209results about "Sub-atmospheric pressure processes" patented technology

The invention relates to the technical field of mine solid waste treatment and carbon dioxide sealing and storage, and particularly discloses a system and a method for sealing and storing carbon dioxide by utilizing coal-based solid waste and mine water to prepare slurry. The system comprises a cement bin, a gangue bin, a coal ash bin, a gasified slag bin, a mine water storage tank, a stirring reaction kettle, a carbon dioxide storage tank, a slurry temporary storage tank, a vacuum pump and a slurry pump, and the stability and adsorption efficiency of carbon dioxide fixation are improved in the mode that coal-based solid waste, mine water and carbon dioxide are subjected to chemical reaction and physical adsorption; meanwhile, the prepared backfill slurry has high-strength anti-pressure ability, the stability of the backfilled underground goaf is better improved, further, coal-based solid waste and mine water are utilized for waste recycling, and the carbon dioxide storage cost is reduced.

The invention relates to the technical field of chemical engineering, and particularly discloses a palladium-carbon catalytic hydrogenation reaction material treatment system, which comprises a three-dimensional workshop structure, an air-operated hoist, an air supply system, an air supply system and an air supply system, wherein the top of the three-dimensional workshop structure is provided with an elevator and a hoisting ton bag; the palladium-carbon circulating unit comprises a palladium-carbon preparation kettle, a hydrogenation reaction kettle, a decarbonization filter, a filter pressing cylinder, a sample splitter and a glove box which are connected in sequence, and the sample splitter is connected back to the palladium-carbon preparation kettle through a closed pipeline; the solid feeding unit comprises a ton bag feeder, a pneumatic valve and a spiral conveying pipe, and the tail end of the solid feeding unit is connected with a top feeding hole of the hydrogenation reaction kettle; the gas supply system comprises a hydrogen cylinder group and is connected to a gas distributor at the bottom of the hydrogenation reaction kettle through a pressure reducing valve and a flow regulating valve; through the multi-stage separation design and the safety interlocking mechanism of the palladium-carbon circulating unit, the recovery rate of the catalyst is increased, meanwhile, the pressure, temperature and stirring state are monitored in real time to trigger nitrogen purging or pressure relief, and the risks of hydrogen leakage and reaction out-of-control are reduced in combination with inert gas protection of the glove box.

The invention relates to a preparation method and system of high-molecular-weight polyethylene glycol oxalate, and the preparation method comprises the following steps: adding oxalic acid diester, ethylene glycol and a first catalyst, and carrying out transesterification to obtain an ester; adding a second catalyst, and carrying out a pre-polycondensation reaction on the esterified product to obtain a glycol oxalate oligomer; polymerizing the ethylene glycol oxalate oligomer, and carrying out final polymerization reaction to obtain polyethylene glycol oxalate; the molar ratio of the oxalic acid diester to the ethylene glycol is (1.05-1.3): 1. Compared with the prior art, by controlling excessive oxalic acid diester in the raw material ratio, namely controlling the molar ratio of oxalic acid diester to ethylene glycol to be greater than 1, the reaction rate of ethylene glycol is improved, self-polycondensation of ethylene glycol is prevented, further increase of molecular weight is facilitated, and meanwhile, the thermal performance of the product is improved.

A multifunctional chemical synthesis reaction kettle belongs to the technical field of chemical synthesis equipment and comprises a reaction kettle body, a reaction kettle cover is arranged at the top end of the reaction kettle body, and a synergistic reaction unit is arranged in an inner cavity of the reaction kettle body; the collaborative reaction unit comprises a reaction bin, the center of the reaction bin and the center of the reaction kettle body are located on the same vertical line, a top plate is installed at the top end of an inner cavity of the reaction bin, and a stirring shaft is rotationally arranged in the center of the reaction bin in the vertical direction. Aiming at the limitation of a traditional chemical synthesis reaction kettle, a vacuum space and dynamic pressure change mechanism is adopted, periodic vacuum pressure change is realized through reciprocating lifting, the static flowing limitation of materials is effectively broken through, the reaction kettle deeply acts on the materials with different viscosities and densities, the problems of non-uniform mixing and dead angles are solved, and mechanical stirring is combined. Double synergistic mixing is achieved, the mixing efficiency and uniformity are remarkably improved, the reaction process is accelerated, and the product quality is guaranteed.

