CN1915801A - Technique for synthesizing graphite fluoride and carbon fluoride by using nitrogen trifluoride as fluridizer - Google Patents

Abstract

This invention discloses a method for synthesizing graphite fluoride and carbon fluoride by using NF3 as the fluorinating agent. The method comprises: (1) filling the solid raw materials into a reactor, and evacuating the reaction system; (2) pumping NF3in the reactor; (3) heating the reactor, and keeping the reaction temperature; (4) opening the gas circulating pump to maintain the gas flow; (5) reacting for 4-30 h, and stopping heating; (6) cooling to norma ltemperature, opening the reactor, and taking out graphite fluoride or carbon fluoride. The method uses NF3 as the fluorinating agent to synthesize graphite fluoride and carbon fluoride, thus solves the problems of low process safety, short equipment service life and high produc tcost, and has such advantages as high safety, long equipment service life, no explosion.

Description

With the nitrogen trifluoride is the technology of synthetic fluorographite of fluorizating agent and fluorocarbons

Technical field

The present invention relates to the technology of a kind of synthetic fluorographite and fluorocarbons.

Background technology

Fluorographite is that a class has high chemical stability and stable on heating solid material, and its chemical formula can be expressed as (CF _x) _n, 0＜x＜1.2 wherein.Fluorographite mainly as the positive electrode material of solid lubricant and disposable lithium-battery, only grasped by a few countries such as the U.S. and Japan by the technology of its suitability for industrialized production.Existing synthetic technology route mainly contains two kinds:

(1) pyroprocess is synthetic

When temperature is higher than 380 ℃, graphite can with F ₂Reaction generates fluorographite, can be expressed as formula 1, and temperature is high more, and the fluorine content of product is big more, and 500 ℃ to 600 ℃ can obtain the fluorine carbon ratio approaches 1 product down.But the too high fluorographite that can cause again of temperature decomposes, and generates CF ₄On vapor-phase fluoride and decolorizing carbon.

Synthetic one step of fluorographite reaction of pyroprocess finishes, and has the simple advantage of technological process.But because F at high temperature ₂Big and the poor controllability with graphite exothermic heat of reaction amount causes product to decompose easily, even blast, so pyroprocess synthetic product yield is wayward, the poor stability of process.

(2) low temperature process is synthetic

At non-volatile fluorochemical AlF ₃, MgF ₂, CuF ₂, AgF, LiF or volatile fluorides AsF ₅, IF ₅, OsF ₆, SbF ₅, WF ₆, SbCl ₅Under the condition that exists with anhydrous hydrogen fluoride etc., F ₂Be easy to generate the fluoro-compound between graphite layers with the graphite reaction.In reaction, fluorochemical inserts graphite layers, mainly plays katalysis.Can use the anhydrous hydrogen fluoride wash-out for the non-volatile fluorochemical between interposed layer, and volatile fluorides just can be deviate from interlayer in the heating under vacuum process, thereby obtain highly purified fluoro-compound between graphite layers.At a lower temperature, fluorine gas can obtain the fluorographite product with fluoro-compound between graphite layers continuation reaction.With the synthetic fluorographite of this method, temperature of reaction can be controlled at below 400 ℃, far below its decomposition temperature, help improving the productive rate and the security of reaction, but technology is loaded down with trivial details and the production cycle is longer.

Except that graphite raw material, other carbon material such as calcined petroleum coke, carbon black etc. at high temperature can obtain solid fluorocarbons product with the fluorine gas reaction.The required temperature of reaction of calcined petroleum coke is: 400-550 ℃, and the required temperature of carbon black is lower, for about 300-450 ℃.The fluorocarbons product also has good electrochemical, can substitute fluorographite and make the disposable lithium-battery positive electrode material.

