mixture of ammonium phosphate and phosphoric acid is mixed with ferrous sulfate in a microchannel reactor for reaction. Due to its internal microstructure, the microchannel reactor makes the microreactor equipment have a very large specific surface area, which can reach hundreds or even thousands of times the specific surface area of ​​the stirring tank, has high heat transfer efficiency, and can accurately control the reaction temperature; the microchannel reactor occupies a small area, and is internally provided with a continuous synthesis system; the microchannel reactor has a high mass transfer efficiency, because the width and depth of the microchannels in the reactor are relatively small, generally tens to hundreds of microns, which greatly shortens the diffusion distance between the reactants, the mass transfer speed is fast, and the reactants can be fully mixed in a short time during the flow process; the microchannel reactor has a multi-channel structure, and each channel is equivalent to an independent reactor. When expanding production, it is no longer necessary to enlarge the size of the reactor. It is only necessary to increase the number of channels of the microreactor in parallel, that is, the so-called "parallel amplification" of the channels, so that the production scale can be conveniently expanded and flexibly adjusted. The present invention directly utilizes the existing microchannel reactor, accelerates the mixed reaction efficiency of the phosphorus-containing mixed liquid and ferrous sulfate, and also reduces the floor space of the equipment;

[0019] In the present invention, ferrous sulfate is pumped into a microchannel reactor and fully mixed with a phosphorus-containing mixed liquid to obtain an intermediate mixed liquid. The intermediate mixed liquid and hydrogen peroxide are simultaneously pumped into a first-stage microreactor for reaction. After reacting in the first-stage microreactor for a period of time, the reactants are filtered to obtain a precipitate and a filtrate. The filtrate enters a second-stage microreactor connected to the first-stage microreactor to continue the reaction. After reacting in the second-stage microreactor for a period of time, the reactants are filtered again to obtain a precipitate and a filtrate. The filtrate enters a third-stage microreactor connected to the second-stage microreactor to continue the reaction, and the precipitate and the filtrate are filtered to obtain the precipitate. The materials are collected, washed, and dried to obtain ferric phosphate; the three-stage microreactor of the present invention includes three microreactors, and the three microreactors are combined to fully react the intermediate mixed liquid and hydrogen peroxide. The multi-channel reaction principle is the same as that of the above-mentioned microchannel reactor. The first-stage microreactor of the present invention divides the intermediate mixed liquid and hydrogen peroxide into several parts, and finally the mixed liquid divided into several parts is mixed with several parts of hydrogen peroxide one by one for reaction. The less the amount of reactants added, the less time it takes for uniform mixing in a limited space, and the higher the reaction efficiency; the combination of multi-stage microreactors can make the raw materials react fully, thereby improving the utilization rate of the raw materials.

[0020] Furthermore, the molar ratio of the total amount of ammonium phosphate and phosphoric acid to ferrous sulfate is 1.2-1.6:1.

[0021] The invention optimizes the optimal ratio range of the total amount of ammonium phosphate, phosphoric acid and ferrous sulfate, and the quality of the product can be controlled within a better range.

[0022] Furthermore, the first-stage diaphragm reactor, the second-stage diaphragm reactor, and the third-stage diaphragm reactor are the same type of membrane reactor.

[0023] The diaphragm reactor in the present invention adopts the existing membrane reactor. The three membrane reactors all adopt the same structure and are easy to operate.

[0024] Furthermore, the first-stage microreactor, the second-stage microreactor, and the third-stage microreactor are the same type of microreactor, and the microreactor is provided with multiple feed ports and branch pipes connected to the feed ports in a one-to-one correspondence, so that the first-stage microreactor, the second-stage microreactor, and the third-stage microreactor realize multi-point feeding.

[0025] The three-stage microreactor of the present invention realizes multi-point feeding and ensures that the raw materials are fully mixed and reacted.

