CN116443834A - Method for continuously synthesizing ferric phosphate by using microreactor - Google Patents
Method for continuously synthesizing ferric phosphate by using microreactor Download PDFInfo
- Publication number
- CN116443834A CN116443834A CN202310411622.2A CN202310411622A CN116443834A CN 116443834 A CN116443834 A CN 116443834A CN 202310411622 A CN202310411622 A CN 202310411622A CN 116443834 A CN116443834 A CN 116443834A
- Authority
- CN
- China
- Prior art keywords
- iron
- microreactor
- reaction
- phosphate
- ferric phosphate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- WBJZTOZJJYAKHQ-UHFFFAOYSA-K iron(3+) phosphate Chemical compound [Fe+3].[O-]P([O-])([O-])=O WBJZTOZJJYAKHQ-UHFFFAOYSA-K 0.000 title claims abstract description 74
- 238000000034 method Methods 0.000 title claims abstract description 52
- 239000005955 Ferric phosphate Substances 0.000 title claims abstract description 46
- 229940032958 ferric phosphate Drugs 0.000 title claims abstract description 46
- 229910000399 iron(III) phosphate Inorganic materials 0.000 title claims abstract description 46
- 230000002194 synthesizing effect Effects 0.000 title claims abstract description 14
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 131
- 238000006243 chemical reaction Methods 0.000 claims abstract description 83
- 229910052742 iron Inorganic materials 0.000 claims abstract description 59
- 239000007788 liquid Substances 0.000 claims abstract description 30
- 229910000398 iron phosphate Inorganic materials 0.000 claims abstract description 28
- 239000002002 slurry Substances 0.000 claims abstract description 13
- 230000001590 oxidative effect Effects 0.000 claims abstract description 12
- 239000002994 raw material Substances 0.000 claims abstract description 12
- 239000007790 solid phase Substances 0.000 claims abstract description 10
- 238000003756 stirring Methods 0.000 claims abstract description 10
- 238000002360 preparation method Methods 0.000 claims abstract description 7
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 36
- 238000005406 washing Methods 0.000 claims description 22
- 239000000047 product Substances 0.000 claims description 21
- 239000007787 solid Substances 0.000 claims description 20
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 18
- 238000001354 calcination Methods 0.000 claims description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 12
- 230000008018 melting Effects 0.000 claims description 10
- 238000002844 melting Methods 0.000 claims description 10
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 8
- 238000001914 filtration Methods 0.000 claims description 8
- 238000010438 heat treatment Methods 0.000 claims description 8
- 238000001035 drying Methods 0.000 claims description 7
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 6
- 239000011574 phosphorus Substances 0.000 claims description 6
- 229910052698 phosphorus Inorganic materials 0.000 claims description 6
- 239000005708 Sodium hypochlorite Substances 0.000 claims description 3
- VKJKEPKFPUWCAS-UHFFFAOYSA-M potassium chlorate Chemical compound [K+].[O-]Cl(=O)=O VKJKEPKFPUWCAS-UHFFFAOYSA-M 0.000 claims description 3
- SATVIFGJTRRDQU-UHFFFAOYSA-N potassium hypochlorite Chemical compound [K+].Cl[O-] SATVIFGJTRRDQU-UHFFFAOYSA-N 0.000 claims description 3
- 230000035484 reaction time Effects 0.000 claims description 3
- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 claims description 3
- BZSXEZOLBIJVQK-UHFFFAOYSA-N 2-methylsulfonylbenzoic acid Chemical compound CS(=O)(=O)C1=CC=CC=C1C(O)=O BZSXEZOLBIJVQK-UHFFFAOYSA-N 0.000 claims description 2
- 239000002244 precipitate Substances 0.000 claims description 2
- 230000003647 oxidation Effects 0.000 claims 2
- 238000007254 oxidation reaction Methods 0.000 claims 2
- 239000002245 particle Substances 0.000 abstract description 15
- 238000002156 mixing Methods 0.000 abstract description 9
- 239000000376 reactant Substances 0.000 abstract description 8
- 238000001556 precipitation Methods 0.000 abstract description 7
- 239000007791 liquid phase Substances 0.000 abstract description 5
- 230000003068 static effect Effects 0.000 abstract description 5
- 239000012530 fluid Substances 0.000 abstract description 4
- 230000000903 blocking effect Effects 0.000 abstract description 3
- 230000008021 deposition Effects 0.000 abstract description 3
- 239000000243 solution Substances 0.000 description 40
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 12
- NBIIXXVUZAFLBC-UHFFFAOYSA-M dihydrogenphosphate Chemical compound OP(O)([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-M 0.000 description 12
- 238000006116 polymerization reaction Methods 0.000 description 9
- 239000000463 material Substances 0.000 description 8
- 238000010899 nucleation Methods 0.000 description 6
- 230000006911 nucleation Effects 0.000 description 6
- 238000000926 separation method Methods 0.000 description 5
- 239000006227 byproduct Substances 0.000 description 4
- 239000013049 sediment Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 3
- 230000032683 aging Effects 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 230000003321 amplification Effects 0.000 description 2
- 239000012295 chemical reaction liquid Substances 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000009776 industrial production Methods 0.000 description 2
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 2
- 238000003199 nucleic acid amplification method Methods 0.000 description 2
- 238000004321 preservation Methods 0.000 description 2
- 239000012266 salt solution Substances 0.000 description 2
- 238000002604 ultrasonography Methods 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- SNPLKNRPJHDVJA-ZETCQYMHSA-N D-panthenol Chemical compound OCC(C)(C)[C@@H](O)C(=O)NCCCO SNPLKNRPJHDVJA-ZETCQYMHSA-N 0.000 description 1
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 238000013019 agitation Methods 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 description 1
- 229910052921 ammonium sulfate Inorganic materials 0.000 description 1
- 235000011130 ammonium sulphate Nutrition 0.000 description 1
- 239000010405 anode material Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- MNNHAPBLZZVQHP-UHFFFAOYSA-N diammonium hydrogen phosphate Chemical compound [NH4+].[NH4+].OP([O-])([O-])=O MNNHAPBLZZVQHP-UHFFFAOYSA-N 0.000 description 1
- 239000003085 diluting agent Substances 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 235000003891 ferrous sulphate Nutrition 0.000 description 1
- 239000011790 ferrous sulphate Substances 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 1
- 229910001416 lithium ion Inorganic materials 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000006053 organic reaction Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 229940101267 panthenol Drugs 0.000 description 1
- 235000020957 pantothenol Nutrition 0.000 description 1
- 239000011619 pantothenol Substances 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 238000004886 process control Methods 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 238000001878 scanning electron micrograph Methods 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 238000009827 uniform distribution Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/16—Oxyacids of phosphorus; Salts thereof
- C01B25/26—Phosphates
- C01B25/37—Phosphates of heavy metals
- C01B25/375—Phosphates of heavy metals of iron
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/01—Particle morphology depicted by an image
- C01P2004/03—Particle morphology depicted by an image obtained by SEM
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/11—Powder tap density
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/12—Surface area
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Physical Or Chemical Processes And Apparatus (AREA)
Abstract
The invention discloses a method for continuously synthesizing ferric phosphate by using a microreactor, and relates to the technical field of ferric phosphate preparation. Respectively introducing the iron phosphate raw material liquid synthesized by an iron method and the oxidizing liquid into a microreactor for mixing; reacting in a dynamic environment microreactor and obtaining product slurry; post-treating the product slurry to obtain ferric phosphate; the dynamic environment microreactor is at least one of a dynamic tubular reactor, an oscillating flat plate microchannel or an ultrasonic microreactor. The dynamic environment such as stirring, ultrasonic and vibration is adopted to promote each point of the reaction system to still keep relatively uniform reactant concentration and temperature environment in a larger space size, so that continuously grown ferric phosphate particles are ensured to flow out smoothly along with fluid while being suspended in a liquid phase, the full continuity of inorganic precipitation reaction is realized, the common layering and blocking conditions in a microreactor are effectively avoided, and the pipeline blocking caused by solid phase deposition in a static pipeline is effectively avoided.
Description
Technical Field
The invention relates to the technical field of iron phosphate preparation, in particular to a method for continuously synthesizing iron phosphate by using a microreactor.
Background
The existing preparation method of the lithium ion battery anode material lithium iron phosphate precursor ferric phosphate mainly adopts an ammonium method, namely ferrous salt (such as ferrous sulfate) reacts with phosphoric acid, ammonium hydrogen phosphate, ammonia water, oxidizing solution and the like to obtain ferric phosphate. The method has the advantages of large byproduct of ammonium salt (ammonium sulfate) diluent, large water consumption in process washing, high environmental protection treatment pressure and low byproduct value. Meanwhile, as the reaction time is long and the process control is complex, the traditional ammonium method mostly uses a kettle type intermittent reaction mode to prepare ferric phosphate in industrial production, so that the common problems of difference of products among kettles and poor uniformity of product quality are caused.
