Preparation method, production system and application of electronic-grade hydrofluoric acid

Abstract

The invention belongs to the technical field of electronic-grade hydrofluoric acid industry, and discloses a preparation method of electronic-grade hydrofluoric acid, which comprises the following steps: conveying industrial-grade anhydrous hydrogen fluoride liquid to the middle part of a rectifying tower, and conveying a high-purity oxidant to the bottom of the rectifying tower; total reflux is used at the top of the rectifying tower, and the uncondensed high-purity oxidizing agent and the oxidizing agent entering from the bottom of the rectifying tower converge and then are recycled; hydrogen fluoride liquid obtained at the bottom of the rectifying tower is conveyed to the upper part of the de-heavy tower; feeding all hydrogen fluoride gas at the top of the de-heavy tower to the lower part of a water scrubber, and feeding ultrapure water from the middle part of the water scrubber; and enabling the condensed hydrogen fluoride liquid part to flow back to the water washing tower, filtering the extracted hydrogen fluoride liquid, and blending with ultrapure water to obtain the final electronic-grade hydrofluoric acid product. According to the method, the equipment investment cost of the reactor is saved, and the circulating oxidant is used for oxidation, so that the usage amount of the oxidant is reduced, the oxidation effect of the oxidant is ensured, and the safety of the production process and the final product quality are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of electronic-grade hydrofluoric acid industry, and in particular to a preparation method, a production system and application of electronic-grade hydrofluoric acid. Background Art

[0002] Electronic-grade hydrofluoric acid solution is often made from ultra-high-purity hydrogen fluoride and ultra-pure water. It is highly corrosive to glass and metal and can be used as a cleaning agent and etching agent in the photovoltaic and semiconductor industries.

[0003] At present, the ultra-high-purity hydrogen fluoride used in the production process of electronic-grade hydrofluoric acid is often purified by distillation and rectification of industrial-grade anhydrous hydrogen fluoride products. The distillation method has a small application range and has great limitations in industrial production. Therefore, the rectification method is currently the main purification method for the production of electronic-grade hydrofluoric acid. The distillation process can remove most of the impurities in anhydrous hydrogen fluoride, but arsenic ion impurities mostly exist in the form of trivalent arsenic, and its compound arsenic trifluoride forms an azeotrope with hydrogen fluoride, and it is difficult to separate the two by distillation. By adding an oxidant to anhydrous hydrogen fluoride, trivalent arsenic can be oxidized to pentavalent arsenic. The volatility of pentavalent arsenic compounds is relatively low, and the arsenic ion impurities can be removed by the distillation process. Potassium permanganate, ammonium persulfate and hydrogen peroxide are currently used as oxidants for removing arsenic ion impurities from anhydrous hydrogen fluoride raw materials. For example, Chinese patent CN116835531A is a device and method for preparing electronic-grade hydrofluoric acid, Chinese patent CN101570319A is a method for producing ultra-clean high-purity hydrofluoric acid, and Chinese patent CN102092684A is a method for preparing electronic-grade ultra-high-purity hydrofluoric acid. All of them use one or more combinations of the above-mentioned oxidants to produce electronic-grade hydrofluoric acid. However, the above-mentioned oxidants inevitably introduce new impurity elements into the system, or generate excess water, resulting in increased difficulty in removing impurities that are easily soluble in water and azeotropic with water. Chinese patent CN102320573A is a method for preparing electronic-grade hydrofluoric acid, using fluorine gas as an oxidant in the anhydrous hydrogen fluoride purification process, avoiding the negative impact of other oxidants on the electronic-grade hydrofluoric acid generation process and product quality. However, existing patents still have shortcomings such as complex processes, numerous equipment, and high energy consumption. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a preparation method, a production system and applications of electronic grade hydrofluoric acid.

[0005] The technical solution adopted by the present invention to solve the technical problem is:

[0006] A method for preparing electronic grade hydrofluoric acid comprises the following steps:

[0007] (1) Industrial-grade anhydrous hydrogen fluoride liquid is transported from a raw material storage tank, i.e., anhydrous hydrogen fluoride storage tank, to the middle of an oxidation distillation tower, and a high-purity oxidant is transported from a gas storage tank to the bottom of the oxidation distillation tower. A first condenser is disposed at the top of the oxidation distillation tower, and a first reboiler is disposed at the bottom of the tower;

[0008] (2) The top of the oxidation distillation tower uses total reflux, a portion of the uncondensed high-purity oxidant is diverted and discharged, and the remaining condensed high-purity oxidant is combined with the oxidant entering the bottom of the oxidation distillation tower and then recycled; the hydrogen fluoride liquid obtained at the bottom of the oxidation distillation tower is sent to the upper part of the de-weighting tower, no condenser is set at the top of the de-weighting tower, and a second reboiler is set at the bottom of the tower;

[0009] (3) The hydrogen fluoride gas at the top of the deweighting tower is all sent to the lower part of the water scrubber, and ultrapure water is fed from the middle of the water scrubber. A second condenser is set at the top of the water scrubber, and a third reboiler is set at the bottom of the tower. The condensed hydrogen fluoride liquid is obtained at the top of the water scrubber, and part of it is refluxed to the water scrubber. The extracted hydrogen fluoride liquid is filtered and mixed with ultrapure water to obtain the final electronic grade hydrofluoric acid product.

[0010] Furthermore, in the raw material industrial anhydrous hydrogen fluoride liquid in step (1), the hydrogen fluoride content is ≥99.99%, the fluorosilicic acid content is ≤0.0007%, the sulfur dioxide content is ≤0.0001%, the non-volatile acid (in terms of H2SO4) is ≤0.001%, the water content is ≤0.0004%, the sulfur component content is ≤99.06 mg / kg, and the arsenic component content is ≤2.3 mg / kg;

[0011] Alternatively, in step (1), the high-purity oxidant is selected from one or more of fluorine gas, oxygen, fluorine-nitrogen mixed gas, and oxygen-nitrogen mixed gas, preferably fluorine-nitrogen mixed gas, in which the volume ratio of fluorine gas to nitrogen in the fluorine-nitrogen mixed gas is 1:5-10.

[0012] Furthermore, the mass flow ratio of the high-purity oxidant to the anhydrous hydrogen fluoride liquid in step (1) is 0.05-0.5:1;

[0013] Alternatively, the material of the oxidation distillation tower in step (1) is selected from one of stainless steel or carbon steel lined with polytetrafluoroethylene material, stainless steel or carbon steel lined with silicon carbide material, and stainless steel or carbon steel lined with low borosilicate material, preferably stainless steel lined with polytetrafluoroethylene material.