The invention relates to an interfacial polycondensation tubular reactor for preparing polycarbonate, which is characterized in that a U-shaped structure is adopted, a spiral turbulent flow device is arranged in a straight pipe section, and a high-viscosity melt is disturbed, laminar flow is eliminated and mixing is enhanced in an active or passive mode; a multi-stage independent temperature control module is arranged outside, so that the temperature of each reaction section is accurately regulated and controlled. The inlet, the outlet and the temperature control interface of the reactor adopt high-temperature-resistant and corrosion-resistant sealing design, and U-shaped modular flange connection is convenient for disassembly, assembly, cleaning and continuous expansion. The design solves the problems of non-uniform heat transfer and material residue of a traditional horizontal disc reactor, poor flow distribution of a tubular reactor and the like, and has the following advantages: the melt flow uniformity is improved, and local overheating and excessive polycondensation are avoided; the reaction efficiency and molecular weight distribution are optimized through segmented temperature control; the structure is compact without dead angles, the side reaction and inner wall corrosion risks are reduced, and the device is suitable for efficient continuous synthesis of polycarbonate.

The invention relates to the field of inorganic chemical industry production, and discloses a high-purity selenium dioxide continuous production process and equipment, the equipment comprises a cooling crystallization barrel, one side of the cooling crystallization barrel is provided with a selenium dioxide production mechanism, the selenium dioxide production mechanism is used for selenium dioxide production, and the cooling crystallization barrel is provided with a cooling crystallization barrel. An air pressure generation mechanism is arranged outside the cooling crystallization barrel, a gas on-off mechanism is arranged at the top of the air pressure generation mechanism, an air exhaust filtering mechanism is arranged at the top of the cooling crystallization barrel, and a tail barrel is arranged on the side, away from the selenium dioxide production mechanism, of the cooling crystallization barrel; the air pressure generating mechanism is used for keeping the negative pressure state in the cooling crystallization barrel and the tail barrel. According to the selenium dioxide production device, the inside of the feeding pipeline is filled with the materials, so that the materials can be supplemented in time after the materials are consumed, and selenium dioxide can be continuously and efficiently produced, so that the yield and the purity are improved, economic benefits are directly brought, energy waste is avoided, and economic loss is avoided.

The present invention relates to a system, method, and use for the unloading of solid material particles used in a physical, chemical, and / or biological process in a tank and for the inertization of the tank. The receiving tank and the pump are fluidically connected. The inert gas supply device is fluidically connected to the tank and to at least one injector. The at least one injector is arranged along the transport line that connects the tank to the receiving tank and is configured to inject inert gas into the transport line. The pump is configured to generate negative pressure in the receiving tank and in the tank, and the inert gas supply device is configured to insert inert gas into the tank and supply inert gas to at least one injector, to allow the displacement of solid material particles from the tank to the receiving tank.

The invention relates to a preparation method of dichloromolybdenum dioxide, which comprises the following steps: S1, putting a raw material metal molybdenum into a reactor, and then vacuumizing the reactor; s2, heating the reactor, controlling the temperature to be 180-600 DEG C, introducing oxygen and hydrogen chloride into the reactor, and reacting for 0.5-3 hours; s3, performing two-stage purification on the reaction product obtained in S2, controlling the temperature of the first-stage purification to be 150-350 DEG C, controlling the temperature of the second-stage purification to be-50-50 DEG C, controlling the pressure to be-0.09-0.05 Mpa, and keeping for 0.5-2 hours; and S4, after the purification is finished, carrying out sampling detection on the dichloromolybdenum dioxide for many times, and collecting the dichloromolybdenum dioxide after the indexes are qualified. According to the method, high-purity hydrogen chloride and oxygen are used as reaction gases to react with metal molybdenum, and the two-stage purification process is performed after the reaction, so that the purity of the product is effectively improved, and the purity of the dichloromolybdenum dioxide prepared by the method can reach 99.99% or above.

The invention relates to the technical field of manufacturing of fusible polytetrafluoroethylene resin, in particular to a method for treating an unstable terminal group of fusible polytetrafluoroethylene, which is used for solving the problem that the unstable terminal group cannot be thoroughly treated in the prior art. The method comprises the following steps: heating fusible polytetrafluoroethylene resin to a molten state, after self-reaction, introducing high-purity fluorine-nitrogen mixed gas to carry out fluoridation reaction, and extracting impurities generated by the reaction to obtain unstable soluble polytetrafluoroethylene resin with a treated terminal group; according to the method, soluble polytetrafluoroethylene resin is heated to a molten state, and unstable terminal groups are thoroughly treated through self-reaction and fluorination reaction.