In order to solve the common problems of high environmental protection treatment pressure in the process and poor product quality uniformity caused by intermittent reaction due to the large byproduct and washing water amount in the traditional ammonium method, the iron method developed later forms ferrous dihydrogen phosphate (Fe (H) 2 PO 4 ) 2 Then continuously reacting with the oxidizing solution to obtain the ferric phosphate.
CN114644327a discloses a preparation method of ferric phosphate, in which ferrous dihydrogen phosphate is put into a reaction kettle, hydrogen peroxide is added for stirring reaction, but because the reaction rate of an iron method is fast, the requirements on the accuracy of controlling the heat transfer and the reaction conditions are high, and the ferric phosphate with stable quality and controllable morphology is difficult to synthesize through the traditional kettle reaction.
In addition, during continuous production, materials in the reaction kettle can be conveyed by adopting a pipe and a pipeline, and the reaction channel is easily blocked because the liquid-liquid phase is extremely rapidly changed to the solid-liquid phase in the reaction process, so that the continuous reaction of ferrous dihydrogen phosphate and oxidizing liquid to synthesize ferric phosphate is difficult to realize by using a common tubular reaction.
The method for preparing the ferric phosphate by the iron method has the advantages that although byproducts are few, the reaction rate is high, the nucleation and polymerization processes in the precipitation process depend on the concentration and reaction temperature, and the excessive concentration gradient and temperature gradient of the reactants can cause great differences in the nucleation state and polymerization degree of substances in a reaction system, so that the particle size, morphology, elemental components and crystal structure of the obtained ferric phosphate product after calcination are influenced.
The "aging" process of iron phosphate refers to a bi-directional reaction process in which individual iron phosphate particles are continuously grown and dissolved, the reaction rate of each direction of the process being a function of the temperature, the concentration of the reactants, and the concentration of the iron phosphate particles, and whether stable and uniform iron phosphate particles can be formed depends on whether the temperature, the concentration of the reactants, and the concentration of the iron phosphate particles in each region of the reaction system can be precisely controlled simultaneously.
However, the conventional batch reactor is difficult to realize in-situ control of temperature and substances, the material concentration and the temperature of each site in the reaction kettle are difficult to obtain uniform distribution through stirring rods, and the reaction kettle is difficult to be involved in disturbance sources such as ultrasound and vibration to realize dynamic environment, so that the problems of poor stability, poor batch property and the like of the ferric phosphate product caused by random nucleation, polymerization, growth and dissolution processes are finally caused.
Meanwhile, the difference of the material concentration and the temperature can be more serious along with the amplification of the volume of the reaction kettle, even a reaction static dead angle exists in the oversized reaction kettle, and the industrialized amplification and standardized production of the method are seriously hindered.
Microreactors, i.e. microchannel reactors, are microreactors with feature sizes between 10 and 1000 microns manufactured using precision machining techniques. The microreactor has excellent heat and mass transfer capability, and can realize instant uniform mixing of materials and efficient heat transfer, so that a plurality of reactions which cannot be realized in the conventional reactor can be realized in the microreactor.
The existing microreactors are mainly used for organic reactions such as: the preparation of high molecular polymer (Chen. Application of microchannel reactor in polymerization field is developed [ J ]. Zhejiang chemical 2021,52 (09): 31-36.), and panthenol synthesis reaction (CN 201910353549.1).
The problems of laminar flow and blockage in the reaction space of a micro-size reactor are limited, and the use of the micro-reactor for inorganic precipitation reaction is rarely reported. CN115108543a discloses a method for synthesizing battery grade ferric phosphate, wherein a monobasic phosphate solution is mixed with an ferric salt solution, or with a ferrous salt solution and an oxidizing agent, in a microchannel mixer or reaction kettle, preferably a microchannel mixer, which is selected from one of a laminar flow mixing microreactor, a turbulent flow mixing microreactor, and a reflux mixing microreactor. The iron phosphate is prone to localized precipitation, which makes smooth transport of solid particles in the microchannels difficult.
Disclosure of Invention
The invention aims to provide a method for continuously synthesizing ferric phosphate by using a microreactor, which solves the problems of poor quality stability, low conductivity and unsmooth transportation of a microstructure of the ferric phosphate prepared by the existing method.
