阅读说明：本技术 一种生产干法氟化铝的集约式氟化反应器 (Intensive fluorination reactor for producing dry-process aluminum fluoride ) 是由 肖建楠 陈居玲 夏娇彬 *** 于 2019-09-29 设计创作，主要内容包括：本发明公开了一种生产干法氟化铝的集约式氟化反应器,由Ⅰ段氟化反应器和与之连接的Ⅱ段氟化反应器组成,氢氧化铝高位料仓依次通过第一氮气密封室、螺旋给料机、密封室连接所述Ⅰ段氟化反应器的入口；所述Ⅰ段氟化反应器通过流态化逆向输送管连接Ⅱ段氟化反应器。氟化铵高位料仓通过第二氮气密封室、氟化铵螺旋给料热解器连接所述Ⅱ段氟化反应器,所述Ⅱ段氟化反应器的出料口连接氮封卸料器。本发明是针对我国目前干法氟化铝、无水氟化铝生产工艺所存在的不足而开发的一种新型氟化反应器。该反应器缩短了干法氟化铝生产流程、有利亍保障产品质量、确保生产过程无害化,适合于以氢氧化铝和氟化铵/氟化氢铵为原料生产干法氟化铝产品。(The invention discloses an intensive fluorination reactor for producing dry-process aluminum fluoride, which consists of a section I fluorination reactor and a section II fluorination reactor connected with the fluorination reactor, wherein an aluminum hydroxide high-level bin is connected with an inlet of the section I fluorination reactor through a first nitrogen sealing chamber, a screw feeder and a sealing chamber in sequence; the first section of fluorination reactor is connected with the second section of fluorination reactor through a fluidized reverse conveying pipe. The ammonium fluoride overhead bin is connected with the second section of fluorination reactor through a second nitrogen sealing chamber and an ammonium fluoride spiral feeding pyrolyzer, and a discharge port of the second section of fluorination reactor is connected with a nitrogen sealing discharger. The invention relates to a novel fluorination reactor which is developed aiming at the defects of the prior dry-method aluminum fluoride and anhydrous aluminum fluoride production process in China. The reactor shortens the production flow of dry-method aluminum fluoride, is favorable for ensuring the product quality and ensuring the harmless production process, and is suitable for producing the dry-method aluminum fluoride product by taking aluminum hydroxide and ammonium fluoride/ammonium bifluoride as raw materials.)

1. An intensive fluorination reactor for producing dry-process aluminum fluoride, which is characterized in that: the reactor consists of a first-stage fluorination reactor and a second-stage fluorination reactor connected with the first-stage fluorination reactor; the aluminum hydroxide high-level bin is connected with the section I fluorination reactor sequentially through the first nitrogen sealing chamber, the screw feeder and the sealing chamber; the first nitrogen input pipeline is connected with the nitrogen sealing chamber, the sealing chamber and the first section fluorination reactor are of an integral structure, and a reaction tail gas outlet is formed in the head end of the first section fluorination reactor; the barrel of the first-stage fluorination reactor and the second-stage fluorination reactor is of a drum-type structure, the inner cavity of the barrel is a fluorination reaction chamber, the inner wall of the barrel is provided with a lifting plate, the outer wall of the barrel is provided with a heating chamber, the heating chamber is provided with a heating gas inlet and a heating gas outlet, and the barrel is driven to rotate by a driving device; the first-section fluorination reactor is connected with a sealing chamber of the second-section fluorination reactor through a reverse fluidization conveying pipe, a mechanical seal is arranged between the reverse fluidization conveying pipe and the sealing chamber, a heater and a combustion tail gas outlet are arranged in a heating chamber of the second-section fluorination reactor, and the combustion tail gas outlet is connected with a heating gas inlet of the heating chamber of the first-section fluorination reactor through a pipeline; the ammonium fluoride high-level stock bin is connected with the second section of fluorination reactor through a second nitrogen gas sealing chamber and an ammonium fluoride spiral feeding pyrolyzer, and the second nitrogen gas sealing chamber 2 is connected with a second nitrogen gas input pipeline; the feed inlet side of II sections fluorination reactor also is equipped with the seal chamber, connects II sections fluorination reactor barrels and nitrogen through the seal chamber and seals the tripper, nitrogen seals the tripper and has third nitrogen gas input pipeline through the control valve intercommunication.

2. The intensive fluorination reactor for producing dry-process aluminum fluoride according to claim 1, wherein the angle of inclination of said I-stage fluorination reactor is 1 ~ 5 °.

3. The intensive fluorination reactor for producing dry-process aluminum fluoride according to claim 1, wherein the rotation speed of the cylinders of the first-stage fluorination reactor and the second-stage fluorination reactor is 0.5 ~ 5r/min, and the pressure of the reaction system is-0.01 ~ -0.09 MPa.

4. The intensive fluorination reactor of claim 1 for producing dry aluminum fluoride, wherein: the sealing mode of the sealing chamber is a dynamic sealing structure, a mechanical sealing structure, a water seal structure or an oil seal structure.

5. The intensive fluorination reactor for producing dry-process aluminum fluoride according to claim 1, wherein the screw feeder is used for variable frequency speed regulation, the feeding speed is regulated by regulating the rotating speed of the conveyor, the ammonium fluoride screw feeding pyrolyzer is used for variable frequency speed regulation, and the outlet of the ammonium fluoride screw feeding pyrolyzer extends into the fluorination reaction chamber 1/3 ~ 2/5 of the second-stage fluorination reactor.

6. The intensive fluorination reactor of claim 1, wherein said risers are equally spaced at an angle of 15 ~ 36 degrees on the inner wall of the reaction chamber, and said risers have straight sections and folded sections, said folded sections being at an angle of 90 ~ 120 degrees to said risers.

7. The intensive fluorination reactor of claim 1 for producing dry aluminum fluoride, wherein: the heater is a gas heater or an electric heater, and gas or electricity is used as a heat source to heat the II-section fluorination reactor.

Technical Field

The invention belongs to the technical field of aluminum fluoride preparation equipment, and particularly relates to an intensive fluorination reactor for producing dry-process aluminum fluoride.

Background

The aluminum fluoride is an important inorganic chemical raw material and is mainly used as an electrolytic aluminum auxiliary agent, a ceramic cosolvent, an alcohol fermentation inhibitor, a nonmetal smelting solvent and the like. The anhydrous aluminum fluoride is a sand-like powder, and the wet aluminum fluoride is a white powder, and is a needle-like crystal. At present, the common processes in the production of aluminum fluoride in China comprise a dry process and a wet process, wherein the dry process is divided into a traditional process and an anhydrous process. The aluminum fluoride produced by different production methods has great difference in chemical and physical properties, and directly influences the operation, index, product quality and environment of electrolytic production.

The wet aluminum fluoride takes 30 percent hydrofluoric acid as a fluorine source and industrial aluminum hydroxide or aluminum sulfate and aluminum chloride as aluminum sources to generate AlF_3·3H₂And O, separating, washing and drying to prepare the aluminum fluoride product. Although the process has short production flow, the process has the defects of high treatment cost, high impurity content of products, poor fluidity, low additional value and poor environmental protection. Therefore, the process is listed as a process method sequence eliminated by the national industry structure adjustment guidance catalogue in 2004.

The dry process aluminium fluoride uses 80 ~ 99% hydrogen fluoride gas prepared by reacting fluorite with sulfuric acid and industrial aluminium hydroxide as raw materials, and produces aluminium fluoride products by high-temperature gas-solid reaction in a fluidized bed reactor, because the product quality is good, and no secondary pollution is caused in the preparation process, the process has obvious competitive advantage, so the process is most commonly applied in large-scale aluminium smelting plants in China.

The anhydrous aluminum fluoride is developed on the basis of a dry method, the process liquefies hydrogen fluoride gas with the content of 80 ~ 99 percent and gasifies the hydrogen fluoride gas, water and other impurities are removed, the anhydrous hydrogen fluoride with the content of more than 99.9 percent is prepared, and then the anhydrous hydrogen fluoride and industrial aluminum hydroxide react in a fluidized bed reactor to prepare an anhydrous aluminum fluoride product.

Disclosure of Invention

Aiming at the defects of the prior dry-process aluminum fluoride and anhydrous aluminum fluoride production process in China, the invention provides an intensive fluorination reactor for producing the dry-process aluminum fluoride, which is suitable for producing the dry-process aluminum fluoride product by taking aluminum hydroxide and ammonium fluoride/ammonium bifluoride as raw materials, and aims to shorten the production flow, ensure the product quality and ensure the harmless production process.

In order to achieve the purpose, the invention adopts the technical scheme that: an intensive fluorination reactor for producing dry-process aluminum fluoride, which is characterized in that: the device consists of a first-section fluorination reactor and a second-section fluorination reactor connected with the first-section fluorination reactor, wherein an aluminum hydroxide high-level bin is connected with an inlet of the first-section fluorination reactor through a first nitrogen sealing chamber, a screw feeder and a sealing chamber in sequence; the first section of the fluorination reactor is provided with a first nitrogen input pipeline; the barrel of the first-stage fluorination reactor and the second-stage fluorination reactor is of a drum-type structure, the inner cavity of the barrel is a fluorination reaction chamber, the inner wall of the barrel is provided with a lifting plate, the outer wall of the barrel is provided with a heating chamber, the heating chamber is provided with a heating gas inlet and a heating gas outlet, and the barrel is driven to rotate by a driving device; the first-section fluorination reactor is connected with a sealing chamber of the second-section fluorination reactor through a reverse fluidization conveying pipe, a mechanical sealing structure is arranged between the reverse fluidization conveying pipe and the sealing chamber, a heater and a hot gas outlet are arranged in a heating chamber of the second-section fluorination reactor, and the hot gas outlet is connected with a heating gas inlet of the heating chamber of the first-section fluorination reactor through a pipeline; the ammonium fluoride high-level stock bin is connected with the second section of fluorination reactor through a second nitrogen gas sealing chamber and an ammonium fluoride spiral feeding pyrolyzer, and the second nitrogen gas sealing chamber is connected with a second nitrogen gas input pipeline; the feed inlet side of II sections fluorination reactors also is equipped with the seal chamber, connects nitrogen through the seal chamber and seals the tripper, nitrogen seals the tripper and has third nitrogen gas input pipeline through the control valve intercommunication.

The inclination angle of the I-section fluorination reactor is 1 ~ 5 degrees.

The sealing mode of the sealing chamber is a dynamic sealing structure, a mechanical sealing structure, a water seal structure or an oil seal structure.

The spiral feeder has frequency-variable speed regulation, the feeding speed is regulated by regulating the running speed of the conveyer, the spiral feeder pyrolyzer has frequency-variable speed regulation and the outlet of the spiral feeder pyrolyzer extends into a fluorination reaction chamber 1/3 ~ 2/5 of the second-stage fluorination reactor.

The lifting plates are uniformly distributed on the inner wall of the reaction chamber at equal intervals according to an angle of 15 ~ 36 degrees, each lifting plate is provided with a straight plate section and a folded plate section, and the folded plates and the lifting plates form an angle of 90 ~ 120 degrees.

The heater is a gas heater or an electric heater, and gas or electricity is used as a heat source to heat the II-section fluorination reactor.

The rotating speed of the barrel bodies of the first-stage fluorination reactor and the second-stage fluorination reactor is 0.5 ~ 5r/min, and the pressure of a reaction system is-0.01 ~ -0.09 MPa.

The intensive fluorination reactor of the dry-process aluminum fluoride combines the description of the production and use processes on the structure:

starting the second-stage fluorination reactor, heating the kiln body of the second-stage fluorination reactor by using a burner (which can also be heated by an electric heating tube), and synchronously starting other matched facilities. When the temperature in the reaction chambers of the second-section fluorination reactor and the first-section fluorination reactor reaches a preset value, respectively starting a screw feeder of the feed inlet of the first-section fluorination reactor and an ammonium fluoride screw feeder pyrolyzer of the feed inlet of the second-section fluorination reactor, and respectively adding dried aluminum hydroxide and ammonium fluoride which do not contain free water into the first-section fluorination reactor and the second-section fluorination reactor at a specific flow rate according to stoichiometry.

The aluminum hydroxide entering the first-stage fluorination reactor is contacted with gas (mixed gas of hydrogen fluoride and ammonia after the reaction is started, hereinafter referred to as mixed gas) from the second-stage fluorination reactor, and the aluminum hydroxide is dehydrated and converted into aluminum oxide by high temperature and then reacts with the hydrogen fluoride in the mixed gas to generate the aluminum fluoride. The fluorination rate at this stage is about 60% of the total reaction mass, i.e. there is 60% conversion of aluminum hydroxide/alumina to aluminum fluoride.

After the ammonium fluoride solid phase and the mixed gas are moved out of an outlet of the ammonium fluoride spiral feeding pyrolyzer, the hydrogen fluoride in the mixed gas is contacted with the solid reactant from the first-stage fluorination reactor to continue the fluorination reaction, the ammonium fluoride solid phase is mixed with the solid reactant from the first-stage fluorination reactor and is subjected to the pyrolysis reaction at the temperature of 500 ~ 600 ℃ to generate the mixed gas of the hydrogen fluoride and the ammonia, and the hydrogen fluoride in the mixed gas also rapidly reacts with the alumina/aluminum hydroxide in the solid reactant to generate the aluminum fluoride.

The hydrogen fluoride gas which is not fully reacted in the second-stage fluorination reactor and ammonia gas enter the first-stage fluorination reactor through a fluidized reverse conveying pipe and react with aluminum hydroxide/aluminum oxide added by a screw feeder, so that most (about 60%) of the added aluminum hydroxide is converted into aluminum fluoride.

In the I-section fluorination reactor and the II-section fluorination reactor, the solid materials are fluidized by raising plates arranged in the reactors through raising, and are fully contacted with hydrogen fluoride in the mixed gas to carry out fluorination reaction. In the first-stage and second-stage fluorination reactors, hydrogen fluoride reacts with solid materials (aluminum hydroxide or aluminum oxide), and ammonia in the mixed gas does not react with the materials. The ammonia enters the first-stage fluorination reactor from the second-stage fluorination reactor in a gaseous state, and then enters the fluosilicic acid ammoniation reactor from a reaction tail gas outlet of the first-stage fluorination reactor after being cooled and dedusted in sequence through a pipeline to be used as an ammoniating agent in the fluosilicic acid ammoniation process. Solid materials (aluminum hydroxide/aluminum oxide) entering from the first-stage fluorination reactor enter the second-stage fluorination reactor after dehydration and primary fluorination reaction, are fully fluorinated and converted into aluminum fluoride, are discharged from a nitrogen-filled discharger arranged at the tail part of the second-stage fluorination reactor, and are cooled and packaged to prepare an aluminum fluoride product.

Because the reaction between the hydrogen fluoride gas in the first-section fluorination reactor and the aluminum hydroxide/aluminum oxide is exothermic, and the heat released in the reaction process can meet the heat requirement of the fluorination reaction in the first-section fluorination reactor, the high-temperature tail gas generated by the heating chamber of the second-section fluorination reactor is not required to be used for heating under the normal operation condition. However, when the production is started, because the hot gas outlet of the heating chamber of the second-section fluorination reactor is connected with the heating gas inlet of the heating chamber of the first-section fluorination reactor, the high-temperature tail gas generated by the heating chamber of the second-section fluorination reactor can be introduced into the heating chamber of the first-section fluorination reactor to be used as a heat source to initiate the first-section fluorination reaction. After the reaction enters a normal state, introducing high-temperature tail gas generated by the heating chamber of the second-stage fluorination reactor into an aluminum hydroxide and ammonium fluoride drying procedure to be used as a heat source.

The nitrogen sealing device is additionally arranged at the material inlet and the material outlet, and the sealing chambers are additionally arranged at the positions of the feed inlet and the discharge outlet of the reactor and the connecting part of the reactor and the cylinder body, so that the mixing of gas (ammonia and air) can be effectively avoided, and the occurrence of ammonia explosion accidents can be prevented. The discharge port of the II-section fluorination reactor is provided with a nitrogen-filled discharger 12 so as to avoid mixing with ammonia gas in the reaction chamber in the aluminum fluoride discharge process due to air entering, and the ammonia concentration is changed to cause explosion danger.

A fluidized reverse conveying pipe is arranged between the first-section fluorination reactor and the second-section fluorination reactor, materials discharged from the first-section fluorination reactor in the conveying pipe flow from the first-section fluorination reactor to the second-section fluorination reactor, and mixed gas of hydrogen fluoride and ammonia generated by the second-section fluorination reactor reversely enters a reaction chamber of the first-section fluorination reactor. The fluidized reverse conveying pipe is provided with a mechanical seal at the inlet end of the II-section fluorination reactor to avoid air mixing in the operation process.

Compared with the prior art, the invention has the beneficial effects that:

1. and the aluminum hydroxide and ammonium fluoride solids are put into the intensive fluorination reactor, and the fluorination reaction is completed in the same device, so that the intensification and simplification of the aluminum fluoride production process are realized, the process flow is shortened, and the equipment investment is saved.

2. Because the direct reaction between the solid ammonium hydroxide and the solid ammonium fluoride is realized, the preparation of the hydrogen fluoride gas is not needed, and the additional investment for constructing a hydrogen fluoride gas production device, a sulfuric acid preparation device, a gas purification device and the like is not needed.

3. The use of sulfuric acid is avoided.

4. Through the device, the cyclic utilization of ammonia gas is realized, the ammonia gas is used as an ammoniating agent to treat the fluosilicic acid, and the obtained ammonium fluoride is returned to the intensive fluorination reactor to be used as a fluorinating agent, so that the production cost is greatly reduced, and the totally-closed cyclic utilization of ammonia in the production process is realized.

5. The intensive fluorination reactor solves the technical problem of ammonia concentration control in the process of producing aluminum fluoride by taking ammonium fluoride as a fluorine source, avoids ammonia explosion accidents, and improves the safety of the production process.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a schematic diagram of the arrangement structure of the raising plate.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

An intensive fluorination reactor for producing dry aluminum fluoride as shown in fig. 1 and 2 comprises a first section fluorination reactor and a second section fluorination reactor connected with the first section fluorination reactor, an aluminum hydroxide high-level bin 1 is sequentially connected with a first nitrogen sealing chamber 2, a screw feeder 3 and a sealing chamber 4 to an inlet of the first section fluorination reactor, the sealing chamber 4 and the first section fluorination reactor are of an integral structure, a fluidized reaction tail gas outlet is arranged at the head end of the first section fluorination reactor, aluminum hydroxide required for producing aluminum fluoride is added from a feed inlet of the first section fluorination reactor, the screw feeder 3 is subjected to variable frequency speed regulation, the feeding speed is regulated by regulating the operating speed of a conveyor, the nitrogen sealing chamber 2 is connected with a first nitrogen input pipeline, a proper amount of nitrogen is continuously introduced during the operation of equipment to avoid air from entering and being mixed with ammonia gas generated in a reaction chamber, ammonia concentration enters an explosion limit, the cylinder of the first section fluorination reactor is of a structure with an inclination angle of 1 ~ degrees, the inner cavity of the cylinder is a fluorination reaction chamber 7, a plate 14 is arranged on the inner wall of the cylinder, the cylinder 14 is connected with a fluidized reaction chamber, the cylinder 14 is connected with a fluidized reaction chamber, the air inlet of a fluidized reaction chamber, the cylinder 7 is connected with a fluidized reaction chamber, the cylinder 7 is connected with a fluidized reaction chamber, the cylinder 7 is connected with a mechanical sealing reactor, the cylinder 7, the cylinder 7 is connected with a fluidized reaction chamber, the cylinder 7, the cylinder is connected with a fluidized reaction chamber, the cylinder 7 is connected with a fluidized reaction chamber, the cylinder is connected with a fluidized reaction chamber, the cylinder is connected with a fluidized reaction chamber, the cylinder, the.

The barrel of the second-stage fluorination reactor is of a drum-type structure, the inner cavity of the barrel is a fluorination reaction chamber 7, the inner wall of the barrel is provided with a lifting plate 14, as shown in fig. 2, the lifting plate 14 is uniformly distributed on the inner wall of the reaction chamber at an angle of 15 ~ degrees at equal intervals, the lifting plate is provided with a straight plate section and a folded plate section, the folded plate and the lifting plate form an angle of 90 ~ degrees, the outer wall of the barrel is provided with a heating chamber 6, a heater 13 and a hot gas outlet are arranged in the heating chamber 6 of the second-stage fluorination reactor, the heater is a gas heater 13 or an electric heater, the gas or electricity is used as a heat source to heat the second-stage fluorination reactor, the barrel of the second-stage fluorination reactor is used as the reaction chamber, the ammonium fluoride solid phase and the mixed gas leave the outlet of the spiral ammonium fluoride feeder 10, hydrogen fluoride in the mixed gas is contacted with the solid reactant from the first-stage fluorination reactor to continue the fluorination reaction, the ammonium fluoride solid phase is mixed with the solid reactant from the first-stage fluorination reactor, the solid phase and the solid-phase are subjected to pyrolysis reaction under the condition of heating at a heating temperature, the pyrolysis reaction to generate mixed gas of hydrogen fluoride and pyrolysis reaction, the mixed gas of hydrogen fluoride, the mixed gas is rapidly introduced into a high-temperature-required by a high-temperature-required aluminum fluoride spiral ammonium fluoride reactor, the spiral feeder system, the spiral feeder is introduced into a high-temperature-reaction-temperature-.

The second nitrogen gas sealing chamber is connected with a second nitrogen gas input pipeline; the feed inlet side of II sections fluorination reactors also is equipped with the seal chamber, connects nitrogen through the seal chamber and seals tripper 12 to avoid forming the mixture at aluminium fluoride ejection of compact process because of the air admission and the ammonia in the reaction chamber, make the ammonia concentration change and cause the explosion danger. The nitrogen seal discharger 12 is communicated with a third nitrogen input pipeline through a control valve.

In the structure of the invention, except for an aluminum hydroxide high-level bin 1, a first nitrogen sealing chamber 2, a sealing chamber 4, a driving device 5, an ammonium fluoride high-level bin 9, a nitrogen sealing discharger 12 and a heater 13 in the equipment, all parts contacting with materials are made of Monel, inconel or other high nickel alloys, and can also be made of 304, 316L, 310 and 321 stainless steel.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention.