53 results about "Phosphorus pentafluoride" patented technology

The invention relates to a preparation method of a lithium difluoro bis (oxalate) phosphate concentrated solution, and belongs to the technical field of lithium battery electrolyte additives. Adding lithium oxalate into a solvent, stirring and dissolving to obtain a lithium oxalate solution; the method comprises the following steps: adding a modified fluorine ion chelating agent into a lithium oxalate solution, stirring, filtering, putting into a reactor, and slowly introducing phosphorus pentafluoride gas; after the introduction is finished, heating and stirring for reaction; after the reaction is finished, filtering reaction liquid to remove unreacted solid impurities, so as to obtain a lithium difluoro bis (oxalate) phosphate concentrated solution; the modified fluorine ion chelating agent is prepared from D301 ion exchange resin, dichloroethane, propylene-1-base boronic acid pinacol ester, mercaptoethyl guanidine dihydro bromide and sodium tert-butoxide. The lithium difluoro bis (oxalate) phosphate prepared by the method is high in purity and high in yield, and meets the use requirements of lithium ion battery electrolyte on lithium salt.

This invention belongs to the field of lithium-ion battery electrolyte material preparation technology, and provides a solid lithium hexafluorophosphate with low fine crystal content and its preparation method. The preparation method involves adding lithium fluoride to anhydrous hydrogen fluoride to form anhydrous hydrogen fluoride slurry. A portion of the anhydrous hydrogen fluoride slurry and phosphorus pentafluoride gas are fed into a primary continuous reaction crystallizer. The resulting slurry is subjected to low-temperature fractionation to form a first stream and a second stream. The second stream enters a secondary continuous growth crystallizer and continues to react with phosphorus pentafluoride gas, followed by solid-liquid separation to obtain a solid wet product and mother liquor. The first stream, another portion of the anhydrous hydrogen fluoride slurry, and a portion of the mother liquor enter a pre-conditioning section, and the resulting pre-conditioned stream is returned to the feed end of the primary continuous reaction crystallizer. The solid wet product is then subjected to low-temperature washing and programmed vacuum drying to obtain the final product. This method, through the combination of fractional reflux, mother liquor participation in pre-conditioning, and continuous growth processes, reduces fine crystal entrainment and improves particle size distribution stability.

The invention relates to the technical field of synthesis of hexafluorophosphate, in particular to a synthesis method and a synthesis system of liquid hexafluorophosphate. The synthesis method of the liquid hexafluorophosphate is a new process route, phosphorus trichloride is used as an initial raw material, and a reaction is carried out with a reaction kettle; phosphorus pentafluoride sequentially subjected to oxidation, fluorination, deep fluorination and solvent in-situ capture reacts with alkali metal fluoride to obtain liquid hexafluorophosphate; the whole technical route process has the advantages of controllability, low cost, greenness, high safety and few impurities.

An integrated process for co-production of phosphorus pentafluoride (PF5) and fluorosulfonic acid (HSO3F) in high yield and purity through a single reaction step is provided. The method comprises reacting a first reagent comprising an aqueous solution of hexafluorophosphoric acid (HPF6) and hydrofluoric acid (HF) with a second reagent comprising fuming sulfuric acid (H2SO4SO3), and recovering a product mixture comprising phosphorus pentafluoride (PF5) and fluorosulfonic acid (HSO3F).

The invention discloses a preparation method of phosphorus pentafluoride, which comprises the following steps: 1) mixing fluorine-containing inorganic salt and hydrogen-containing inorganic salt, and carrying out activation process treatment; and 2) adding phosphorus pentoxide into the system in the step 1) for reaction to generate phosphorus pentafluoride gas. The method has the advantages of low reaction temperature and high product purity, does not need to use high-toxicity and high-corrosivity hydrogen fluoride, and is environment-friendly, simple in process and suitable for industrial production.

The invention discloses a method for separating phosphorus pentafluoride-hydrogen chloride mixed gas, which comprises the following steps of: introducing the phosphorus pentafluoride-hydrogen chloride mixed gas into a reaction kettle by taking a perfluoropolypropyl ether fluorinated solution as a solvent and lithium fluoride as a raw material, so that the phosphorus pentafluoride and the lithium fluoride react to generate lithium hexafluorophosphate, and hydrogen chloride is discharged in a gas phase manner; heating the generated lithium hexafluorophosphate to decompose the lithium hexafluorophosphate into phosphorus pentafluoride and lithium fluoride, discharging the phosphorus pentafluoride in a gas phase manner, and retaining the lithium fluoride in the perfluoropolypropyl ether fluorinated solution for recycling; the solvent and raw materials provided by the invention can be recycled for multiple times, the whole process flow is greatly simplified, and efficient and stable separation of HCl and phosphorus pentafluoride is realized.

The invention relates to a preparation process of high-purity lithium hexafluorophosphate, which comprises the following specific steps: S1, quantitatively adding anhydrous hydrogen fluoride into a corresponding reaction kettle body, and controlling the environment temperature in the reaction kettle body at-50 DEG C to-20 DEG C through a temperature control device; s2, maintaining the pressure in the reaction kettle body at 0.1-0.5 MPa, dispersing and adding solid phosphorus pentachloride into the reaction kettle body through a corresponding feeding device, and enabling the solid phosphorus pentachloride to react with the anhydrous hydrogen fluoride in the step S1 at the temperature of-50 DEG C to-20 DEG C to obtain phosphorus pentafluoride and gaseous hydrogen chloride, the gaseous hydrogen chloride escapes from the reaction liquid and then is discharged for recovery or absorption treatment; and S3, dispersing and adding lithium fluoride into the reaction kettle body through the feeding device, and carrying out complexing reaction on the lithium fluoride and phosphorus pentafluoride in the anhydrous hydrogen fluoride to obtain lithium hexafluorophosphate. The reaction process is high in controllability, so that the high-purity lithium hexafluorophosphate product can be stably prepared.

The invention belongs to the technical field of chemical synthesis, and relates to a lithium battery electrolyte raw material production technology, in particular to a preparation method of phosphorus pentafluoride. The method comprises the following steps: adding phosphorus trichloride, liquid chlorine and hydrogen fluoride into a reactor in proportion, and reacting to prepare hydrogen chloride and phosphorus pentafluoride; the molar ratio of phosphorus trichloride to liquid chlorine to hydrogen fluoride is preferably 1: 1: 5, and the reactor comprises a bottom reaction section, a middle filler section and a top condensation section. The working pressure of the reactor is 0.1-3.0 MpaG, the temperature of the reaction section is 0-40 DEG C, and the temperature of the condensation section is-20 to-60 DEG C. The mixed gas of phosphorus pentafluoride and hydrogen chloride can be prepared in one step and conveyed to the rear end to be refined and separated. The method has the advantages of simple process flow, easily available raw materials, low production cost and high efficiency.

The present invention provides a phosphorus pentafluoride preparation method, which comprises: mixing a hexafluorophosphoric acid solution and a dehydrating agent, and carrying out a dehydration reaction at a temperature of 30-160 DEG C under a pressure of 0.1-3 MPa, wherein the hexafluorophosphoric acid solution contains water and hydrogen fluoride; after the dehydration reaction is finished, the reaction system is subjected to rapid pressure relief, and mixed gas containing phosphorus pentafluoride is obtained; wherein the pressure relief rate of the rapid pressure relief is greater than or equal to 0.1 MPa / min; and carrying out purification treatment on the mixed gas containing phosphorus pentafluoride to prepare the phosphorus pentafluoride gas.

Disclosed in the present application is a method for preparing lithium hexafluorophosphate. According to the embodiments of the present application, the method comprises: performing mixing treatment on phosphorus pentafluoride gas and a lithium fluoride solution to give a first treatment product; and performing reaction treatment on the first treatment product to give a reaction solution containing lithium hexafluorophosphate, wherein the mixing treatment is performed in a first continuous flow reactor, and the reaction treatment is performed in a second continuous flow reactor. The method of the present application overcomes the defects in existing batch production techniques and effectively avoids the ineffective operation time of the start and end stages in conventional production, thereby improving the production efficiency and output per unit time.

The invention discloses tris (trimethylsilyl) phosphate and a preparation method thereof, and belongs to the field of chemical synthesis. The invention relates to a preparation method of tris (trimethylsilyl) phosphate, in particular to a preparation method of tris (trimethylsilyl) phosphate, which comprises the following steps: hexamethyldisiloxane and phosphorus pentafluoride are subjected to heating reaction under a stirring condition to obtain tris (trimethylsilyl) phosphate, and the molar ratio of hexamethyldisiloxane to phosphorus pentafluoride is (5-10): 1. Phosphorus pentachloride is replaced with phosphorus pentafluoride, and due to the fact that fluorine atoms are small in radius and large in electronegativity, phosphorus is high in electropositivity and small in steric hindrance, phosphorus pentafluoride can react with hexamethyldisiloxane more easily, a catalyst is not needed, the cost of tris (trimethylsilyl) phosphate can be greatly reduced, and the yield of tris (trimethylsilyl) phosphate is high.

The application discloses a method for producing phosphorus pentafluoride by electrolysis. The method is to use white phosphorus and anhydrous hydrogen fluoride as raw materials, fluorometal salt or quaternary ammonium fluoride salt as conductive agent, and to carry out electrolysis reaction in a high-nickel anode electrolysis container to produce phosphorus pentafluoride. The preparation method can produce high-purity phosphorus pentafluoride in one step, and the impurities are few when used for synthesizing lithium hexafluorophosphate, and no additional hydrogen chloride gas is produced, the post-processing cost is lower, and the production process is safer and more efficient. In addition, the electrolysis reaction condition is mild, the by-product waste is less, the environmental pollution is small, and the phosphorus pentafluoride gas with a purity greater than 99.99% can be obtained.

This invention belongs to the field of inorganic fluoride preparation technology, and relates to a method for preparing high-purity phosphorus pentafluoride gas. A phosphorus pentafluoride mixed gas is passed into dimethyl carbonate, and the mixture is sequentially heated and pressurized for reaction, cooled to precipitate, and filtered to obtain a phosphorus pentafluoride complex solid. The phosphorus pentafluoride complex solid is then sequentially washed, re-dissolved, and distilled to obtain high-purity phosphorus pentafluoride gas. Compared to traditional methods using multi-stage distillation and washing, this method can efficiently and easily remove impurities such as hydrofluoric acid and hydrogen chloride from the phosphorus pentafluoride gas, and does not generate a large amount of waste acid. The purity of the prepared gas is above 99.9%, and the gas yield is above 90%. When high-purity phosphorus pentafluoride gas is used in lithium-ion batteries, it can meet the performance requirements of lithium-ion battery electrolytes.

The application discloses a continuous preparation process and device of liquid lithium hexafluorophosphate, and comprises the following operation steps: A10), continuously feeding lithium fluoride suspension to the top of a hexafluoride reaction plate tower; continuously feeding gaseous high-purity phosphorus pentafluoride to the bottom of the hexafluoride reaction plate tower; A20), carrying out reaction in the hexafluoride reaction plate tower, and feeding the reaction product from the bottom of the hexafluoride reaction tower into a bottom tank; A30), feeding the remaining reaction product output by a circulating heat exchanger into a liquid lithium hexafluorophosphate product extraction tank in one way and into a lithium fluoride suspension preparation kettle in the other way; and A40), connecting a filter to the product extraction end of the product extraction tank to remove the excessive solid-phase material after reaction, so as to obtain the liquid lithium hexafluorophosphate, the hydrogen chloride content of which is less than 25 ppm, and the hydrogen fluoride is not detected; the application has high continuous level and stability, does not need additional deacidification treatment, and has obviously higher output efficiency, and does not have the hidden troubles of shutdown maintenance due to problems such as blockage.

The invention provides a preparation method and device of phosphorus pentafluoride, and the preparation method comprises the following steps: 1) carrying out atomization treatment on a mixed acid solution comprising a hexafluorophosphoric acid solution and a sulfuric acid solution to obtain atomized mixed acid; and 2) carrying out a thermal cracking reaction on the atomized mixed acid to obtain phosphorus pentafluoride. The preparation method of phosphorus pentafluoride provided by the invention can improve the purity of the prepared phosphorus pentafluoride, and has the advantages of high reaction efficiency, simple process and the like.

A method for manufacturing phosphorus pentafluoride includes a dehydration step of dehydrating hexafluorophosphate hydrate using sulfuric acid containing less than 5% by mass of sulfur trioxide. Preferably, it also includes steps a) and b). a) a step of concentrating the sulfuric acid after the dehydration step. b) a step of reusing the sulfuric acid concentrated in step a) for the dehydration of hexafluorophosphate hydrate, and then using the sulfuric acid for the manufacture of phosphorus pentafluoride. Preferably, the dehydration step is carried out in the presence of hydrogen fluoride, and step c) is included before step a). c) a step of recovering the hydrogen fluoride after the dehydration step.

The present application relates to the technical field of chemical engineering, and provides a lithium hexafluorophosphate solution, and a preparation method therefor and a device therefor. The method comprises: performing a first contact reaction on a first phosphorus pentafluoride gas and a lithium fluoride solution to obtain a first reaction product; performing a second contact reaction on the first reaction product and a second phosphorus pentafluoride gas to obtain a second reaction product; and performing a third contact reaction on the second reaction product and a third phosphorus pentafluoride gas to obtain the lithium hexafluorophosphate solution. The phosphorus pentafluoride gas is step-fed, such that the feeding ratio of phosphorus pentafluoride to lithium fluoride can be dynamically and accurately controlled; and according to the reaction kinetic characteristics, the reaction process is optimized, and the chemical reaction speed between phosphorus pentafluoride and lithium fluoride is accelerated, so the lithium hexafluorophosphate solution can be efficiently synthesized in a short time, and the purity and the yield of the lithium hexafluorophosphate solution are improved.

The present application relates to the technical field of lithium hexafluorophosphate production, and discloses a lithium hexafluorophosphate purification method and system. The method comprises the following steps: heat-decomposing lithium fluoride-containing lithium hexafluorophosphate powder to obtain a gas mixture containing phosphorus pentafluoride; obtaining phosphorus pentafluoride gas after purification; drying lithium hexafluorophosphate wet product, and then reacting with the phosphorus pentafluoride gas to convert lithium fluoride into lithium hexafluorophosphate, so as to reduce the insoluble content in the product. The system comprises: a ripening gas preparation unit for producing purified phosphorus pentafluoride gas; a main process unit for preparing lithium hexafluorophosphate dry product; and a ripening treatment unit for ripening reaction of the dry product with the phosphorus pentafluoride gas. The present application realizes efficient conversion of lithium fluoride and effective removal of impurities, and improves the purity of lithium hexafluorophosphate.

The application provides a method for preparing sodium hexafluorophosphate for sodium batteries from sodium bifluoride, which comprises the following steps: taking electronic-grade sodium hydroxide and electronic-grade hydrofluoric acid as raw materials to generate an intermediate product sodium fluoride, and then reacting the intermediate product with phosphorus pentafluoride to obtain high-purity sodium hexafluorophosphate for sodium batteries. The particle size distribution and yield of sodium fluoride crystals are controlled by adjusting the stirring rate and cooling conditions, and then the purity and yield of sodium hexafluorophosphate are controlled, so that the purity of the finally obtained sodium hexafluorophosphate can reach more than 99.8%, the yield can reach more than 85%, the sodium hexafluorophosphate has the advantages of low cost and high yield, and is beneficial to industrialized production.

Provided in the present application is a method for preparing phosphorus pentafluoride, comprising: mixing a hexafluorophosphoric acid solution and a dehydrating agent, and then performing a dehydration reaction, the dehydration reaction being performed at 30-160°C under a pressure of 0.1-3 MPa, and the hexafluorophosphoric acid solution containing water and hydrogen fluoride; after the dehydration reaction is completed, performing quick pressure relief on the reaction system to obtain a mixed gas containing phosphorus pentafluoride, the pressure relief rate of the quick pressure relief being greater than or equal to 0.1 MPa / min; and purifying the mixed gas containing phosphorus pentafluoride to prepare phosphorus pentafluoride gas.

The invention provides a treatment method of tail gas containing phosphorus pentafluoride and a preparation method and device of lithium hexafluorophosphate. The treatment method of the tail gas containing phosphorus pentafluoride comprises the following steps: 1) carrying out first absorption treatment on the tail gas containing phosphorus pentafluoride by adopting a first absorption liquid containing lithium fluoride to obtain a first lithium hexafluorophosphate solution and a first mixed gas containing hydrogen fluoride; 2) carrying out first reaction on phosphorus pentachloride and the first mixed gas to obtain second mixed gas containing phosphorus pentafluoride; and 3) carrying out second absorption treatment on the second mixed gas by using a second absorption liquid containing lithium fluoride to obtain a second lithium hexafluorophosphate solution and a third mixed gas containing hydrogen fluoride and hydrogen chloride. According to the treatment method of the tail gas containing phosphorus pentafluoride, provided by the invention, the content of phosphorus pentafluoride in the tail gas can be reduced, and the resource utilization rate is improved.

The application relates to the technical field of phosphorus pentafluoride preparation, and provides a phosphorus pentafluoride gas generator, which comprises a generator cylinder body and a filtering structure, the generator cylinder body is internally provided with a reaction cavity, the generator cylinder body comprises an upper cylinder body and a lower cylinder body, the upper cylinder body is provided with a first feeding port for feeding phosphorus pentachloride solids into the reaction cavity, and the lower cylinder body is provided with a second feeding port for feeding hydrogen fluoride liquid into the reaction cavity; the filtering structure is arranged between the reaction cavity and the second feeding port, and is used for permeating the hydrogen fluoride liquid and blocking the phosphorus pentachloride solids. The phosphorus pentafluoride gas generator provided by the application can make the hydrogen fluoride liquid and the phosphorus pentachloride solids fully contact in the reaction cavity by arranging the filtering structure for permeating the hydrogen fluoride liquid and blocking the phosphorus pentachloride solids, so that the reaction rate is improved, and the preparation efficiency of phosphorus pentafluoride gas is improved.

The application belongs to the field of battery materials, and relates to a method for preparing lithium hexafluorophosphate by reacting a tertiary amine salt of hexafluorophosphoric acid and lithium fluoride. The method comprises neutralizing a tertiary amine with hexafluorophosphoric acid to obtain a tertiary amine salt of hexafluorophosphoric acid, and then reacting the obtained tertiary amine salt of hexafluorophosphoric acid with lithium fluoride in an inert gas atmosphere and an organic solvent to obtain lithium hexafluorophosphate precipitation. After removing the solvent and the remaining reactants and reaction byproducts, lithium hexafluorophosphate is obtained. The preparation method avoids the generation of phosphorus pentafluoride and chlorides, and the tertiary amine and the organic solvent can be recycled, so that the method has safety advantages, economic advantages and innovation, and is suitable for industrial production.

The invention relates to a preparation method and application of a phosphorus pentafluoride adsorbent, in particular to an adsorption material capable of selectively adsorbing and recycling phosphorus pentafluoride in fluorine-containing mixed gas. The adsorbent prepared by the method can be in contact with mixed gas containing phosphorus pentafluoride, hydrogen fluoride, hydrogen chloride and other fluorine-containing compounds, and gaseous phosphorus pentafluoride is converted into a stable solid compound through a chemical adsorption effect, so that effective purification of the mixed gas is realized, and purified gas without phosphorus pentafluoride is obtained. By adopting the adsorbent and the process disclosed by the invention, the content of phosphorus in fluorine-containing industrial byproducts (such as byproduct hydrochloric acid) can be effectively reduced, meanwhile, efficient recovery and reutilization of phosphorus pentafluoride are realized, the atom utilization rate of the phosphorus element is remarkably improved, the emission of phosphorus-containing wastes is reduced, and the environmental pollution is reduced; and the resource recycling level and the clean production degree in the fluorine-containing chemical production process are comprehensively improved.

The utility model discloses a liquid lithium hexafluorophosphate synthesis device which comprises a preparation kettle, a synthesis kettle and a refining kettle, a lithium fluoride feed port, a solvent feed port, a lithium fluoride content measuring device, an online thermometer A and an observation port are arranged at the top of the preparation kettle; the top of the synthesis kettle is provided with a preparation liquid feeding hole, a phosphorus pentafluoride gas inlet, a lithium hexafluorophosphate content measuring device A, a radar liquid level meter, an online thermometer B and a gas outlet; the top of the refining kettle is provided with a synthesis liquid feeding hole, a solvent feeding hole and a lithium hexafluorophosphate content measuring device B; the preparation kettle is connected with the synthesis kettle through an on-line liquid flow meter B, and the synthesis kettle is connected with the refining kettle through a filtering device, a material transfer pump and an on-line liquid flow meter C; the phosphorus pentafluoride gas inlet is connected with a phosphorus pentafluoride gas inlet pipeline through an on-line gas flowmeter, the phosphorus pentafluoride gas inlet extends into the bottom of the synthesis kettle, and a gas distributor is arranged at the tail end of the phosphorus pentafluoride gas inlet; the utility model has the advantages of high production efficiency, good product quality and low product storage and transportation risk.

This invention discloses a method for the deep separation of fluorinated HCl from lithium hexafluorophosphate synthesis tail gas. Specifically, the lithium hexafluorophosphate synthesis tail gas, containing hydrogen chloride, hydrogen fluoride, and phosphorus pentafluoride, is passed through an Fe / NaF@hydroxylated multi-walled carbon nanotube adsorbent to deeply remove hydrogen fluoride and phosphorus pentafluoride from the tail gas. This method can effectively solve the problem of large-scale production of fluorinated HCl as a byproduct in the lithium hexafluorophosphate industry, address the bottleneck issue of waste disposal during industry capacity expansion, and increase the added value of the byproduct HCl.

The invention relates to a preparation method of a lithium hexafluorophosphate solution, which comprises the following steps: dispersing lithium fluoride in a perfluorinated organic solvent dissolved with an auxiliary agent, then introducing phosphorus pentafluoride gas, reacting, mixing with a carbonate solvent, filtering out insoluble substances, standing and layering filtrate, and taking supernatant liquid to obtain the lithium hexafluorophosphate solution. According to the invention, the perfluorinated organic solvent is used for replacing a carbonic ester organic solvent, so that not only is the reaction of phosphorus pentafluoride and carbonic acid avoided to generate impurities, but also the mass transfer and reaction rate of phosphorus pentafluoride are promoted due to the solubility of the perfluorinated solvent to phosphorus pentafluoride. Particularly, an auxiliary agent trifluoromethylpyridine is used, two reactants including lithium fluoride and phosphorus pentafluoride are activated at the same time, the reaction activation energy is reduced, the reaction can be rapidly and efficiently carried out at a low temperature, and the industrialization cost is greatly reduced.

This invention discloses a method for preparing electronic-grade hydrogen chloride and hydrogen fluoride from the tail gas of fluorinated lithium salt synthesis. The steps are as follows: Fluorinated lithium salt synthesis tail gas A is sequentially passed through a cryogenic reactor and a cryogenic phase separator for liquefaction and gas-liquid separation. The resulting liquid phase is pumped into a hydrogen chloride distillation column for separation. The liquid phase obtained from the top gas phase of the hydrogen chloride distillation column is condensed and then passed into a cryogenic phase separator for solid-liquid separation. The resulting liquid phase is electronic-grade hydrogen chloride B, and the solid phase, after vaporization, is industrial-grade phosphorus pentafluoride C. The liquid phase obtained from the bottom of the column is passed into a hydrogen fluoride distillation column for separation. The liquid phase obtained from the top gas phase of the hydrogen fluoride distillation column is condensed and then passed into electronic-grade hydrogen fluoride D. The liquid phase obtained from the bottom of the column is industrial-grade hydrogen fluoride E. The gas phases obtained from the cryogenic phase separator and the top of the condenser are combined to form non-condensable tail gas F. The method of this invention yields electronic-grade hydrogen chloride and hydrogen fluoride with high purity, avoiding the high energy consumption and equipment corrosion problems caused by complex high-temperature compression; it also solves the difficulty of separating hydrogen chloride and phosphorus pentafluoride.

The invention provides a phosphorus pentafluoride product and a preparation method and equipment thereof, and the method comprises the following steps: in a continuous flow reactor, reacting a hexafluorophosphoric acid solution with concentrated sulfuric acid to obtain a reaction solution containing phosphorus pentafluoride; and carrying out flash evaporation treatment on the reaction liquid containing phosphorus pentafluoride to obtain a phosphorus pentafluoride product. The phosphorus pentafluoride product prepared by the method is low in phosphorus oxyfluoride content, the refining process of the phosphorus pentafluoride product is simplified, the application value of the phosphorus pentafluoride is improved, the method can be applied to preparation of lithium hexafluorophosphate and lithium batteries, and the quality of the lithium hexafluorophosphate and the performance of the lithium batteries are improved.

The present invention provides a method for producing phosphorus trifluoride and a method for producing phosphorus pentafluoride, which have high reaction efficiency, low reaction temperature and an excellent energy efficiency. The method for producing phosphorus trifluoride comprises: a step of introducing phosphorus trichloride and hydrogen fluoride into a first reactor; and a step of discharging phosphorus trifluoride from the first reactor, wherein the first reactor contains carbon material. The method for producing dichloro-phosphorus trifluoride comprises a step of introducing the phosphorus trifluoride obtained above and chlorine into a second reactor; and a step of discharging dichloro-phosphorus trifluoride from the second reactor. The method for producing phosphorus pentafluoride comprises: a step of introducing the dichloro-phosphorus trifluoride obtained above and hydrogen fluoride into a third reactor; and a step of discharging phosphorus pentafluoride from the third reactor. The method for producing lithium hexafluorophosphate comprises a step of introducing the phosphorus pentafluoride obtained above and lithium fluoride into a fourth reactor; and a step of discharging lithium hexafluorophosphate from the fourth reactor.