In order to solve the technical problems, the invention adopts the following technical scheme: a method for continuously synthesizing ferric phosphate by using a microreactor, which is characterized by comprising the following steps:
s1, respectively introducing iron phosphate raw material liquid synthesized by an iron method and oxidizing liquid into a microreactor to mix;
s2, reacting in a dynamic environment microreactor to obtain product slurry;
s3, carrying out post-treatment on the product slurry to obtain ferric phosphate;
wherein the dynamic environment microreactor is at least one of a dynamic tubular reactor, an oscillating flat micro-channel or an ultrasonic microreactor.
The further technical scheme is that the preparation steps of the iron method synthesized ferric phosphate raw material liquid in the step S1 are as follows: adding an iron source into a reaction kettle, adding a phosphoric acid solution, heating to 70-80 ℃ to perform an iron melting reaction until iron is completely consumed, filtering the reaction solution until the reaction solution is clean and transparent, and taking no suspended precipitate as an iron method to synthesize an iron phosphate raw material solution for use.
The further technical proposal is that the iron source is selected from iron blocks, iron bars and iron powder with the iron content of more than 99.5 percent; the concentration of the phosphoric acid solution is 16-27%; the iron source and the phosphorus source are added according to the mole ratio of Fe to P of 0.35-0.38.
The further technical proposal is that the oxidizing solution is at least one selected from sodium hypochlorite, potassium hypochlorite, hydrogen peroxide, potassium chlorate and sodium chlorate, the concentration is 5-35 percent, and the feed flow rate ratio of the iron phosphate raw material liquid synthesized by an iron method to the oxidizing solution is 1:12.5-50.
The further technical proposal is that the reaction time of the iron method synthesized ferric phosphate raw material liquid and the oxidizing liquid in the dynamic environment microreactor in the step S2 is 2-30 min, and the reaction temperature is 80-90 ℃. More specifically, the laminar flow mixing residence time is controlled to be 3-20 ms, and a disturbance source is introduced through at least one of agitation, oscillation or ultrasound in the micro-channel after the residence time of 30-60 s. The strengthening effect of the micro-channel on the precipitation reaction and the smooth transportation of the solid particles in the micro-channel are ensured at the same time under the state of local laminar flow or certain turbulence.
The further technical proposal is that after the product slurry in the step S3 is filtered, the solid phase is washed until the conductivity value of the washing liquid is less than 25us/cm, the washed solid is dried for 1 to 2 hours at the temperature of 90 to 110 ℃, and then calcined for 3 to 5 hours at the temperature of 500 to 650 ℃ to obtain the anhydrous ferric phosphate.
The further technical proposal is that the stirring frequency of the dynamic tubular reactor is 30-50Hz, the oscillating frequency of the oscillating flat micro-channel is 300-3000 rpm, and the ultrasonic frequency of the ultrasonic micro-reactor is more than 20000 Hz.
Reaction mechanism: and (3) iron melting: placing the iron simple substance into phosphoric acid solution, heating to perform iron-dissolving reaction to obtain Fe (H) 2 P0 4 ) 2 Is a reaction solution of (a);
the microchannel continuous reaction: ferrous dihydrogen phosphate (Fe (H) 2 PO 4 ) 2 ) After the solution and the oxidizing solution are rapidly and uniformly mixed and reacted in a micro-reactor, heating and reacting in a dynamic tubular reactor, an oscillating flat micro-channel or an ultrasonic micro-reactor, and collecting product slurry;
filtering and washing, namely performing solid-liquid separation on the product slurry, performing water washing on the separated solid phase, and collecting a solid ferric phosphate product;
drying and calcining: and drying, dewatering and calcining the solid ferric phosphate product at different temperatures to obtain a final product.
In the process, the iron method synthesized ferric phosphate raw material liquid and the oxidizing liquid realize instantaneous homogeneous mixing of reactants in the microreactor, and trigger the nucleation and polymerization processes of ferric phosphate at uniform reaction temperature, thereby reducing randomness caused by concentration gradient and temperature gradient, and greatly reducing fluctuation range of product particle size, morphology, elemental components and crystal structure after calcination. In the subsequent solid polymerization and growth process, dynamic environments such as stirring, ultrasonic and vibration are used to promote the fluid to keep relatively uniform reactant concentration and temperature environment in a larger space size, and ensure that continuously grown ferric phosphate particles suspend in a liquid phase and smoothly flow out along with the fluid, so that the full continuity of inorganic precipitation reaction is realized, and the pipeline blockage caused by solid phase deposition in a static pipeline is avoided.
Compared with the prior art, the invention has the beneficial effects that:
1) The method can realize instantaneous homogeneous mixing of reactants in the microreactor, uniformly and effectively trigger nucleation and polymerization processes of ferric phosphate at multiple points in the reactor at uniform reaction temperature, reduce the randomness of nucleation and polymerization occurrence areas in a reaction system caused by concentration gradient and temperature gradient, and greatly reduce the fluctuation range of product particle size, morphology, element components and crystal structures after calcination.
2) According to the method, in the subsequent solid particle polymerization and growth process, dynamic environments such as stirring, ultrasonic and vibration are adopted to promote each point of a reaction system to still keep relatively uniform reactant concentration and temperature environment in a larger space size, so that continuously grown ferric phosphate particles are ensured to be suspended in a liquid phase and smoothly flow out along with the fluid, the full continuity of inorganic precipitation reaction is realized, the common layering and blocking conditions in a micro-reactor are effectively avoided, and the pipeline blockage caused by solid phase deposition in a static pipeline is effectively avoided.
Drawings
FIG. 1 is a schematic flow chart of the present invention.
FIG. 2 is an XRD pattern of the samples of examples 1-4 of the present invention.
FIG. 3 is an SEM image of a sample of examples 1-2 according to the invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
Example 1
Step S1: preparing ferrous dihydrogen phosphate solution:
purified phosphoric acid was slowly stirred and dissolved in pure water to prepare a 16% phosphoric acid solution. After 30.6g of iron rods (with the iron content of more than 99.5%) are piled up in a reaction kettle, 869g of phosphoric acid solution is added, and after the solution is heated to 70 ℃, the iron melting reaction is carried out until the solid iron material is completely consumed.
The obtained reaction solution is filtered to be clean and transparent, no suspended sediment exists, the iron content of the iron melting solution is controlled to be 42g/L, and the mole ratio of an iron source to a phosphorus source is controlled to be 0.35.
Step S2: microreactor reaction:
ferrous dihydrogen phosphate (Fe (H) 2 PO 4 ) 2 ) The solution and hydrogen peroxide with the concentration of 20 percent are introduced into a dynamic tubular reactor at the flow rate ratio of 1:50 for quick and uniform mixing, and then heated to 80 ℃ for reaction, the reaction residence time was 30 minutes and the stirring frequency of the dynamic tubular reactor (which can be used with the dynamic tubular reactor disclosed in patent 202220415543X) was 30-50Hz; continuously stirring and reacting for 0.5 hour under the heat preservation condition of 80 ℃;
step S3: and (3) filtering and washing:
carrying out solid-liquid separation on the product slurry after the reaction, washing the solid phase until the conductivity value of the washing liquid is less than 25us/cm, and collecting solid ferric phosphate;
step S4: drying and calcining
Baking the solid ferric phosphate obtained by washing at 90-110 ℃ for 1-2 hours to remove water, heating to 500-650 ℃ and calcining for 3-5 hours to obtain anhydrous ferric phosphate.
Example 2
Step S1: preparing ferrous dihydrogen phosphate solution:
purified phosphoric acid was slowly stirred and dissolved in pure water to prepare a 20% phosphoric acid solution. After 35.9 g of iron blocks (iron content is more than 99.5%) are piled up in a reaction kettle, 847.4 g of phosphoric acid solution is added, and after the solution is heated to 75 ℃, iron melting reaction is carried out until the solid iron material is completely consumed. The obtained reaction solution is filtered to be clean and transparent, no suspended sediment exists, the iron content of the molten iron is controlled at 43.5g/L, and the molar ratio of an iron source to a phosphorus source is 0.36.
Step S2: microreactor reaction:
ferrous dihydrogen phosphate (Fe (H) 2 PO 4 ) 2 ) The solution and sodium hypochlorite with the concentration of 21 percent are introduced into an oscillating flat micro-channel or an ultrasonic micro-reactor at the flow rate ratio of 1:12.5, heated to 85 ℃ for reaction, the reaction residence time is 25 minutes, and the oscillating frequency of the oscillating flat micro-channel (using an internal electrode to provide pulse or ultrasonic) is 300-2000rpm;
step S3: and (3) filtering and washing:
carrying out solid-liquid separation on the product slurry after the reaction, washing the solid phase until the conductivity value of the washing liquid is less than 25us/cm, and collecting solid ferric phosphate;
step S4: drying and calcining
Baking the solid ferric phosphate obtained by washing at 90-110 ℃ for 1-2 hours to remove water, heating to 500-650 ℃ and calcining for 3-5 hours to obtain anhydrous ferric phosphate.
