阅读说明：本技术 一种高纯六氟化钨连续纯化方法 (A kind of high-purity tungsten hexafluoride process for continuous purification ) 是由 张琴 张长金 杨万吉 王占卫 彭立培 张帅 李丹丹 胡帅 王志民 谢兵飞 于 2019-08-20 设计创作，主要内容包括：本发明涉及一种高纯六氟化钨连续纯化方法,属于含氟精细化工分离技术领域。该方法先经过低温纯化塔凝华成固体排出杂质气体,再通过调控精馏工艺参数经过高效精馏获得纯度99.9999vol％的六氟化钨。本发明所述方法能够实现对于纯度在30vol％以上的六氟化钨粗品气进行纯化,使用范围广,可操作性强,收率高,成本低,效率高,易于规模化生产。(The present invention relates to a kind of high-purity tungsten hexafluoride process for continuous purification, belong to fluorine-containing fine chemistry industry separation technology field.This method first passes through cryogenic purincation tower and sublimates into solid discharge foreign gas, then obtains the tungsten hexafluoride of purity 99.9999vol% by highly efficient distilling by regulation rectification process parameter.The tungsten hexafluoride crude product gas that the method for the invention can be realized for purity in 30vol% or more purifies, and use scope is wide, strong operability, and high income is at low cost, high-efficient, is easy to large-scale production.)

1. a kind of high-purity tungsten hexafluoride process for continuous purification, it is characterised in that: the device that the method is related to includes having heating The cryogenic purincation tower (1) and rectifying column (9) of function, rectifying section theoretical cam curve 80~100 and the stripping section reason of rectifying column (9) By the number of plates 100~120, it is machined with tower bottom discharge port (17) close on the side of rectifying column (9) tower bottom one end, rectifying column (9) Middle filling surface area is greater than 1000m²/m³Structured packing, the feed inlet of the discharge port of cryogenic purincation tower (1) and rectifying column (9) connects It connects；

Specific step is as follows for purifying:

It is -180 DEG C~-150 DEG C and pressure that step 1. purity, which is passed through temperature in the tungsten hexafluoride crude product gas of 30vol% or more, For in -0.1MPa~0MPa cryogenic purincation tower (1), tungsten hexafluoride sublimates into rapidly solid, and foreign gas is pure from low temperature Change column overhead and carries out emptying discharge；

Step 2. utilizes the heating function of cryogenic purincation tower (1) at gas, first to import the solid heating sublimation of its internal gathering Portion gas makes the liquid level in rectifying column (9) lower than tower bottom discharge port (17) in rectifying column (9), and adjusts rectifying column (9) and return entirely Stream, after rectifying column (9) tower bottom discharge port (17) tungsten hexafluoride qualified, then starts the continuous feed in rectifying column (9), from Low pure tungsten hexafluoride gaseous mixture is continuously discharged in rectifying column (9) tower top discharge port, continuously adopts from rectifying column (9) tower bottom discharge port (17) High-purity tungsten hexafluoride gas out；

Wherein, the tower body temperature of rectifying column (9) is 30 DEG C~36 DEG C, and column bottom temperature is 1 DEG C~2 DEG C higher than tower top temperature；Rectifying column (9) tower body pressure 0.05MPa~0.1MPa, tower bottom pressure are 5kPa~8kPa higher than tower top pressure.

2. high-purity tungsten hexafluoride process for continuous purification according to claim 1, it is characterised in that: low pure tungsten hexafluoride mixing The discharge rate of gas is the 5wt%~30wt% of rectifying column (9) inlet amount, and the produced quantity of high-purity tungsten hexafluoride gas is rectifying column (9) 70wt%~95wt% of inlet amount.

3. high-purity tungsten hexafluoride process for continuous purification according to claim 1, it is characterised in that: cryogenic purincation tower (1) Material selection austenitic stainless steel.

4. high-purity tungsten hexafluoride process for continuous purification according to claim 1, it is characterised in that: the material of rectifying column (9) Select monel metal, nickel alloy or austenitic stainless steel.

5. high-purity tungsten hexafluoride process for continuous purification according to claim 1, it is characterised in that: tungsten hexafluoride crude product gas When purity is 30vol%~60vol%, the blowdown pressure of cryogenic purincation tower (1) is -0.05MPa~-0.03MPa, rectifying column (9) tower bottom pressure is higher by 7kPa~8kPa than tower top pressure.

6. high-purity tungsten hexafluoride process for continuous purification according to claim 1, it is characterised in that: tungsten hexafluoride crude product gas When purity is greater than 60vol% less than 80vol%, the blowdown pressure of cryogenic purincation tower (1) is -0.03MPa~-0.01MPa, rectifying The tower bottom pressure of tower (9) is higher by 6kPa~7kPa than tower top pressure.

7. high-purity tungsten hexafluoride process for continuous purification according to claim 1, it is characterised in that: tungsten hexafluoride crude product gas For purity in 80vol% or more, the blowdown pressure of cryogenic purincation tower (1) is -0.02MPa~0MPa, the tower bottom pressure of rectifying column (9) Power is higher by 5kPa~6kPa than tower top pressure.

8. high-purity tungsten hexafluoride process for continuous purification according to claim 1, it is characterised in that: rectifying column (9) tower bottom goes out Material mouth (17) is located at 20cm~50cm on rectifying liquid level.

Technical field

The present invention relates to a kind of high-purity tungsten hexafluoride process for continuous purification, belong to fluorine-containing fine chemistry industry separation technology field.

Background technique

Tungsten hexafluoride is uniquely stabilized in the fluoride of tungsten and by the kind of industrialized production and application, in production super large When scale circuit and semiconductor material, the chemical deposition process of tungsten is exactly using tungsten hexafluoride as raw material.It is heavy with chemistry Product technique, can largely avoid the radioactive particles such as uranium, thorium caused soft error in Memorability circuit, have low resistance The advantages that rate, high resistance to electromigration and excellent planarization.The tungsten hexafluoride that semicon industry needs has suitable High purity just can guarantee the stability and yield of semiconductor product.

A kind of purification process of tungsten hexafluoride of Chinese patent CN104973629A discloses and first passes through fluorinated hydrogen tower, then By the purifying process of rectifying still, the tungsten hexafluoride product that purity reaches 99.999% is obtained.

The purification devices and method of a kind of tungsten hexafluoride of Chinese patent CN105417583B, disclose by rectifying still, The purification devices of rectifying column and condenser composition, can be purified to 99.9999% for tungsten hexafluoride crude product gas.The device and method It is 80%~90% to the purity requirement of tungsten hexafluoride crude product gas, when rectifying need to close tungsten hexafluoride feed inlet, belong to interval essence Evaporate operation.

The purification process of Chinese patent CN100486900C tungsten hexafluoride discloses a kind of by impure tungsten hexafluoride gas Body removes hydrogen fluoride, then the technique for being passed through rectifying column rectifying by the adsorption tower equipped with sodium fluoride or potassium fluoride.Tower bottom when rectifying It is continually fed into high-purity helium, so that tungsten hexafluoride in tower is kept boiling reflux state, removes impurity.Tower top impurity concentration is detected simultaneously When up to standard, the tungsten hexafluoride of purity 99.999% is obtained.This method belongs to batch fractionating, and to the requirement of tungsten hexafluoride crude product gas 99.5% or more.

Chinese patent CN108658129A discloses a kind of tungsten hexafluoride purification devices using bismuth doping low temperature material, By sodium fluoride adsorption tower, light component remover, fluorine gas deep cooling tank, the major process units such as rectifying column produce 99.999% Tungsten hexafluoride.

A kind of method and device of continuous rectification purifying tungsten hexafluoride of Chinese patent CN103922414B, discloses by taking off Gently, the purification devices of two towers of weight composition are taken off, tungsten hexafluoride crude product to be purified is introduced into lightness-removing column, enters back into weight-removing column, so The tungsten hexafluoride in weight-removing column collected overhead after purification, purity can achieve 99.9999% afterwards.But it is to be purified described in the patent Tungsten hexafluoride crude product purity requirement it is higher, preferably 99%~99.99%.

In conclusion existing tungsten hexafluoride purifying document is more, generally using fluorinated hydrogen adsorption tower, batch fractionating tower etc. Process, it is generally more stringent to the purity requirement of tungsten hexafluoride crude product gas, or cannot operate continuously, efficiency is lower, at This is higher, and the tungsten hexafluoride purity produced is not high.

Summary of the invention

For the deficiencies in the prior art, the present invention provides a kind of high-purity tungsten hexafluoride process for continuous purification, the party Method uses cryogenic purincation tower and high-efficient spiral-screen column tandem with heating function to realize purity in 30vol% or more crude product gas Purifying, and can get the tungsten hexafluoride of purity 99.9999vol%, this method strong operability may be implemented to operate continuously, High income, and it is easy to large-scale production.

The purpose of the present invention is what is be achieved through the following technical solutions.

A kind of high-purity tungsten hexafluoride process for continuous purification, the device that the method is related to include the low temperature with heating function Purification column and rectifying column, the rectifying section theoretical cam curve 80~100 and stripping section theoretical cam curve 100~120 of rectifying column, connect Tower bottom discharge port is machined on the side of nearly rectifying tower bottom one end, filling surface area is greater than 1000m in rectifying column²/m³It is regular Filler, the discharge port of cryogenic purincation tower and the feed inlet of rectifying column connect；

Specific step is as follows for purifying:

(1) it is -180 DEG C~-150 DEG C and pressure that purity, which is passed through temperature in the tungsten hexafluoride crude product gas of 30vol% or more, For in -0.1MPa~0MPa cryogenic purincation tower, tungsten hexafluoride sublimates into rapidly solid, N₂、F₂、NF₃, the impurity gas such as HF Body carries out emptying discharge from cryogenic purincation column overhead；

(2) it utilizes the heating function of cryogenic purincation tower by the solid heating sublimation of its internal gathering at gas, first imports essence Evaporating portion gas in tower makes the liquid level in rectifying column lower than tower bottom discharge port, and adjusts rectifying column infinite reflux, to rectifying tower bottom After discharge port tungsten hexafluoride qualified, then start the continuous feed into rectifying column, is continuously discharged from the top of the distillation column discharge port The low pure tungsten hexafluoride gaseous mixture of low pure tungsten hexafluoride gaseous mixture, discharge can be purified again with cycle into cryogenic purincation tower, from Rectifying tower bottom discharge port continuously produces high-purity tungsten hexafluoride gas.

Rectifying tower temperature is 30 DEG C~36 DEG C, and column bottom temperature is 1 DEG C~2 DEG C higher than tower top temperature, tower body pressure 0.05MPa~0.1MPa, tower bottom pressure are 5kPa~8kPa higher than tower top pressure.The discharge rate of low pure tungsten hexafluoride gaseous mixture is essence Evaporate 5wt%~30wt% of tower inlet amount, the produced quantity of high-purity tungsten hexafluoride gas be the 70wt% of rectifying column inlet amount~ 95wt%.

Further, the cryogenic purincation tower with heating function is such as difficult to understand using low temperature resistant, corrosion resistant alloy material production Family name's body stainless steel；Rectifying column is using monel metal, nickel alloy or austenitic stainless steel production.

Further, when the purity of tungsten hexafluoride crude product gas is 30vol%~60vol%, the emptying pressure of cryogenic purincation tower Power is -0.05MPa~-0.03MPa, and the tower bottom pressure of rectifying column is higher by 7kPa~8kPa than tower top pressure.

Further, when the purity of tungsten hexafluoride crude product gas is greater than 60vol% less than 80vol%, cryogenic purincation tower is put Pneumatics power is -0.03MPa~-0.01MPa, and the tower bottom pressure of rectifying column is higher by 6kPa~7kPa than tower top pressure.

Further, the purity of tungsten hexafluoride crude product gas is in 80vol% or more, and the blowdown pressure of cryogenic purincation tower is- The tower bottom pressure of 0.02MPa~0MPa, rectifying column are higher by 5kPa~6kPa than tower top pressure.

Further, rectifying tower bottom discharge port is located at 20cm~50cm on rectifying liquid level.

The utility model has the advantages that

(1) concentration range of the method for the invention processing tungsten hexafluoride crude product gas is wide, applied widely, exists for purity The tungsten hexafluoride crude product gas of 30vol% or more can be carried out purifying, and purification effect is excellent, can obtain purity The high-purity tungsten hexafluoride of 99.9999vol%, and the content of HF is in 0.2ppmv or less；

(2) the method for the invention can carry out continuous rectification purification process, continuous feed, while continuous extraction qualification High-purity tungsten hexafluoride product, operating procedure is simple, shortens the process of purifying, improves production efficiency；

(3) the method for the invention does not use the unclassified stores such as fluoride adsorption tower or helium, avoids in operating process Introduce other impurities；

(4) the method for the invention strong operability, the high income of high-purity tungsten hexafluoride is at low cost, is easy to scale metaplasia It produces.

Detailed description of the invention

Fig. 1 is that schematic device used by tungsten hexafluoride is purified in embodiment.

Wherein, 1- cryogenic purincation tower, 2- cooling medium inlet, 3- platinum resistance, 4- feed inlet I, 5- discharge port, 6- emptying Pipe, the outlet of 7- cooling medium, 8- heater, 9- rectifying column, 10- reboiler, 11- condenser, 12- feed inlet II, 13- tower top go out Material mouth, 14- return pipe, 15- sewage pipe, 16- analyzer tube, 17- tower bottom discharge port.

Specific embodiment

The present invention is further elaborated With reference to embodiment, wherein the method is equal unless otherwise instructed For conventional method, the raw material can be gotten from open business unless otherwise instructed.

In following embodiment, purifying the used device of tungsten hexafluoride includes cryogenic purincation tower 1 and rectifying column 9；Cryogenic purincation Tower 1 base diameter 800mm, tower height 10m；Rectifying column 9 diameter 300mm, tower height 15m；

Having heaters is arranged in 1 tower bottom of cryogenic purincation tower, realizes the heating function of cryogenic purincation tower 1, and supervise by platinum resistance 3 Survey the temperature inside cryogenic purincation tower 1；Inside cryogenic purincation tower 1 be equipped with cooling recirculation system, cooling medium from cooling medium into Mouth 2 enters cooling recirculation system and from 7 discharge of cooling medium outlet, by being constantly filled with cooling medium into cooling recirculation system Cryogenic purincation tower 1 can be made to maintain lower temperature；The feed inlet I 4 and tungsten hexafluoride crude product gas source at 1 middle part of cryogenic purincation tower Connection, the discharge port 5 at 1 middle part of cryogenic purincation tower and the feed inlet II 12 (on the rectifying liquid level of rectifying column) of rectifying column 9 connect It connects；1 tower top of cryogenic purincation tower is provided with blow-down pipe 6, for foreign gas to be discharged；

The tower bottom of rectifying column 9 is provided with reboiler 10 and the sewage pipe 15 for heavy constituent impurity to be discharged；Rectifying column 9 connects Tower bottom discharge port 17 (rectifying liquid level 20cm~50cm apart from rectifying column) is provided on the side of nearly tower bottom one end and is used for Detect the analyzer tube 16 of tower bottom tungsten hexafluoride ingredient；9 tower top of rectifying column is connected with condenser 11, and condenser 11 also passes through return pipe 14 connect with 9 tower top side of rectifying column.