It can be seen from the above: existing fluorographite and fluorocarbons synthesis technique all need to use fluorine gas as fluorizating agent.Fluorine gas is the extremely strong gas of a kind of oxidisability, and security is relatively poor in producing, transport, store and using; Thereby fluorine gas has the work-ing life that severe corrosive influences equipment; If condition control is improper, at high temperature fluorine gas can be blasted with graphite or other charcoal element; The market value of fluorine gas is higher in addition.

Summary of the invention

It is the technology of synthetic fluorographite of fluorizating agent and fluorocarbons with the nitrogen trifluoride that the object of the invention provides a kind of, and it has solved the shortcoming that existing process safety is poor, service life of equipment is short, product cost is high.

Technical solution of the present invention is: a kind of is the technology of synthetic fluorographite of fluorizating agent and fluorocarbons with the nitrogen trifluoride, may further comprise the steps:

Step 1] prepare solid material 5 and equipment: solid material is adorned 5 insert reactor 3, the reactive system of finding time;

Step 2] feeding NF ₃Gas: with NF ₃ Gas feeds reactor 3;

Step 3] reactor heating reacts: reactor heating 3 maintains temperature of reaction; Open gas recycle pump 10, keep gas flow; Reacted 4 to 30 hours, and stopped heating;

Step 4] cooling reactor 3, take out product: after question response device 3 is cooled to normal temperature, open reactor 3, take out product.

Above-mentioned steps 1 also comprises the pre-treatment step of solid material, and the pre-treatment step of described solid material is earlier with solid material under 110 ℃ of temperature dry 24 to 48 hours, and then inserts in the reactor 3.

Solid material in the above-mentioned steps 1 comprises graphite, calcined petroleum coke, carbon black etc.

Temperature of reaction in the above-mentioned steps 3 is: 400 ℃～650 ℃ in graphite; 300 ℃～550 ℃ of refinery cokes; 200 ℃～550 ℃ of carbon blacks.

NF in the above-mentioned steps 3 ₃Pressure be 30KPa～500KPa.

NF in the above-mentioned steps 2 ₃The add-on of gas is according to being calculated as follows:

$\frac{x}{3}\mathrm{<figure-callout\; id="3"\; label="N\; F"\; filenames="A20061010504300111.png"\; state="\{\{state\}\}">N</figure-callout>}{F}_{}{}_3+C\&RightArrow;C{F}_x\left(s\right)+\frac{x}{6}{\mathrm{<figure-callout\; id="2"\; label="N"\; filenames="A20061010504300111.png,A20061010504300182.png"\; state="\{\{state\}\}">N</figure-callout>}}_2.$

Above-mentioned steps 4 also comprises the equipment post-processing step, and described equipment post-processing step is: after question response device 3 is cooled to normal temperature, tail gas treatment device 12 is preheating to more than 150 ℃ the reactive system of slowly finding time; In reactor 3, feed the high pure nitrogen protection, open reactor 3, take out product.

Above-mentioned steps 4 also comprises the product post-processing step, and described product post-processing step is: with the vacuum-drying 6 hours under 120 ℃ of temperature of the product that takes out in the reactor 3, sealing is preserved.

Above-mentioned reactive system comprises reactor 3, gas recycle pump 10, tail gas treatment device 12 and gas piping.

The material of above-mentioned reactor 3 is nickel or Monel metal.

Adopt nitrogen trifluoride to substitute fluorine gas among the present invention, have following advantage as synthetic fluorographite of the plain reaction of fluorizating agent and different charcoals and fluorocarbons:

1, safe.Nitrogen trifluoride is inertia at normal temperatures, and therefore security is higher in producing, transport, store and using;

2, service life of equipment is long.At high temperature the oxidisability of nitrogen trifluoride is lower than fluorine gas, a little less than the corrosion to equipment, with the graphite sluggish and should not blast;

3, production cost is low.The market value of nitrogen trifluoride (98%) is lower than fluorine gas (98%), therefore adopts gas of nitrogen trifluoride can reduce production costs as the synthetic fluorinated graphite material of fluorination reagent.

The explanation of accompanying drawing drawing

Fig. 1 is a process flow diagram;

Fig. 2 is the infrared spectra of embodiment 1 product;

Fig. 3 is the EDS analysis of spectra of embodiment 1 product;

Fig. 4 is the infrared spectra of embodiment 2 products;

Fig. 5 is the EDS analysis of spectra of embodiment 2 products;

Fig. 6 is the infrared spectra of embodiment 3 products;

Fig. 7 is the EDS analysis of spectra of embodiment 3 products;

Fig. 8 is the infrared spectra of embodiment 4 products;

Fig. 9 is the EDS analysis of spectra of embodiment 4 products;

Figure 10 is the infrared spectra of embodiment 5 products;

Figure 11 is the EDS analysis of spectra of embodiment 5 products;

Figure 12 is the infrared spectra of embodiment 6 products;

Figure 13 is the EDS analysis of spectra of embodiment 6 products;

Figure 14 is the infrared spectra of embodiment 7 products;

Figure 15 is the EDS analysis of spectra of embodiment 7 products;

Figure 16 is the infrared spectra of embodiment 8 products;

Figure 17 is the EDS analysis of spectra of embodiment 8 products;

Wherein: 1-NF ₃Bomb, 2-valve (A), 3-reactor, 4-nickel porous plate, 5-solid material, 6-electrothermal oven, 7-temperature controller and temp probe, 8-tensimeter, 9-valve (B), 10-gas recycle pump, 11-valve (C), 12-tail gas treatment device.

Embodiment

1, major equipment

NF ₃Need under hot conditions, just can react with graphite or other carbon material.The synthesizer flow process that the present invention sets up as shown in Figure 1, can be divided into several parts such as reactor 3, heating and temperature controlling device, tail gas treatment device 12, gas piping, heating and temperature controlling device comprises electrothermal oven 6 and temperature controller and temp probe 7, and gas piping comprises valve (A) 2, valve (B) 9, valve (C) 11, gas recycle pump 10:

(1) NF ₃Bomb 1: be NF in the bomb 1 ₃Gas, it communicates with reactor 3, is provided with valve (A) 2 therebetween.

(2) reactor 3: the material of reactor 3 is nickel or Monel metal, with NF under the opposing high temperature ₃Corrodibility, the lower end is nickel porous plate 4 fixedly, the inner a certain amount of solid material 5 (graphite or other carbon material) that adds, flange seal is adopted at the reactor two ends, its outer setting has electrothermal oven 6, also be provided with on the reactor 3-temperature controller and temp probe 7 and tensimeter 8, reactor 3 two ends constitute gas circulation loop by gas recycle pump 10 and valve (B) 9.

(3) tail gas treatment device 12: tail gas treatment device 12 inserts in the gas circulation loop by valve (C) 11, loads granulated active carbon in it, and voidage is about 30% to 35%, and device external assembling heating jacket should be preheating to 120 ℃ to 250 ℃ before handling tail gas.

2, technical process

The equipment of use for the first time should be found time the equipment that connects earlier, opens valve (A) 2, feeds a small amount of fluorine gas and carries out Passivation Treatment, and fluorine gas pressure is 10KPa, and passivation time is no less than 24 hours.

(1) preserves down with solid material under 110 ℃ of temperature dry 24 to 48 hours, and in dry environment.

(2) dried solid material is packed into reactor 3, the reactor 3 of finding time, gas recycle pump 10, tail gas treatment device 12 and gas piping.Open valve (A) 2, with NF ₃ Gas feeds reactor 3, NF ₃Add-on according to calculating by formula 2.

$\frac{x}{3}\mathrm{<figure-callout\; id="3"\; label="N\; F"\; filenames="A20061010504300111.png"\; state="\{\{state\}\}">N</figure-callout>}{F}_{}{}_3+C\&RightArrow;C{F}_x\left(s\right)+\frac{x}{6}{N}_2---\left(2\right)$

(calculate NF ₃During requirement, generally by x=1)

(3) valve-off (A) 2, reactor heating 3 maintains temperature of reaction.Open gas recycle pump 10 and valve (B) 9, keep certain gas flow.Reacted 4 to 30 hours, and stopped heating.

(4) after the question response device is cooled to normal temperature, tail gas treatment device 12 is preheating to more than 150 ℃, opens valve (C) 11, the reactive system of slowly finding time.In reactor 3, feed the high pure nitrogen protection, open reactor 3, take out product.

(5) vacuum-drying is after 6 hours under 120 ℃ of temperature for product, and sealing is preserved.

3, processing parameter

(1) temperature of reaction

NF ₃And the range of reaction temperature of graphite raw material is between 400 ℃ to 650 ℃, graphite and NF ₃The starting temperature of reaction is 400 ℃, and temperature high reaction rate more is big more.But when temperature of reaction was higher than 650 ℃, product decomposed generation gaseous state fluorinated hydrocarbons in a large number, and the rate of recovery is lower.NF ₃Can generate solid-state fluorocarbons with other carbon raw material reactions such as refinery coke, carbon blacks, the optimized scope of temperature of reaction is respectively: 300 ℃～550 ℃ of refinery cokes; 200 ℃～550 ℃ of carbon blacks.

(2) NF ₃Pressure

NF during reaction ₃Pressure should remain between 30KPa to 500KPa NF ₃The big more speed of reaction of pressure is high more, and corresponding product fluorine content is high more.

(3) reaction times

Reaction times should be controlled at 4～30 hours, can obtain the product of high fluorine carbon ratio.Reaction times is short more, and the fluorine content of product is low more.But the reaction times, the long product yield that may cause reduced.

(4) under above-mentioned processing condition, effectively control reaction temperature, pressure and time, can obtain solid-state fluorographite and fluorocarbons product (CF _x) _n, 0.25＜x＜1.2.

4, the analysis and characterization of product

The present invention selects for use X ray energy dispersive spectrometer (EDS) to carry out ultimate analysis, and EDS belongs to semi-quantitative analysis method, can direct analysis obtains the fluorine carbon ratio of product.

Utilize infrared spectrometer can the bonding state of product be characterized, C-F key absorption peak is positioned at 1000cm in the material ^-1To 1400cm ^-1Between wave number, with the ionic enhancing of valence link, lower wave number district, 1081cm are shifted to by high wave number district in the peak position ^-1The wave number place is corresponding to half ionic linkage, 1219cm ^-1Wave number is corresponding to covalent linkage, 1340cm ^-1Wave number then corresponding to because of cross fluoridize generation＞CF ₂Group.

Embodiment 1

Dried Graphite Powder 99 is packed in the reactor, feed pure NF ₃Gas, pressure reaches 150KPa.Heat up, keep temperature of reaction, reacted 30 hours at 450 ℃.Product is taken out in the cooling back, and the fluorine carbon ratio of product is 0.48, and yield is 92%.The infrared absorption spectrum of product and ultimate analysis EDS spectrogram are respectively as shown in Figures 2 and 3.

Embodiment 2

Dried Graphite Powder 99 is packed in the reactor, feed pure NF ₃Gas, pressure reaches 150KPa.Heat up, keep temperature of reaction, reacted 15 hours at 540 ℃.Product is taken out in the cooling back, and the fluorine carbon ratio of product is 0.95, and yield is 87%.The infrared absorption spectrum of product and ultimate analysis EDS spectrogram are respectively as shown in Figure 4 and Figure 5.

Embodiment 3

Dried Graphite Powder 99 is packed in the reactor, feed pure NF ₃Gas, pressure reaches 100KPa.Heat up, keep temperature of reaction, reacted 4 hours at 640 ℃.Product is taken out in the cooling back, and the fluorine carbon ratio of product is 1.12, and yield is 55%.The infrared absorption spectrum of product and ultimate analysis EDS spectrogram are respectively as shown in Figure 6 and Figure 7.

Embodiment 4

Dried Graphite Powder 99 is packed in the reactor, feed NF ₃, total pressure reaches 50KPa.Heat up, keep temperature of reaction, reacted 15 hours at 540 ℃.Product is taken out in the cooling back, and the fluorine carbon ratio of product is 0.75, and yield is 86%.The infrared absorption spectrum of product and ultimate analysis EDS spectrogram are respectively as Fig. 8 and shown in Figure 9.

Embodiment 5

Dried Graphite Powder 99 is packed in the reactor, feed NF ₃, pressure reaches 300KPa, heats up, and keeps temperature of reaction at 560 ℃, reacts 8 hours.Product is taken out in the cooling back, and the fluorine carbon ratio of product is 0.81, and yield is 88%.The infrared absorption spectrum of product and ultimate analysis EDS spectrogram are respectively as shown in Figure 10 and Figure 11.

Embodiment 6

Dried Graphite Powder 99 is packed in the reactor, feed pure NF ₃Gas, pressure reaches 500KPa.Heat up, keep temperature of reaction, reacted 20 hours at 560 ℃.Product is taken out in the cooling back, and the fluorine carbon ratio of product is 0.99, and yield is 89%, and the infrared absorption spectrum of product and ultimate analysis EDS spectrogram are respectively as Figure 12 and shown in Figure 13.

Embodiment 7

Dried acetylene carbon black powder is packed in the reactor, feed pure NF ₃Gas, pressure reaches 100KPa.Heat up, keep temperature of reaction, reacted 15 hours at 460 ℃.Product is taken out in the cooling back, and the fluorine carbon ratio of product is 0.95, and yield is 98%.The infrared absorption spectrum of product and ultimate analysis EDS spectrogram are respectively as Figure 14 and shown in Figure 15.

Embodiment 8

Dried calcined petroleum coke powder is packed in the reactor, feed pure NF ₃Gas, pressure reaches 150KPa.Heat up, keep temperature of reaction, reacted 10 hours at 530 ℃.Product is taken out in the cooling back, and the fluorine carbon ratio of product is 0.99, and yield is 90%.The infrared absorption spectrum of product and ultimate analysis EDS spectrogram are respectively as Figure 16 and shown in Figure 17.

The principle of the invention:

Disclosed by the invention is NF ₃As synthetic fluorographite of fluorizating agent and the synthetic route of fluoridizing the raw material of wood-charcoal material, promptly adopt nitrogen trifluoride to substitute fluorine gas and react synthetic fluorographite and fluoridize the raw material of wood-charcoal material as fluorizating agent and different charcoals element, the reaction formula is: $\frac{x}{3}\mathrm{<figure-callout\; id="3"\; label="N\; F"\; filenames="A20061010504300111.png"\; state="\{\{state\}\}">N</figure-callout>}{F}_{}{}_3+C\&RightArrow;C{F}_x\left(s\right)+\frac{x}{6}{\mathrm{<figure-callout\; id="2"\; label="N"\; filenames="A20061010504300111.png,A20061010504300182.png"\; state="\{\{state\}\}">N</figure-callout>}}_2.$

NF ₃Need under hot conditions, just can react with graphite or other carbon material, so the present invention needs corresponding high temperature synthesizer.Reactor material is nickel or Monel metal, with NF under the opposing high temperature ₃Corrodibility; The effect of tail gas treatment device.

NF ₃And the range of reaction temperature of graphite raw material is between 400 ℃ to 650 ℃, graphite and NF ₃The starting temperature of reaction is 400 ℃, and temperature high reaction rate more is big more.But when temperature of reaction was higher than 650 ℃, product decomposed generation gaseous state fluorinated hydrocarbons in a large number, and the rate of recovery is lower.NF ₃Can generate solid-state fluorocarbons with other carbon raw material reactions such as refinery coke, carbon blacks.NF during reaction ₃Pressure should remain between 30KPa to 500KPa NF ₃The big more speed of reaction of pressure is high more, and corresponding product fluorine content is high more.Reaction times should be controlled at 4～30 hours, can obtain the product of high fluorine carbon ratio.Reaction times is short more, and the fluorine content of product is low more.But the reaction times, the long product yield that may cause reduced.Effectively control reaction temperature, pressure and time, can obtain solid-state fluorographite and fluorocarbons product.

Claims (10)

1, a kind of is the technology of synthetic fluorographite of fluorizating agent and fluorocarbons with the nitrogen trifluoride, and it is characterized in that: it may further comprise the steps:

Step 1] preparation solid material (5) and equipment:

Solid material dress (5) is inserted reactor (3), the reactive system of finding time;

Step 2] feeding NF ₃Gas:

With NF ₃Gas feeds reactor (3);

Step 3] reactor heating (3) reacts:

Reactor heating (3) maintains temperature of reaction; Open gas recycle pump (10), keep gas flow; Reacted 4 to 30 hours, and stopped heating;

Step 4] cooling reactor (3), take out product:

After question response device (3) is cooled to normal temperature, open reactor (3), take out product.

2, according to claim 1 is the technology of synthetic fluorographite of fluorizating agent and fluorocarbons with the nitrogen trifluoride, it is characterized in that:

Described step 1 also comprises the pre-treatment step of solid material, and the pre-treatment step of described solid material is earlier with solid material under 110 ℃ of temperature dry 24 to 48 hours, and then inserts in the reactor (3).

3, according to claim 1 and 2 is the technology of synthetic fluorographite of fluorizating agent and fluorocarbons with the nitrogen trifluoride, it is characterized in that:

Solid material in the described step 1 comprises graphite, calcined petroleum coke, carbon black etc.

4, according to claim 3 is the technology of synthetic fluorographite of fluorizating agent and fluorocarbons with the nitrogen trifluoride, it is characterized in that:

Temperature of reaction in the described step 3 is: 400 ℃～650 ℃ in graphite; 300 ℃～550 ℃ of refinery cokes; 200 ℃～550 ℃ of carbon blacks.

5, according to claim 4 is the technology of synthetic fluorographite of fluorizating agent and fluorocarbons with the nitrogen trifluoride, it is characterized in that:

NF in the described step 3 ₃Pressure be 30KPa～500KPa.

6, according to claim 1 and 2 is the technology of synthetic fluorographite of fluorizating agent and fluorocarbons with the nitrogen trifluoride, it is characterized in that:

NF in the described step 2 ₃The add-on of gas is according to being calculated as follows:

7, according to claim 1 is the technology of synthetic fluorographite of fluorizating agent and fluorocarbons with the nitrogen trifluoride, it is characterized in that:

Described step 4 also comprises the equipment post-processing step, and described equipment post-processing step is: after question response device (3) is cooled to normal temperature, tail gas treatment device (12) is preheating to more than 150 ℃ the reactive system of slowly finding time; In reactor (3), feed the high pure nitrogen protection, open reactor (3), take out product.

8, according to claim 1 or 7 described be the technology of synthetic fluorographite of fluorizating agent and fluorocarbons with the nitrogen trifluoride, it is characterized in that:

Described step 4 also comprises the product post-processing step, and described product post-processing step is: with the vacuum-drying 6 hours under 120 ℃ of temperature of the product that takes out in the reactor (3), sealing is preserved.

9, according to claim 1 or 2 or 7 described be the technology of synthetic fluorographite of fluorizating agent and fluorocarbons with the nitrogen trifluoride, it is characterized in that:

Described reactive system comprises reactor (3), gas recycle pump (10), tail gas treatment device (12) and gas piping.

10, according to claim 9 is the technology of synthetic fluorographite of fluorizating agent and fluorocarbons with the nitrogen trifluoride, it is characterized in that:

The material of described reactor (3) is nickel or Monel metal.

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