Example 3
Step S1: preparing ferrous dihydrogen phosphate solution:
purified phosphoric acid was slowly stirred and dissolved in pure water to prepare a 22% phosphoric acid solution. 36.1 g of iron powder (iron content is more than 99.5%) is added into a reaction kettle, 832.0 g of phosphoric acid solution is added, and after the reaction kettle is heated to 80 ℃, iron melting reaction is carried out until solid iron materials are completely consumed. The obtained reaction solution is filtered to be clean and transparent, no suspended sediment exists, the iron content of the iron melting solution is controlled to be 48g/L, and the mole ratio of an iron source to a phosphorus source is controlled to be 0.38.
Step S2: microreactor reaction:
ferrous dihydrogen phosphate (Fe (H) 2 PO 4 ) 2 ) The solution and potassium hypochlorite with the concentration of 21 percent are introduced into an ultrasonic micro-reactor at the flow rate ratio of 1:30, heated to 90 ℃ for reaction, the reaction residence time is 2 minutes, and the ultrasonic frequency of the ultrasonic micro-reactor is 20000Hz;
step S3: and (3) filtering and washing:
carrying out solid-liquid separation on the product slurry after the reaction, washing the solid phase until the conductivity value of the washing liquid is less than 25us/cm, and collecting solid ferric phosphate;
step S4: drying and calcining
Baking the solid ferric phosphate obtained by washing at 90-110 ℃ for 1-2 hours to remove water, heating to 500-650 ℃ and calcining for 3-5 hours to obtain anhydrous ferric phosphate.
Example 4
Step S1: preparing ferrous dihydrogen phosphate solution:
purified phosphoric acid was slowly stirred and dissolved in pure water to prepare a 27% phosphoric acid solution. 42g of iron powder (iron content is more than 99.5%) is added into a reaction kettle, 799.0 g of phosphoric acid solution is added, and after the reaction kettle is heated to 80 ℃, the iron melting reaction is carried out until the solid iron material is completely consumed. The obtained reaction solution is filtered to be clean and transparent, no suspended sediment exists, the iron content of the iron melting solution is controlled to be 46g/L, and the mole ratio of an iron source to a phosphorus source is controlled to be 0.37.
Step S2: microreactor reaction:
ferrous dihydrogen phosphate (Fe (H) 2 PO 4 ) 2 ) The solution and potassium chlorate with the concentration of 21 percent are introduced into an oscillating flat micro-channel or an ultrasonic micro-reactor at the flow rate ratio of 1:40, heated to 85 ℃ for reaction, the reaction residence time is 20 minutes, and the oscillating frequency of the oscillating flat micro-channel is 1000-3000rpm;
step S3: aging:
stirring and reacting for 0.5-2 hours under the heat preservation condition of 80-90 ℃;
step S4: and (3) filtering and washing:
discharging reaction liquid from the micro-reactor or carrying out solid-liquid separation on the reaction liquid obtained after aging treatment, washing the solid phase until the conductivity value of the washing liquid is less than 25us/cm, and collecting solid ferric phosphate;
step S5: drying and calcining
Baking the washed solid at 90-110 ℃ for 1-2 hours to remove water, heating to 500-650 ℃ and calcining for 3-5 hours to obtain anhydrous ferric phosphate.
Anhydrous iron phosphate samples 1# -4# were obtained in examples 1-4, respectively, wherein the sample performance parameters are as follows. From the data in Table 1, it is known that the iron phosphate product synthesized under each condition meets the main index of the industry standard of battery iron phosphate HG/T4701-2021, and the prepared lithium iron phosphate has good electrical property. XRD results of sample 1# -4# are shown in FIG. 2, and SEM results of sample 1# -2# are shown in FIG. 3. The sample in FIG. 2 is a sample collected after the reaction is continuously carried out for 72 hours, and it is known that the iron phosphate can be prepared by adopting the method, and the method can not cause pipeline blockage in the microreactor, and the reaction can smoothly pass through the reactor, so that the industrial production of the battery-grade iron phosphate can be realized. As can be seen from fig. 3, the iron phosphate particles with uniform morphology can be obtained by the method provided by the application, and the morphology of each particle is uniform under the same scale as can be seen from fig. 3, which shows that the temperature gradient and the concentration gradient in the reaction system of the method are uniform, the generation of static dead angles can be effectively avoided, and the controllable reaction precision is improved.