[0026] Furthermore, the microreactor includes a mixing reactor body, which includes a reaction tank, a sealing assembly is detachably mounted on the front end of the reaction tank, and a mixing unit is provided inside the reaction tank;

[0027] The mixing unit is detachably mounted inside the reaction tank, the mixing unit comprising a main outlet arranged on the front end of the interior of the reaction tank, a main pipe being fixedly mounted at the connection of the main outlet, a plurality of branch pipes being arranged outside the main pipe, all of which are evenly distributed circumferentially around the main pipe, a feed port being fixedly connected to the input end of the branch pipe, a plurality of evenly distributed Y-shaped pipes being fixedly connected to the outer wall of the main pipe, the Y-shaped pipe being located between two adjacent branch pipes, the Y-shaped pipe comprising a main pipe and branch pipes located on both sides of the main pipe, the branch pipes on both sides of the main pipe being communicated with the main pipe, the branch pipes of the Y-shaped pipe being respectively communicated with the adjacent branch pipes on both sides through elastic hoses, and the main pipe of the Y-shaped pipe being communicated with the main pipe;

[0028] When the intermediate mixed liquid and hydrogen peroxide are simultaneously pumped into the first-stage microreactor, the intermediate mixed liquid is pumped into the branch pipe connected to one side of the Y-shaped tube, and hydrogen peroxide is pumped into the branch pipe on the other side of the same Y-shaped tube. The intermediate mixed liquid and hydrogen peroxide on both sides of the same Y-shaped tube are mixed and reacted at the tee of the Y-shaped tube. The primary reactant obtained by the mixed reaction enters the main pipeline and then enters the solid-liquid separation structure between the first-stage microreactor and the second-stage microreactor through the total outlet. The obtained filtrate component enters the various branch pipes and Y-shaped tubes in the second-stage microreactor for secondary reaction. The secondary reactant enters the solid-liquid separation structure between the second-stage microreactor and the third-stage microreactor through the total outlet of the second-stage microreactor for filtration. The obtained filtrate component enters the various branch pipes and Y-shaped tubes in the third-stage microreactor for tertiary reaction.

[0029] The present invention designs a new microreactor. In the microreactor, a Y-shaped tube is fixedly connected to the outer surface of a main pipeline, and elastic hoses are fixedly connected to both sides of the top of the Y-shaped tube. The other end of the elastic hose is fixedly connected to the outer surface of a branch pipe. A feed port is provided to facilitate pouring raw materials into the interior. The raw materials flow from the feed port to the branch pipe respectively, and then flow to the elastic hose respectively through the Y-shaped tube, and are guided into the main pipeline by the elastic hose. The two materials are mixed at the tee of the Y-shaped tube, which can avoid material collision. Various materials are divided into several parts, and then mixed and reacted one by one, thereby ensuring uniform mixing and improving the working efficiency of the mixing reaction.

[0030] Furthermore, the molar ratio of the total amount of ammonium phosphate and phosphoric acid to ferrous sulfate is 1.5:1.

[0031] The present invention optimizes the best ratio.

[0032] Furthermore, the concentration of the phosphoric acid solution is 85%.

[0033] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0034] 1. The nano-ferric phosphate production process of the present invention changes some of the reaction equipment used in the reaction process, replacing the existing stirring tank or reactor with a three-stage diaphragm reactor, a microchannel reactor, and a three-stage microreactor. This not only shortens the mixing time of the various components, but also reduces the space occupied by the equipment;

[0035] 2. The nano-ferric phosphate production process of the present invention defines the connection mode of each reaction device and the order of participating in the reaction, and also defines the order of adding each raw material, so as to achieve the best reaction efficiency;

[0036] 3. The present invention designs a new microreactor for the production process of nano-ferric phosphate. The two materials are mixed at the Y-tube tee, which can avoid the material collision. The various materials are divided into several parts and then mixed and reacted one by one, so that the mixing is uniform and the working efficiency of the mixing reaction is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be considered as limiting the scope. A person of ordinary skill in the art can also derive other relevant drawings based on these drawings without inventive effort, among which:

[0038] Figure 1 It is a reaction flow chart of the present invention;

[0039] Figure 2 It is a schematic structural diagram of the microreactor of the present invention;

[0040] Figure 3 Schematic diagram of the structure of the mixing unit of the present invention.

[0041] Markings in the figure: 1-mixing reactor body, 2-reaction tank, 3-sealing assembly, 331-branch pipe, 332-main outlet, 333-main pipe, 334-Y-type pipe. DETAILED DESCRIPTION

[0042] In order to make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present invention and are not intended to limit the present invention. That is, the embodiments described herein are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and illustrated in the drawings herein may be arranged and designed in various different configurations.

