A production method and system for hydrogen fluoride

Abstract

The present invention relates to the technical field of hydrogen fluoride preparation, and particularly to a production method and system of hydrogen fluoride, comprising the following steps: A) Fluorosilicic acid and first concentrated sulfuric acid react in the main reaction zone to generate silicon tetrafluoride gas and a sulfuric acid solution containing hydrogen fluoride; B) The silicon tetrafluoride gas is introduced into the silicon tetrafluoride generation zone; the sulfuric acid solution containing hydrogen fluoride is split into at least two paths for preparing hydrogen fluoride gas; wherein: the first part of the sulfuric acid solution containing hydrogen fluoride is introduced into the distillation zone for separation, and the separated hydrogen fluoride gas is introduced into the hydrogen fluoride generation zone to remove moisture, and dry crude hydrogen fluoride gas is collected; the second part of the sulfuric acid solution containing hydrogen fluoride and second concentrated sulfuric acid are introduced into the mixing zone, and the diluted sulfuric acid solution after mixing treatment is recycled to the main reaction zone. The present invention directly performs parallel sulfuric acid circulation treatment in the separation section, uses sulfuric acid to treat the gas in each section, and improves the HF yield and purity.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen fluoride preparation, and particularly to a production method and system of hydrogen fluoride. Background Art

[0002] The main reaction formula for the one-step preparation of anhydrous hydrogen fluoride from fluosilicic acid in the prior art is shown in formula (1):

[0003]

[0004] Concentrated fluosilicic acid generates silicon tetrafluoride and hydrogen fluoride under the decomposition of concentrated sulfuric acid. The reaction principle is that concentrated fluosilicic acid is decomposed by heat under the heat release of concentrated sulfuric acid dilution. In the current hydrogen fluoride production systems on the market, there are mainly two methods for separating silicon tetrafluoride and hydrogen fluoride: the first is that the generated HF and SiF 4 are both released as gases from the reaction solution, and then the HF gas is separated from the mixed gas; the other is that SiF 4 is released as a gas from the solution while most of the HF remains in the reaction solution, and then the HF is separated from the sulfuric acid solution. In the above separation methods, part of the hydrogen fluoride escapes into the backend tail gas treatment system along with silicon tetrafluoride, and the purified tail gas still contains a certain amount of silicon tetrafluoride and hydrogen fluoride gases.

[0005] Hydrogen fluoride is a toxic gas. If it is discharged without treatment, it will pollute the environment and cause harm to the human body. Moreover, silicon tetrafluoride and hydrogen fluoride in the tail gas still have economic value, and direct discharge will lead to the loss of fluorine resources, thus causing waste of resources. The solutions of the prior art usually involve washing the tail gas, so that silicon tetrafluoride in the tail gas can be converted into fluosilicic acid and recycled to the reaction end as a raw material. Although this solution optimizes the utilization rate of fluorine resources to a certain extent, it does not directly solve the loss of hydrogen fluoride escape. Therefore, there is an urgent need to develop a production method that can effectively reduce the loss of hydrogen fluoride and improve the yield of hydrogen fluoride. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a production method and system of hydrogen fluoride, with relatively high yield and purity of hydrogen fluoride.

[0007] Another object of the present invention is to reduce energy consumption while reducing fluorine loss.

[0008] The present invention provides a production method of hydrogen fluoride, including the following steps:

[0009] A) Fluosilicic acid and the first concentrated sulfuric acid react in the main reaction zone to generate silicon tetrafluoride gas and a sulfuric acid solution containing hydrogen fluoride;

[0010] B) The silicon tetrafluoride gas is introduced into the silicon tetrafluoride generation area;

[0011] The sulfuric acid solution containing hydrogen fluoride is shunted into at least two paths for preparing hydrogen fluoride gas; wherein:

[0012] The first part of the sulfuric acid solution containing hydrogen fluoride is introduced into a distillation zone for separation, and the separated hydrogen fluoride gas is introduced into a hydrogen fluoride production zone to remove moisture, and dry crude hydrogen fluoride gas is collected;

[0013] The second part of the sulfuric acid solution containing hydrogen fluoride is heated and introduced into a mixing zone together with second concentrated sulfuric acid, and the diluted sulfuric acid solution after mixing treatment is recycled as a raw material to the main reaction zone.

[0014] Further, in step B), the mixing zone includes a silicon tetrafluoride production zone;

[0015] The second concentrated sulfuric acid flows through the silicon tetrafluoride production zone and is mixed with the second part of the sulfuric acid solution containing hydrogen fluoride and then recycled to the main reaction zone for drying and / or absorbing one or more gases in the silicon tetrafluoride production zone;

[0016] The temperature of the silicon tetrafluoride production zone is 20-120°C.

[0017] Further, in step B), after the separation in the distillation zone, it further includes:

[0018] The distillation mother liquor separated in the distillation zone is stripped to obtain high-temperature hydrogen fluoride gas and is transported to the silicon tetrafluoride production zone.

[0019] Further, in step B), after obtaining the crude hydrogen fluoride gas, it further includes:

[0020] The crude hydrogen fluoride gas is condensed and rectified to obtain purified hydrogen fluoride gas;

[0021] The light component gas generated during the rectification process is transported to the hydrogen fluoride production zone.

[0022] Further, in step B), the mixing zone includes an independent silicon tetrafluoride production zone and a hydrogen fluoride recovery zone; the second concentrated sulfuric acid flows through the silicon tetrafluoride production zone and the hydrogen fluoride recovery zone in sequence, and is mixed with the second part of the sulfuric acid solution containing hydrogen fluoride in the hydrogen fluoride recovery zone and then recycled to the main reaction zone for drying and / or absorbing one or more gases in the silicon tetrafluoride production zone and the hydrogen fluoride recovery zone;

[0023] The temperature of the silicon tetrafluoride production zone is 20-120°C; the temperature of the hydrogen fluoride recovery zone is 100-200°C.

[0024] Further, in step B), after the separation in the distillation zone, it further includes:

[0025] The distillation mother liquor separated in the distillation zone is stripped to obtain high-temperature hydrogen fluoride gas, which is then transported to the hydrogen fluoride recovery zone;

[0026] The hydrogen fluoride gas in the hydrogen fluoride recovery zone is transported to the silicon tetrafluoride generation zone for absorption.

[0027] Furthermore, in step B), after obtaining the crude hydrogen fluoride gas, it further includes:

[0028] The crude hydrogen fluoride gas is condensed and rectified to obtain purified hydrogen fluoride gas;

[0029] The light component gas generated during the rectification process is transported to the hydrogen fluoride recovery zone.

[0030] Furthermore, in step B), the mixing zone includes an independent silicon tetrafluoride generation zone, a hydrogen fluoride recovery zone, and a hydrogen fluoride absorption zone; the second concentrated sulfuric acid flows through the silicon tetrafluoride generation zone and the hydrogen fluoride absorption zone simultaneously to form two parallel flow paths;

[0031] The sulfuric acid solution flowing out of the silicon tetrafluoride generation zone is mixed with the second sulfuric acid solution containing hydrogen fluoride in the hydrogen fluoride recovery zone and then recycled to the main reaction zone for drying and / or absorbing one or more gases in the silicon tetrafluoride generation zone and the hydrogen fluoride recovery zone;

[0032] The sulfuric acid solution flowing out of the hydrogen fluoride absorption zone is mixed with the sulfuric acid solution in the hydrogen fluoride generation zone and then recycled to the main reaction zone for drying and / or absorbing one or more gases in the hydrogen fluoride absorption zone and the hydrogen fluoride generation zone;

[0033] The temperature of the silicon tetrafluoride generation zone is 20 - 120 °C; the temperature of the hydrogen fluoride recovery zone is 100 - 200 °C; the temperature of the hydrogen fluoride absorption zone is 10 - 140 °C.

[0034] Furthermore, after the distillation zone is separated, it further includes:

[0035] The distillation mother liquor separated in the distillation zone is stripped to obtain high-temperature hydrogen fluoride gas, which is then transported to the hydrogen fluoride recovery zone;

[0036] The hydrogen fluoride gas in the hydrogen fluoride recovery zone is transported to the hydrogen fluoride absorption zone for absorption.

[0037] Furthermore, in step B), after obtaining the crude hydrogen fluoride gas, it further includes:

[0038] The crude hydrogen fluoride gas is condensed and rectified to obtain purified hydrogen fluoride gas;

[0039] The light component gas generated during the rectification process is transported to the hydrogen fluoride recovery zone.

[0040] Furthermore, in step A), the mass concentration of fluosilicic acid in the main reaction zone is 30% - 55%, the mass concentration of the first concentrated sulfuric acid is 65% - 95%, and the reaction temperature is 80 - 130 °C;

[0041] In step B), the mass concentration of the second concentrated sulfuric acid is 96 - 98%.

[0042] The present invention also provides a hydrogen fluoride production system, comprising:

[0043] A main reaction device for adding fluosilicic acid and the first concentrated sulfuric acid for mixing reaction and discharging gas products and liquid products; the main reaction device is provided with at least two liquid outlets;

[0044] A distillation device for separating hydrogen fluoride gas from a part of fluorosulfuric acid discharged from the main reaction device; the distillation device is connected to one of the liquid outlets of the main reaction device;

[0045] A mixing device, including a hydrogen fluoride generating device for preparing crude hydrogen fluoride gas; the mixing device is connected to each liquid outlet of the main reaction device and a sulfuric acid inlet, and is used for mixing sulfuric acids from different sections and recycling them to the main reaction device to realize the sulfuric acid circulation for treating hydrogen fluoride gas.

[0046] The present invention provides a method for producing hydrogen fluoride, comprising the following steps: A) reacting fluosilicic acid and concentrated sulfuric acid in a main reaction zone to generate silicon tetrafluoride gas and a sulfuric acid solution containing hydrogen fluoride; B) introducing the silicon tetrafluoride gas into a silicon tetrafluoride generating zone; the sulfuric acid solution containing hydrogen fluoride is shunted into at least two paths for preparing hydrogen fluoride gas; wherein: introducing the first part of the sulfuric acid solution containing hydrogen fluoride into a distillation zone for separation, introducing the separated hydrogen fluoride gas into a hydrogen fluoride generating zone to remove moisture, and collecting dry crude hydrogen fluoride gas; introducing the second part of the sulfuric acid solution containing hydrogen fluoride and the initial concentrated sulfuric acid into a mixing zone, and recycling the diluted sulfuric acid solution after mixing treatment to the main reaction zone.

[0047] The present invention directly conducts sulfuric acid circulation treatment in parallel in the separation section, uses sulfuric acid to treat the gases in each section, recovers the silicon tetrafluoride gas generated in the reaction section, the light component gas generated in the purification section, and the hydrogen fluoride in the stripping section, thereby reducing the HF emission in the tail gas, improving the HF yield and purity, and innovating a new path for fluorine recovery in the system. In addition, the method for producing hydrogen fluoride provided by the present invention can reduce energy consumption while reducing fluorine loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the hydrogen fluoride production method of the present invention;

[0049] Figure 2Schematic diagram of the hydrogen fluoride production method provided by the first embodiment of the present invention;

[0050] Figure 3 Schematic diagram of the hydrogen fluoride production method provided by the second embodiment of the present invention;

[0051] Figure 4 Schematic diagram of the hydrogen fluoride production method provided by the third embodiment of the present invention;

[0052] Figure 5 Schematic diagram of the hydrogen fluoride production method provided by the fourth embodiment of the present invention. Detailed implementation manners

[0053] Next, in combination with the embodiments of the present invention, the technical solutions of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0054] As Figure 1 shown, the present invention provides a method for producing hydrogen fluoride, including the following steps:

[0055] A) Fluorosilicic acid and the first concentrated sulfuric acid react in the main reaction zone to generate silicon tetrafluoride gas and a sulfuric acid solution containing hydrogen fluoride;

[0056] B) The silicon tetrafluoride gas is introduced into the silicon tetrafluoride generation area;

[0057] The sulfuric acid solution containing hydrogen fluoride is divided into at least two paths for preparing hydrogen fluoride gas; among them:

[0058] The first part of the sulfuric acid solution containing hydrogen fluoride is introduced into the distillation area for separation, and the separated hydrogen fluoride gas is introduced into the hydrogen fluoride generation area to remove moisture, and dry crude hydrogen fluoride gas is collected;

[0059] The second part of the sulfuric acid solution containing hydrogen fluoride is heated and introduced into the mixing area together with the second concentrated sulfuric acid, and the diluted sulfuric acid solution after mixing treatment is recycled as a raw material to the main reaction zone.

[0060] In step A):

[0061] Fluorosilicic acid and the first concentrated sulfuric acid react in the main reaction zone to generate silicon tetrafluoride gas and a sulfuric acid solution containing hydrogen fluoride.

[0062] In certain embodiments of the present invention, the mass concentration of fluosilicic acid used in the main reaction zone is 30% to 55%, the mass concentration of the first concentrated sulfuric acid is 68% to 95%, and in the product solution obtained by reaction dilution, the mass concentration of sulfuric acid is about 65% to 80%.

[0063] In certain embodiments of the present invention, the source of the fluosilicic acid includes phosphate rock or fluorite, and it can be prepared by water absorption of SiF 4 obtained by water absorption, or prepared from silica sand and hydrofluoric acid, or prepared by mixing and heating silica sand, calcium fluoride and concentrated sulfuric acid.

[0064] In certain embodiments of the present invention, the sulfuric acid solution containing hydrogen fluoride in the second part can recover heat through a pipeline, and further circulate the heat to the main reaction zone.

[0065] The present invention has no special restrictions on the reaction parameters of the fluosilicic acid and the first concentrated sulfuric acid in the main reaction zone, and the reaction parameters well-known to those skilled in the art can be adopted; preferably, the reaction temperature of the fluosilicic acid and the first concentrated sulfuric acid is 80 to 130 °C. After the reaction, the gas containing silicon tetrafluoride contains a small amount of hydrogen fluoride gas, which is released from the solution, and most of the hydrogen fluoride remains in the sulfuric acid solution.

[0066] In step B):

[0067] The silicon tetrafluoride gas is introduced into the silicon tetrafluoride generation zone;

[0068] The sulfuric acid solution containing hydrogen fluoride is shunted into at least two paths for preparing hydrogen fluoride gas; among them:

[0069] The first part of the sulfuric acid solution containing hydrogen fluoride is introduced into the distillation zone for separation, and the separated hydrogen fluoride gas is introduced into the hydrogen fluoride generation zone to remove moisture, and dry crude hydrogen fluoride gas is collected;

[0070] The second part of the sulfuric acid solution containing hydrogen fluoride is heated and introduced into the mixing zone together with the second concentrated sulfuric acid, and the diluted sulfuric acid solution after mixing treatment is recycled as a raw material to the main reaction zone.

[0071] In certain embodiments of the present invention, in the gas containing silicon tetrafluoride obtained in step A), there are impurities such as H 2 O, HF, H 2 SO 4 steam, etc.

[0072] In certain embodiments of the present invention, the volume ratio of the first part of the sulfuric acid solution containing hydrogen fluoride to the second part of the sulfuric acid solution containing hydrogen fluoride is 0.25 to 4:1.

[0073] In certain embodiments of the present invention, in the hydrogen fluoride generation zone, the treatment temperature is 70 to 100 °C; the mass concentration of sulfuric acid is 70% to 85%.

[0074] In certain embodiments of the present invention, the temperature of the silicon tetrafluoride generation zone is 20 to 120 °C, preferably 60 to 120 °C; the mass concentration of the second concentrated sulfuric acid introduced into the silicon tetrafluoride generation zone is 80% to 95%.

[0075] Specifically, Figure 1 The function of the mixing zone is to achieve impurity removal, recovery, and drying through different sulfuric acid cycles of the materials, so as to improve the yield and purity of hydrogen fluoride gas. In the mixing zone, at least two sulfuric acid towers can be specifically used to treat the target gas.

[0076] Two-tower scheme:

[0077] In certain embodiments of the present invention, as Figure 2 shown, the mixing zone includes a silicon tetrafluoride generation zone, and the silicon tetrafluoride generation zone is provided with an inlet for concentrated sulfuric acid for adding the second concentrated sulfuric acid; this process route adds a new sulfuric acid treatment line compared with the conventional industry technology, that is: 1) main reaction zone → silicon tetrafluoride generation zone (tower 2) → main reaction zone;

[0078] Fluorosilicic acid and the first concentrated sulfuric acid react in the main reaction zone to generate silicon tetrafluoride gas and a sulfuric acid solution containing hydrogen fluoride; after the reaction, on the basis of the conventional distillation to separate the fluorine-containing sulfuric acid solution (the first part is the sulfuric acid solution containing hydrogen fluoride, simply referred to as the fluorine-containing sulfuric acid for separation), another part of the fluorine-containing sulfuric acid solution for circulation (the second part is the sulfuric acid solution containing hydrogen fluoride, simply referred to as the fluorine-containing sulfuric acid for circulation) is branched out and introduced into the silicon tetrafluoride generation zone; and, the second concentrated sulfuric acid also flows through the silicon tetrafluoride generation zone to dry the silicon tetrafluoride gas led out from the main reaction zone; after the second concentrated sulfuric acid flows through the silicon tetrafluoride generation zone, it is mixed with the fluorine-containing sulfuric acid for circulation in the silicon tetrafluoride generation zone and is reused as a raw material in the main reaction zone.

[0079] Furthermore, the fluorine-containing sulfuric acid for circulation can absorb excess heat during the circulation process and recover this part of the heat for the main reaction zone to increase the temperature of the reaction zone, reduce the steam consumption required for the fluorine-containing sulfuric acid for separation, and can significantly reduce energy consumption.

[0080] In certain embodiments of the present invention, after the distillation in the distillation zone, it further includes:

[0081] The distillation mother liquor separated in the distillation zone is stripped to obtain high-temperature hydrogen fluoride gas and is transported to the silicon tetrafluoride generation zone;

[0082] The initial concentrated sulfuric acid enters the silicon tetrafluoride generation zone to dry the silicon tetrafluoride gas led out from the main reaction zone and the high-temperature hydrogen fluoride gas obtained by stripping; the second concentrated sulfuric acid enters the silicon tetrafluoride generation zone, is mixed with the fluorosulfuric acid for recycling, and then is recycled to the main reaction zone. During this sulfuric acid recycling process, heat is absorbed, the temperature of the reaction zone is increased, the steam consumption required for separating the fluorosulfuric acid is reduced, and the energy consumption can be significantly reduced. The separated hydrogen fluoride gas is introduced into the hydrogen fluoride generation zone to remove moisture, and the sulfuric acid solution in the hydrogen fluoride generation zone is also recycled to the main reaction zone to reduce material loss.

[0083] In certain embodiments of the present invention, after obtaining the crude hydrogen fluoride gas, it further includes:

[0084] Condensing and rectifying the crude hydrogen fluoride gas to obtain purified hydrogen fluoride gas;

[0085] The light component gas generated during the rectifying process is transported to the hydrogen fluoride generation zone, and the hydrogen fluoride gas in the production system can be further recovered to improve the product yield.

[0086] In certain embodiments of the present invention, the condensation is carried out in a condensation tower. The crude hydrogen fluoride gas has a low water content but may have residual sulfuric acid, so condensation can remove the high-boiling sulfuric acid. The sulfuric acid solution obtained by condensation is recycled to the hydrogen fluoride generation zone.

[0087] Three-tower scheme:

[0088] In certain embodiments of the present invention, the mixing zone includes an independent silicon tetrafluoride generation zone and a hydrogen fluoride recovery zone; as Figure 3 shown, this process route adds two new sulfuric acid treatment lines compared with the conventional industry technology, namely: 1) main reaction zone → hydrogen fluoride recovery zone → main reaction zone; 2) initial concentrated sulfuric acid → silicon tetrafluoride generation zone → hydrogen fluoride recovery zone → main reaction zone.

[0089] Fluorosilicic acid and the first concentrated sulfuric acid react in the main reaction zone to generate silicon tetrafluoride gas and a sulfuric acid solution containing hydrogen fluoride; as described above, after the reaction, the fluorosulfuric acid is split into two paths. Different from the two-tower scheme described above, the fluorosulfuric acid for recycling is introduced into the hydrogen fluoride recovery zone; and the second concentrated sulfuric acid flows through the silicon tetrafluoride generation zone. The silicon tetrafluoride gas generated in this zone contains H 2 O, HF, H 2 SO 4 steam and other impurities. The above impurities enter the sulfuric acid solution. In the hydrogen fluoride absorption zone, the fluorosulfuric acid for recycling and the sulfuric acid solution flowing through the silicon tetrafluoride generation zone are mixed and used as raw materials to be recycled to the main reaction zone.

[0090] In certain embodiments of the present invention, after the separation in the distillation zone, it further includes:

[0091] The distilled mother liquor separated from the distillation zone is stripped to obtain high-temperature hydrogen fluoride gas, which is then transported to the hydrogen fluoride recovery zone; the second concentrated sulfuric acid sequentially enters the silicon tetrafluoride generation zone and the hydrogen fluoride recovery zone. The mass concentration of sulfuric acid in the hydrogen fluoride recovery zone is 68% - 85%, and the treatment temperature is 100 - 200 °C, preferably 120 - 160 °C. It is used to dry the silicon tetrafluoride gas led out from the main reaction zone and the high-temperature hydrogen fluoride gas obtained by stripping; the second concentrated sulfuric acid enters the silicon tetrafluoride generation zone, mixes with the recycled fluorine-containing sulfuric acid in the hydrogen fluoride recovery zone, and then is recycled to the main reaction zone. During this process, heat is absorbed in the sulfuric acid circulation process, the temperature of the reaction zone is increased, and the steam consumption required for the fluorine-containing sulfuric acid for separation is reduced, which can significantly reduce energy consumption.

[0092] The hydrogen fluoride gas in the hydrogen fluoride recovery zone is transported to the silicon tetrafluoride generation zone for drying.

[0093] In certain embodiments of the present invention, after obtaining the crude hydrogen fluoride gas, it further includes:

[0094] The crude hydrogen fluoride gas is condensed and rectified to obtain purified hydrogen fluoride gas;

[0095] The light component gas generated during the rectification process is transported to the hydrogen fluoride recovery zone, which can further recover the hydrogen fluoride gas in the production system and improve the product yield.

[0096] In certain embodiments of the present invention, the condensation is carried out in a condensation tower. The crude hydrogen fluoride gas has a low water content but may have residual sulfuric acid. Therefore, condensation can remove the high-boiling sulfuric acid. The sulfuric acid solution obtained by condensation is recycled to the hydrogen fluoride generation zone.

[0097] In the three-tower scheme, the hydrogen fluoride gas returned to the hydrogen fluoride recovery zone from each route, such as the high-temperature hydrogen fluoride gas obtained by stripping and the light component gas recovered by rectification, can be further dried through the above-mentioned circulation pipeline, and the soluble impurities contained in the gas can be removed.

[0098] Four-tower scheme (I):

[0099] In certain embodiments of the present invention, such as Figure 4As shown, the mixing zone includes an independent silicon tetrafluoride generation zone, a hydrogen fluoride recovery zone, and a hydrogen fluoride absorption zone; sulfuric acid inlets are respectively arranged on the silicon tetrafluoride generation zone and the hydrogen fluoride absorption zone for adding second concentrated sulfuric acid. The second concentrated sulfuric acid flows through the silicon tetrafluoride generation zone and the hydrogen fluoride absorption zone simultaneously to form two parallel flow paths. Three additional sulfuric acid treatment lines are added to this process route compared with the conventional industry technology, namely: 1) main reaction zone → hydrogen fluoride recovery zone → main reaction zone; 2) initial concentrated sulfuric acid → silicon tetrafluoride generation zone → hydrogen fluoride recovery zone → main reaction zone; 3) initial concentrated sulfuric acid → hydrogen fluoride absorption zone → hydrogen fluoride generation zone → main reaction zone.

[0100] Fluorosilicic acid and the first concentrated sulfuric acid react in the main reaction zone to generate silicon tetrafluoride gas and a sulfuric acid solution containing hydrogen fluoride. Different from the aforementioned three-tower scheme, a parallel additional flow path of a circulating sulfuric acid pipeline is provided to further absorb free hydrogen fluoride gas in the system. Based on this embodiment, those skilled in the art can also add more parallel pipelines to increase the circulation, and similar modifications are covered within the concept of the present invention.

[0101] In certain embodiments of the present invention, after the separation in the distillation zone, it further includes:

[0102] The distillation mother liquor separated from the distillation zone is stripped to obtain high-temperature hydrogen fluoride gas and is transported to the hydrogen fluoride recovery zone;

[0103] The initial concentrated sulfuric acid is divided into two paths and enters the hydrogen fluoride absorption zone and the silicon tetrafluoride generation zone respectively, which are respectively used to dry or absorb the gas therein. The sulfuric acid solution flowing through the hydrogen fluoride absorption zone flows to the hydrogen fluoride generation zone and then is recycled to the main reaction zone. The sulfuric acid concentration in the hydrogen fluoride absorption zone is 68% - 85%, and the treatment temperature is 10 - 140 °C, preferably 20 - 100 °C. The sulfuric acid solution flowing through the silicon tetrafluoride generation zone flows to the hydrogen fluoride recovery zone and is mixed with the fluorine-containing sulfuric acid for recycling and then used in the main reaction zone.

[0104] The hydrogen fluoride gas flowing through to the hydrogen fluoride recovery zone is transported to the hydrogen fluoride absorption zone and is absorbed by sulfuric acid to remove impurities.

[0105] In certain embodiments of the present invention, after obtaining the crude hydrogen fluoride gas, it further includes:

[0106] The crude hydrogen fluoride gas is condensed and rectified to obtain purified hydrogen fluoride gas;

[0107] The light component gas generated during the rectification process is transported to the hydrogen fluoride recovery zone, and the hydrogen fluoride gas in the production system can be further recovered, improving the product yield.

[0108] In certain embodiments of the present invention, the condensation is carried out in a condensation tower. The crude hydrogen fluoride gas has a low water content, but there may be residual sulfuric acid. Therefore, condensation can remove the high-boiling sulfuric acid. The sulfuric acid solution obtained by condensation is recycled to the hydrogen fluoride production area.

[0109] In the four-tower scheme (1), the second concentrated sulfuric acid enters the silicon tetrafluoride production area to dry the silicon tetrafluoride gas led out from the main reaction area; the second concentrated sulfuric acid enters the hydrogen fluoride absorption area to dry the high-temperature hydrogen fluoride gas obtained by stripping and the light-component gas recovered by rectification.

[0110] Four-tower scheme (II):

[0111] In certain embodiments of the present invention, as Figure 5 shown, the mixing area includes an independent silicon tetrafluoride production area and a hydrogen fluoride recovery area; the silicon tetrafluoride production area is provided with an inlet for concentrated sulfuric acid for adding the second concentrated sulfuric acid; the second concentrated sulfuric acid flows through the silicon tetrafluoride production area and the hydrogen fluoride recovery area in sequence, and is mixed with the second part of the sulfuric acid solution containing hydrogen fluoride in the hydrogen fluoride recovery area to dry and / or absorb one or more gases in the silicon tetrafluoride production area and the hydrogen fluoride recovery area; the crude hydrogen fluoride gas is mixed with the sulfuric acid solution in the pre-purification area for pre-purification to obtain pre-purified hydrogen fluoride gas.

[0112] The hydrogen fluoride gas led out from the hydrogen fluoride production area is introduced into the pre-purification area to remove high-boiling impurities (mainly sulfuric acid).

[0113] This process route adds three new sulfuric acid treatment lines compared with the conventional industry technology, namely: 1) main reaction area → hydrogen fluoride recovery area → main reaction area; 2) second concentrated sulfuric acid → silicon tetrafluoride production area → hydrogen fluoride recovery area → main reaction area; 3) hydrogen fluoride production area → pre-purification tower → main reaction area.

[0114] Fluorosilicic acid and the first concentrated sulfuric acid react in the main reaction area to generate silicon tetrafluoride gas and a sulfuric acid solution containing hydrogen fluoride; as described above, after the reaction, the fluorine-containing sulfuric acid is split into two paths. Different from the aforementioned three-tower scheme, the treated sulfuric acid solution is recycled to the main reaction area as a raw material. The hydrogen fluoride gas led out from the hydrogen fluoride production area is introduced into the pre-purification area to remove high- and low-boiling impurities, further recover sulfuric acid and enter the main reaction area, and the light-component gas separated from the upper part of the pre-purification tower is recycled into the system for re-absorption. On the basis of this embodiment, those skilled in the art can also add a circulation recovery pipeline, and similar modifications are covered within the concept of the present invention.

[0115] The top of the pre-purification area is controlled by two-stage temperature to ensure the removal effect of high- and low-boiling impurities.

[0116] The hydrogen fluoride gas in the hydrogen fluoride recovery area is transported to the silicon tetrafluoride generation area for drying.

[0117] In certain embodiments of the present invention, after obtaining the pre-purified hydrogen fluoride gas, it further includes:

[0118] Condensing and rectifying the pre-purified hydrogen fluoride gas to obtain purified hydrogen fluoride gas;

[0119] The light component gas generated during the pre-purification and rectification processes is transported to the hydrogen fluoride recovery area, which can further recover the hydrogen fluoride gas in the production system and improve the product yield.

[0120] In certain embodiments of the present invention, the condensation is carried out in a condensation tower. The crude hydrogen fluoride gas has a low water content but may have residual sulfuric acid. Therefore, condensation can remove the high-boiling sulfuric acid. The sulfuric acid solution obtained by condensation is recycled to the hydrogen fluoride generation area.

[0121] In the four-tower scheme (II), the second concentrated sulfuric acid enters the silicon tetrafluoride generation area to dry the silicon tetrafluoride gas led out from the main reaction area and the light component gas recovered by rectification.

[0122] In certain embodiments of the present invention, in the hydrogen fluoride recovery area, the treatment temperature is 100 - 200 °C, preferably 120 - 160 °C; the mass concentration of sulfuric acid is 68% - 85%.

[0123] In certain embodiments of the present invention, in the pre-purification area, the temperature of the HF gas is 10 - 80 °C, specifically 70 - 80 °C; the temperature of the recovered sulfuric acid is 60 - 100 °C; the mass concentration of the recovered sulfuric acid is greater than 90%.

[0124] The present invention also provides a production system for hydrogen fluoride implementing the above-mentioned production method, including:

[0125] A main reaction device for adding fluorosilicic acid and the first concentrated sulfuric acid for mixing reaction and discharging gas products and liquid products; the main reaction device has at least two liquid outlets;

[0126] A distillation device for separating hydrogen fluoride gas from a part of the fluorosulfuric acid containing fluorine discharged from the main reaction device; the distillation device is connected to one of the liquid outlets of the main reaction device;

[0127] A mixing device including a hydrogen fluoride generation device for preparing crude hydrogen fluoride gas; the mixing device is connected to each liquid outlet of the main reaction device and the sulfuric acid inlet, and is used for mixing sulfuric acid from different sections and recycling it to the main reaction device to realize the cyclic treatment of hydrogen fluoride gas with sulfuric acid.

[0128] Specifically, it includes:

[0129] The main reaction device; the main reaction device is provided with a silicon tetrafluoride gas outlet, a first fluorosulfuric acid outlet, a second fluorosulfuric acid outlet, and a sulfuric acid inlet;

[0130] The distillation device; the distillation device is connected to the first fluorosulfuric acid outlet of the main reaction device;

[0131] The mixing device; the mixing device is provided with a concentrated sulfuric acid inlet and a fluorosulfuric acid inlet, and the fluorosulfuric acid inlet of the mixing device is connected to the second fluorosulfuric acid outlet of the main reaction device; the sulfuric acid outlet of the mixing device is connected to the sulfuric acid inlet of the main reaction device.

[0132] The hydrogen fluoride generation device; the hydrogen fluoride generation device is provided with a hydrogen fluoride gas inlet, and the hydrogen fluoride gas inlet is connected to the gas outlet of the distillation device.

[0133] The hydrogen fluoride production system provided by the present invention includes a main reaction device. The main reaction device is provided with a silicon tetrafluoride gas outlet, a first fluorosulfuric acid outlet, a second fluorosulfuric acid outlet, and a sulfuric acid inlet. In certain embodiments of the present invention, the main reaction device is a main reactor. The present invention does not impose any special restrictions on the type and size of the main reaction device, and a reaction vessel well-known to those skilled in the art can be used.

[0134] The hydrogen fluoride production system provided by the present invention further includes a distillation device. The distillation device is connected to the first fluorosulfuric acid outlet of the main reaction zone. In certain embodiments of the present invention, the distillation device is a distiller. The present invention does not impose any special restrictions on the structure and type of the distillation device, and it can be a generally commercially available distiller.

[0135] The hydrogen fluoride production system provided by the present invention further includes a mixing device. The mixing device is provided with a concentrated sulfuric acid inlet and a fluorosulfuric acid inlet, and the fluorosulfuric acid inlet of the mixing device is connected to the second fluorosulfuric acid outlet of the main reaction device; the sulfuric acid outlet of the mixing device is connected to the recycled sulfuric acid inlet of the main reaction device.

[0136] The hydrogen fluoride production system provided by the present invention further includes a hydrogen fluoride generation device; the hydrogen fluoride generation device is provided with a hydrogen fluoride gas inlet, and the hydrogen fluoride gas inlet of the hydrogen fluoride generation device is connected to the gas outlet of the distillation device.

[0137] In certain embodiments of the present invention, the hydrogen fluoride generation device is a first sulfuric acid tower. The first sulfuric acid tower can be a generally commercially available sulfuric acid tower.

[0138] The first scheme:

[0139] In certain embodiments of the present invention, the mixing device includes a silicon tetrafluoride generation device;

[0140] The gas inlet of the silicon tetrafluoride generation device is connected to the gas outlet of the main reaction device;

[0141] The silicon tetrafluoride generation device is provided with a concentrated sulfuric acid inlet and a fluorosulfuric acid inlet, and the fluorosulfuric acid inlet of the silicon tetrafluoride generation device is connected to the second fluorosulfuric acid outlet of the main reaction device.

[0142] The sulfuric acid solution outlet of the hydrogen fluoride generation device is connected to the first circulating sulfuric acid inlet of the main reaction device.

[0143] The sulfuric acid solution outlet of the silicon tetrafluoride generation device is connected to the second circulating sulfuric acid inlet of the main reaction device.

[0144] In certain embodiments of the present invention, the silicon tetrafluoride generation device is a second sulfuric acid tower. The second sulfuric acid tower can be a generally commercially available sulfuric acid tower.

[0145] In certain embodiments of the present invention, the production system further includes a stripping device;

[0146] The inlet of the stripping device is connected to the distillation mother liquor outlet of the distillation device;

[0147] The outlet of the stripping device is connected to the hydrogen fluoride gas inlet of the silicon tetrafluoride generation device.

[0148] In certain embodiments of the present invention, the stripping device is a stripping tower. The stripping tower can be a generally commercially available stripping tower.

[0149] In certain embodiments of the present invention, the production system further includes: a condensation tower and a rectification tower;

[0150] The gas inlet of the condensation tower is connected to the hydrogen fluoride gas outlet of the hydrogen fluoride generation device; the liquid outlet of the condensation tower is connected to the liquid inlet of the hydrogen fluoride generation device;

[0151] The condensation tower further includes a light component gas outlet, and the light component gas outlet of the condensation tower is connected to the first light component gas inlet of the hydrogen fluoride generation device.

[0152] The liquid inlet of the rectification tower is connected to the liquid outlet of the condensation tower; the hydrogen fluoride gas outlet of the rectification tower obtains purified hydrogen fluoride gas.

[0153] The rectification tower further includes a light component gas outlet, and the light component gas outlet of the rectification tower is connected to the second light component gas inlet of the hydrogen fluoride generation device.

[0154] In certain embodiments of the present invention, the condensation tower is a commonly commercially available condensation tower; the rectification tower is a commonly commercially available rectification tower.

[0155] The second scheme:

[0156] In certain embodiments of the present invention, the mixing zone includes: a silicon tetrafluoride generation device and a hydrogen fluoride recovery device independently arranged;

[0157] The gas inlet of the silicon tetrafluoride generation device is connected to the gas outlet of the main reaction device;

[0158] The silicon tetrafluoride generation device is provided with a concentrated sulfuric acid inlet;

[0159] The hydrogen fluoride recovery device is provided with a fluorosulfuric acid inlet, the fluorosulfuric acid inlet of the hydrogen fluoride recovery device is connected to the second fluorosulfuric acid outlet of the main reaction device, the hydrogen fluoride recovery device is further provided with a sulfuric acid inlet, and the sulfuric acid inlet is connected to the sulfuric acid outlet of the silicon tetrafluoride generation device.

[0160] In certain embodiments of the present invention, the silicon tetrafluoride generation device is a second sulfuric acid tower. The second sulfuric acid tower can be a commonly commercially available sulfuric acid tower.

[0161] In certain embodiments of the present invention, the hydrogen fluoride recovery device is a third sulfuric acid tower. The third sulfuric acid tower can be a commonly commercially available sulfuric acid tower.

[0162] In certain embodiments of the present invention, the production system further includes a stripping device;

[0163] The inlet of the stripping device is connected to the distillation mother liquor outlet of the distillation device;

[0164] The outlet of the stripping device is connected to the hydrogen fluoride gas inlet of the hydrogen fluoride recovery device.

[0165] In certain embodiments of the present invention, the stripping device is a stripping tower. The stripping tower can be a commonly commercially available stripping tower.

[0166] In certain embodiments of the present invention, the production system further includes: a condensation tower and a rectification tower;

[0167] The gas inlet of the condensation tower is connected to the hydrogen fluoride gas outlet of the hydrogen fluoride generation device; the liquid outlet of the condensation tower is connected to the liquid inlet of the hydrogen fluoride generation device;

[0168] The condensation tower further includes a light component gas outlet, and the light component gas outlet of the condensation tower is connected to the first light component gas inlet of the hydrogen fluoride recovery device.

[0169] The liquid inlet of the rectification column is connected to the liquid outlet of the condensation column; the purified hydrogen fluoride gas is obtained from the hydrogen fluoride gas outlet of the rectification column;

[0170] The rectification column further includes a light component gas outlet, and the light component gas outlet of the rectification column is connected to the second light component gas inlet of the hydrogen fluoride recovery device.

[0171] In certain embodiments of the present invention, the condensation column is a commonly commercially available condensation column; the rectification column is a commonly commercially available rectification column.

[0172] The hydrogen fluoride gas outlet of the hydrogen fluoride recovery device is connected to the hydrogen fluoride gas inlet of the silicon tetrafluoride generation device.

[0173] The third scheme:

[0174] In certain embodiments of the present invention, the mixing zone includes: a silicon tetrafluoride generation device, a hydrogen fluoride recovery device, and a hydrogen fluoride absorption device independently arranged;

[0175] The gas inlet of the silicon tetrafluoride generation device is connected to the gas outlet of the main reaction device;

[0176] The silicon tetrafluoride generation device is provided with a concentrated sulfuric acid inlet; the hydrogen fluoride recovery device is provided with a fluorosulfuric acid inlet, and the fluorosulfuric acid inlet of the hydrogen fluoride recovery device is connected to the second fluorosulfuric acid outlet of the main reaction device. The hydrogen fluoride recovery device is further provided with a sulfuric acid inlet, and the sulfuric acid inlet is connected to the sulfuric acid outlet of the silicon tetrafluoride generation device;

[0177] The hydrogen fluoride absorption device is provided with a concentrated sulfuric acid inlet and a sulfuric acid outlet; the sulfuric acid outlet of the hydrogen fluoride absorption device is connected to the sulfuric acid inlet of the hydrogen fluoride generation device.

[0178] In certain embodiments of the present invention, the silicon tetrafluoride generation device is a second sulfuric acid tower. The second sulfuric acid tower can be a commonly commercially available sulfuric acid tower.

[0179] In certain embodiments of the present invention, the hydrogen fluoride recovery device is a third sulfuric acid tower. The third sulfuric acid tower can be a commonly commercially available sulfuric acid tower.

[0180] In certain embodiments of the present invention, the hydrogen fluoride absorption device is a fourth sulfuric acid tower. The fourth sulfuric acid tower can be a commonly commercially available sulfuric acid tower.

[0181] In certain embodiments of the present invention, the production system further includes a stripping device;

[0182] The inlet of the stripping device is connected to the distillation mother liquor outlet of the distillation device;

[0183] The outlet of the stripping device is connected to the hydrogen fluoride gas inlet of the hydrogen fluoride recovery device.

[0184] In certain embodiments of the present invention, the stripping device is a stripping tower. The stripping tower can be a commonly commercially available stripping tower.

[0185] In certain embodiments of the present invention, the production system further includes: a condensation tower and a rectification tower;

[0186] The gas inlet of the condensation tower is connected to the hydrogen fluoride gas outlet of the hydrogen fluoride generation device; the liquid outlet of the condensation tower is connected to the liquid inlet of the hydrogen fluoride generation device;

[0187] The condensation tower further includes a light component gas outlet, and the light component gas outlet of the condensation tower is connected to the first light component gas inlet of the hydrogen fluoride recovery device.

[0188] The gas inlet of the rectification tower is connected to the gas outlet of the condensation tower; the purified hydrogen fluoride gas is obtained from the hydrogen fluoride gas outlet of the rectification tower;

[0189] The rectification tower further includes a light component gas outlet, and the light component gas outlet of the rectification tower is connected to the light component gas inlet of the hydrogen fluoride recovery device.

[0190] The hydrogen fluoride gas outlet of the hydrogen fluoride recovery device is connected to the hydrogen fluoride gas inlet of the hydrogen fluoride absorption device.

[0191] In certain embodiments of the present invention, the condensation tower is a commonly commercially available condensation tower; the rectification tower is a commonly commercially available rectification tower.

[0192] The fourth scheme:

[0193] In certain embodiments of the present invention, the mixing zone includes: a separately provided silicon tetrafluoride generation device and a hydrogen fluoride recovery device;

[0194] The gas inlet of the silicon tetrafluoride generation device is connected to the gas outlet of the main reaction device;

[0195] The silicon tetrafluoride generation device is provided with a concentrated sulfuric acid inlet;

[0196] The hydrogen fluoride recovery device is provided with a fluorosulfuric acid inlet, the fluorosulfuric acid inlet of the hydrogen fluoride recovery device is connected to the second fluorosulfuric acid outlet of the main reaction device, the hydrogen fluoride recovery device is further provided with a sulfuric acid inlet, and the sulfuric acid inlet is connected to the sulfuric acid outlet of the silicon tetrafluoride generation device.

[0197] In certain embodiments of the present invention, the silicon tetrafluoride generation device is a second sulfuric acid tower. The second sulfuric acid tower can be a commonly commercially available sulfuric acid tower.

[0198] In certain embodiments of the present invention, the hydrogen fluoride recovery device is a third sulfuric acid tower. The third sulfuric acid tower can be a generally commercially available sulfuric acid tower.

[0199] In certain embodiments of the present invention, the production system further includes: a pre-purification device; the gas inlet of the pre-purification device is connected to the hydrogen fluoride gas outlet of the hydrogen fluoride generation device; the high-boiling impurity outlet of the pre-purification device is connected to the high-boiling impurity inlet of the hydrogen fluoride generation device. In certain embodiments of the present invention, the pre-purification device is a fifth sulfuric acid tower. The fifth sulfuric acid tower can be a generally commercially available sulfuric acid tower.

[0200] In certain embodiments of the present invention, the production system further includes: a condensation tower and a rectification tower;

[0201] The gas inlet of the condensation tower is connected to the hydrogen fluoride gas outlet of the pre-purification device; the liquid outlet of the condensation tower is connected to the liquid inlet of the pre-purification device;

[0202] The condensation tower further includes a light component gas outlet, and the light component gas outlet of the condensation tower is connected to the first light component gas inlet of the hydrogen fluoride recovery device.

[0203] The liquid inlet of the rectification tower is connected to the liquid outlet of the condensation tower; the purified hydrogen fluoride gas is obtained from the hydrogen fluoride gas outlet of the rectification tower;

[0204] The rectification tower further includes a light component gas outlet, and the light component gas outlet of the rectification tower is connected to the second light component gas inlet of the hydrogen fluoride recovery device.

[0205] The hydrogen fluoride gas outlet of the hydrogen fluoride recovery device is connected to the hydrogen fluoride gas inlet of the silicon tetrafluoride generation device.

[0206] In certain embodiments of the present invention, the condensation tower is a generally commercially available condensation tower; the rectification tower is a generally commercially available rectification tower.

[0207] The present invention places no special restrictions on the sources of the raw materials used above, and they can be generally commercially available.

[0208] To further illustrate the present invention, the following provides a detailed description of a method for producing hydrogen fluoride according to the present invention in conjunction with embodiments, but it should not be construed as limiting the protection scope of the present invention.

[0209] Example 1

[0210] Using the hydrogen fluoride production system as Figure 2 shown, including:

[0211] Main reaction device (main reactor);

[0212] Distillation device (distiller); the distillation device is connected to the first fluorosulfuric acid outlet of the main reaction device;

[0213] Hydrogen fluoride generation device (first sulfuric acid tower); the hydrogen fluoride generation device is provided with a hydrogen fluoride gas inlet, and the hydrogen fluoride gas inlet of the hydrogen fluoride generation device is connected to the gas outlet of the distillation device; the sulfuric acid solution outlet of the hydrogen fluoride generation device is connected to the first circulating sulfuric acid inlet of the main reaction device; the sulfuric acid solution outlet of the silicon tetrafluoride generation device is connected to the second circulating sulfuric acid inlet of the main reaction device;

[0214] Silicon tetrafluoride generation device (second sulfuric acid tower); the gas inlet of the silicon tetrafluoride generation device is connected to the gas outlet of the main reaction device; the silicon tetrafluoride generation device is provided with a concentrated sulfuric acid inlet (for adding second concentrated sulfuric acid) and a fluorosulfuric acid inlet, and the fluorosulfuric acid inlet of the silicon tetrafluoride generation device is connected to the second fluorosulfuric acid outlet of the main reaction device;

[0215] Stripping device (stripping tower); the inlet of the stripping device is connected to the distillation mother liquor outlet of the distillation device; the outlet of the stripping device is connected to the hydrogen fluoride gas inlet of the silicon tetrafluoride generation device;

[0216] Condensation tower and rectification tower;

[0217] The gas inlet of the condensation tower is connected to the hydrogen fluoride gas outlet of the hydrogen fluoride generation device; the liquid outlet of the condensation tower is connected to the liquid inlet of the hydrogen fluoride generation device;

[0218] The condensation tower further includes a light component gas outlet, and the light component gas outlet of the condensation tower is connected to the first light component gas inlet of the hydrogen fluoride generation device.

[0219] The liquid inlet of the rectification tower is connected to the liquid outlet of the condensation tower; the purified hydrogen fluoride gas is obtained from the hydrogen fluoride gas outlet of the rectification tower.

[0220] The rectification tower further includes a light component gas outlet, and the light component gas outlet of the rectification tower is connected to the second light component gas inlet of the hydrogen fluoride generation device.

[0221] The method for producing hydrogen fluoride includes:

[0222] 1) Concentrated fluorosilicic acid (mass concentration of 48%) and first concentrated sulfuric acid (mass concentration of 80%) react in the main reactor to generate a gas containing silicon tetrafluoride and a sulfuric acid solution containing hydrogen fluoride; the temperature of the reaction product solution is 110 °C, and in the product solution, the mass concentration of sulfuric acid is 65%;

[0223] 2) The silicon tetrafluoride gas is introduced into the silicon tetrafluoride generation device;

[0224] The first part of the sulfuric acid solution containing hydrogen fluoride is introduced into the distillation device for separation. The separated hydrogen fluoride gas is introduced into the hydrogen fluoride generation device. The treatment temperature is 70 °C, and the mass concentration of sulfuric acid is 85%) to remove moisture, and dry crude hydrogen fluoride gas is collected;

[0225] The crude hydrogen fluoride gas is condensed in a condensation tower and rectified in a rectification tower to obtain purified hydrogen fluoride gas and light component gas; the light component gas generated during the rectification process is transported to the hydrogen fluoride generation device. The sulfuric acid solution obtained by condensation is recycled to the hydrogen fluoride generation device;

[0226] The second concentrated sulfuric acid flows through the silicon tetrafluoride generation device (the treatment temperature is 70 °C, and the mass concentration of sulfuric acid is 95%), and is mixed with the second part of the sulfuric acid solution containing hydrogen fluoride in the silicon tetrafluoride generation device; the diluted sulfuric acid solution after treatment in the silicon tetrafluoride generation device is recycled to the main reaction device;

[0227] The volume ratio of the first part of the sulfuric acid solution containing hydrogen fluoride to the second part of the sulfuric acid solution containing hydrogen fluoride is 2:1;

[0228] The distillation mother liquor separated by the distiller is stripped to obtain high-temperature hydrogen fluoride gas, which is transported to the silicon tetrafluoride generation device, mixed with the second part of the sulfuric acid solution containing hydrogen fluoride, and then recycled to the main reaction device.

[0229] After calculation and detection, the yield of the purified hydrogen fluoride obtained from the rectification tower is 97.9%, and the purity is 99.99%. Specifically, the calculation method of the yield is the ratio of the actually collected hydrogen fluoride to the theoretical value calculated from the reaction materials.

[0230] Example 2

[0231] Adopt as Figure 3 The shown hydrogen fluoride production system includes:

[0232] Main reaction device (main reactor);

[0233] Distillation device (distiller); The distillation device is connected to the first fluorine-containing sulfuric acid outlet of the main reaction device;

[0234] Hydrogen fluoride generation device (first sulfuric acid tower); The hydrogen fluoride generation device is provided with a hydrogen fluoride gas inlet, and the hydrogen fluoride gas inlet of the hydrogen fluoride generation device is connected to the gas outlet of the distillation device;

[0235] Silicon tetrafluoride generating device (second sulfuric acid tower); the gas inlet of the silicon tetrafluoride generating device is connected to the gas outlet of the main reactor; the silicon tetrafluoride generating device is provided with a concentrated sulfuric acid inlet for adding second concentrated sulfuric acid;

[0236] Hydrogen fluoride recovery device (third sulfuric acid tower); the hydrogen fluoride recovery device is provided with a fluorosulfuric acid inlet, the fluorosulfuric acid inlet of the hydrogen fluoride recovery device is connected to the second fluorosulfuric acid outlet of the main reaction device, the hydrogen fluoride recovery device is further provided with a sulfuric acid inlet, and the sulfuric acid inlet is connected to the sulfuric acid outlet of the silicon tetrafluoride generating device;

[0237] Stripping device (stripping tower); the inlet of the stripping device is connected to the distillation mother liquor outlet of the distillation device; the outlet of the stripping device is connected to the hydrogen fluoride gas inlet of the hydrogen fluoride recovery device;

[0238] Condensation tower and rectification tower;

[0239] The gas inlet of the condensation tower is connected to the hydrogen fluoride gas outlet of the hydrogen fluoride generating device; the liquid outlet of the condensation tower is connected to the liquid inlet of the hydrogen fluoride generating device;

[0240] The condensation tower further includes a light component gas outlet, and the light component gas outlet of the condensation tower is connected to the first light component gas inlet of the hydrogen fluoride recovery device;

[0241] The liquid inlet of the rectification tower is connected to the liquid outlet of the condensation tower; the purified hydrogen fluoride gas is obtained from the hydrogen fluoride gas outlet of the rectification tower;

[0242] The rectification tower further includes a light component gas outlet, and the light component gas outlet of the rectification tower is connected to the second light component gas inlet of the hydrogen fluoride recovery device.

[0243] The method for producing hydrogen fluoride includes:

[0244] 1) Concentrated fluorosilicic acid (mass concentration of 48%) and first concentrated sulfuric acid (mass concentration of 85%) react in the main reactor to generate a gas containing silicon tetrafluoride and a sulfuric acid solution containing hydrogen fluoride; the temperature of the reaction product solution is 110°C, and in the product solution, the mass concentration of sulfuric acid is 70%;

[0245] 2) The silicon tetrafluoride gas is introduced into the silicon tetrafluoride generating device;

[0246] First, a part of the sulfuric acid solution containing hydrogen fluoride is introduced into the distillation device for separation, and the separated hydrogen fluoride gas is introduced into the hydrogen fluoride generating device (treatment temperature is 90°C, mass concentration of sulfuric acid is 80%) to remove moisture, and dry crude hydrogen fluoride gas is collected;

[0247] The crude hydrogen fluoride gas is condensed in a condensation tower and rectified in a rectification tower to obtain purified hydrogen fluoride gas and light component gas; the light component gas generated during the rectification process is transported to a hydrogen fluoride recovery device; the sulfuric acid solution obtained by condensation is recycled to the hydrogen fluoride generation device; the hydrogen fluoride gas in the hydrogen fluoride recovery device is transported to a silicon tetrafluoride generation device for drying; the sulfuric acid solution obtained by condensation is recycled to the hydrogen fluoride generation device;

[0248] The second concentrated sulfuric acid flows through a silicon tetrafluoride generation area (treatment temperature is 90 °C, mass concentration of sulfuric acid is 90%) and a hydrogen fluoride recovery device (treatment temperature is 135 °C, mass concentration of sulfuric acid is 75%) in sequence, and is mixed with the second part of the sulfuric acid solution containing hydrogen fluoride in the hydrogen fluoride recovery device for drying and / or absorbing one or more gases in the silicon tetrafluoride generation device and the hydrogen fluoride recovery device;

[0249] The volume ratio of the first part of the sulfuric acid solution containing hydrogen fluoride to the second part of the sulfuric acid solution containing hydrogen fluoride is 2:1;

[0250] The distillation mother liquor separated by the distillation device is stripped to obtain high-temperature hydrogen fluoride gas, which is transported to the hydrogen fluoride recovery device and mixed with the second part of the sulfuric acid solution containing hydrogen fluoride and then recycled to the main reaction device.

[0251] Through calculation and detection, the yield of the purified hydrogen fluoride obtained by the rectification tower is 99.2%, the purity is 99.99%, the impurity gas is basically silicon tetrafluoride gas, the volume content of water in the impurity gas is less than 3%, and the volume content of air is less than 1%.

[0252] Example 3

[0253] Adopt as Figure 4 shown hydrogen fluoride production system, including:

[0254] Main reaction device (main reactor);

[0255] Distillation device (distiller); the distillation device is connected to the first fluorine-containing sulfuric acid outlet of the main reaction device;

[0256] Hydrogen fluoride generation device (first sulfuric acid tower); the hydrogen fluoride generation device is provided with a hydrogen fluoride gas inlet, and the hydrogen fluoride gas inlet of the hydrogen fluoride generation device is connected to the gas outlet of the distillation device;

[0257] Silicon tetrafluoride generation device (second sulfuric acid tower); the gas inlet of the silicon tetrafluoride generation device is connected to the gas outlet of the main reactor; the silicon tetrafluoride generation device is provided with a concentrated sulfuric acid inlet for adding the second concentrated sulfuric acid;

[0258] Hydrogen fluoride recovery device (third sulfuric acid tower); the hydrogen fluoride recovery device is provided with a fluorosulfuric acid inlet, and the fluorosulfuric acid inlet of the hydrogen fluoride recovery device is connected to the second fluorosulfuric acid outlet of the main reaction device. The hydrogen fluoride recovery device is also provided with a sulfuric acid inlet, and the sulfuric acid inlet is connected to the sulfuric acid outlet of the silicon tetrafluoride generation device;

[0259] The hydrogen fluoride absorption device (fourth sulfuric acid tower) is provided with a concentrated sulfuric acid inlet for adding initial concentrated sulfuric acid; the sulfuric acid outlet of the hydrogen fluoride absorption device is connected to the sulfuric acid inlet of the hydrogen fluoride generation device;

[0260] Stripping device; the inlet of the stripping device is connected to the distillation mother liquor outlet of the distillation device; the outlet of the stripping device is connected to the hydrogen fluoride gas inlet of the hydrogen fluoride recovery device;

[0261] Condensation tower and rectification tower;

[0262] The gas inlet of the condensation tower is connected to the hydrogen fluoride gas outlet of the hydrogen fluoride generation device; the liquid outlet of the condensation tower is connected to the liquid inlet of the hydrogen fluoride generation device;

[0263] The condensation tower further includes a light component gas outlet, and the light component gas outlet of the condensation tower is connected to the first light component gas inlet of the hydrogen fluoride recovery device;

[0264] The gas inlet of the rectification tower is connected to the gas outlet of the condensation tower; the purified hydrogen fluoride gas is obtained from the hydrogen fluoride gas outlet of the rectification tower; the rectification tower further includes a light component gas outlet, and the light component gas outlet of the rectification tower is connected to the light component gas inlet of the hydrogen fluoride recovery device.

[0265] The hydrogen fluoride gas outlet of the hydrogen fluoride recovery device is connected to the hydrogen fluoride gas inlet of the hydrogen fluoride absorption device.

[0266] The method for producing hydrogen fluoride includes:

[0267] 1) Concentrated fluorosilicic acid (mass concentration of 45%) and first concentrated sulfuric acid (mass concentration of 80%) react in the main reactor to generate a gas containing silicon tetrafluoride and a sulfuric acid solution containing hydrogen fluoride; the temperature of the reaction product solution is 110°C, and in the product solution, the mass concentration of sulfuric acid is 75%;

[0268] 2) The silicon tetrafluoride gas is introduced into the silicon tetrafluoride generation device;

[0269] The first part of the sulfuric acid solution containing hydrogen fluoride is introduced into the distillation device for separation, and the separated hydrogen fluoride gas is introduced into the hydrogen fluoride generation device (treatment temperature is 70°C, mass concentration of sulfuric acid is 85%) to remove moisture, and dry crude hydrogen fluoride gas is collected;

[0270] The crude hydrogen fluoride gas is condensed in a condensation tower and rectified in a rectification tower to obtain purified hydrogen fluoride gas and light component gas; the light component gas generated during the rectification process is transported to a hydrogen fluoride recovery device (the treatment temperature is 120 °C and the mass concentration of sulfuric acid is 70%); the sulfuric acid solution obtained by condensation is recycled to the hydrogen fluoride generation device; the hydrogen fluoride gas in the hydrogen fluoride recovery device is transported to a hydrogen fluoride absorption device for drying; the sulfuric acid solution obtained by condensation is recycled to the hydrogen fluoride generation device;

[0271] The second concentrated sulfuric acid flows through a silicon tetrafluoride generation device (the treatment temperature is 120 °C and the mass concentration of sulfuric acid is 95%) and a hydrogen fluoride absorption device (the treatment temperature is 60 °C and the mass concentration of sulfuric acid is 85%) simultaneously to form two parallel flow paths;

[0272] The sulfuric acid solution flowing out from the silicon tetrafluoride generation device is mixed with the second part of the sulfuric acid solution containing hydrogen fluoride in the hydrogen fluoride recovery device for drying and / or absorbing one or more gases in the silicon tetrafluoride generation device and the hydrogen fluoride recovery device;

[0273] The sulfuric acid solution flowing out from the hydrogen fluoride absorption device is mixed with the sulfuric acid solution in the hydrogen fluoride generation device for drying and / or absorbing one or more gases in the hydrogen fluoride absorption device and the hydrogen fluoride generation device;

[0274] The volume ratio of the first part of the sulfuric acid solution containing hydrogen fluoride to the second part of the sulfuric acid solution containing hydrogen fluoride is 2:1;

[0275] The distillation mother liquor separated by the distillation device is stripped to obtain high-temperature hydrogen fluoride gas, which is transported to the hydrogen fluoride recovery device and mixed with the second part of the sulfuric acid solution containing hydrogen fluoride and then recycled to the main reaction device.

[0276] Through calculation and detection, the yield of the purified hydrogen fluoride obtained by the rectification tower is 98.3% and the purity is 99.99%.

[0277] Example 4

[0278] Adopt as Figure 5 shown hydrogen fluoride production system, including:

[0279] Main reaction device (main reactor);

[0280] Distillation device (distiller); the distillation device is connected to the first fluorine-containing sulfuric acid outlet of the main reaction device;

[0281] Hydrogen fluoride production device (first sulfuric acid tower); the hydrogen fluoride production device is provided with a hydrogen fluoride gas inlet, and the hydrogen fluoride gas inlet of the hydrogen fluoride production device is connected to the gas outlet of the distillation device;

[0282] Silicon tetrafluoride production device (second sulfuric acid tower); the gas inlet of the silicon tetrafluoride production device is connected to the gas outlet of the main reaction device; the silicon tetrafluoride production device is provided with a concentrated sulfuric acid inlet for adding second concentrated sulfuric acid;

[0283] Hydrogen fluoride recovery device (third sulfuric acid tower); the hydrogen fluoride recovery device is provided with a fluorosulfuric acid inlet, the fluorosulfuric acid inlet of the hydrogen fluoride recovery device is connected to the second fluorosulfuric acid outlet of the main reaction device, the hydrogen fluoride recovery device is further provided with a sulfuric acid inlet, and the sulfuric acid inlet is connected to the sulfuric acid outlet of the silicon tetrafluoride production device;

[0284] Pre-purification device (fifth sulfuric acid tower); the gas inlet of the pre-purification device is connected to the hydrogen fluoride gas outlet of the hydrogen fluoride production device; the high-boiling impurity outlet of the pre-purification device is connected to the high-boiling impurity inlet of the hydrogen fluoride production device;

[0285] Condensation tower and rectification tower;

[0286] The inlet of the condensation tower is connected to the hydrogen fluoride gas outlet of the pre-purification device; the liquid outlet of the condensation tower is connected to the liquid inlet of the pre-purification device;

[0287] The condensation tower further includes a light component gas outlet, and the light component gas outlet of the condensation tower is connected to the first light component gas inlet of the hydrogen fluoride recovery device;

[0288] The liquid inlet of the rectification tower is connected to the liquid outlet of the condensation tower; the hydrogen fluoride gas outlet of the rectification tower obtains purified hydrogen fluoride gas;

[0289] The rectification tower further includes a light component gas outlet, and the light component gas outlet of the rectification tower is connected to the second light component gas inlet of the hydrogen fluoride recovery device;

[0290] The hydrogen fluoride gas outlet of the hydrogen fluoride recovery device is connected to the hydrogen fluoride gas inlet of the silicon tetrafluoride production device.

[0291] The method for producing hydrogen fluoride includes:

[0292] 1) Concentrated fluosilicic acid (mass concentration of 48%) and first concentrated sulfuric acid (mass concentration of 85%) react in the main reactor to generate a gas containing silicon tetrafluoride and a sulfuric acid solution containing hydrogen fluoride; the temperature of the reaction product solution is 110°C, and in the product solution, the mass concentration of sulfuric acid is 80%;

[0293] 2) The silicon tetrafluoride gas is introduced into the silicon tetrafluoride generating device;

[0294] The first part of the sulfuric acid solution containing hydrogen fluoride is introduced into a distillation device for separation, and the separated hydrogen fluoride gas is introduced into a hydrogen fluoride generating device (the treatment temperature is 70 °C, and the mass concentration of sulfuric acid is 85%) to remove moisture, and dry crude hydrogen fluoride gas is collected;

[0295] The crude hydrogen fluoride gas is mixed with the sulfuric acid solution in the pre-purification area (in the pre-purification area, the temperature of the HF gas is 70 - 80 °C, and the temperature of the recycled sulfuric acid is 60 - 100 °C) for pre-purification to obtain pre-purified hydrogen fluoride gas;

[0296] The pre-purified hydrogen fluoride gas is condensed in a condensation tower and rectified in a rectification tower to obtain purified hydrogen fluoride gas and light component gas; the light component gas generated during the rectification process is transported to a hydrogen fluoride recovery device; the sulfuric acid solution obtained by condensation is recycled to the hydrogen fluoride generating device; the hydrogen fluoride gas in the hydrogen fluoride recovery device is transported to the silicon tetrafluoride generating device for drying; the sulfuric acid solution obtained by condensation is recycled to the hydrogen fluoride generating device;

[0297] The initial concentrated sulfuric acid flows through the silicon tetrafluoride generating device (the treatment temperature is 70 °C, and the mass concentration of sulfuric acid is 98%) and the hydrogen fluoride recovery device (the treatment temperature is 120 - 160 °C, and the mass concentration of sulfuric acid is 70%) in sequence, and is mixed with the second part of the sulfuric acid solution containing hydrogen fluoride in the hydrogen fluoride recovery device for drying and / or absorbing one or more gases in the silicon tetrafluoride generating device and the hydrogen fluoride recovery device;

[0298] The volume ratio of the first part of the sulfuric acid solution containing hydrogen fluoride to the second part of the sulfuric acid solution containing hydrogen fluoride is 2:1.

[0299] The diluted sulfuric acid solution after being treated by the hydrogen fluoride recovery device is recycled to the main reaction device.

[0300] Through calculation and detection, the yield of the purified hydrogen fluoride obtained from the rectification tower is 97.9%, and the purity is 99.99%.

[0301] Example 5

[0302] The production process of this example is the same as that of Example 2, the difference is that: the mass concentration of concentrated fluosilicic acid is 30%, the temperature of the product solution after the reaction is 120 °C, in the product solution, the mass concentration of sulfuric acid is 65%; the treatment temperature of the initial concentrated sulfuric acid flowing through the silicon tetrafluoride generating device is 60 °C, and the temperature of the hydrogen fluoride generating device is 70 °C.

[0303] The yield of the purified hydrogen fluoride gas after calculation and detection is 97.5%, and the purity is 99.99%.

[0304] Example 6

[0305] The production process of this example is the same as that of Example 2, the difference is that: the mass concentration of concentrated fluorosilicic acid is 30%, the temperature of the product solution after reaction is 90 °C, in the product solution, the mass concentration of sulfuric acid is 70%; the treatment temperature of the initial concentrated sulfuric acid flowing through the silicon tetrafluoride generation device is 50 °C, and the sulfuric acid treatment temperature of the hydrogen fluoride generation device is 80 °C.

[0306] The yield of the purified hydrogen fluoride gas after calculation and detection is 98.3%, and the purity is 99.99%.

[0307] Example 7

[0308] The production process of this example is the same as that of Example 2, the difference is that: the mass concentration of concentrated fluorosilicic acid is 45%, the temperature of the product solution after reaction is 100 °C, in the product solution, the mass concentration of sulfuric acid is 70%; the treatment temperature of the initial concentrated sulfuric acid flowing through the silicon tetrafluoride generation device is 110 °C, and the sulfuric acid treatment temperature of the hydrogen fluoride generation device is 100 °C.

[0309] The yield of the purified hydrogen fluoride gas after calculation and detection is 98.9%, and the purity is 99.99%.

[0310] Example 8

[0311] The production process of this example is the same as that of Example 6, the difference is that: in the product solution, the mass concentration of sulfuric acid is 85%; the volume ratio of the first part of the sulfuric acid solution containing hydrogen fluoride to the second part of the sulfuric acid solution containing hydrogen fluoride is 1:1.

[0312] The yield of the purified hydrogen fluoride gas after calculation and detection is 97.5%, and the purity is 99.99%.

[0313] Example 9

[0314] The production process of this example is the same as that of Example 8, the difference is that: the volume ratio of the first part of the sulfuric acid solution containing hydrogen fluoride to the second part of the sulfuric acid solution containing hydrogen fluoride is 3:1.

[0315] The yield of the purified hydrogen fluoride gas after calculation and detection is 98.6%, and the purity is 99.99%.

[0316] Example 10

[0317] The production process of this embodiment is the same as that of Embodiment 9, the difference being that the mass concentration of concentrated fluosilicic acid is 50%, and the volume ratio of the first sulfuric acid solution containing hydrogen fluoride to the second sulfuric acid solution containing hydrogen fluoride is 1:2.

[0318] After calculation and detection, the yield of the purified hydrogen fluoride gas is 98.1% and the purity is 99.99%.

[0319] The relevant data of the above embodiments are shown in Table 1.

[0320] Table 1 Relevant parameters and effects of Embodiments 1 - 9

[0321]

[0322]

[0323] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A production method of hydrogen fluoride, comprising the following steps: A) Reacting fluosilicic acid and first concentrated sulfuric acid in the main reaction zone to generate silicon tetrafluoride gas and a sulfuric acid solution containing hydrogen fluoride; In step A), the mass concentration of fluosilicic acid in the main reaction zone is 30% - 55%, the mass concentration of the first concentrated sulfuric acid is 65% - 85%, the reaction temperature is 80 - 130 °C, and in the product solution obtained by reaction dilution, the mass concentration of sulfuric acid is 65% - 80%; B) Feeding the silicon tetrafluoride gas into the silicon tetrafluoride generation zone; The sulfuric acid solution containing hydrogen fluoride is divided into at least two paths for preparing hydrogen fluoride gas; among them: Feeding the first part of the sulfuric acid solution containing hydrogen fluoride into the distillation zone for separation, and feeding the separated hydrogen fluoride gas into the hydrogen fluoride generation zone to remove moisture, and collecting the dry crude hydrogen fluoride gas; Heating the second part of the sulfuric acid solution containing hydrogen fluoride and feeding it into the mixing zone together with the second concentrated sulfuric acid, and using the diluted sulfuric acid solution after mixing treatment as a raw material to be recycled to the main reaction zone; The volume ratio of the first part of the sulfuric acid solution containing hydrogen fluoride to the second part of the sulfuric acid solution containing hydrogen fluoride is 1 - 4:

1.

2. The production method according to claim 1, characterized in that, in step B), the mixing zone includes a silicon tetrafluoride generation zone; The second concentrated sulfuric acid flows through the silicon tetrafluoride generation zone and is mixed with the second part of the sulfuric acid solution containing hydrogen fluoride and then recycled to the main reaction zone for drying and / or absorbing one or more gases in the silicon tetrafluoride generation zone; The temperature of the silicon tetrafluoride generation zone is 20 - 120 °C.

3. The production method according to claim 2, characterized in that, in step B), after the separation in the distillation zone, it further includes: Stripping the distillation mother liquor separated in the distillation zone to obtain high-temperature hydrogen fluoride gas and transporting it to the silicon tetrafluoride generation zone.

4. The production method according to claim 2 or 3, characterized in that, in step B), after obtaining the crude hydrogen fluoride gas, it further includes: Condensing and rectifying the crude hydrogen fluoride gas to obtain purified hydrogen fluoride gas; The light component gas generated during the rectification process is transported to the hydrogen fluoride generation zone.

5. The production method according to claim 1, characterized in that, in step B), the mixing zone includes an independent silicon tetrafluoride generation zone and a hydrogen fluoride recovery zone; the second concentrated sulfuric acid flows through the silicon tetrafluoride generation zone and the hydrogen fluoride recovery zone in sequence, and is mixed with the second part of the sulfuric acid solution containing hydrogen fluoride in the hydrogen fluoride recovery zone and then recycled to the main reaction zone for drying and / or absorbing one or more gases in the silicon tetrafluoride generation zone and the hydrogen fluoride recovery zone; The temperature of the silicon tetrafluoride generation zone is 20 - 120 °C; the temperature of the hydrogen fluoride recovery zone is 100 - 200 °C.

6. The production method according to claim 5, characterized in that, in step B), after the separation in the distillation zone, it further includes: Stripping the distillation mother liquor separated in the distillation zone to obtain high-temperature hydrogen fluoride gas and transporting it to the hydrogen fluoride recovery zone; The hydrogen fluoride gas in the hydrogen fluoride recovery zone is transported to the silicon tetrafluoride generation zone for absorption.

7. The production method according to claim 5 or 6, characterized in that, in step B), after obtaining the crude hydrogen fluoride gas, it further includes: condensing and rectifying the crude hydrogen fluoride gas to obtain purified hydrogen fluoride gas; the light component gas generated during the rectifying process is transported to the hydrogen fluoride recovery area.

8. The production method according to claim 1, characterized in that, in step B), the mixing area includes an independent silicon tetrafluoride generation area, a hydrogen fluoride recovery area, and a hydrogen fluoride absorption area; the second concentrated sulfuric acid flows through the silicon tetrafluoride generation area and the hydrogen fluoride absorption area simultaneously to form two parallel flow paths; the sulfuric acid solution flowing out from the silicon tetrafluoride generation area is mixed with the second part of the sulfuric acid solution containing hydrogen fluoride in the hydrogen fluoride recovery area and then recycled to the main reaction area for drying and / or absorbing one or more gases in the silicon tetrafluoride generation area and the hydrogen fluoride recovery area; the sulfuric acid solution flowing out from the hydrogen fluoride absorption area is mixed with the sulfuric acid solution in the hydrogen fluoride generation area and then recycled to the main reaction area for drying and / or absorbing one or more gases in the hydrogen fluoride absorption area and the hydrogen fluoride generation area; the temperature of the silicon tetrafluoride generation area is 20 - 120 °C; the temperature of the hydrogen fluoride recovery area is 100 - 200 °C; the temperature of the hydrogen fluoride absorption area is 10 - 140 °C.

9. The production method according to claim 8, characterized in that, after the separation in the distillation area, it further includes: stripping the distillation mother liquor separated from the distillation area to obtain high-temperature hydrogen fluoride gas and transporting it to the hydrogen fluoride recovery area; the hydrogen fluoride gas in the hydrogen fluoride recovery area is transported to the hydrogen fluoride absorption area for absorption.

10. The production method according to claim 8 or 9, characterized in that, in step B), after obtaining the crude hydrogen fluoride gas, it further includes: condensing and rectifying the crude hydrogen fluoride gas to obtain purified hydrogen fluoride gas; the light component gas generated during the rectifying process is transported to the hydrogen fluoride recovery area.

11. The production method according to claim 2 or 5 or 8, characterized in that, in step B), the mass concentration of the second concentrated sulfuric acid is 96 - 98%.

12. A hydrogen fluoride production system for the production method according to any one of claims 1 - 11, comprising: a main reaction device for adding fluorosilicic acid and the first concentrated sulfuric acid for mixing reaction and discharging gas products and liquid products; the main reaction device is provided with at least two liquid outlets; a distillation device for separating hydrogen fluoride gas from a part of the fluorine-containing sulfuric acid discharged from the main reaction device; the distillation device is connected to one of the liquid outlets of the main reaction device; a mixing device including a hydrogen fluoride generation device for preparing crude hydrogen fluoride gas; the mixing device is connected to each liquid outlet of the main reaction device and a sulfuric acid inlet for mixing sulfuric acid from different sections and recycling it to the main reaction device to realize the cyclic treatment of hydrogen fluoride gas with sulfuric acid.

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