A kind of preparation method of chlorine trifluoride
Technical field
The present invention relates to a kind of preparation method of chlorine trifluoride, being specifically related to a kind of fluorine gas and tetracol phenixin and/or silicon tetrachloride is the method that chlorine trifluoride prepared by raw material, belongs to field of fine chemical.
Background technology
Chlorine trifluoride is the most active haloid fluoride of known chemical property, is a kind of very competent fluorizating agent.The boiling point of chlorine trifluoride is 11.5 DEG C, is the gas being easy to condensation under normal conditions, and can select gas on demand, liquid any state reacts, this is less than general fluorizating agent.To react with chlorine trifluoride when many metal oxides and muriate heating and generate corresponding muriate, utilize this characteristic of chlorine trifluoride, many important metal fluorides can be obtained, especially can be used for isolation andpurification rare elements.Along with the fast development of semi-conductor, liquid crystal, sun power and LED industry, chlorine trifluoride is widely used in its CVD chamber cleaning link, and the gesture of demand constantly in rising, one of chlorine trifluoride crucial special gas having become IC industry.
Chlorine trifluoride is a kind of important fluorizating agent, can carry out many reactions by substitute element fluorine, may be used for following purposes: (1) chlorine trifluoride and uranium react the separation and Extraction being used for uranium at industrial circle; (2) preparation with metal fluoride is fluoridized as fluorination reagent for organic; (3) can as the oxidisability propelling agent of rocket or guided missile in space flight and military field; (4) in semi-conductor, liquid crystal, sun power and LED industry, chlorine trifluoride can be used for the cleaning of CVD chamber.At present, the topmost purposes of chlorine trifluoride is for semi-conductor, liquid crystal, sun power and LED industry, with other fluoro-gas (as NF
3, C
2f
6and CF
4) different; chlorine trifluoride at room temperature just can react with semiconductor material; therefore it can clean the CVD chamber of cold wall; carrying out cleaning with chlorine trifluoride is a kind of chemical etching process, there is not the high-energy ion bombardment process that plasma body is such, can drop to bottom line to the damage of equipment; chlorine trifluoride cleaning simultaneously belongs to cleaning process on the spot; can equipment downtime be reduced, the quantity of granule foreign can also be reduced, and decrease the open-assembly time of operator.Compare the cleaning of plasma cracking fluorine, chlorine trifluoride cleaning is simply efficient, and cleaning performance is better.There are not obvious Greenhouse effect in chlorine trifluoride, therefore it has broad application prospects in semi-conductor, liquid crystal, sun power and LED industry.
Because chlorine trifluoride chemical property is active, corrodibility is extremely strong, very harsh to the requirement of the control of manufacturing condition and the selection of equipment, significantly limit its production, application.The preparation method of chlorine trifluoride is proposed by Ruff and Krug the earliest, first chlorine monofluoride (formula (1)) is generated by fluorine gas and chlorine reaction, chlorine monofluoride reacts with fluorine gas further and generates chlorine trifluoride (formula (2)), reaction is carried out in two steps, needs the purification and separation process through twice.And raw material chlorine has the characteristic of deep-etching, high poison, there is larger security risk in storage and transport.
Cl
2+F
2=2ClF (1)
ClF+F
2=ClF
3(2)
Patent US2006006057 reports the method (formula (3) ~ (6)) that another kind prepares chlorine trifluoride, and the method is with HCl and/or Cl
2for raw material and F
2, NF
3or SF
6in plasma reactor, reaction generates chlorine trifluoride, and on the spot for the cleaning of CVD chamber.The advantage of this patent is that raw material has more selection, and shortcoming is that structure of reactor is complicated, and the temperature of plasma body is too high, and the cell materials of reactor is difficult to tolerate F
2, ClF
3corrosion, cause the damage of equipment, the method is difficult to realize industrialized production and use.
Cl
2+2NF
3=2ClF
3+N
2(3)
3HCl+4NF
3=3ClF
3+3HF+2N
2(4)
Cl
2+3SF
6=2ClF
3+3SF
4(5)
HCl+4SF
6=2ClF
3+2HF+4SF
4(6)
Patent RU2223908 reports the method (formula (7) ~ (9)) that another kind prepares chlorine trifluoride, and the method is with solid metal chlorides (NaCl and/or CaCl
2) generating chlorine and chlorine monofluoride for raw material and fluorine gas react, chlorine and chlorine monofluoride react with fluorine gas further and generate chlorine trifluoride.The advantage of this patent is that raw material is easy to get, and shortcoming relates to gas-solid reaction, and temperature of reaction is high, structure of reactor is complicated, and the transformation efficiency of reaction is lower, and reaction needed proceed step by step, relate to twice separation, purification process, complex operation.
3NaCl+2F
2=3NaF+ClF+Cl
2(7)
3CaCl
2+4F
2=3CaF
2+2ClF+2Cl
2(8)
ClF+Cl
2+4F
2=3ClF
3(9)
In sum, chlorine trifluoride preparation method known today mainly exists that equipment dependability is low, there is the problems such as larger security risk in the storage of complex manufacturing, raw material chlorine and transport.
Summary of the invention
In view of this, the object of the invention is a kind of preparation method of chlorine trifluoride, described method is with liquid phase chlorination thing (CCl
4and/or SiCl
4) be raw material with fluorine gas, the advantages such as reaction generates chlorine trifluoride, and the transformation efficiency have that raw material is easy to get, structure of reactor is simple, input and output material is convenient, reacting is high, by product is easily separated, are easy to realize suitability for industrialized production.
Preparation method of the present invention is mainly divided into 3 technological processs:
(1) by liquid phase chlorination thing (CCl
4and/or SiCl
4) add in gas-liquid reactor, fluorine gas is passed into by reactor bottom, and liquid phase chlorination thing and fluorine gas blistering reaction in liquid phase material generates Cl
2, CF
4and/or SiF
4, gas liquid reaction liberated heat is taken away by the interchanger being arranged on gas-liquid reactor inside, maintains stable temperature of reaction; Gas-liquid reactor is provided with fluid level controller, can the timely used up liquid phase chlorination thing of postreaction (CCl
4and/or SiCl
4), control liquid phase material during operation liquid level maintains in certain region;
(2) by the resultant in gas-liquid reactor, (main component comprises Cl
2, CF
4and/or SiF
4with unreacted fluorine gas completely) pass into synthesis reactor, meanwhile, pass into a certain amount of fluorine gas in the reactor, fluorine gas and chlorine are adjusted within the scope of predetermined stoichiometric ratio, reaction generates chlorine trifluoride at a predetermined temperature;
(3) by the resultant in synthesis reactor, (main component comprises ClF
3, ClF, CF
4and/or SiF
4with unreacted Cl completely
2and F
2) pass into cold-trap, chlorine trifluoride liquefaction is collected, meanwhile, ClF, Cl in product
2, F
2, CF
4and/or SiF
4discharge after harmless treatment Deng light impurity, the chlorine trifluoride in income cold-trap enters in storage tank or steel cylinder by turning stockline.
Object of the present invention is realized by following technical scheme:
A preparation method for chlorine trifluoride, described method concrete steps are as follows:
(1) add in gas-liquid reactor by excessive liquid phase chlorination thing, bottom gas-liquid reactor, pass into fluorine gas, there is blistering reaction in liquid phase chlorination thing and fluorine gas, obtain product 1 at-20 ~ 50 DEG C;
(2) product 1, rare gas element and fluorine gas are passed into synthesis reactor, react at 100 ~ 400 DEG C, obtain product 2;
(3), after product 2 being liquefied, arranging light, vaporization process, chlorine trifluoride of the present invention is obtained;
Wherein, the preferred CCl of step (1) described liquid phase chlorination thing
4and SiCl
4in more than one;
The flow velocity preferably 0.1 ~ 1L/min of described fluorine gas;
Described blistering reaction temperature is-20 ~ 50 DEG C, preferably 10 ~ 30 DEG C, and reaction pressure is-0.09 ~ 0.6MPa, preferably-0.07 ~ 0.2MPa;
Step (2) described rare gas element is more than one in nitrogen, argon gas, helium and tetrafluoro-methane;
The flow velocity preferably 0.1 ~ 1L/min of described product 1; The flow velocity preferably 0.3 ~ 4L/min of fluorine gas; The flow velocity preferably 0.51 ~ 40L/min of rare gas element;
Described synthesis reactor is tubular reactor, and the material of tubular reactor is nickel or Monel metal, preferred nickel;
Temperature of reaction preferably 200 ~ 300 DEG C, reaction pressure is-0.09 ~ 0.6MPa, preferably-0.04 ~ 0.3MPa.
Step (3) described liquefaction and row gently carry out in cold-trap; Synthesis reactor is connected by pipeline with cold-trap, and the material of pipeline is stainless steel, carbon steel, copper, nickel or Monel metal, preferred carbon steel or stainless steel;
Described liquefaction parameter: temperature is-100 ~ 0 DEG C, preferably-60 ~-30 DEG C, pressure is-0.09 ~ 0.6MPa, is preferably 0 ~ 0.2MPa;
Described vaporization temperature preferably 20 ~ 40 DEG C.
Beneficial effect
(1) preparation method's cheaper starting materials of the present invention, be easy to get, avoid adopt highly corrosive, highly toxic chlorine, improve productions, transport and storage process in security, by product CF
4and/or SiF
4separable, recovery, can be used as industrial goods and use, what technological process adopted is gas phase and liquid phase material, and operability is good, can realize the industrial operation of serialization.And the advantage such as structure of reactor is simple, input and output material is convenient, the transformation efficiency of reaction is high, by product is easily separated, be easy to realize suitability for industrialized production.
(2) high purity 98.1% of the chlorine trifluoride gas prepared by preparation method of the present invention, hydrofluoric content is less than 0.2%, and this gas can directly use as industrial gasses, also can become high purity chlorine trifluoride by purification further.
Accompanying drawing explanation
The process flow sheet of Fig. 1 chlorine trifluoride preparation method of the present invention;
Wherein, 1-rare gas element pipeline one, 2-fluorine gas pipeline one, 3-rare gas element pipeline two, 4-fluorine gas pipeline two, 5-gas-liquid reactor, 6-chlorine pipeline, 7-synthesis reactor, 8-crude product chlorine trifluoride pipeline, 9-cold-trap, 10-fine work chlorine trifluoride pipeline, 11-vent line, 12-chlorine trifluoride storage tank, 13-vacuum pump, 14-vacuum pump outlet, 15-purges offgas outlet.
Embodiment
With specific embodiment in detail the present invention is described in detail below, but is not limited thereto.
Under following examples are normal temperature and pressure, fluorine gas is passed into liquid phase chlorination thing (CCl
4and/or SiCl
4) in, the chlorine atom displaced in reactant generates chlorine, and then fluorine gas and chlorine reaction generate chlorine trifluoride.Reaction equation such as formula shown in (10) ~ (12), raw material and product physical property as shown in table 1:
CCl
4+2F
2=CF
4+2Cl
2(10)
SiCl
4+2F
2=SiF
4+2Cl
2(11)
Cl
2+3F
2=2ClF
3(12)
Table 1 raw material and product physical property table look-up
In following examples, the process flow sheet of chlorine trifluoride preparation method as shown in Figure 1, and the device that described preparation method uses mainly comprises gas-liquid reactor 5, synthesis reactor 7, cold-trap 9, chlorine trifluoride storage tank 12, and vacuum pump 13; Gas-liquid reactor 5, synthesis reactor 7, is connected successively by pipeline between cold-trap 9 and chlorine trifluoride storage tank 12.Wherein, gas-liquid reactor 5 is connected by chlorine pipeline 6 with synthesis reactor 7; Synthesis reactor 7 is connected by crude product chlorine trifluoride pipeline 8 with cold-trap 9; Cold-trap 9 is connected by fine work chlorine trifluoride pipeline 10 with chlorine trifluoride storage tank 12.
Before system starts, first carry out vacuumizing pre-treatment with vacuum pump 13, then with the air that rare gas element pipeline 1,3 purges, displacement is residual and moisture.After having carried out pretreatment work, by fluorine gas pipeline 4, fluorine gas is passed in gas-liquid reactor 5, the CCl in fluorine gas and gas-liquid reactor 5
4and/or SiCl
4reaction generates Cl
2, CF
4and/or SiF
4this reaction product passes in synthesis reactor 7 via chlorine pipeline 6, simultaneously, fluorine gas and diluent gas are entered in synthesis reactor 7 by rare gas element pipeline 1 and fluorine gas pipeline 2 respectively after metering and react, the temperature of reactor controls at 100 ~ 400 DEG C, and fluorine gas and chlorine react and generates chlorine trifluoride in synthesis reactor 7.Process gas in synthesis reactor 7 enters cold-trap 9 via crude product chlorine trifluoride pipeline 8, at low temperatures chlorine trifluoride is liquefied, be collected in cold-trap 9 with liquid phase state, low-boiling point gas impurity is drained into vacuum pump outlet 14 by vent line 11 and/or purged offgas outlet 15 delivers to exhaust treatment system, emptying after harmless treatment.The chlorine trifluoride of the collection in cold-trap 9 is proceeded in chlorine trifluoride storage tank by fine work chlorine trifluoride pipeline 10.
Embodiment 1
(1) first pre-treatment is vacuumized by each parts of vacuum pump to device; Again with residual air and moisture in fluorine gas purging, exchange system; Again by excessive CCl
4add in gas-liquid reactor, and with the flow velocity of 0.1L/min for pass into fluorine gas bottom gas-liquid reactor, CCl
4there is blistering reaction with fluorine gas in 0.6MPa, at 50 DEG C, obtain product 1;
(2) pass into the flow velocity of 0.1L/min, 0.3L/min and 1.2L/min respectively product 1, fluorine gas and nitrogen are passed into synthesis reactor, the working pressure arranging synthesis reactor is 0.6MPa, reacts, obtain product 2 at 100 DEG C;
(3) product 2 is passed into cold-trap, the working pressure arranging cold-trap is 0.6MPa, liquefies, low-boiling point gas impurity is delivered to exhaust treatment system by emptying pipeline, emptying after harmless treatment at 0 DEG C to product 2.After 20h, stop passing into unstripped gas, the heating of stopped reaction device.Close the terminal valve of cold-trap, with nitrogen and vacuum-treat reactive system, reduce corrosive gases to the corrosion of equipment, pipeline, valve instrument.Cold-trap is warming up to 40 DEG C, by preserving in pipeline press-in chlorine trifluoride storage tank after chlorine trifluoride gas vaporization.
The yield of chlorine trifluoride is 81.3%, and purity is 98.1%, and wherein, hydrofluoric content is 1000 × 10
-6mg/m
3, a nitrogen content is 500 × 10
-6mg/m
3.
Wherein, the constituent material of described synthesis reactor is Monel metal, and the diameter of reactor is 100mm, and height is 1500mm, and the coil pipe heating of Monel is equipped with in inside.
The purity of described fluorine gas is 99%, and wherein the content of hydrogen is 500 × 10
-6mg/m
3; Tetracol phenixin purity is 99%, and moisture content is 500 × 10
-6mg/m
3.
Embodiment 2
(1) first pre-treatment is vacuumized by each parts of vacuum pump to device; Again with air residual in nitrogen purging, exchange system and moisture; Again by excessive SiCl
4add in gas-liquid reactor, and with the flow velocity of 1L/min for pass into fluorine gas bottom gas-liquid reactor, SiCl
4there is blistering reaction with fluorine gas in 0.03MPa, at 25 DEG C, obtain product 1;
(2) pass into the flow velocity of 1L/min, 4L/min and 40L/min respectively product 1, fluorine gas and nitrogen are passed into synthesis reactor, the working pressure arranging synthesis reactor is 0.32MPa, reacts, obtain product 2 at 380 DEG C;
(3) product 2 is passed into cold-trap, the working pressure arranging cold-trap is 0.05MPa, liquefies, low-boiling point gas impurity is delivered to exhaust treatment system by emptying pipeline, emptying after harmless treatment at-95 DEG C to product 2.After 3h, stop passing into unstripped gas, the heating of stopped reaction device.Close the terminal valve of cold-trap, with nitrogen and vacuum-treat reactive system, reduce corrosive gases to the corrosion of equipment, pipeline, valve instrument.Cold-trap is warming up to 20 DEG C, by preserving in pipeline press-in chlorine trifluoride storage tank after chlorine trifluoride gas vaporization.
The yield of chlorine trifluoride is 84.6%, and purity is 95.3%, and wherein, hydrofluoric content is 1900 × 10
-6mg/m
3, a nitrogen content is 830 × 10
-6mg/m
3.
Wherein, the constituent material of described synthesis reactor is nickel, and the diameter of reactor is 100mm, and height is 1500mm, and the coil pipe heating of Monel is equipped with in inside.
The purity of described fluorine gas is 99%, and wherein the content of hydrogen is 500 × 10
-6mg/m
3; SiCl
4purity is 99%, and moisture content is 1 × 10
-6mg/m
3.
Embodiment 3
(1) first pre-treatment is vacuumized by each parts of vacuum pump to device; Again with air residual in nitrogen purging, exchange system and moisture; Again by excessive CCl
4and SiCl
4mixed solution (CCl
4with SiCl
4volume ratio be 2:1) add in gas-liquid reactor, and bottom gas-liquid reactor, pass into fluorine gas with the flow velocity of 0.5L/min, CCl
4, SiCl
4there is blistering reaction with fluorine gas in-0.09MPa, at-20 DEG C, obtain product 1;
(2) pass into the flow velocity of 0.5L/min, 1L/min and 0.51L/min respectively product 1, fluorine gas and nitrogen are passed into synthesis reactor, the working pressure arranging synthesis reactor is-0.09MPa, reacts, obtain product 2 at 400 DEG C;
(3) product 2 is passed into cold-trap, the working pressure arranging cold-trap is-0.09MPa, liquefies at-100 DEG C to product 2, and low-boiling point gas impurity is delivered to exhaust treatment system by emptying pipeline, emptying after harmless treatment.After 10h, stop passing into unstripped gas, the heating of stopped reaction device.Close the terminal valve of cold-trap, with nitrogen and vacuum-treat reactive system, reduce corrosive gases to the corrosion of equipment, pipeline, valve instrument.Cold-trap is warming up to 30 DEG C, by preserving in pipeline press-in chlorine trifluoride storage tank after chlorine trifluoride gas vaporization.
The yield of chlorine trifluoride is 75.8%, and purity is 97.5%, and wherein, hydrofluoric content is 1300 × 10
-6mg/m
3, a nitrogen content is 50 × 10
-6mg/m
3.
Wherein, the constituent material of described synthesis reactor is Monel metal, and the coil pipe heating of Monel is equipped with in inside; The diameter of reactor is 100mm, and height is 1500mm.
The purity of described fluorine gas is 98%, and wherein hydrogen fluoride content is 600 × 10
-6mg/m
3; CCl
4purity be 99%, moisture content 500 × 10
-6mg/m
3; SiCl
4purity be 99.9%, moisture content is 2 × 10
-6mg/m
3;
The present invention includes but be not limited to above embodiment, every any equivalent replacement of carrying out under the principle of spirit of the present invention or local improvement, all will be considered as within protection scope of the present invention.