[0043] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely intended to represent selected embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0044] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0045] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0046] Example 1

[0047] like Figure 1 As shown, a nano-ferric phosphate production process comprises the following steps: using ammonium phosphate, phosphoric acid, ferrous sulfate, and hydrogen peroxide as raw materials, and using a three-stage diaphragm reactor, a microchannel reactor, and a three-stage microreactor as partial reaction equipment to prepare nano-ferric phosphate;

[0048] The three-stage diaphragm reactor includes a first-stage diaphragm reactor, a second-stage diaphragm reactor, and a third-stage diaphragm reactor that are connected in sequence;

[0049] The three-stage microreactor includes a first-stage microreactor, a second-stage microreactor, and a third-stage microreactor connected in sequence, a solid-liquid separation structure is provided between the first-stage microreactor and the second-stage microreactor, and a solid-liquid separation structure is provided between the second-stage microreactor and the third-stage microreactor;

[0050] The third-stage diaphragm reactor, the microchannel reactor, and the first-stage microreactor are connected in sequence;

[0051] The specific steps are as follows:

[0052] S1, ammonium phosphate and phosphoric acid are configured into a solution of a certain concentration and then pumped into a first-stage diaphragm reactor through different feeding ports for a first mixing reaction. After a period of time after the first mixing reaction, the solution is fed into a second-stage diaphragm reactor for a second mixing reaction. After a period of time after the second mixing reaction, the solution is fed into a third-stage diaphragm reactor to obtain a phosphorus-containing mixed solution;

[0053] S2, the phosphorus-containing mixed liquid enters the microchannel reactor connected to the third-stage diaphragm reactor through the third-stage diaphragm reactor, and at the same time, ferrous sulfate is pumped into the microchannel reactor to be fully mixed with the phosphorus-containing mixed liquid to obtain an intermediate mixed liquid;

[0054] S3, the intermediate mixed liquid, and hydrogen peroxide are simultaneously pumped into the first-stage microreactor for reaction; after reacting for a period of time in the first-stage microreactor, the reactants are filtered to obtain a precipitate and a filtrate; the filtrate enters a second-stage microreactor connected to the first-stage microreactor to continue the reaction; after reacting for a period of time in the second-stage microreactor, the reactants are filtered again to obtain a precipitate and a filtrate; the filtrate enters a third-stage microreactor connected to the second-stage microreactor to continue the reaction; and the precipitates obtained by the three filtrations are collected, washed, and dried to obtain ferric phosphate;

[0055] S4. Drying and calcining the iron phosphate to obtain nano iron phosphate.

[0056] The concentration of the phosphoric acid solution is 85%.

[0057] The molar ratio of the total amount of ammonium phosphate and phosphoric acid to ferrous sulfate is 1.2-1.6:1.

[0058] The first-stage diaphragm reactor, the second-stage diaphragm reactor and the third-stage diaphragm reactor are the same type of membrane reactor.

[0059] The first-stage microreactor, the second-stage microreactor and the third-stage microreactor are the same type of microreactor, which are provided with multiple feed ports and branch pipes connected to the feed ports in a one-to-one correspondence. The first-stage microreactor, the second-stage microreactor and the third-stage microreactor realize multi-point feeding.

[0060] The present invention is based on the existing nano-ferric phosphate production process, using ammonium phosphate, phosphoric acid and ferrous sulfate as raw materials. The principle and reaction process of preparing ferric phosphate from ammonium phosphate, phosphoric acid and ferrous sulfate are existing technologies. The present invention changes some reaction equipment used in the reaction process, replacing the existing stirring tank or reactor with a three-stage diaphragm reactor, a microchannel reactor and a three-stage microreactor, which not only shortens the mixing time of the various components but also reduces the space occupied by the equipment.

[0061] The three-stage diaphragm reactor, microchannel reactor and three-stage microreactor of the present invention all occupy a small area and are combined to replace the existing stirring tank. In addition, the reaction system formed by the three-stage diaphragm reactor, microchannel reactor and three-stage microreactor of the present invention enables the raw materials to undergo a mixing reaction in a closed channel, the reaction conditions can be precisely controlled, and the mixing speed and efficiency are greatly improved.

[0062] Compared with the reaction time of the existing reaction equipment using a stirring tank, the reaction time of the present invention is half of the reaction time of the prior art. The purity of the nano-ferric phosphate product prepared by the present invention is as high as over 99%.

[0063] The molar ratio of the total amount of ammonium and phosphoric acid to ferrous sulfate is a preferred range based on the prior art and the system of the present invention. Within this range, the purity of the nano-ferric phosphate product is as high as over 99%.

[0064] Example 2

[0065] Based on Example 1, Figure 2 、 Figure 3 As shown, the microreactor includes a mixing reactor body 1, which includes a reaction tank 2. A sealing assembly 3 is detachably mounted on the front end of the reaction tank 2, and a mixing unit is provided inside the reaction tank 2.

[0066] The mixing unit is detachably mounted inside the reaction tank 2. The mixing unit includes a total outlet 332 provided on the front end of the interior of the reaction tank 2. A main pipe 333 is fixedly installed at the connection of the total outlet 332. A plurality of branch pipes 331 are provided outside the main pipe 333. All branch pipes 331 are evenly distributed circumferentially around the main pipe 333. A feed port 33 is fixedly connected to the input end of the branch pipe 331. A plurality of evenly distributed Y-shaped pipes 334 are fixedly connected to the outer wall of the main pipe 333. The Y-shaped pipe 334 is located between two adjacent branch pipes 331. The Y-shaped pipe 334 includes a main pipe and branch pipes located on both sides of the main pipe. The branch pipes on both sides of the main pipe are connected to the main pipe. The branch pipes of the Y-shaped pipe 334 are respectively connected to the branch pipes 331 adjacent to each other on both sides through elastic hoses 335. The main pipe of the Y-shaped pipe 334 is connected to the main pipe 333.

[0067] When the intermediate mixed liquid and hydrogen peroxide are simultaneously pumped into the first-stage microreactor, the intermediate mixed liquid is pumped into the branch pipe 331 connected to one side of the Y-shaped tube 334, and hydrogen peroxide is pumped into the branch pipe 331 on the other side of the same Y-shaped tube 334. The intermediate mixed liquid and hydrogen peroxide on both sides of the same Y-shaped tube 334 are mixed and reacted at the tee of the Y-shaped tube 334. The primary reactant obtained by the mixed reaction enters the main pipeline 333 and then enters the solid-liquid separation structure between the first-stage microreactor and the second-stage microreactor through the total outlet 332. The obtained filtrate component enters the various branch pipes 331 and Y-shaped tube 334 in the second-stage microreactor for secondary reaction. The secondary reactant enters the solid-liquid separation structure between the second-stage microreactor and the third-stage microreactor through the total outlet 332 of the second-stage microreactor for filtration. The obtained filtrate component enters the various branch pipes 331 and Y-shaped tube 334 in the third-stage microreactor for tertiary reaction.

[0068] Example 3

[0069] Based on the above embodiment, the molar ratio of the total amount of ammonium phosphate and phosphoric acid to ferrous sulfate is 1.5:1.

[0070] The present invention optimizes the optimal ratio, and the obtained product has the best purity, which can reach 99.6%.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made by any technician familiar with the field within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A process for producing nano-ferric phosphate, characterized in that: The following steps are involved: Nano-ferric phosphate is prepared using ammonium phosphate, phosphoric acid, ferrous sulfate and hydrogen peroxide as raw materials and a three-stage diaphragm reactor, a microchannel reactor and a three-stage microreactor as partial reaction equipment. The three-stage diaphragm reactor includes a first-stage diaphragm reactor, a second-stage diaphragm reactor, and a third-stage diaphragm reactor that are connected in sequence; The three-stage microreactor includes a first-stage microreactor, a second-stage microreactor, and a third-stage microreactor connected in sequence, a solid-liquid separation structure is provided between the first-stage microreactor and the second-stage microreactor, and a solid-liquid separation structure is provided between the second-stage microreactor and the third-stage microreactor; The third-stage diaphragm reactor, the microchannel reactor, and the first-stage microreactor are connected in sequence; The first-stage microreactor, the second-stage microreactor, and the third-stage microreactor are the same type of microreactor, and the microreactor is provided with a plurality of feed ports and branch pipes connected to the feed ports in a one-to-one correspondence, so that the first-stage microreactor, the second-stage microreactor, and the third-stage microreactor realize multi-point feeding; The microreactor comprises a main pipe, a Y-shaped pipe (334) is fixedly connected to the outer surface of the main pipe, and elastic hoses are fixedly connected to both sides of the top of the Y-shaped pipe, and the other end of the elastic hose is fixedly connected to the outer surface of the branch pipe (331); Ammonium phosphate and phosphoric acid are reacted through a three-stage diaphragm reactor to obtain a phosphorus-containing mixed liquid. The phosphorus-containing mixed liquid reacts with ferrous sulfate through a microchannel reactor to obtain an intermediate mixed liquid. When the intermediate mixed liquid and hydrogen peroxide are simultaneously pumped into the first-stage microreactor, the intermediate mixed liquid is pumped into the branch pipe (331) connected to one side of the Y-type tube (334), and hydrogen peroxide is pumped into the branch pipe (331) on the other side of the same Y-type tube (334). The intermediate mixed liquid and hydrogen peroxide on both sides of the same Y-type tube (334) are mixed and reacted at the three-way joint of the Y-type tube (334). The primary reactant obtained by the mixed reaction enters the main pipeline (333) and then enters the solid-liquid separation structure between the first-stage microreactor and the second-stage microreactor through the total outlet (332). The obtained filtrate component enters each branch pipe (331) and the Y-type tube (334) in the second-stage microreactor for secondary reaction.

