CN216997672U - Device for removing impurity arsenic in preparation process of electronic-grade hydrofluoric acid - Google Patents

Abstract

The utility model discloses a device for removing arsenic impurity in the preparation process of electronic-grade hydrofluoric acid, which comprises a first-stage pre-reaction condenser, a second-stage pre-reaction condenser, a reaction kettle, a reaction rectifying tower and a degassing distillation tower, wherein a feed inlet at the upper part of the reaction kettle is respectively connected with a discharge outlet at the lower part of a shell pass and a discharge outlet at the bottom of the first-stage pre-reaction condenser and the second-stage pre-reaction condenser through a pipeline and a valve, a feed inlet at the middle part of the reaction rectifying tower is connected with a discharge outlet at the bottom of the reaction kettle through a pipeline, a feed inlet at the middle part of the degassing distillation tower is connected with a gas phase outlet at the top of the reaction rectifying tower through a pipeline, and an oxidant pipeline is respectively connected with the first-stage pre-reaction condenser, the reaction kettle and a distributor in the reaction rectifying tower through pipelines. The method can effectively convert trivalent arsenic ions in the industrial raw material gas into pentavalent arsenic ions with lower volatility so as to meet the index requirement of downstream electronic-grade hydrofluoric acid production on arsenic content.

Description

Device for removing impurity arsenic in preparation process of electronic-grade hydrofluoric acid

Technical Field

The utility model is suitable for the technical field of hydrofluoric acid strong oxidation arsenic removal equipment, and particularly relates to a device for removing arsenic impurities in the preparation process of electronic-grade hydrofluoric acid.

Background

The electronic grade hydrofluoric acid is an aqueous solution of anhydrous hydrogen fluoride, is a colorless transparent liquid, is one of fluorine fine chemicals, is one of the most applied electronic chemicals in the semiconductor manufacturing process, can be used together with electronic grade reagents such as nitric acid, acetic acid, ammonium hydroxide, hydrogen peroxide and the like, is used as an etchant, a cleaning agent and the like, and is widely applied to the aspects of microelectronic industries such as large-scale integrated circuits, thin film liquid crystal displays, semiconductors and the like. In addition, it can be used as an analytical reagent and for the production of high purity fluorochemicals. The purity and cleanliness of electronic-grade hydrofluoric acid have very important influences on the yield, electrical property and reliability of integrated circuits. The indexes of the electronic grade hydrofluoric acid are divided differently at home and abroad, no uniform standard exists, and the purity of the electronic grade hydrofluoric acid has correspondingly different requirements according to different purposes. At present, the mass fraction of impurities in the process of preparing large-scale integrated circuits is required to be 10 in the standard requirements of the International society for semiconductors^–9A rank.

The impurities in the electronic-grade hydrofluoric acid mainly come from hydrogen fluoride, the impurities in the hydrogen fluoride depend on fluorite and sulfuric acid, and particularly the production place of the fluorite often contains ion impurities formed by Si, P, N, S, As, B, alkali metals, other metal elements and the like. The metal elements can be removed by rectification and water washing, while the low-boiling-point non-metal impurity elements such as arsenic and the like are difficult to remove by a simple direct rectification mode. Therefore, the arsenic removal method is a difficult point in the preparation of electronic grade hydrofluoric acid. At present, methods for removing arsenic from hydrofluoric acid mainly include an oxidation method, a sulfide method, an electrolysis method, a polymeric chelating agent and a mixed bed anion-cation system adsorption method, and the like, wherein the oxidation method is divided into: hydrogen peroxide process, oxidizer potassium permanganate process, oxidizer fluorine process, and oxidizer PtF₆Methods, and the like. Removal of key impurity arsenic in preparation process of electronic grade hydrofluoric acidIn the method, the residual acid amount after the purification by the oxidant fluorine gas method is relatively less, and the product quality of the electronic grade hydrofluoric acid product is superior to that of other oxidant methods. However, in the conventional techniques, in order to ensure that the oxidation reaction can be sufficiently performed, an excessive amount of fluorine gas is often introduced, which increases the production cost and has a problem of safety. Therefore, how to reduce the consumption of fluorine gas and improve the economy and safety of the process in the industrial production process is the main problem of arsenic removal by the oxidant fluorine gas method.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a device for removing arsenic impurity in the preparation process of electronic grade hydrofluoric acid, which can effectively convert trivalent arsenic ions in industrial raw material gas into pentavalent arsenic ions with low volatility so as to meet the index requirement of downstream electronic grade hydrofluoric acid production on arsenic content.

In order to achieve the purpose, the utility model adopts the following technical scheme to realize the purpose:

a device for removing impurity arsenic in the preparation process of electronic grade hydrofluoric acid is characterized by comprising a primary pre-reaction condenser, a secondary pre-reaction condenser, a reaction kettle, a reaction rectifying tower and a degassing distillation tower, wherein a shell pass top gas phase outlet of the primary pre-reaction condenser is connected with a shell pass bottom gas phase inlet of the secondary pre-reaction condenser through a pipeline, a shell pass bottom gas phase inlet of the primary pre-reaction condenser is connected with a raw material gas pipeline through a pipeline, a bottom tube pass inlet of the primary pre-reaction condenser is connected with a circulating chilled water pipeline after being intersected with a tube pass inlet pipeline at the bottom of the secondary pre-reaction condenser through a pipeline, a top tube pass outlet of the primary pre-reaction condenser is connected with a circulating chilled water return pipeline after being intersected with a tube pass outlet at the top of the secondary pre-reaction condenser through a pipeline, and a shell pass top gas phase outlet of the secondary pre-reaction condenser is connected with a non-condensable gas pipeline through a pipeline;

the upper feed inlet of the reaction kettle is respectively connected with a shell pass lower discharge port and a bottom discharge port of the primary pre-reaction condenser and the secondary pre-reaction condenser through pipelines, and a top gas phase outlet of the reaction kettle is connected with a non-condensable gas pipeline through a pipeline;

the middle feed inlet of reaction rectifying column passes through the pipeline and is connected with reation kettle 3's bottom discharge mouth, and its top gas phase export passes through the pipeline and is connected with the middle part feed inlet of degasification distillation column, and the liquid phase discharge gate of its bottom passes through the pipeline and is connected with the heavy ends pipeline, the liquid phase discharge gate of degasification bottom passes through the pipeline and takes off arsenic hydrogen fluoride pipe connection, and its top gas phase export passes through the pipeline and is connected with noncondensable gas pipe.

Furthermore, the first-stage pre-reaction condenser, the second-stage pre-reaction condenser and the reaction kettle are respectively internally provided with an independent oxidant distributor, the reaction rectifying tower is internally provided with a third-stage oxidant distributor, and the six oxidant distributors are respectively connected with an oxidant pipeline through pipelines.

Furthermore, the shell pass lower liquid phase outlet of the first-stage pre-reaction condenser or the second-stage pre-reaction condenser is respectively connected with respective liquid level regulating valves through pipelines, the liquid level regulating valves are positioned below the shell pass lower air inlet and above the oxidant distributor, and the liquid phase exhaust ports at the bottom of the shell pass are respectively connected with respective exhaust valves through pipelines.

The utility model has the following beneficial effects:

1. by arranging the two-stage pre-reaction condenser, the traditional two-stage condensation task of crude hydrogen fluoride gas from a washing tower is realized, the effective volume of the shell side holding liquid of the condenser is fully utilized, the first-stage pre-oxidation reaction is carried out, and the requirements of the downstream on the reaction time and fluorine gas introduction amount required by the fluorination oxidation reaction are reduced;

2. the reaction kettle replaces a traditional crude hydrogen fluoride storage tank, so that the condensate is buffered, the effective volume of the condensate is fully utilized, the secondary main oxidation reaction is carried out, and a special fluorination oxidation reactor is omitted;

3. through the reaction rectifying tower with the multistage oxidant distributor, the task of removing the weight of the traditional rectifying tower is realized, the effective volume of the tower body liquid is fully utilized, the third-stage protective oxidation reaction is carried out, the safety of the system is improved, and the quality of the product is ensured.

Drawings

FIG. 1 is a schematic structural diagram of an apparatus for removing arsenic impurity in the preparation process of electronic grade hydrofluoric acid according to the present invention.

In the figure, a first-stage pre-reaction condenser 1; a secondary pre-reaction condenser 2; a reaction kettle 3; a reactive distillation column 4; a first level regulating valve 6; a second level regulating valve 8; a first purge valve 5; a second purge valve 7; a first oxidant distributor 9; a second oxidant distributor 10; a third oxidant distributor 11; a fourth oxidant distributor 12; a fifth oxidant distributor 13; a sixth oxidant distributor 14; a heat exchange pipe 15; a baffle 16; a degassing distillation column 17; a feed gas line 20; a dearsenifying hydrogen fluoride pipe 21; a noncondensable gas pipe 22; a heavies line 23; a circulating chilled water pipe 24; an oxidant conduit 25; the chilled return water line 26 is circulated.

Detailed Description

The utility model is described in further detail below with reference to the accompanying drawings:

referring to fig. 1, a device for removing arsenic impurity in the preparation process of electronic grade hydrofluoric acid mainly comprises: a first-stage pre-reaction condenser 1, a second-stage pre-reaction condenser 2, a reaction kettle 3, a reaction rectifying tower 4 and a degassing distillation tower 17.

Gas from the top of a washing tower of a hydrogen fluoride production device is sent into a gas phase inlet at the bottom of a shell pass of a primary pre-reaction condenser 1 through a feed gas pipeline 20, flows from bottom to top along a baffle plate 16 after entering the shell pass, is condensed by circulating chilled water flowing from bottom to top in a heat exchange tube 15, and non-condensed gas is sent into a gas phase inlet at the bottom of the shell pass of a secondary pre-reaction condenser 2 through a gas phase outlet at the top of the shell pass of the primary pre-reaction condenser 1, flows from bottom to top along the baffle plate 16 after entering the shell pass, is condensed by the circulating chilled water flowing from bottom to top in the heat exchange tube 15, and the residual non-condensed gas is sent into a non-condensed gas pipeline 22 through a gas phase outlet at the top of the shell pass of the secondary pre-reaction condenser 2; the above-mentioned liquid that condenses, form certain liquid level in the inferior part of shell pass of the first-class pre-reaction condenser 1, second-class pre-reaction condenser 2 separately, the oxidizing agent is sent into first oxidizing agent distributor 9 and second oxidizing agent distributor 10 via the oxidizing agent pipeline 25, inject the oxidizing agent into the above-mentioned liquid retention, carry on the pre-oxidation reaction, the liquid level of the above-mentioned liquid retention can be adjusted through first liquid level control valve 6 and second liquid level control valve 8, in order to adjust the time of the pre-reaction, when the oxidizing agent that is injected is excessive, can open the first purge valve 5 and second purge valve 7, transfer the excessive oxidizing agent to the reaction vessel 3 and use; the circulating chilled water is respectively sent to the tube pass of the primary pre-reaction condenser 1 and the secondary pre-reaction condenser 2 and the circulating refrigeration recovery pipeline 26 in turn through a circulating chilled water pipeline 24 and is sent out of the battery limits.

The pre-reaction liquid condensed from the shell pass of the first-stage pre-reaction condenser 1 and the second-stage pre-reaction condenser 2 is fed into a feed inlet at the upper part of the reaction kettle 3 through a pipeline and a valve respectively through a discharge outlet at the lower part of the shell pass and a discharge outlet at the bottom of the first-stage pre-reaction condenser 1 and the second-stage pre-reaction condenser 2, enters the reaction kettle 3 and forms a certain liquid level, and the oxidant is fed into a third oxidant distributor 11 through an oxidant pipeline 25 and is injected into the reaction liquid to carry out an oxidation main reaction; the shell side top gas phase outlet of the second-stage pre-reaction condenser 2 is connected with a non-condensable gas pipeline 22 through a pipeline, the bottom liquid phase discharge port of the second-stage pre-reaction condenser is connected with the middle feed inlet of the reaction rectifying tower 4 through a pipeline, and reaction liquid is fed into the reaction rectifying tower 4.

A fourth oxidant distributor 12, a fifth oxidant distributor 13 and a sixth oxidant distributor 14 are arranged in the reactive distillation tower 4, and are respectively connected with an oxidant pipeline 25 through pipelines, oxidant is continuously injected into the liquid holdup in the tower for carrying out final protective oxidation reaction, and meanwhile, heavy components obtained through rectification are connected with a heavy component pipeline 23 through a pipeline through a liquid phase discharge port at the bottom of the heavy components and are sent to the upper part of a washing tower of a hydrogen fluoride production device area outside a boundary area again; and the hydrogen fluoride gas after heavy component removal is sent into a middle feed inlet of a degassing distillation tower 17 from a gas phase outlet at the top of the reactive distillation tower 4 through a dearsenifying hydrogen fluoride pipeline 21, the hydrogen fluoride gas containing light component impurities is sent out of a boundary zone in the degassing distillation tower 17 after the light component impurities removed by distillation are connected with a noncondensable gas pipeline 22 through a pipeline through a gas phase outlet at the top of the tower, and a hydrogen fluoride liquid phase product obtained at the bottom of the tower is sent out of the boundary zone and enters a downstream electronic-grade hydrofluoric acid preparation zone for further refining through a liquid outlet at the bottom of the tower and connected with the dearsenifying hydrogen fluoride pipeline 21 through a pipeline. In addition, all the above-mentioned noncondensable gases are collected by the noncondensable gas pipe 22 and then sent out of the tertiary tail gas absorption system of the hydrogen fluoride production device outside the battery limits.

The analysis can show that the device for removing the arsenic impurity in the preparation process of the electronic grade hydrofluoric acid has the characteristics of ingenious design, small total occupied area, reduction of engineering investment, simplicity in operation, large load adjustment elasticity, safety, reliability and the like, and can be applied to engineering; and provides a new optimized solving structure for the technical field of hydrofluoric acid strong oxidation arsenic removal equipment.

While the utility model has been described in further detail with reference to specific preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the utility model as defined by the appended claims.

Claims (3)

1. A device for removing impurity arsenic in the preparation process of electronic grade hydrofluoric acid is characterized by comprising a first-stage pre-reaction condenser (1), a second-stage pre-reaction condenser (2), a reaction kettle (3), a reaction rectifying tower (4) and a degassing distillation tower (17), wherein a shell pass top gas phase outlet of the first-stage pre-reaction condenser (1) is connected with a shell pass bottom gas phase inlet of the second-stage pre-reaction condenser (2) through a pipeline, a shell pass bottom gas phase inlet of the first-stage pre-reaction condenser is connected with a raw material gas pipeline (20) through a pipeline, a bottom tube pass inlet of the first-stage pre-reaction condenser is connected with a circulating chilled water pipeline (24) after intersecting with a tube pass inlet pipeline at the bottom of the second-stage pre-reaction condenser (2) through a pipeline, and a top tube pass outlet of the second-reaction condenser (2) is connected with a circulating freezing water return pipeline (26) after intersecting with the tube pass outlet at the top of the second-stage pre-reaction condenser (2), a shell side top gas phase outlet of the secondary pre-reaction condenser (2) is connected with a non-condensable gas pipeline (22) through a pipeline;

the upper feed inlet of the reaction kettle (3) is respectively connected with the shell pass lower discharge outlet and the bottom discharge outlet of the primary pre-reaction condenser (1) and the secondary pre-reaction condenser (2) through pipelines, and the top gas phase outlet of the reaction kettle is connected with a non-condensable gas pipeline (22) through a pipeline;

the middle feed inlet of reaction rectifying column (4) passes through the pipeline and is connected with the bottom discharge mouth of reation kettle (3), and its top gas phase export passes through the pipeline and is connected with the middle part feed inlet of degasification distillation column (17), and the liquid phase discharge gate of its bottom passes through the pipeline and divides pipeline (23) to be connected, the liquid phase discharge gate of degasification distillation column (17) bottom passes through the pipeline and is connected with dearsenification hydrogen fluoride pipeline (21), and its top gas phase export passes through the pipeline and is connected with noncondensable gas pipeline (22).

2. The device for removing arsenic impurities in the preparation process of electronic grade hydrofluoric acid according to claim 1, wherein the first pre-reaction condenser (1), the second pre-reaction condenser (2) and the reaction kettle (3) are respectively provided with a separate oxidant distributor, the reaction rectifying tower (4) is provided with a third oxidant distributor, and the six oxidant distributors are respectively connected with the oxidant pipeline (25) through pipelines.

3. The apparatus for removing arsenic impurities in electronic grade hydrofluoric acid preparation according to claim 2, wherein the liquid phase outlet at the lower part of the shell side of the first-stage pre-reaction condenser (1) or the second-stage pre-reaction condenser (2) is connected to the respective liquid level adjusting valve through a pipeline, the liquid level adjusting valve is located below the air inlet at the lower part of the shell side and above the oxidant distributor, and the liquid phase exhaust port at the bottom of the shell side is connected to the respective exhaust valve through a pipeline.

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