[0014] Furthermore, the top temperature of the oxidation distillation tower in step (1) is 19-35° C. and the pressure is normal pressure;

[0015] Alternatively, the condenser of the oxidation distillation tower in step (1) uses cooling water or a brine solution with a mass concentration of 25%-33% or ammonia or carbon dioxide as a coolant, and the outlet temperature is controlled at 15.0-21.0°C.

[0016] Furthermore, the mass ratio of the top circulating oxidant to the discharged oxidant of the oxidation distillation tower in step (2) is 7-12:1;

[0017] Alternatively, the material of the deweighting tower in step (2) is selected from one of stainless steel or carbon steel lined with polytetrafluoroethylene material, stainless steel or carbon steel lined with silicon carbide material, and stainless steel or carbon steel lined with low borosilicate material, preferably stainless steel lined with polytetrafluoroethylene material.

[0018] Furthermore, the top temperature of the deweighting tower in step (2) is 18-43°C;

[0019] Alternatively, the pressure of the deweighting tower in step (2) is 1.0-10.0 times the normal pressure.

[0020] Furthermore, the material of the water washing tower in step (3) is selected from one of stainless steel or carbon steel lined with polytetrafluoroethylene material, stainless steel or carbon steel lined with silicon carbide material, and stainless steel or carbon steel lined with low borosilicate material, preferably stainless steel lined with polytetrafluoroethylene material;

[0021] Alternatively, the tower pressure of the water washing tower in step (3) is normal pressure;

[0022] Alternatively, the reflux ratio of the water washing tower in step (3) is 1.0-6.0;

[0023] Alternatively, the condenser of the water washing tower in step (3) uses cooling water or a saline solution with a mass concentration of 25%-33% or ammonia or carbon dioxide as a coolant, and the outlet temperature is controlled at 12.0-19.5° C.;

[0024] Alternatively, the filtration in step (3) is filtration using a polytetrafluoroethylene nanofiltration membrane, and the accuracy of the polytetrafluoroethylene nanofiltration membrane is 0.1-0.5 μm.

[0025] A production system of electronic grade hydrofluoric acid for implementing the preparation method as described above, the production system comprises an anhydrous hydrogen fluoride storage tank, a gas storage tank, an oxidation distillation tower, a first condenser, a first reboiler, a deweighting tower, a second reboiler, a water scrubber, a second condenser and a third reboiler, the anhydrous hydrogen fluoride storage tank can contain industrial grade anhydrous hydrogen fluoride, the gas storage tank can contain a high-purity oxidant; the oxidation distillation tower, the deweighting tower and the water scrubber are all arranged in a vertical direction, the top of the oxidation distillation tower is closely connected to the first condenser, the bottom of the oxidation distillation tower is closely connected to the first reboiler, the middle of the oxidation distillation tower is The upper part is tightly connected with the anhydrous hydrogen fluoride storage tank, the lower part of the oxidation distillation tower is tightly connected with the gas storage tank, the bottom of the oxidation distillation tower is tightly connected with the middle and upper part of the deweighting tower, the top of the deweighting tower is tightly connected with the lower part of the water washing tower, the bottom of the deweighting tower is also connected with a second reboiler, the middle and upper part of the water washing tower is connected with the ultrapure water feed, the top of the water washing tower is tightly connected with a second condenser, the bottom of the water washing tower is tightly connected with a third reboiler, the top of the water washing tower can output the ultra-high purity hydrogen fluoride obtained after treatment, and electronic grade hydrofluoric acid product can be obtained after mixing with ultrapure water.

[0026] Further, the distillation tower comprises an industrial-grade anhydrous hydrogen fluoride inlet, a high-purity oxidant inlet, a steam outlet, a hydrogen fluoride liquid outlet, a hydrogen fluoride reflux liquid inlet and a distillation tower body. The oxidation distillation tower body is arranged in a vertical direction. The anhydrous hydrogen fluoride inlet and the hydrogen fluoride reflux liquid inlet are closely connected and arranged in the middle and upper part of the distillation tower body. The anhydrous hydrogen fluoride storage tank is closely connected with the industrial-grade anhydrous hydrogen fluoride inlet. The industrial-grade anhydrous hydrogen fluoride in the anhydrous hydrogen fluoride storage tank can be input into the middle and upper part of the distillation tower body. The high-purity oxidant inlet is closely connected and arranged in the lower part of the distillation tower body. The gas storage tank is closely connected with the high-purity oxidant inlet. The high-purity oxidant in the gas storage tank can be input into the lower part of the distillation tower body. The high-purity oxidant flows upward from the lower part of the distillation tower body to the top of the distillation tower body. The top of the distillation tower body is closely connected to be provided with a steam outlet, and the steam outlet is closely connected to be provided with a first condenser, the first condenser includes a material inlet, a condensed material outlet and an uncondensed material outlet, the material inlet of the first condenser is closely connected to the steam outlet, and the steam overflowing from the steam outlet can be condensed, the condensed material outlet is closely connected to the hydrogen fluoride reflux liquid inlet, the steam condensed by the first condenser enters the top of the distillation tower body through the condensed material outlet and the hydrogen fluoride reflux liquid inlet, the uncondensed material outlet is connected to the high-purity oxidant inlet, and the uncondensed high-purity oxidant and the oxidant entering the bottom of the distillation tower body are merged through the high-purity oxidant inlet and recycled; the bottom of the distillation tower body is closely connected to be provided with a hydrogen fluoride liquid outlet, and the bottom of the tower is also connected to be provided with a first reboiler;

[0027] The deweighting tower comprises a hydrogen fluoride liquid inlet, a deweighted material outlet, a hydrogen fluoride gas outlet and a deweighting tower body, the deweighting tower body is arranged in a vertical direction, the hydrogen fluoride liquid inlet is closely connected and arranged at the upper part of the deweighting tower body, the hydrogen fluoride liquid inlet is closely connected and arranged with the hydrogen fluoride liquid outlet of the distillation tower, the hydrogen fluoride gas outlet is closely connected and arranged at the top of the deweighting tower body, the deweighted material outlet is closely connected and arranged at the bottom of the deweighting tower body, and the bottom of the deweighting tower body is also connected and arranged with a second reboiler;

[0028] The water washing tower comprises an ultrapure water inlet, a hydrogen fluoride gas inlet, a hydrofluoric acid liquid outlet, a hydrogen fluoride gas outlet, a hydrogen fluoride reflux liquid inlet and a water washing tower body. The water washing tower body is arranged in a vertical direction. The ultrapure water inlet is closely connected and arranged in the middle and upper part of the water washing tower body. Ultrapure water can be input into the water washing tower body from the ultrapure water inlet. The hydrogen fluoride gas inlet is closely connected and arranged in the lower part of the water washing tower body. The hydrogen fluoride gas outlet of the deweighting tower is closely connected with the hydrogen fluoride gas inlet of the water washing tower. The hydrogen fluoride gas at the top of the deweighting tower can be all sent to the lower part of the water washing tower. The top of the water washing tower body is closely connected and arranged with the hydrogen fluoride gas outlet. The gas outlet is closely connected with a second condenser, the second condenser comprises a material inlet and a condensed material outlet, the material inlet of the second condenser is closely connected with the hydrogen fluoride gas outlet of the water washing tower, and the hydrogen fluoride gas overflowing from the hydrogen fluoride gas outlet can be condensed, the condensed material outlet of the second condenser is closely connected with the hydrogen fluoride reflux liquid inlet of the water washing tower, the hydrogen fluoride condensed by the second condenser is condensed through the condensed material outlet of the second condenser, and then enters the top of the water washing tower body through the hydrogen fluoride reflux liquid inlet, the bottom of the water washing tower body is closely connected with a hydrofluoric acid liquid outlet, and the tower bottom is also connected with a third reboiler.