2. A nano-ferric phosphate production process according to claim 1, characterized in that: The specific steps are as follows: S1, ammonium phosphate and phosphoric acid are configured into a solution of a certain concentration and then pumped into a first-stage diaphragm reactor through different feeding ports for a first mixing reaction. After a period of time after the first mixing reaction, the solution is fed into a second-stage diaphragm reactor for a second mixing reaction. After a period of time after the second mixing reaction, the solution is fed into a third-stage diaphragm reactor to obtain a phosphorus-containing mixed solution; S2, the phosphorus-containing mixed liquid enters the microchannel reactor connected to the third-stage diaphragm reactor through the third-stage diaphragm reactor, and at the same time, ferrous sulfate is pumped into the microchannel reactor to be fully mixed with the phosphorus-containing mixed liquid to obtain an intermediate mixed liquid; S3, the intermediate mixed liquid, and hydrogen peroxide are simultaneously pumped into the first-stage microreactor for reaction; after reacting for a period of time in the first-stage microreactor, the reactants are filtered to obtain a precipitate and a filtrate; the filtrate enters a second-stage microreactor connected to the first-stage microreactor to continue the reaction; after reacting for a period of time in the second-stage microreactor, the reactants are filtered again to obtain a precipitate and a filtrate; the filtrate enters a third-stage microreactor connected to the second-stage microreactor to continue the reaction; and the precipitates obtained by the three filtrations are collected, washed, and dried to obtain ferric phosphate; S4. Drying and calcining the iron phosphate to obtain nano iron phosphate.

3. A nano-ferric phosphate production process according to claim 1, characterized in that: The molar ratio of the total amount of ammonium phosphate and phosphoric acid to ferrous sulfate is 1.2-1.6:

1.

4. The nano-ferric phosphate production process according to claim 1, wherein: The first-stage diaphragm reactor, the second-stage diaphragm reactor and the third-stage diaphragm reactor are the same type of membrane reactor.

5. The process for producing nano-ferric phosphate according to claim 1, wherein: The microreactor comprises a mixing reactor body (1), the mixing reactor body (1) comprises a reaction tank (2), a sealing assembly (3) is detachably mounted on the front end of the reaction tank (2), and a mixing unit is arranged inside the reaction tank (2); The mixing unit is detachably mounted inside the reaction tank (2), and comprises a main outlet (332) disposed on the front end of the reaction tank (2). A main pipe (333) is fixedly mounted at the connection of the main outlet (332). A plurality of branch pipes (331) are disposed outside the main pipe (333), and all the branch pipes (331) are evenly distributed around the main pipe (333). A feed port (33) is fixedly connected to the input end of the branch pipe (331). The main pipe (333) is connected to the main pipe (333). ) is fixedly connected to the outer wall of a plurality of evenly distributed Y-shaped tubes (334), the Y-shaped tube (334) being located between two adjacent branch tubes (331), the Y-shaped tube (334) comprising a main tube and branch tubes located on both sides of the main tube, the branch tubes on both sides of the main tube being connected to the main tube, the branch tubes of the Y-shaped tube (334) being connected to the adjacent branch tubes (331) on both sides via elastic hoses (335), and the main tube of the Y-shaped tube (334) being connected to the main tube (333).

6. A nano-ferric phosphate production process according to claim 3, characterized in that: The molar ratio of the total amount of ammonium phosphate and phosphoric acid to ferrous sulfate is 1.5:

1.

7. The process for producing nano-ferric phosphate according to claim 2, wherein: The concentration of the phosphoric acid solution is 85%.

8. The process for producing nano-ferric phosphate according to claim 1, wherein: The secondary reactants enter the solid-liquid separation structure between the second-stage microreactor and the third-stage microreactor through the total outlet (332) of the second-stage microreactor for filtration, and the resulting filtrate components enter the various branch pipes (331) and the Y-shaped tube (334) in the third-stage microreactor for tertiary reactions.

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