TABLE 1
Although the invention has been described herein with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the scope and spirit of the principles of this disclosure. More specifically, various variations and modifications may be made to the component parts or arrangements of the subject combination arrangement within the scope of the disclosure, drawings and claims of this application. In addition to variations and modifications in the component parts or arrangements, other uses will be apparent to those skilled in the art.
Claims (7)
1. A method for continuously synthesizing ferric phosphate by using a microreactor, which is characterized by comprising the following steps:
s1, respectively introducing iron phosphate raw material liquid synthesized by an iron method and oxidizing liquid into a microreactor to mix;
s2, reacting in a dynamic environment microreactor to obtain product slurry;
s3, carrying out post-treatment on the product slurry to obtain ferric phosphate;
wherein the dynamic environment microreactor is at least one of a dynamic tubular reactor, an oscillating flat micro-channel or an ultrasonic microreactor.
2. A method for continuously synthesizing iron phosphate using a microreactor according to claim 1, wherein: the steps are as follows
The preparation method of the iron phosphate raw material liquid synthesized by the iron method in S1 comprises the following steps: adding an iron source into a reaction kettle, adding a phosphoric acid solution, heating to 70-80 ℃ to perform an iron melting reaction until iron is completely consumed, filtering the reaction solution until the reaction solution is clean and transparent, and taking no suspended precipitate as an iron method to synthesize an iron phosphate raw material solution for use.
3. A method for continuously synthesizing iron phosphate using a microreactor according to claim 2, wherein: the iron source is selected from iron blocks, iron bars and iron powder with the iron content of more than 99.5%; the concentration of the phosphoric acid solution is 16-27%; the iron source and the phosphorus source are added according to the mole ratio of Fe to P of 0.35-0.38.
4. A method for continuously synthesizing iron phosphate using a microreactor according to claim 1, wherein: the oxidation liquid is at least one selected from sodium hypochlorite, potassium hypochlorite, hydrogen peroxide, potassium chlorate and sodium chlorate, the concentration is 5% -35%, and the feed flow rate ratio of the iron phosphate raw material liquid synthesized by an iron method to the oxidation liquid is 1:12.5-50.
5. A method for continuously synthesizing iron phosphate using a microreactor according to claim 1, wherein: and in the step S2, the reaction time of the iron method synthesized ferric phosphate raw material liquid and the oxidizing liquid in the dynamic environment microreactor is 2-30 min, and the reaction temperature is 80-90 ℃.
6. A method for continuously synthesizing iron phosphate using a microreactor according to claim 1, wherein: and (3) filtering the product slurry in the step (S3), washing the solid phase with water until the conductivity value of the washing liquid is smaller than 25us/cm, drying the washed solid at 90-110 ℃ for 1-2 h, and calcining at 500-650 ℃ for 3-5 h to obtain anhydrous ferric phosphate.