The invention discloses a device and method for preparing a high-performance ternary positive electrode material, the device comprises a first passive drainage type spiral material mixing mechanism, the vacuumizing end of a vacuum type mixing mechanism is communicated with the outlet end of the first passive drainage type spiral material mixing mechanism, and the outlet end of the vacuum type mixing mechanism is communicated with the inlet end of a multi-disc type drying mechanism; the outlet end of the multi-disc drying mechanism is communicated with the inlet end of the intermediate tank, the inlet end of the second passive drainage type spiral mixing mechanism is communicated with the outlet end of the intermediate tank, and the outlet end of the second passive drainage type spiral mixing mechanism is communicated with the inlet end of the material tank; according to the method, the device is used for preparing the high-performance ternary positive electrode material. According to the invention, the crystal lattice change degree can be effectively reduced, the problem of crystal boundary cracking is avoided, the performance of the battery is improved, the service life of the battery is prolonged, and potential safety hazards are prevented. The method is suitable for the technical field of preparation of battery positive electrode materials.

Thermochemical gas decomposition reactor systems and methods of decomposing gas are disclosed herein. The system includes a reactor including a reaction zone comprising an active material, a gas heating zone, and a gas distribution plate assembly interposed between the reaction zone and the gas heating zone. An exemplary system may include a plurality of reactors. Methods may include providing one or more reactors, and performing one or more of oxidation and / or reduction processes using each of the reactors.

The production equipment comprises a base, the upper end of the base is connected with a kettle body, the base is connected with a preparation part, and the preparation part comprises a spinning device installed on the base; the processing part is arranged on the kettle body and used for assisting in processing spandex waste silk, the processing part comprises a first motor installed on the right side of the top of the kettle body, the output end of the left side of the first motor is connected with a bevel gear assembly, and the upper end in the kettle body is connected with an adjusting part. According to the production equipment and process for regenerating the spandex filaments from the spandex polymerization waste liquid, the air supply piece is matched with the cylinder body, the stirring frame, the ventilation ring, the guide pipe, the communicating groove, the ventilation block, the heat-resistant air bag, the movable ring and the safety valve, and the function of adjusting the space in the kettle body is achieved through telescopic adjustment of the heat-resistant air bag while heating and stirring in the kettle body are not affected.

The invention discloses a narrow-band light-emitting indium phosphide quantum dot reaction device and a method thereof. The reaction device comprises a supergravity device and a photo-thermal device, the supergravity device comprises a shell, a motor, a turntable, a shear filler, a liquid distributor, a reaction cavity, a filler cover, a gas outlet, a liquid outlet and a liquid inlet; the photo-thermal device comprises a laser heating device, a circuit and water cooling device, a reflecting layer and a laser controller; infrared laser is coupled into the supergravity reactor, water or organic matter and other solvent media are used for absorbing infrared light and converting the infrared light into heat energy to increase the temperature of the supergravity reactor, the nucleation reaction of reactant precursors in the micro-droplet reactor is excited, controllable growth of quantum dots in the micro-droplet reactor is achieved, and the quantum dots are obtained. And finally, nano-particles with uniform sizes are obtained by controlling the laser irradiation heating time.

Systems and methods for producing hydrogen, or gaseous mixtures containing a substantial proportion of hydrogen, by electrical pyrolysis of hydrocarbons, and, more particularly, electrical pyrolysis of methane to produce hydrogen or gaseous mixtures containing a substantial proportion of hydrogen via the use of joule heating of powders and gases. The systems and methods utilize joule heating of powders and gases to enable thermal decomposition of the gases in a volume of electrically conductive powder that is confined inside a joule heated reactor. The systems and methods can be used in the thermal decomposition of methane gas into at least hydrogen gas and carbon inside a reactor, wherein the methane is infused within a volume of gas permeable electrically conductive powder and the heat for the thermal decomposition is provided by joule heating the powder.

The present disclosure provides a method of operating a dehydrogenation reactor requiring vacuum pressure during the dehydrogenation reaction, the method including feeding a hydrocarbon to a reactor comprising a catalyst bed and configured to dehydrogenate the hydrocarbon under vacuum pressure; purging the reactor to remove remaining hydrocarbon; regenerating the catalyst bed with air from a regeneration air source; and evacuating the reactor to induce vacuum pressure, wherein the evacuating comprises passing a motive gas through a reactor evacuation ejector in fluid connection with the reactor, wherein the motive gas is nitrogen or air in the absence of steam. A system for dehydrogenation of a hydrocarbon is also provided, which includes a dehydrogenation reactor and a reactor evacuation ejector in fluid communication with the dehydrogenation reactor and a motive gas source, wherein the motive gas is nitrogen or air in the absence of steam.

The invention relates to the technical field of cable adhesive production, and particularly discloses a reaction kettle for cable adhesive production, which comprises a kettle body and a stirring mechanism, the stirring mechanism comprises a stirring rod and a stirring blade, the stirring rod is rotatably arranged in the kettle body, the stirring blade is connected to the stirring rod, the stirring rod can rotate, and the reaction kettle also comprises an apportionment mechanism, the apportioning mechanism comprises a lifting part and an apportioning part, the lifting part comprises a mounting cylinder, a rotating cylinder and a spiral blade, the mounting cylinder is connected to the kettle body, the rotating cylinder is connected to the stirring rod, the spiral blade is connected to the stirring rod, the apportioning part is mounted on the mounting cylinder, the spiral blade is located in the mounting cylinder, and the mounting cylinder can extend into the upper-layer cable glue; the stirring rod rotates to drive the spiral blade to rotate, so that the spiral blade lifts the cable adhesive upwards and conveys the cable adhesive to the allocation part for allocation; according to the reaction kettle for cable adhesive production, cable adhesive can be conveyed to the allocation part and is allocated, and the speed of eliminating bubbles in the cable adhesive is increased.

An object is to provide a drying method for continuous processing under reduced pressure, which affords high drying efficiency by bringing about an ideal fluidized state of a process product, the method including, with a median diameter (D50) of a granular starting material ranging from 1 µm to 1000 µm and under reduced pressure at an absolute pressure of 4 to 30, performing a drying treatment by fluidizing the granular starting material, through heating with a heating medium at a temperature 15 to 120°C higher than the boiling point of a solvent in the granular starting material under the above reduced pressure.

A vacuum ultraviolet collimated parallel light reactor and a water treatment method, the vacuum ultraviolet collimated parallel light reactor comprising: an irradiation cavity, provided with a first chamber, an irradiation window arranged at the bottom of the first chamber, and an air outlet connected to the first chamber; a pillar, supporting the irradiation cavity; a light source, arranged in the first chamber and connected to the irradiation cavity, configured to emit vacuum ultraviolet rays to the irradiation window; and a reaction cavity, connected to the bottom of the irradiation cavity, provided with a second chamber whose top is connected to the irradiation window and an air inlet connected to the second chamber; wherein the air inlet is used to receive anoxic gas so that the anoxic gas fills the first chamber and the second chamber, and the air outlet is used to discharge the gas in the first chamber. The technical problem to be solved by the present application is how to efficiently utilize vacuum ultraviolet rays.

The present invention relates to a tubular heating device for preparing silicon oxide, characterized in that it comprises: a furnace frame base is arranged below the tubular heating device for preparing silicon oxide; a furnace chamber is fixed above the furnace frame base; a furnace tube structure is horizontally inserted into the furnace chamber; the furnace tube structure is fixed on the furnace chamber through a flange; a main control system controls the temperature of the furnace tube structure; silicon oxide is prepared in a reaction crucible arranged in the furnace tube structure, and silicon oxide powder is collected in a collection bucket in the furnace tube structure. The present silicon oxide production device is composed of a vacuum-evacuable alumina ceramic refractory tube, and when working, the mixed SiO2 and Si are placed at one end of a sealed tube, heated in a vacuum state until the raw materials are gasified, and then deposited at the other end of the refractory tube. However, this device has technical problems such as low production efficiency and the reaction tube is very easy to break.

The embodiment of the present application provides a stirring device for a reduction kettle and a diaminobenzoic acid reduction method, which relate to the field of chemical technology. The stirring device for the reduction kettle includes a premixing tank, a connecting tank, a reduction kettle, a driving shaft, a slow injection component and an adjustable stirring component, wherein the slow injection component includes a gear ring, and the driving motor is started to drive the driving shaft to rotate. The premixed additives can be premixed through the slow injection component in the reduction kettle, and can slowly flow into the reduction kettle through the conveying hole for reduction processing, effectively reducing the impact of the violent reaction caused by the reduction reaction on the reduction kettle, providing the practicality of the reduction kettle, and then the adjustable stirring component in the reduction kettle can change the stirring diameter to adjust the mixing effect according to the strength of the reduction reaction, thereby improving the mixing effect of the reduction kettle and the accuracy of the reduction effect.

The present invention discloses a reaction device and method for narrow-band luminescent indium phosphide quantum dots. The reaction device comprises a hypergravity device and a photothermal device. The hypergravity device comprises a housing, a motor, a turntable, a shear filler, a liquid distributor, a reaction chamber, a filler cover, a gas outlet, a liquid outlet, and a liquid inlet. The photothermal device comprises a laser heating device, a circuit and a water cooling device, a reflective layer, and a laser controller. The present invention couples an infrared laser into a hypergravity reactor, utilizes a solvent medium such as water or organic matter to absorb the infrared light and convert it into heat energy to increase its temperature, stimulates the nucleation reaction of a reactant precursor in a "micro-droplet reactor", realizes the controllable growth of quantum dots in the micro-droplet reactor, and finally obtains nanoparticles of uniform size by controlling the laser irradiation and heating time.

The invention relates to a salification-polymerization integrated production device and a production method of bio-based nylon 56. The device comprises a salification tank, an additive storage tank, a reaction kettle, a vacuum system, a granulator, a drying device and a control system. The control system of the method adopts a PLC (Programmable Logic Controller), the control systems of all main devices are mutually independent and have certain relation, all the devices are divided into different process stages according to different functions in the implementation process, and when the conditions meet the pre-designed process conditions, the system can automatically enter the next process stage without manual intervention. According to the present invention, the bio-based nylon 56 salt solutions with different pH values and different concentrations can be blended, and the blended raw materials are subjected to concentration, polymerization, granulation and drying so as to obtain the integrated polymerization method, such that the time is saved for the subsequent production, the production efficiency is improved, the environmental protection is provided, and the good market prospect and the good development space are provided for the prior art.

A production apparatus for cyclic esters, the production apparatus comprising: a barrel (10), which comprises a material chamber (101), and a feed inlet, a melt outlet (112) and at least one vacuum vent that are in communication with the material chamber (101); a hollow shaft (20) passing through the barrel (10) along a material feeding direction, wherein the hollow shaft (20) is provided with a medium chamber (201) therein; and several hollow disks (30) disposed in the barrel (10) along the feeding direction, wherein the hollow disks (30) are disposed on the outer periphery of the hollow shaft (20); and a medium flow channel (301) in communication with the medium chamber (201) is provided in each hollow disk (30), at least part of the medium flow channel (301) being a spiral from the outside to the inside, and / or the medium flow channel (301) comprising a plurality of parallel medium sub-channels (305). After entering the medium chamber (201), a heat medium flows into the medium flow channels (301) and is uniformly distributed within the hollow disks (30) via the medium flow channels (301). The hollow shaft (20) and the hollow disks (30) cooperate with each other to uniformly heat oligomers in the material chamber (101), thereby avoiding carbonization and coking caused by the non-uniform heating of the oligomers.

A system and method of preventing reverse migration of contaminant molecules includes an enclosure and a quantity of metal materials included within the enclosure. The quantity of metal materials includes multiple metal material surfaces. The metal material surfaces are conditioned to be attractive to at least a first portion of contaminant molecules. The first portion of contaminant molecules are adsorbed on the multiple metal material surfaces. The enclosure can be a canister with UHP gas flowing from an inlet to an outlet and the first portion of contaminant molecules randomly pass through the canister outlet into the canister.

The invention discloses a device and a method for generating hydroxyacetonitrile through reaction of gas-phase hydrocyanic acid. The device comprises a hydroxylation reaction tower I and a hydroxylation reaction tower II. Gas-phase hydrocyanic acid enters the first hydroxylation reaction tower from a tower kettle inlet of the first hydroxylation reaction tower to react with a formaldehyde solution, and the proportion, temperature and pH of raw materials and the retention time of the materials in the glycolonitrile reaction kettle are controlled; unreacted gas-phase hydrocyanic acid is conveyed to a tower kettle gas-phase inlet of the second hydroxylation reaction tower from a tower top gas-phase outlet of the second hydroxylation reaction tower to continuously react with fresh formaldehyde, and completely reacted glycolonitrile tower kettle liquid is conveyed to the first hydroxylation reaction tower. According to the invention, gas-phase hydrocyanic acid is directly reacted with formaldehyde, the conditions of the reaction process are controlled, the reaction rate is accelerated, the residence time of tower bottoms is prolonged, meanwhile, the emission of cyanogen-containing waste gas is reduced, the utilization rate of raw materials and the production safety are improved, and the purpose of continuously producing formaldehyde with the content of 1t is achieved; the content of the hydrocyanic acid is less than or equal to 1%.

The invention discloses a lithium hexafluorophosphate purification device convenient to clean, and relates to the technical field of chemical purification equipment, the lithium hexafluorophosphate purification device comprises a base, a vacuum treatment device and an outer cylinder mounted in the middle of the top of the base, the outer cylinder is internally provided with an inner cylinder, one side of the outer cylinder is provided with a mounting plate, and the lithium hexafluorophosphate purification device further comprises a reciprocating motor, the reciprocating motor is fixedly mounted on the upper portion of one side of the mounting plate, the output end of the reciprocating motor is fixedly connected with a main shaft, and the main shaft is fixedly connected with the outer barrel; the cleaning mechanism is arranged in the outer barrel; the buffer mechanism is arranged in the middle of the top of the base and comprises an arc-shaped ring and an arc block, and the problems that part of lithium hexafluorophosphate crystals can be attached to the inner wall of the barrel, are difficult to discharge and are prone to deterioration to generate by-products, and then subsequent vacuum purification treatment of the lithium hexafluorophosphate crystals is troublesome are solved; and the purification precision of the lithium hexafluorophosphate crystal is reduced.

The invention belongs to the technical field of polydextrose preparation, and relates to a polydextrose continuous polymerization production system and a method thereof. The system comprises a pre-polymerization tank and at least three polymerization tanks which are sequentially communicated through pipelines, the pre-polymerization tank pretreats a mixed solution to be polymerized entering through a feeding pipe, the mixed solution pretreated by the pre-polymerization tank is subjected to continuous polymerization reaction in the polymerization tanks, and polydextrose generated by the polymerization reaction is input to the next procedure through a liquid outlet pipe; a liquid level meter is arranged on the pre-polymerization tank, a liquid conveying pump is arranged on the liquid conveying pipe, a pneumatic control valve is arranged on a high-temperature heat conduction oil inlet pipeline of each polymerization tank, and a thermometer is arranged on each polymerization tank; the frequency of the infusion pump is in signal linkage with the liquid level meter so as to adjust the infusion flow of the infusion pipe, and the pneumatic control valve of each polymerization tank is in signal linkage with the thermometer so as to adjust the polymerization temperature in the tank. The automatic continuous polymerization production of polydextrose is realized, the labor cost is saved, and the production operation is stable.

An object is to provide a drying method for continuous processing under reduced pressure, which affords high drying efficiency by bringing about an ideal fluidized state of a process product, the method including, with a median diameter (D50) of a granular starting material ranging from 1 μm to 1000 μm and under reduced pressure at an absolute pressure of 4 to 30, performing a drying treatment by fluidizing the granular starting material, through heating with a heating medium at a temperature 15 to 120° C. higher than the boiling point of a solvent in the granular starting material under the above reduced pressure.

The invention relates to a reaction device for preparing a magnesium hydroxide flame retardant based on a gas phase method and a preparation method thereof, and belongs to the technical field of chemical engineering equipment and inorganic non-metallic material preparation. The reaction device comprises a precursor precise conveying system, a multi-temperature-zone laminar flow reaction system, an efficient particle collecting system and a central process control system. According to the method, a magnesium source precursor gas-phase flow, a hydrolytic agent gas-phase flow and a surface modifier gas-phase flow are respectively provided by the precursor precision conveying system, are introduced into the multi-temperature-zone laminar flow reaction system through the three coaxial laminar flow nozzles, and are sequentially subjected to controlled mixing in the preheating mixing zone. The whole process is carried out in a gas-phase low-pressure laminar flow environment, hard agglomeration of particles is effectively avoided, the prepared magnesium hydroxide flame retardant has the advantages of being uniform in primary particle size, good in dispersity and high in surface organification degree, and the compatibility and flame retardant efficiency of the magnesium hydroxide flame retardant in a polymer matrix are remarkably improved.