[0029] The production system as described above is used for the preparation of electronic grade hydrofluoric acid.

[0030] The advantages and positive effects achieved by the present invention are:

[0031] 1. The method of the present invention combines the reaction of high-purity oxidant gas to oxidize trivalent arsenic in anhydrous hydrogen fluoride raw material with the distillation process, saving the equipment investment cost of the reactor, and using a circulating oxidant for oxidation, which not only reduces the amount of oxidant used, but also ensures the oxidizing effect of the oxidant, thereby improving the safety of the production process and the final product quality.

[0032] 2. Ultra-high-purity electronic-grade hydrogen fluoride can be obtained at the top of the water washing tower of the present invention, and the quality of the electronic-grade hydrofluoric acid product obtained by mixing it with ultra-pure water can meet the SEMI-G5 (UP-SSS) standard.

[0033] 3. The preparation method of the present invention has simple process, safety and reliability, stable product quality, low energy consumption and is easy for industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a process flow diagram of the method of the present invention and a structural connection diagram of the production system of the present invention. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with the embodiments. The following embodiments are descriptive rather than restrictive, and the protection scope of the present invention cannot be limited by the following embodiments.

[0036] The various experimental operations involved in the specific embodiments are all routine techniques in the art. For parts not specially annotated in this document, ordinary technicians in the art can implement them by referring to various commonly used reference books, scientific and technological literature or related instructions, manuals, etc. before the filing date of this invention.

[0037] A method for preparing electronic grade hydrofluoric acid comprises the following steps:

[0038] (1) Industrial-grade anhydrous hydrogen fluoride liquid is transported from a raw material storage tank, i.e., anhydrous hydrogen fluoride storage tank, to the middle of an oxidation distillation tower, and a high-purity oxidant is transported from a gas storage tank to the bottom of the oxidation distillation tower. A condenser is disposed at the top of the oxidation distillation tower, and a first reboiler is disposed at the bottom of the tower;

[0039] (2) The top of the oxidation distillation tower uses total reflux, a portion of the uncondensed high-purity oxidant is diverted and discharged, and the remaining condensed high-purity oxidant is combined with the oxidant entering the bottom of the oxidation distillation tower and then recycled; the hydrogen fluoride liquid obtained at the bottom of the oxidation distillation tower is sent to the upper part of the de-weighting tower, no condenser is set at the top of the de-weighting tower, and a second reboiler is set at the bottom of the tower;

[0040] (3) The hydrogen fluoride gas at the top of the deweighting tower is all sent to the lower part of the water scrubber, and ultrapure water is fed from the middle of the water scrubber. A second condenser is set at the top of the water scrubber, and a third reboiler is set at the bottom of the tower. The condensed hydrogen fluoride liquid is obtained at the top of the water scrubber, and part of it is refluxed to the water scrubber. The extracted hydrogen fluoride liquid is filtered and mixed with ultrapure water to obtain the final electronic grade hydrofluoric acid product.

[0041] Preferably, the raw material industrial anhydrous hydrogen fluoride liquid in step (1) has a hydrogen fluoride content of ≥99.99%, a fluorosilicic acid content of ≤0.0007%, a sulfur dioxide content of ≤0.0001%, a non-volatile acid (in terms of H2SO4) of ≤0.001%, a water content of ≤0.0004%, a sulfur component content of ≤99.06 mg / kg, and an arsenic component content of ≤2.3 mg / kg;

[0042] Alternatively, in step (1), the high-purity oxidant is selected from one or more of fluorine gas, oxygen, fluorine-nitrogen mixed gas, and oxygen-nitrogen mixed gas, preferably fluorine-nitrogen mixed gas, in which the volume ratio of fluorine gas to nitrogen in the fluorine-nitrogen mixed gas is 1:5-10.

[0043] Preferably, the mass flow ratio of the high-purity oxidant to the anhydrous hydrogen fluoride liquid in step (1) is 0.05-0.5:1;

[0044] Alternatively, the material of the oxidation distillation tower in step (1) is selected from one of stainless steel or carbon steel lined with polytetrafluoroethylene material, stainless steel or carbon steel lined with silicon carbide material, and stainless steel or carbon steel lined with low borosilicate material, preferably stainless steel lined with polytetrafluoroethylene material.

[0045] Preferably, the top temperature of the oxidation distillation tower in step (1) is 19-35° C. and the pressure is atmospheric pressure;

[0046] Alternatively, the condenser of the oxidation distillation tower in step (1) uses cooling water or a brine solution with a mass concentration of 25%-33% or ammonia or carbon dioxide as a coolant, and the outlet temperature is controlled at 15.0-21.0°C.

[0047] Preferably, the mass ratio of the top circulating oxidant to the discharged oxidant of the oxidation distillation tower in step (2) is 7-12:1;

[0048] Alternatively, the material of the deweighting tower in step (2) is selected from one of stainless steel or carbon steel lined with polytetrafluoroethylene material, stainless steel or carbon steel lined with silicon carbide material, and stainless steel or carbon steel lined with low borosilicate material, preferably stainless steel lined with polytetrafluoroethylene material.

[0049] Preferably, the top temperature of the deweighting tower in step (2) is 18-43°C;

[0050] Alternatively, the pressure of the deweighting tower in step (2) is 1.0-10.0 times the normal pressure.

[0051] Preferably, the material of the water washing tower in step (3) is selected from one of stainless steel or carbon steel lined with polytetrafluoroethylene material, stainless steel or carbon steel lined with silicon carbide material, and stainless steel or carbon steel lined with low borosilicate material, preferably stainless steel lined with polytetrafluoroethylene material;

[0052] Alternatively, the tower pressure of the water washing tower in step (3) is normal pressure;

[0053] Alternatively, the reflux ratio of the water washing tower in step (3) is 1.0-6.0;

[0054] Alternatively, the condenser of the water washing tower in step (3) uses cooling water or a saline solution with a mass concentration of 25%-33% or ammonia or carbon dioxide as a coolant, and the outlet temperature is controlled at 12.0-19.5° C.;

[0055] Alternatively, the filtration in step (3) is filtration using a polytetrafluoroethylene nanofiltration membrane, and the accuracy of the polytetrafluoroethylene nanofiltration membrane is 0.1-0.5 μm.

[0056] A production system of electronic grade hydrofluoric acid for implementing the preparation method as described above, the production system comprises an anhydrous hydrogen fluoride storage tank, a gas storage tank, an oxidation distillation tower, a first condenser, a first reboiler, a deweighting tower, a second reboiler, a water scrubber, a second condenser and a third reboiler, the anhydrous hydrogen fluoride storage tank can contain industrial grade anhydrous hydrogen fluoride, the gas storage tank can contain a high-purity oxidant; the oxidation distillation tower, the deweighting tower and the water scrubber are all arranged in a vertical direction, the top of the oxidation distillation tower is closely connected to the first condenser, the bottom of the oxidation distillation tower is closely connected to the first reboiler, the middle of the oxidation distillation tower is The upper part is tightly connected with the anhydrous hydrogen fluoride storage tank, the lower part of the oxidation distillation tower is tightly connected with the gas storage tank, the bottom of the oxidation distillation tower is tightly connected with the middle and upper part of the deweighting tower, the top of the deweighting tower is tightly connected with the lower part of the water washing tower, the bottom of the deweighting tower is also connected with a second reboiler, the middle and upper part of the water washing tower is connected with the ultrapure water feed, the top of the water washing tower is tightly connected with a second condenser, the bottom of the water washing tower is tightly connected with a third reboiler, the top of the water washing tower can output the ultra-high purity hydrogen fluoride obtained after treatment, and electronic grade hydrofluoric acid product can be obtained after mixing with ultrapure water.

[0057] Preferably, the distillation tower comprises an industrial-grade anhydrous hydrogen fluoride inlet, a high-purity oxidant inlet, a steam outlet, a hydrogen fluoride liquid outlet, a hydrogen fluoride reflux liquid inlet and a distillation tower body. The oxidation distillation tower body is arranged in the vertical direction. The anhydrous hydrogen fluoride inlet and the hydrogen fluoride reflux liquid inlet are closely connected and arranged in the middle and upper part of the distillation tower body. The anhydrous hydrogen fluoride storage tank is closely connected with the industrial-grade anhydrous hydrogen fluoride inlet. The industrial-grade anhydrous hydrogen fluoride in the anhydrous hydrogen fluoride storage tank can be input into the middle and upper part of the distillation tower body. The high-purity oxidant inlet is closely connected and arranged in the lower part of the distillation tower body. The gas storage tank is closely connected with the high-purity oxidant inlet. The high-purity oxidant in the gas storage tank can be input into the lower part of the distillation tower body. The high-purity oxidant flows upward from the lower part of the distillation tower body to the top of the distillation tower body. The top of the distillation tower body is closely connected to be provided with a steam outlet, and the steam outlet is closely connected to be provided with a first condenser, the first condenser includes a material inlet, a condensed material outlet and an uncondensed material outlet, the material inlet of the first condenser is closely connected to the steam outlet, and the steam overflowing from the steam outlet can be condensed, the condensed material outlet is closely connected to the hydrogen fluoride reflux liquid inlet, the steam condensed by the first condenser enters the top of the distillation tower body through the condensed material outlet and the hydrogen fluoride reflux liquid inlet, the uncondensed material outlet is connected to the high-purity oxidant inlet, and the uncondensed high-purity oxidant and the oxidant entering the bottom of the distillation tower body are merged through the high-purity oxidant inlet and recycled; the bottom of the distillation tower body is closely connected to be provided with a hydrogen fluoride liquid outlet, and the bottom of the tower is also connected to be provided with a first reboiler;

[0058] The deweighting tower comprises a hydrogen fluoride liquid inlet, a deweighted material outlet, a hydrogen fluoride gas outlet and a deweighting tower body, the deweighting tower body is arranged in a vertical direction, the hydrogen fluoride liquid inlet is closely connected and arranged at the upper part of the deweighting tower body, the hydrogen fluoride liquid inlet is closely connected and arranged with the hydrogen fluoride liquid outlet of the distillation tower, the hydrogen fluoride gas outlet is closely connected and arranged at the top of the deweighting tower body, the deweighted material outlet is closely connected and arranged at the bottom of the deweighting tower body, and the bottom of the deweighting tower body is also connected and arranged with a second reboiler;

[0059] The water washing tower comprises an ultrapure water inlet, a hydrogen fluoride gas inlet, a hydrofluoric acid liquid outlet, a hydrogen fluoride gas outlet, a hydrogen fluoride reflux liquid inlet and a water washing tower body. The water washing tower body is arranged in a vertical direction. The ultrapure water inlet is closely connected and arranged in the middle and upper part of the water washing tower body. Ultrapure water can be input into the water washing tower body from the ultrapure water inlet. The hydrogen fluoride gas inlet is closely connected and arranged in the lower part of the water washing tower body. The hydrogen fluoride gas outlet of the deweighting tower is closely connected with the hydrogen fluoride gas inlet of the water washing tower. The hydrogen fluoride gas at the top of the deweighting tower can be all sent to the lower part of the water washing tower. The top of the water washing tower body is closely connected and arranged with the hydrogen fluoride gas outlet. The gas outlet is closely connected with a second condenser, the second condenser comprises a material inlet and a condensed material outlet, the material inlet of the second condenser is closely connected with the hydrogen fluoride gas outlet of the water washing tower, and the hydrogen fluoride gas overflowing from the hydrogen fluoride gas outlet can be condensed, the condensed material outlet of the second condenser is closely connected with the hydrogen fluoride reflux liquid inlet of the water washing tower, the hydrogen fluoride condensed by the second condenser is condensed through the condensed material outlet of the second condenser, and then enters the top of the water washing tower body through the hydrogen fluoride reflux liquid inlet, the bottom of the water washing tower body is closely connected with a hydrofluoric acid liquid outlet, and the tower bottom is also connected with a third reboiler.

[0060] The production system as described above is used for the preparation of electronic grade hydrofluoric acid.

[0061] Specifically, the relevant preparation and detection are as follows:

[0062] Example 1

[0063] Industrial-grade anhydrous hydrogen fluoride liquid is transported from the raw material storage tank, that is, the anhydrous hydrogen fluoride storage tank to the middle of the oxidation distillation tower, and the flow rate is controlled at 10kg / h. The high-purity fluorine-nitrogen mixed gas is sent to the bottom of the oxidation distillation tower from the mixed gas storage tank. The volume ratio of fluorine gas to nitrogen in the mixed gas is 1:9, and the mixed gas flow rate is set to 0.5kg / h. The pressure of the oxidation distillation tower is atmospheric pressure, the distillation tower is made of stainless steel lined with polytetrafluoroethylene material, the top temperature is controlled at 19-35℃, the top condenser tube uses cooling water as the coolant, and the first condensation outlet temperature is set to 18℃. The top of the oxidation distillation tower uses full reflux, and a part of the uncondensed fluorine-nitrogen mixed gas is diverted, and the rest is recycled after being combined with the mixed gas entering the bottom of the oxidation distillation tower. The volume ratio of the circulating fluorine-nitrogen mixed gas to the discharged mixed gas is 11:1. The hydrogen fluoride liquid obtained at the bottom of the oxidation distillation tower is sent to the upper part of the deweighting tower. The deweighting tower is set to atmospheric pressure. The material is stainless steel lined with polytetrafluoroethylene. The outlet temperature of hydrogen fluoride gas at the top of the tower is 25°C. The pressure of the water washing tower is atmospheric pressure. The material is stainless steel lined with polytetrafluoroethylene. The top condenser of the water washing tower uses a saline solution with a mass concentration of 25%-33% as a coolant. The hydrogen fluoride liquid obtained by condensation is partially refluxed to the water washing tower. The reflux ratio is set to 2.0. The produced hydrogen fluoride liquid is filtered through a 0.5μm precision polytetrafluoroethylene nanofiltration membrane and mixed with ultrapure water to obtain electronic grade hydrofluoric acid products.

[0064] Example 2

[0065] Industrial-grade anhydrous hydrogen fluoride liquid is transported from the raw material storage tank, i.e., the anhydrous hydrogen fluoride storage tank, to the middle of the oxidation distillation tower, and the flow rate is controlled at 10kg / h. The high-purity fluorine-nitrogen mixed gas is sent from the mixed gas storage tank to the bottom of the oxidation distillation tower. The volume ratio of fluorine gas to nitrogen in the mixed gas is 1:9, and the mixed gas flow rate is set to 0.5kg / h. The pressure of the oxidation distillation tower is atmospheric pressure, the distillation tower is made of stainless steel lined with polytetrafluoroethylene material, the top temperature of the tower is controlled at 19-35℃, the top condenser tube uses cooling water as the coolant, and the first condensation outlet temperature is set to 18℃. The top of the oxidation distillation tower uses full reflux, and a part of the uncondensed fluorine-nitrogen mixed gas is diverted, and the rest is recycled after being combined with the mixed gas entering the bottom of the oxidation distillation tower. The volume ratio of the circulating fluorine-nitrogen mixed gas to the discharged mixed gas is 10:1. The hydrogen fluoride liquid obtained at the bottom of the oxidation distillation tower is sent to the upper part of the deweighting tower. The deweighting tower pressure is set to 1.5 times the normal pressure. The material is stainless steel lined with polytetrafluoroethylene material. The outlet temperature of hydrogen fluoride gas at the top of the tower is 20°C. The pressure of the water washing tower is normal pressure. The material is stainless steel lined with polytetrafluoroethylene material. The top condenser of the water washing tower uses a saline solution with a mass concentration of 25%-33% as a coolant. The hydrogen fluoride liquid obtained by condensation is partially refluxed to the water washing tower. The reflux ratio is set to 2.0. The extracted hydrogen fluoride liquid is filtered through a 0.2μm precision polytetrafluoroethylene nanofiltration membrane and mixed with ultrapure water to obtain electronic grade hydrofluoric acid products.

[0066] Example 3

[0067] Industrial-grade anhydrous hydrogen fluoride liquid is transported from the raw material storage tank, i.e., the anhydrous hydrogen fluoride storage tank, to the middle of the oxidation distillation tower, and the flow rate is controlled at 10kg / h. High-purity fluorine gas is sent from the fluorine gas storage tank to the bottom of the oxidation distillation tower, and the flow rate is set to 1.2kg / h. The pressure of the oxidation distillation tower is atmospheric pressure, and the distillation tower is made of stainless steel lined with polytetrafluoroethylene. The top temperature of the tower is controlled at 19-35℃. The top condenser tube uses cooling water as the coolant, and the condensation outlet temperature is set to 18℃. The top of the oxidation distillation tower uses total reflux, and a part of the uncondensed fluorine gas is diverted, and the rest is combined with the fluorine gas entering the bottom of the oxidation distillation tower and recycled. The volume ratio of the circulating fluorine gas to the discharged fluorine gas is 10:1. The hydrogen fluoride liquid obtained at the bottom of the oxidation distillation tower is sent to the upper part of the deweighting tower. The deweighting tower pressure is set to 1.5 times the atmospheric pressure. The material is stainless steel lined with polytetrafluoroethylene, and the outlet temperature of the hydrogen fluoride gas at the top of the tower is 19.5℃. The pressure of the water washing tower is normal pressure, and the material is stainless steel lined with polytetrafluoroethylene. The top condenser of the water washing tower uses a saline solution (mass concentration of 29.1%) as a coolant. The hydrogen fluoride liquid obtained by condensation is partially refluxed to the water washing tower. The reflux ratio is set to 3.0. The produced hydrogen fluoride liquid is filtered through a 0.2μm precision polytetrafluoroethylene nanofiltration membrane and mixed with ultrapure water to obtain electronic grade hydrofluoric acid products.

[0068] Example 4

[0069] Industrial-grade anhydrous hydrogen fluoride liquid is transported from the raw material storage tank, i.e., the anhydrous hydrogen fluoride storage tank, to the middle of the oxidation distillation tower, and the flow rate is controlled at 10kg / h. High-purity fluorine gas is sent from the fluorine gas storage tank to the bottom of the oxidation distillation tower, and the flow rate is set to 1.8kg / h. The pressure of the oxidation distillation tower is atmospheric pressure, and the distillation tower is made of stainless steel lined with polytetrafluoroethylene. The top temperature of the tower is controlled at 19-35℃. The top condenser tube uses cooling water as the coolant, and the condensation outlet temperature is set to 18℃. The top of the oxidation distillation tower uses full reflux, and a part of the uncondensed fluorine gas is diverted, and the rest is combined with the fluorine gas entering the bottom of the oxidation distillation tower and recycled. The volume ratio of the circulating fluorine gas to the discharged fluorine gas is 9:1. The hydrogen fluoride liquid obtained at the bottom of the oxidation distillation tower is sent to the upper part of the deweighting tower. The deweighting tower pressure is set to 2.0 times the atmospheric pressure. The material is stainless steel lined with polytetrafluoroethylene, and the outlet temperature of the hydrogen fluoride gas at the top of the tower is 19.5℃. The pressure of the water washing tower is normal pressure, and the material is stainless steel lined with polytetrafluoroethylene. The top condenser of the water washing tower uses a saline solution (mass concentration of 29.1%) as a coolant. The hydrogen fluoride liquid obtained by condensation is partially refluxed to the water washing tower. The reflux ratio is set to 3.0. The produced hydrogen fluoride liquid is filtered through a 0.2μm precision polytetrafluoroethylene nanofiltration membrane and mixed with ultrapure water to obtain electronic grade hydrofluoric acid products.

[0070] Example 5

[0071] Industrial-grade anhydrous hydrogen fluoride liquid is transported from the raw material storage tank, i.e., the anhydrous hydrogen fluoride storage tank, to the middle of the oxidation distillation tower, and the flow rate is controlled at 10kg / h. The high-purity fluorine-nitrogen mixed gas is sent from the mixed gas storage tank to the bottom of the oxidation distillation tower. The volume ratio of fluorine gas to nitrogen in the mixed gas is 1:10, and the mixed gas flow rate is set to 1.8kg / h. The pressure of the oxidation distillation tower is atmospheric pressure, the distillation tower is made of stainless steel lined with polytetrafluoroethylene material, the top temperature is controlled at 19-35℃, the top condenser tube uses cooling water as the coolant, and the condensation outlet temperature is set to 18℃. The top of the oxidation distillation tower uses full reflux, and a part of the uncondensed fluorine-nitrogen mixed gas is diverted, and the rest is recycled after being combined with the mixed gas entering the bottom of the oxidation distillation tower. The volume ratio of the circulating fluorine-nitrogen mixed gas to the discharged mixed gas is 9:1. The hydrogen fluoride liquid obtained at the bottom of the oxidation distillation tower is sent to the upper part of the deweighting tower. The deweighting tower pressure is set to 2.0 times the normal pressure. The material is stainless steel lined with polytetrafluoroethylene material. The outlet temperature of hydrogen fluoride gas at the top of the tower is 19.5°C. The pressure of the water washing tower is normal pressure. The material is stainless steel lined with polytetrafluoroethylene material. The top condenser of the water washing tower uses a saline solution (mass concentration of 29.1%) as a coolant. The hydrogen fluoride liquid obtained by condensation is partially refluxed to the water washing tower. The reflux ratio is set to 2.0. The extracted hydrogen fluoride liquid is filtered through a 0.1μm precision polytetrafluoroethylene nanofiltration membrane and mixed with ultrapure water to obtain electronic grade hydrofluoric acid products.

[0072] A production system for electronic grade hydrofluoric acid implementing the preparation method as described above, such as Figure 1 As shown, the production system comprises an anhydrous hydrogen fluoride storage tank 1, a gas storage tank 2, an oxidation distillation tower 3, a first condenser 4, a first reboiler 5, a deweighting tower 6, a second reboiler 7, a water scrubber 8, a second condenser 9 and a third reboiler 10, wherein the anhydrous hydrogen fluoride storage tank can contain industrial-grade anhydrous hydrogen fluoride, and the gas storage tank can contain high-purity oxidant; the oxidation distillation tower, the deweighting tower and the water scrubber are all arranged in a vertical direction, the top of the oxidation distillation tower is closely connected to the first condenser, the bottom of the oxidation distillation tower is closely connected to the first reboiler, and the middle and upper parts of the oxidation distillation tower are connected to the anhydrous hydrogen fluoride. The hydrogen storage tank is closely connected, the lower part of the oxidation distillation tower is closely connected with the gas storage tank, the bottom of the oxidation distillation tower is closely connected with the middle and upper part of the deweighting tower, the top of the deweighting tower is closely connected with the lower part of the water washing tower, the bottom of the deweighting tower is also connected with a second reboiler, the middle and upper part of the water washing tower is connected with the ultrapure water feed, the top of the water washing tower is closely connected with a second condenser, the bottom of the water washing tower is closely connected with a third reboiler, the top of the water washing tower can output the ultra-high purity hydrogen fluoride obtained after treatment, and electronic grade hydrofluoric acid product can be obtained after mixing with ultrapure water.

[0073] The production system has a simple structure and is easy to connect. It combines the reaction of high-purity oxidant gas to oxidize trivalent arsenic in anhydrous hydrogen fluoride raw materials with the distillation process, saving the equipment investment cost of the reactor. In addition, the circulating oxidant is used for oxidation, which not only reduces the amount of oxidant used, but also ensures the oxidation effect of the oxidant.

[0074] Specifically, the distillation tower comprises an industrial-grade anhydrous hydrogen fluoride inlet 31, a high-purity oxidant inlet 32, a steam outlet 33, a hydrogen fluoride liquid outlet 34, a hydrogen fluoride reflux liquid inlet 35 and a distillation tower body (not numbered in the figure), the oxidation distillation tower body is arranged in the vertical direction, the anhydrous hydrogen fluoride inlet and the hydrogen fluoride reflux liquid inlet are closely connected and arranged in the middle and upper part of the distillation tower body, the anhydrous hydrogen fluoride storage tank is closely connected with the industrial-grade anhydrous hydrogen fluoride inlet, the industrial-grade anhydrous hydrogen fluoride in the anhydrous hydrogen fluoride storage tank can be input into the middle and upper part of the distillation tower body, the high-purity oxidant inlet is closely connected and arranged in the lower part of the distillation tower body, the gas storage tank is closely connected with the high-purity oxidant inlet, the high-purity oxidant in the gas storage tank can be input into the lower part of the distillation tower body, the high-purity oxidant flows upward from the lower part of the distillation tower body to the top of the distillation tower body, and the distillation tower body The top of the distillation tower is closely connected to a steam outlet, and the steam outlet is closely connected to a first condenser. The first condenser includes a material inlet (not numbered in the figure), a condensed material outlet 41 and an uncondensed material outlet 42. The material inlet of the first condenser is closely connected to the steam outlet, and the steam overflowing from the steam outlet can be condensed. The condensed material outlet is closely connected to the hydrogen fluoride reflux liquid inlet, and the steam condensed by the first condenser enters the top of the distillation tower body through the condensed material outlet and the hydrogen fluoride reflux liquid inlet. The uncondensed material outlet is connected to the high-purity oxidant inlet, and the uncondensed high-purity oxidant and the oxidant entering the bottom of the distillation tower body are recycled after merging through the high-purity oxidant inlet, which saves costs. The bottom of the distillation tower body is closely connected to a hydrogen fluoride liquid outlet, and the bottom of the tower is also connected to a first reboiler to provide energy for distillation separation.

[0075] The deweighting tower comprises a hydrogen fluoride liquid inlet 61, a deweighted material outlet 62, a hydrogen fluoride gas outlet 63 and a deweighting tower body (not numbered in the figure). The deweighting tower body is arranged in a vertical direction. The hydrogen fluoride liquid inlet is closely connected and arranged at the upper part of the deweighting tower body. The hydrogen fluoride liquid inlet is closely connected and arranged with the hydrogen fluoride liquid outlet of the distillation tower. The hydrogen fluoride gas outlet is closely connected and arranged at the top of the deweighting tower body. The deweighted material outlet is closely connected and arranged at the bottom of the deweighting tower body. The bottom of the deweighting tower body is also connected and arranged with a second reboiler to provide energy for distillation separation.

[0076] The water washing tower comprises an ultrapure water inlet 81, a hydrogen fluoride gas inlet 82, a hydrofluoric acid liquid outlet 83, a hydrogen fluoride gas outlet 84, a hydrogen fluoride reflux liquid inlet 85 and a water washing tower body (not numbered in the figure). The water washing tower body is arranged in a vertical direction. The ultrapure water inlet is closely connected and arranged in the middle and upper part of the water washing tower body. Ultrapure water can be input into the water washing tower body from the ultrapure water inlet. The hydrogen fluoride gas inlet is closely connected and arranged in the lower part of the water washing tower body. The hydrogen fluoride gas outlet of the deweighting tower is closely connected with the hydrogen fluoride gas inlet of the water washing tower. The hydrogen fluoride gas at the top of the deweighting tower can be all sent to the lower part of the water washing tower. The top of the water washing tower body is closely connected and arranged with the hydrogen fluoride gas outlet. The second condenser is closely connected with the outlet of the water washing tower, and the second condenser includes a material inlet (not numbered in the figure) and a condensed material outlet (not numbered in the figure). The material inlet of the second condenser is closely connected with the hydrogen fluoride gas outlet of the water washing tower, and can condense the hydrogen fluoride gas overflowing from the hydrogen fluoride gas outlet. The condensed material outlet of the second condenser is closely connected with the hydrogen fluoride reflux liquid inlet of the water washing tower. The hydrogen fluoride condensed by the second condenser is condensed through the condensed material outlet of the second condenser, and then enters the top of the water washing tower body through the hydrogen fluoride reflux liquid inlet. The bottom of the water washing tower body is closely connected with the hydrofluoric acid liquid outlet, and the bottom of the tower is also connected with a third reboiler to provide energy for distillation separation.

[0077] The test results of the products obtained in the above five embodiments, namely the electronic grade hydrofluoric acid products, are as follows:

[0078]

[0079]

[0080] In the results of the above five embodiments, the arsenic ion impurity content was reduced to less than 10ppt, proving that the trivalent arsenic in the industrial-grade anhydrous hydrogen fluoride raw material was fully oxidized. Using fluorine gas and fluorine-nitrogen mixed gas oxidants, no impurities outside the original system are introduced. Compared with other oxidants, the present invention greatly reduces the difficulty of the separation process. After the de-weighting distillation separation process and the water washing distillation separation process, the non-metallic ion impurities and metal ion impurities in the system are fully removed, and the quality of the electronic-grade hydrofluoric acid product finally obtained can meet the SEMI-G5 (UP-SSS) standard.

[0081] Although the embodiments of the present invention are disclosed for illustrative purposes, those skilled in the art will appreciate that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments.

Claims

1. A method for preparing electronic grade hydrofluoric acid, characterized in that: The steps include: (1) Industrial-grade anhydrous hydrogen fluoride liquid is transported from a raw material storage tank, i.e., anhydrous hydrogen fluoride storage tank, to the middle of an oxidation distillation tower, and a high-purity oxidant is transported from a gas storage tank to the bottom of the oxidation distillation tower. A first condenser is disposed at the top of the oxidation distillation tower, and a first reboiler is disposed at the bottom of the tower; (2) The top of the oxidation distillation tower uses total reflux, a portion of the uncondensed high-purity oxidant is diverted and discharged, and the remaining condensed high-purity oxidant is combined with the oxidant entering the bottom of the oxidation distillation tower and then recycled; the hydrogen fluoride liquid obtained at the bottom of the oxidation distillation tower is sent to the upper part of the de-weighting tower, no condenser is set at the top of the de-weighting tower, and a second reboiler is set at the bottom of the tower; (3) The hydrogen fluoride gas at the top of the deweighting tower is all sent to the lower part of the water scrubber, and ultrapure water is fed from the middle of the water scrubber. A second condenser is set at the top of the water scrubber, and a third reboiler is set at the bottom of the tower. The condensed hydrogen fluoride liquid is obtained at the top of the water scrubber, and part of it is refluxed to the water scrubber. The extracted hydrogen fluoride liquid is filtered and mixed with ultrapure water to obtain the final electronic grade hydrofluoric acid product.

2. The preparation method according to claim 1, characterized in that: The raw material industrial anhydrous hydrogen fluoride liquid in step (1) has a hydrogen fluoride content of ≥99.99%, a fluorosilicic acid content of ≤0.0007%, a sulfur dioxide content of ≤0.0001%, a non-volatile acid (in terms of H2SO4) of ≤0.001%, a water content of ≤0.0004%, a sulfur component content of ≤99.06 mg / kg, and an arsenic component content of ≤2.3 mg / kg; Alternatively, the high-purity oxidant in step (1) is selected from one or more of fluorine gas, oxygen, a fluorine-nitrogen mixed gas, and an oxygen-nitrogen mixed gas.

3. The preparation method according to claim 1, characterized in that: The mass flow ratio of the high-purity oxidant to the anhydrous hydrogen fluoride liquid in step (1) is 0.05-0.5:1; Alternatively, the material of the oxidation distillation tower in step (1) is selected from one of stainless steel or carbon steel lined with polytetrafluoroethylene material, stainless steel or carbon steel lined with silicon carbide material, and stainless steel or carbon steel lined with low borosilicate material.

4. The preparation method according to claim 1, characterized in that: The top temperature of the oxidation distillation tower in step (1) is 19-35° C. and the pressure is normal pressure; Alternatively, the condenser of the oxidation distillation tower in step (1) uses cooling water or a brine solution with a mass concentration of 25%-33% or ammonia or carbon dioxide as a coolant, and the outlet temperature is controlled at 15.0-21.0°C.

5. The preparation method according to claim 1, characterized in that: The mass ratio of the top circulating oxidant to the discharged oxidant of the oxidation distillation tower in step (2) is 7-12:1; Alternatively, the material of the deweighting tower in step (2) is selected from one of stainless steel or carbon steel lined with polytetrafluoroethylene material, stainless steel or carbon steel lined with silicon carbide material, and stainless steel or carbon steel lined with low borosilicate material.

6. The preparation method according to claim 1, characterized in that: The top temperature of the deweighting tower in step (2) is 18-43° C. Alternatively, the pressure of the deweighting tower in step (2) is 1.0-10.0 times the normal pressure.

7. The preparation method according to claim 1, characterized in that: The material of the water washing tower in step (3) is selected from one of stainless steel or carbon steel lined with polytetrafluoroethylene material, stainless steel or carbon steel lined with silicon carbide material, and stainless steel or carbon steel lined with low borosilicate material, preferably stainless steel lined with polytetrafluoroethylene material; Alternatively, the tower pressure of the water washing tower in step (3) is normal pressure; Alternatively, the reflux ratio of the water washing tower in step (3) is 1.0-6.0; Alternatively, the condenser of the water washing tower in step (3) uses cooling water or a saline solution with a mass concentration of 25%-33% or ammonia or carbon dioxide as a coolant, and the outlet temperature is controlled at 12.0-19.5° C.; Alternatively, the filtration in step (3) is filtration using a polytetrafluoroethylene nanofiltration membrane, and the accuracy of the polytetrafluoroethylene nanofiltration membrane is 0.1-0.5 μm.

8. A production system for electronic grade hydrofluoric acid for implementing the preparation method according to any one of claims 1 to 7, characterized in that: The production system comprises an anhydrous hydrogen fluoride storage tank, a gas storage tank, an oxidation distillation tower, a first condenser, a first reboiler, a deweighting tower, a second reboiler, a water scrubber, a second condenser and a third reboiler. The anhydrous hydrogen fluoride storage tank can contain industrial-grade anhydrous hydrogen fluoride, and the gas storage tank can contain a high-purity oxidant. The oxidation distillation tower, the deweighting tower and the water scrubber are all arranged in a vertical direction. The top of the oxidation distillation tower is closely connected to the first condenser, the bottom of the oxidation distillation tower is closely connected to the first reboiler, and the upper and middle parts of the oxidation distillation tower are closely connected to the anhydrous hydrogen fluoride storage tank. The connection is arranged, the lower part of the oxidation distillation tower is tightly connected with the gas storage tank, the bottom of the oxidation distillation tower is tightly connected with the middle and upper part of the deweighting tower, the top of the deweighting tower is tightly connected with the lower part of the water washing tower, the bottom of the deweighting tower is also connected with a second reboiler, the middle and upper part of the water washing tower is connected with the ultrapure water feed, the top of the water washing tower is tightly connected with a second condenser, the bottom of the water washing tower is tightly connected with a third reboiler, the top of the water washing tower can output the ultra-high purity hydrogen fluoride obtained after treatment, and electronic grade hydrofluoric acid product can be obtained after mixing with ultrapure water.

9. The production system according to claim 8, characterized in that: The distillation tower comprises an industrial-grade anhydrous hydrogen fluoride inlet, a high-purity oxidant inlet, a steam outlet, a hydrogen fluoride liquid outlet, a hydrogen fluoride reflux liquid inlet and a distillation tower body. The oxidation distillation tower body is arranged in a vertical direction. The anhydrous hydrogen fluoride inlet and the hydrogen fluoride reflux liquid inlet are closely connected and arranged in the middle and upper part of the distillation tower body. The anhydrous hydrogen fluoride storage tank is closely connected with the industrial-grade anhydrous hydrogen fluoride inlet. The industrial-grade anhydrous hydrogen fluoride in the anhydrous hydrogen fluoride storage tank can be input into the middle and upper part of the distillation tower body. The high-purity oxidant inlet is closely connected and arranged in the lower part of the distillation tower body. The gas storage tank is closely connected with the high-purity oxidant inlet. The high-purity oxidant in the gas storage tank can be input into the lower part of the distillation tower body. The high-purity oxidant flows upward from the lower part of the distillation tower body to the top of the distillation tower body. The top of the tower body is closely connected to be provided with a steam outlet, and the steam outlet is closely connected to be provided with a first condenser, the first condenser includes a material inlet, a condensed material outlet and an uncondensed material outlet, the material inlet of the first condenser is closely connected to the steam outlet, and can perform a condensation operation on the steam overflowing from the steam outlet, the condensed material outlet is closely connected to the hydrogen fluoride reflux liquid inlet, the steam condensed by the first condenser enters the top of the distillation tower body through the condensed material outlet and the hydrogen fluoride reflux liquid inlet, the uncondensed material outlet is connected to the high-purity oxidant inlet, and the uncondensed high-purity oxidant and the oxidant entering the bottom of the distillation tower body are merged through the high-purity oxidant inlet and recycled; the bottom of the distillation tower body is closely connected to be provided with a hydrogen fluoride liquid outlet, and the bottom of the tower is also connected to be provided with a first reboiler; The deweighting tower comprises a hydrogen fluoride liquid inlet, a deweighted material outlet, a hydrogen fluoride gas outlet and a deweighting tower body, the deweighting tower body is arranged in a vertical direction, the hydrogen fluoride liquid inlet is closely connected and arranged at the upper part of the deweighting tower body, the hydrogen fluoride liquid inlet is closely connected and arranged with the hydrogen fluoride liquid outlet of the distillation tower, the hydrogen fluoride gas outlet is closely connected and arranged at the top of the deweighting tower body, the deweighted material outlet is closely connected and arranged at the bottom of the deweighting tower body, and the bottom of the deweighting tower body is also connected and arranged with a second reboiler; The water washing tower comprises an ultrapure water inlet, a hydrogen fluoride gas inlet, a hydrofluoric acid liquid outlet, a hydrogen fluoride gas outlet, a hydrogen fluoride reflux liquid inlet and a water washing tower body. The water washing tower body is arranged in a vertical direction. The ultrapure water inlet is closely connected and arranged in the middle and upper part of the water washing tower body. Ultrapure water can be input into the water washing tower body from the ultrapure water inlet. The hydrogen fluoride gas inlet is closely connected and arranged in the lower part of the water washing tower body. The hydrogen fluoride gas outlet of the deweighting tower is closely connected with the hydrogen fluoride gas inlet of the water washing tower. The hydrogen fluoride gas at the top of the deweighting tower can be all sent to the lower part of the water washing tower. The top of the water washing tower body is closely connected and arranged with the hydrogen fluoride gas outlet. The gas outlet is closely connected with a second condenser, the second condenser comprises a material inlet and a condensed material outlet, the material inlet of the second condenser is closely connected with the hydrogen fluoride gas outlet of the water washing tower, and the hydrogen fluoride gas overflowing from the hydrogen fluoride gas outlet can be condensed, the condensed material outlet of the second condenser is closely connected with the hydrogen fluoride reflux liquid inlet of the water washing tower, the hydrogen fluoride condensed by the second condenser is condensed through the condensed material outlet of the second condenser, and then enters the top of the water washing tower body through the hydrogen fluoride reflux liquid inlet, the bottom of the water washing tower body is closely connected with a hydrofluoric acid liquid outlet, and the tower bottom is also connected with a third reboiler.

10. Use of the production system according to claim 8 or 9 in the preparation of electronic grade hydrofluoric acid.

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