7. A method for continuously synthesizing iron phosphate using a microreactor according to claim 1, wherein: the stirring frequency of the dynamic tubular reactor is 30-50Hz, the oscillating frequency of the oscillating flat plate micro-channel is 300-3000 rpm, and the ultrasonic frequency of the ultrasonic micro-reactor is over 20000 Hz.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310411622.2A CN116443834A (en) | 2023-04-13 | 2023-04-13 | Method for continuously synthesizing ferric phosphate by using microreactor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310411622.2A CN116443834A (en) | 2023-04-13 | 2023-04-13 | Method for continuously synthesizing ferric phosphate by using microreactor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116443834A true CN116443834A (en) | 2023-07-18 |
Family
ID=87135237
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310411622.2A Pending CN116443834A (en) | 2023-04-13 | 2023-04-13 | Method for continuously synthesizing ferric phosphate by using microreactor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116443834A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009107046A1 (en) * | 2008-02-25 | 2009-09-03 | Philips Intellectual Property & Standards Gmbh | Preparation of nanoparticles from metal salts or metal oxides |
| CN105480960A (en) * | 2015-12-29 | 2016-04-13 | 河北斯霖百特新能源科技有限公司 | Iron phosphate preparation method |
| CN107433177A (en) * | 2017-07-28 | 2017-12-05 | 纳威科技（深圳）有限公司 | A kind of dynamic pipe reaction device and method thereof for preparing micro-nano powder |
| CN114031060A (en) * | 2021-12-08 | 2022-02-11 | 华东理工大学 | Preparation method of battery-grade anhydrous iron phosphate with lamellar structure |
| CN115108543A (en) * | 2022-05-31 | 2022-09-27 | 丁兴立 | Method for synthesizing battery-grade iron phosphate |
-
2023
- 2023-04-13 CN CN202310411622.2A patent/CN116443834A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009107046A1 (en) * | 2008-02-25 | 2009-09-03 | Philips Intellectual Property & Standards Gmbh | Preparation of nanoparticles from metal salts or metal oxides |
| CN105480960A (en) * | 2015-12-29 | 2016-04-13 | 河北斯霖百特新能源科技有限公司 | Iron phosphate preparation method |
| CN107433177A (en) * | 2017-07-28 | 2017-12-05 | 纳威科技（深圳）有限公司 | A kind of dynamic pipe reaction device and method thereof for preparing micro-nano powder |
| CN114031060A (en) * | 2021-12-08 | 2022-02-11 | 华东理工大学 | Preparation method of battery-grade anhydrous iron phosphate with lamellar structure |
| CN115108543A (en) * | 2022-05-31 | 2022-09-27 | 丁兴立 | Method for synthesizing battery-grade iron phosphate |
Non-Patent Citations (1)
| Title |
|---|
| 赵风云, 王建英, 高卿, 胡永琪: "微反应器技术制备纳米磷酸铁的研究与表征", 无机盐工业, vol. 44, no. 3, 31 March 2012 (2012-03-31), pages 22 - 24 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102140691B (en) | Method for synthesizing vanadium acid zinc micro/nanowire material by adopting hydrothermal method | |
| CN103785859B (en) | Method for manufacturing nanometer mesoporous material | |
| CN110228797B (en) | Method for preparing two-dimensional molybdenum nitride or tungsten nitride nanosheets at low cost | |
| CN110112386B (en) | Preparation method of high-nickel ternary positive electrode precursor | |
| CN105562122A (en) | Perovskite type core-shell structured metal oxide and preparation method and application thereof | |
| CN102351744A (en) | Synthesis process for 2-acrylamido-2-methyl propane sulfonic acid through continuous method | |
| CN103539210A (en) | Preparation method of cobalt molybdate microcrystals | |
| CN107486231B (en) | A kind of preparation method of graphite phase carbon nitride colloid photochemical catalyst | |
| CN101544361A (en) | Process and device for continuous preparation of lithium hexafluorophosphate | |
| CN104108749B (en) | A kind of preparation method of strontium titanate doping | |
| CN102745662A (en) | Preparation method of amorphous iron phosphate | |
| CN110627122A (en) | Preparation of VO by solid phase method2Method for phase change materials | |
| CN102992513A (en) | Method for producing ferric salt-series purifiers by recycling and comprehensive utilizing stainless steel waste etching solution | |
| CN107827153B (en) | A kind of preparation method of nanometer of silver vanadate | |
| CN104368340B (en) | A kind of preparation of sponge silver catalyst and the application in cinnamic acid oxidation synthesizing cinnamic acid thereof | |
| CN110937587A (en) | Method and device for preparing lithium hexafluorophosphate by adopting microreactor | |
| CN110817831A (en) | Continuous synthesis method and device of lithium hexafluorophosphate | |
| CN116443834A (en) | Method for continuously synthesizing ferric phosphate by using microreactor | |
| CN111377834A (en) | Continuous preparation method of acetoacetamidosulfonic acid triethylamine | |
| CN100355656C (en) | Preparation method of polymerized aluminium chloride having high aluminium content | |
| CN109761278B (en) | Method for synthesizing barium chromate nano material by taking surfactant-free microemulsion as template | |
| CN116285977B (en) | Continuous preparation CsPbX by ultrasonic microreactor3Method for preparing perovskite quantum dot material | |
| KR20120118874A (en) | Pharmaceutical reactor for efficient reaction with blade works by worm gear | |
| CN108910952A (en) | A kind of foam-like molybdenum dioxide and preparation method thereof | |
| CN108892114A (en) | The method and electrocatalytic oxidation impurity removing equipment of electrocatalytic oxidation Yellow phosphorus arsenic removing |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |