150results about "Fluorine/hydrogen-fluoride" patented technology

The invention discloses a big data-driven hydrogen fluoride purification risk entropy assessment and multi-parameter monitoring system, which relates to the technical field of chemical process monitoring, comprises a multi-mode heterogeneous sensor network, and realizes high-precision detection and three-dimensional monitoring by using a nanowire FET (Field Effect Transistor) and the like. The space-time tensor decomposition module extracts features and identifies a causal relationship; the risk entropy manifold learning module evaluates the risk; the self-adaptive twin network monitors the abnormity and simulates and disposes the abnormity; and a knowledge graph-reinforcement learning system decision making subsystem and a plurality of subsystems such as an optical monitoring subsystem and a multi-scale modeling subsystem are also provided, so that whole-process risk management and control are realized. The hydrogen fluoride purification monitoring level is greatly improved, the detection sensitivity and the anomaly detection accuracy are remarkably improved, risk early warning is more timely, decision response is accelerated, the production efficiency is improved, energy consumption is reduced, the system has self-repairing and self-power-supply capabilities, data are safe and traceable, reliable operation of the system is guaranteed, and economic losses and potential safety hazards are reduced.

The invention discloses an in-kettle environment pressure stabilizing structure applied to an anhydrous hydrogen fluoride arsenic removal process, relates to the technical field of arsenic removal processes, and provides an improvement process about a rubber isolation pad and a lower supporting table on the basis of an oxidation reaction process in the anhydrous hydrogen fluoride arsenic removal process and on the basis of not changing the reaction process. The basic content is as follows: the reaction volume in the reaction cavity is changed by utilizing the elastic deformation of the rubber isolation pad and the supporting effect of the lower supporting table, so that the effect of preliminarily adjusting the environmental pressure in the reaction cavity is achieved; a combined or independent regulation and control process is carried out mainly aiming at a low-pressure state and an overpressure state, a pressure difference and pressure balance transfer principle is further utilized, and the environment pressure stabilizing effect in a container is achieved through the simplest and effective structure.

The utility model discloses an electronic-grade hydrofluoric acid production system, industrial hydrofluoric acid is input into the system to obtain high-purity electronic-grade hydrofluoric acid, and the system comprises a graphite evaporator, a rectifying tower and a condenser, the graphite evaporator is provided with a feeding pipeline and a condensed water outlet, and the feeding pipeline is used for inputting industrial hydrofluoric acid into the graphite evaporator; a steam pipeline is further arranged on the graphite evaporator, the other end of the steam pipeline is connected with the rectifying tower, the steam pipeline is used for conveying gas heated by the graphite evaporator into the rectifying tower, and the rectifying tower is used for rectifying and separating hydrofluoric acid gas produced by the graphite evaporator; industrial hydrofluoric acid is added into the graphite evaporator to be heated to obtain hydrofluoric acid, then the hydrofluoric acid is fed into the rectifying tower with a certain height to be distilled, backflow is conducted in proportion, the product quality meets the requirement, and continuous production can be achieved through combination of the graphite evaporator and the rectifying tower; liquid hydrofluoric acid is used as a raw material, high risk of anhydrous hydrogen fluoride gas is avoided, and safety of the system is improved.

The invention relates to a high-temperature acidolysis reaction defluorination method, and belongs to the technical field of phosphorus chemical resource recycling. The technical problem to be solved by the invention is to provide a high-temperature acidolysis reaction defluorination method which is simple to operate and high in defluorination rate. According to the method, phosphorite powder / white fertilizer is subjected to high-temperature acidolysis, fluoride in the phosphorite powder / white fertilizer reacts with strong acid, fluorine is separated from a reaction system in a gas form, and hydrofluoric acid is obtained through condensation. The method is simple, is simple and convenient to operate, and is easy to realize technologized large-scale production. Meanwhile, due to the destructive effect of the strong acid on the lattice structure of the phosphorus-calcium compound, citrate-soluble phosphorus can be converted into soluble phosphate, subsequent phosphorus recovery is facilitated, comprehensive utilization of phosphorite and elimination of white fertilizer output are achieved, meanwhile, the problems of material accumulation and resource waste of enterprises are solved, and the method conforms to the circular economy concept of green development.

The utility model relates to the technical field of chemical production equipment, and particularly discloses a chlorine-containing hydrogen fluoride separation system which comprises a condensing tower and an absorption separation tower which are sequentially connected, an absorption separation device comprises a tower body, a distribution disc and a filler section are sequentially arranged in the tower body from top to bottom, and a liquid inlet and a gas outlet are formed in the upper end of the tower body; a liquid outlet and an air inlet are formed in the lower end of the tower body, the air inlet and the liquid inlet are both formed in the radial direction of the tower body, and the liquid outlet and the air outlet are both formed in the axial direction of the tower body; dilute sulfuric acid is introduced into the liquid inlet. The utility model aims to solve the problem that the absorption and separation effect of chloride ions in fluosilicic acid of a separation system is not ideal in an existing production system for preparing hydrofluoric acid by a fluosilicic acid method.

The application relates to a method and a preparation system for preparing hydrogen fluoride from fluosilicic acid, which comprises a reaction kettle, a hydrogen fluoride absorption tower, a condenser and a silicon tetrafluoride absorption tower which are sequentially communicated; a gas outlet of the reaction kettle is communicated with a gas inlet of the hydrogen fluoride absorption tower, and a gas outlet of the hydrogen fluoride absorption tower is communicated with a gas inlet of the condenser; the generated fluorosulfonic acid in the reaction kettle is introduced into a stripping tower, fluorosulfonic acid generated in a side reaction is re-generated into hydrogen fluoride, the generation of intermediate products is reduced, the process route of the application is free of waste residues and waste gas, and fluosilicic acid is effectively utilized.

The invention discloses a method for producing anhydrous hydrofluoric acid from photovoltaic fluorine-containing waste materials. The waste materials are fluorine-containing solid press filter residues or filter cake biscuits obtained through solid-liquid separation after photovoltaic fluorine-containing waste liquid treatment. The method comprises the following steps: drying, crushing and screening the waste until the waste is matched with the fluorite powder in particle size, returning the oversize product to the crushing, closed-loop granulating and homogenizing; continuously metering and uniformly mixing the homogenized waste and fluorite powder according to a mass ratio of 20: 1 to obtain a mixed fluorine-containing raw material, and continuously feeding the mixed fluorine-containing raw material into a rotary reaction furnace; fuming sulfuric acid and concentrated sulfuric acid are mixed into mixed acid, the mixed acid is continuously added into a reaction furnace, the mixed acid reacts at the temperature of 300-350 DEG C to generate a fluorine-containing gas phase, and reaction heat is indirectly provided by circulation of high-temperature gas in a jacket of the reaction furnace; the crude product gas enters a degassing tower to remove SO2 and SiF4 after being subjected to dust removal, washing, cooling, condensation, rectification, deacidification and dehydration, and an anhydrous hydrofluoric acid product is obtained. According to the method, waste recycling is achieved, and fluorite consumption and waste disposal amount are reduced.

The invention discloses a method for preparing hydrogen fluoride and co-producing fumed silica from low-concentration fluosilicic acid, which belongs to the technical field of inorganic chemical industry and comprises the following steps: concentrating low-concentration fluosilicic acid under reduced pressure; mixing concentrated sulfuric acid with system circulating sulfuric acid, reacting with concentrated fluosilicic acid, and performing gas-liquid separation to obtain mixed liquid of silicon tetrafluoride gas, hydrogen fluoride and sulfuric acid; and washing the separated silicon tetrafluoride gas and / or silicon tetrafluoride gas generated by a wet-process phosphoric acid process with concentrated sulfuric acid, reacting with water vapor, hydrogen and oxygen, and dedusting to obtain the fumed silica. The method has the advantages of simple process flow, low production cost, high product quality, low three-waste output and the like. Besides, low-grade and low-concentration fluosilicic acid is used as a raw material, fluorine and silicon elements are efficiently separated, high-value fumed silica and high-quality hydrogen fluoride are prepared, and good social and economic values are embodied; and cyclic utilization of byproducts such as sulfuric acid reduces environmental pollution and three-waste treatment pressure, and has good environmental protection benefits.

A degassing tower for preparing hydrogen fluoride relates to the field of hydrogen fluoride preparation, and is characterized in that a cylindrical mesh cage (2) is arranged in the middle of an inner cavity of a tower body (1), an auxiliary assembly (5) is arranged below the cylindrical mesh cage (2), a spraying assembly (3) is arranged above the cylindrical mesh cage (2) in the inner cavity of the tower body (1), and a driving assembly (4) is arranged at the top of the spraying assembly (3); according to the invention, the cylindrical mesh cage which can float and is used for more sufficient contact between the to-be-treated gas and the gathered liquid is arranged in the middle of the tower body, and the spraying assembly used for assisting adsorption of substances except hydrogen fluoride is arranged above the cylindrical mesh cage; the top of the spraying assembly is provided with the driving assembly which is used for rotating the spraying assembly to enable the spraying area of the spraying assembly to be more uniform and providing driving force for the auxiliary assembly, so that non-condensable gases such as sulfur dioxide and silicon tetrafluoride in a hydrogen fluoride gas mixture are removed; and the hydrogen fluoride gas is condensed to obtain a qualified anhydrous hydrogen fluoride product.

The invention discloses a method for recovering HF (hydrogen fluoride) from hydrofluoric acid waste liquid obtained in an aromatic fluoride industrial synthesis process. According to the HF recovery method provided by the invention, sodium fluoride is taken as a carrier, excessive sodium fluoride reacts with hydrogen fluoride in the hydrofluoric acid waste liquid to generate sodium bifluoride, and HF is released through suction filtration, drying and thermal liberation. The HF is subjected to adsorption-desorption circulation through NaF, so that the purpose of recycling HF without discharging three wastes is achieved; meanwhile, the filtrate returns to the aromatic fluoride industrial synthesis process to be recycled as an absorbent of diazonium salt pyrolysis tail gas; the obtained sodium fluoride is recycled as an HF adsorbent, so that the effect of recycling multiple resources is achieved.

The utility model discloses a continuous arsenic removal device for anhydrous hydrogen fluoride, which is characterized in that a product tank is connected with a primary rectifying tower, the primary rectifying tower is in pipeline connection with a heat exchanger, the heat exchanger is respectively in pipeline connection with a first finished product tank, a second finished product tank and a third finished product tank, and the first finished product tank, the second finished product tank and the third finished product tank are respectively connected with a secondary rectifying tower; and the secondary rectifying tower is connected with the product tank. According to the utility model, the first finished product tank, the second finished product tank and the third finished product tank are connected with the existing rectifying tower by adding corresponding pipelines at the outlet of the circulating submerged pump for real-time switching use of arsenic removal oxidation, acid feeding and acid discharging, so that continuous arsenic removal production is realized, and the influence on normal production of the device is avoided.

The utility model discloses a sealing device of a hydrogen fluoride reaction furnace, which belongs to the technical field of hydrogen fluoride processing and particularly comprises a hot air jacket and a furnace tail, and a graphite block sealing mechanism is arranged at the joint of the hot air jacket and the furnace tail. The graphite block further comprises an elastic pressing mechanism, the elastic pressing mechanism comprises fixing frames, a longitudinal elastic piece and a transverse elastic piece, the fixing frames are fixedly connected to the hot air jacket, one end of each fixing frame is located above the graphite block body and fixedly connected with the graphite block body, a pressing plate is movably connected between every two adjacent fixing frames, and the longitudinal elastic piece is fixedly connected with the transverse elastic piece. The pressing plate is connected with the two adjacent fixing frames through a longitudinal elastic piece, and the pressing plate is connected with a hot air jacket through a transverse elastic piece; through the arrangement of the transverse elastic piece, elastic force pointing to the section of the hot air jacket can be provided for the graphite block body, and the possibility that gas leaks between the graphite block body and the section of the hot air jacket is further reduced.

The invention provides an anhydrous hydrogen fluoride desulfurization reaction device, and relates to the technical field of anhydrous hydrogen fluoride preparation, the device comprises a reaction container, the reaction container is internally provided with a first accommodating cavity, and the reaction container is provided with a first feed port, a second feed port and a discharge port which are communicated with the first accommodating cavity; wherein the first feeding hole is used for conveying a liquid catalyst for sulfur removal into the first accommodating cavity, and the second feeding hole is used for outputting sulfur-containing hydrogen fluoride gas from the bottom of the first accommodating cavity; and the height of the discharge port is greater than that of the first feed port so as to discharge the sulfur-removed hydrogen fluoride gas. The method can deeply remove sulfur in anhydrous hydrogen fluoride production, and can avoid influence on production continuity and safety.

The utility model relates to the technical field of production capacity of hydrogen fluoride evaporation systems, in particular to hydrogen fluoride evaporation equipment which comprises a shell pass, a tube pass upper tube box and a tube pass lower tube box, the shell pass comprises a shell pass saturated evaporation section and a shell pass superheat section which are communicated, heat exchange tubes are arranged in the shell pass saturated evaporation section and the shell pass superheat section, and the shell pass upper tube box and the shell pass lower tube box are communicated. The tube pass upper tube box and the tube pass lower tube box are communicated through the heat exchange tube; a hydrogen fluoride inlet is formed in the bottom of the shell pass saturation evaporation section; and a hydrogen fluoride gas outlet is formed in the top of the shell pass overheating section. The hydrogen fluoride evaporation tank overcomes the defects of a traditional hydrogen fluoride evaporation tank, provides a safer and more efficient mode to improve the evaporation and supply capacity of hydrogen fluoride, meets the requirements of an existing process, reduces the storage amount of hydrogen fluoride, reduces steam consumption, improves the production efficiency and reduces the safety risk level.

This application discloses a method for extracting fluorine from a nickel-cobalt-manganese sulfate solution, relating to the field of wastewater treatment. The method comprises the following steps: mixing the nickel-cobalt-manganese sulfate solution with concentrated sulfuric acid for activation, subjecting the activated solution to multi-stage countercurrent extraction using an organic phase comprising tributyl phosphate, isooctyl alcohol, and a diluent, subjecting the fluorine-containing organic phase to multi-stage countercurrent washing, and subjecting the washed fluorine-containing organic phase to multi-stage countercurrent stripping. This application, directed to the extraction of fluorine from a nickel-cobalt-manganese sulfate solution, employs tributyl phosphate as an extractant, while isooctyl alcohol is added in a mixing and settling tank to improve phase separation. The process is simple, and the extraction rate is as high as over 90%.

The application discloses a method for recovering fluorine and triethylamine from fluorine-containing organic wastewater, and belongs to the technical field of fluoride preparation. The method adopts the synergistic effect of an organic phase of an extractant A and an extractant B under the condition that the pH is 0.5-4, realizes selective extraction of fluorine ions and inhibition of extraction of metal impurity cations under the premise that water-soluble triethylamine is not extracted through a one-step liquid-liquid extraction process, thereby realizing efficient and low-loss recovery of fluorine and triethylamine, and further preparing high-purity fluorides and triethylamine. The method has the advantages of short process, no need of complicated impurity removal process, high fluorine recovery rate, low production cost and the like.

The utility model provides a crude distillation tower for preparing hydrogen fluoride, which comprises a crude distillation tower I and a crude distillation tower II, and further comprises a fixed shell I, and the fixed shell I is arranged on the upper side and the lower side of the crude distillation tower I and the crude distillation tower II. An electric push rod drives a first push rod and a second push rod to move, the first push rod and the second push rod move a blocking frame to move, blocking and opening of a first coarse distillation tower and a second coarse distillation tower are facilitated, and therefore conversion of coarse distillation working areas between the first coarse distillation tower and the second coarse distillation tower is well carried out; the coarse distillation tower is plugged through the plugging frame and the plugging block, so that the plugging effect of the plugging structure on the coarse distillation tower is better, the coarse distillation tower I and the coarse distillation tower II can be switched between coarse distillation working areas, the coarse distillation work of the whole coarse distillation tower is not influenced while the maintenance work is better and conveniently carried out, and the maintenance efficiency is improved. And the overall working efficiency is improved.

The utility model discloses a hydrogen fluoride purification device which comprises a placing disc, a cleaning rotating assembly, two supporting rods, a rotating disc, a cleaning lifting assembly, a cleaning adjusting assembly and a cleaning rod, a sliding circular groove is formed in the upper surface of the placing disc, the cleaning rotating assembly is arranged on the placing disc, and the two supporting rods are both fixedly installed on the placing disc. The rotating disc is fixedly installed on the two supporting rods, a sliding circular groove is formed in the upper surface of the rotating disc, the reaction cylinder is arranged on the rotating disc, the two cleaning lifting assemblies are arranged on the cleaning rotating assembly, and the two cleaning adjusting assemblies are arranged on the two cleaning lifting assemblies correspondingly. The two cleaning rods are arranged on the two cleaning adjusting assemblies correspondingly. According to the hydrogen fluoride purification device, the problem that in the prior art provided in the background art, when cleaning cloth is driven by a permanent magnet and a magnet to wipe the inner side wall of a reaction cylinder, manual movement is possibly difficult due to large suction force is solved.

The invention discloses an ionic liquid modified molecular sieve preparation method, a molecular sieve and application, and the preparation method comprises the following steps: preparing a mixed system formed by mixing an activated molecular sieve, an ionic liquid and alcohol; and mixing a proper amount of molecular sieves with the mixed system, stirring, removing ethanol, and performing activation and regeneration. According to the technical scheme, the abundant hydrogen bond network structure of the proper amount of ionic liquid is combined with the molecular sieve, the usage amount of the ionic liquid with high value is reduced, and the adsorption effect of the molecular sieve on HF is greatly improved through combination of the ionic liquid and the molecular sieve.

The utility model relates to the technical field of anhydrous hydrogen fluoride production, and discloses an anhydrous hydrogen fluoride vaporizing device which comprises a vaporizing heating box, the bottom of an inner cavity of the vaporizing heating box is movably connected with a sealing plate through a pushing mechanism, and the portion, located above the sealing plate, in the vaporizing heating box is movably connected with a mounting frame through a sliding assembly. According to the device, the drying agent plate can be quickly fixed through the locking mechanism, so that great convenience is brought to an operator to mount and dismount the drying agent plate, the replacement efficiency of the operator to the drying agent plate is greatly improved, and the sealing plate can be quickly pushed upwards through the pushing mechanism; the device can dry all hydrogen fluoride in the gasification heating box, so that part of hydrogen fluoride gas which is not completely dried can be prevented from remaining in the gasification heating box during drying, waste of the hydrogen fluoride gas is greatly reduced, and the drying efficiency of the device is greatly improved.

The invention relates to the technical field of industrial wastewater treatment and resource recovery, and particularly discloses a method for separating and recovering fluorine in high-purity quartz sand production wastewater. The method comprises the following steps: treating the high-purity quartz sand production wastewater through a diffusion dialysis technology to separate sulfuric acid, hydrochloric acid, nitric acid and hydrofluoric acid from the wastewater to generate mixed acid; adding sodium fluoride into the mixed acid, and heating the mixed acid to 50-60 DEG C; after reacting for a period of time, cooling the mixed acid to below 10 DEG C to form sodium hydrofluoride crystals in the mixed acid; separating and collecting the crystals, heating to 150-160 DEG C, and decomposing the sodium hydrofluoride crystals to form hydrogen fluoride gas; and hydrogen fluoride gas is collected to form high-purity hydrofluoric acid, so that fluorine is separated and recycled from wastewater, and the aim of recycling resources is fulfilled.

The invention belongs to the technical field of fluosilicic acid utilization, and relates to a potassium fluosilicate decomposition method and application of the potassium fluosilicate decomposition method in preparation of hydrogen fluoride from fluosilicic acid. The method comprises the following steps: firstly, mixing an auxiliary agent with ammonia water, then mixing with potassium fluosilicate to form a decomposition system, adjusting the temperature of the decomposition system to 20-70 DEG C, stirring the decomposition system, simultaneously applying ultrasonic waves, and reacting for 5-10 hours to realize decomposition of potassium fluosilicate. In addition, solid potassium fluosilicate is obtained by adding soluble potassium salt into fluosilicic acid; the potassium fluosilicate is decomposed to obtain a fluoride salt solution, the fluoride salt solution is heated to expel ammonia and then reacts with fluosilicic acid to obtain an ammonium fluoride solution, the ammonium fluoride solution reacts with soluble calcium salt to obtain calcium fluoride solid, and the calcium fluoride solid reacts with concentrated sulfuric acid to obtain hydrogen fluoride. The potassium fluosilicate decomposition method can solve the problem that reaction raw materials are wrapped by reaction products, the raw material utilization rate and the product yield are remarkably improved, and the potassium fluosilicate decomposition method can shorten the technological process and reduce the production cost when applied to preparation of hydrogen fluoride from fluosilicic acid.

The invention relates to the technical field of chemical production, and discloses a deep impurity removal technology and device in the hydrofluoric acid production process, the device comprises a bottom plate, an input pipe and a connecting pipe, metal ions in hydrofluoric acid are pretreated through a filter element, the load of a follow-up deep impurity removal module is reduced, hydrofluoric acid is pumped into a low-pressure tower, and the impurity removal efficiency is improved. HCl-SiF mixed liquid obtained through condensation of a condenser is input into a waste liquid tank, a tower bottom liquid phase enters a high-pressure tower, hydrofluoric acid is heated and pressurized to volatilize into a gas phase, the gas phase is input into a liquid storage tank through condensation of the condenser, and a pressure difference transmitter matched with the filter element automatically monitors the pressure difference of an inlet and an outlet of the filter element and automatically cleans the filter element to avoid blockage of the filter element. Metal ions in hydrofluoric acid are removed through resin in the cation column, chloride ions in hydrofluoric acid are adsorbed through the anion column, and regeneration of the cation column and the anion column is achieved by switching to standby resin, introducing a hydrogen chloride solution into the failed cation column and introducing a hydrofluoric acid solution into the anion column.

The present application relates to hydrogen fluoride production technical field, and disclose a kind of electronic grade hydrogen fluoride production preparation device, including stripping reaction kettle and crude fine integrated purification tower, the side of stripping reaction kettle is connected with exhaust pipe, exhaust pipe is connected stripping reaction kettle, crude fine integrated purification tower is provided with anti-blocking screening mechanism, anti-blocking screening mechanism includes horizontal screening assembly and longitudinal screening assembly, horizontal screening assembly includes upper rectangle frame and horizontal screen silk, and the top of upper rectangle frame is evenly distributed with several horizontal screen silk along its length direction;Longitudinal screening assembly includes lower rectangle frame and longitudinal screen silk, and upper rectangle frame and lower rectangle frame have the freedom of movement along the height direction of crude fine integrated purification tower, and the top of lower rectangle frame is equally spaced with several longitudinal screen silk along its width direction, and several longitudinal screen silk contact several horizontal screen silk to form mesh format crude filter screen, for solving the problem that existing purification tower is easily blocked in pretreatment process and cannot be dredged.

The invention relates to methods for processing ammonium polyfluoride and producing nitrogen trifluoride (NF3). The technical result is the creation of a comprehensive, low-waste, explosion-proof technology for producing nitrogen trifluoride and, additionally, a group of inorganic fluorides: nitrogen trifluoride, carbon tetrafluoride, carbonyl fluoride, hydrogen fluoride and hydrofluoric acid. The proposed method envisages removing excess liquid ammonium polyfluoride from a reactor and sending it to be flaked or reacting it with oxygen, or with oxygen and carbon, or with oxygen and hydrogen-containing substances, or with oxygen and carbon and hydrogen-containing substances, or with fluorine, or with fluorine and hydrogen-containing substances, and recovering low-boiling substances by distillation and isolating hydrogen fluoride or hydrofluoric acid.

This invention relates to the field of lithium salt synthesis technology for lithium-ion battery electrolytes, specifically a method for synthesizing lithium hexafluoroarsenate. This method uses 40% hydrofluoric acid as the reaction medium, replacing high-cost anhydrous hydrofluoric acid, and adds 0.5-5 wt% fluoride catalyst. It employs a segmented temperature control mode of mixing at -40 to -30°C, aeration at 20 to 30°C, and heat preservation at 40 to 50°C. Combined with a reactor with a built-in annular baffle plate to improve mixing efficiency, the highly toxic exhaust gas is treated by a three-stage tail gas absorption system of anhydrous calcium chloride-20% sodium hydroxide solution-activated carbon. Simultaneously, it achieves resource recovery of fluoride-containing wastewater through lime slurry pretreatment-sulfuric acid regeneration and hydrofluoric acid recycling. This invention features a safe process operation, reduces costs by more than 30%, produces a product purity ≥99.9%, a yield ≥92%, achieves a fluoride resource recovery rate of ≥85% in wastewater, and meets national standards for tail gas emissions. It realizes efficient and green synthesis of lithium hexafluoroarsenate and is suitable for industrial production.

The invention firstly relates to a method for respectively extracting and producing uranium and, where appropriate, heavy metals and rare earths from phosphato-calcium mineral matrices comprising the steps of a) treatment of said phosphato-calcium mineral matrices with a source of fluoride anions; b) heat treatment of said mixture of fluorides in the presence of calcium metal; and c) separation followed by the individual collection of uranium metal and, where appropriate, of heavy metals and rare earths initially present in the starting material. The invention also relates to a series of methods derived from the implementation of the aforementioned and leading, depending on the pathways followed, to the production, respectively, of phosphoric acid, sulfuric acid, ammonium sulfate or NPK fertilizers and more particularly, respectively, of phosphoric acid, sulfuric acid, ammonium sulfate or NPK fertilizers free of metal contaminants. The invention is defined in the claims. Other objectives of the invention will become apparent over the course of the following description, in particular with reference to the reaction schemes illustrated by the figures below.

The utility model relates to a hydrofluoric acid condensing device. Cooling liquid can be guided in through the liquid inlet and discharged through the liquid outlet to complete circulation, then gasified hydrofluoric acid is guided into the end cover through the feeding port in one end cover, then the hydrofluoric acid enters the condensation tube nest through one guide hole to be condensed, and then the hydrofluoric acid obtained after condensation is completed is discharged through the other guide hole and discharged through the discharging port. When the condensation tube nests need to be replaced, the end cover can be detached, the end cover drives the pressing mechanism to be separated from the sealing guide cover, all the condensation tube nests are in a movable state, then the damaged condensation tube nests are taken down and replaced, then the end cover is covered, the end cover drives the pressing mechanism to be pressed on the sealing guide cover, and all the condensation tube nests are fixed. Therefore, the condensation tube nest can be conveniently replaced after the condensation tube nest is damaged, destructive replacement of the interior of the condensation tank is avoided, it is guaranteed that the service life of the condensation device is shortened, and the maintenance cost is reduced.

The utility model provides a low-temperature distillation purification device for mixed acid containing hydrofluoric acid. The low-temperature distillation purification device comprises a distillation tank, a first shell-and-tube condenser, a second shell-and-tube condenser, an absorption tower, a storage tank, a two-stage heat pump, a dry vacuum pump and a jet vacuum pump, a mixed acid circulation pipeline is arranged among the distillation retort, the first shell-and-tube condenser, the second shell-and-tube condenser and the absorption tower, a condensation pipeline is arranged among the first shell-and-tube condenser, the second shell-and-tube condenser and the two-stage heat pump, and a heating pipeline is arranged between a heating assembly of the distillation retort and the two-stage heat pump; the outer sides of the inner cavities of the distillation retort, the first shell-and-tube condenser, the storage tank and the absorption tower are respectively provided with a vacuum interlayer cavity, and the side walls of the inner cavities of the distillation retort, the first shell-and-tube condenser, the storage tank and the absorption tower are respectively lined with a fluorine layer. The purification device can realize efficient purification and collection of mixed acid, and is low in energy consumption and long in service life.

The utility model discloses an internal slag returning mechanism of an anhydrous hydrogen fluoride reacting furnace. The internal slag returning mechanism specifically comprises a slag returning cylinder, a slag returning spiral blade and a supporting structure, the slag returning barrel is fixedly connected with the inner wall of the reaction furnace through a plurality of supporting legs, and the slag returning spiral blade is reversely arranged in the slag returning barrel and used for reversely conveying slag at the reaction tail back to a reaction area. The supporting structure is arranged in an equal-difference array mode, stress is dispersed, and the stability and durability of the structure are enhanced. The slag returning device has the advantages of being high in slag returning efficiency, high in structural stability, convenient and fast to maintain and operate and the like, effectively solves the problems that in the prior art, a slag returning cylinder is inconvenient to install and maintain, non-uniform in slag returning, prone to damage in structure and the like, improves production efficiency and prolongs service life of equipment.