CN104016334B - Graphite purification method - Google Patents
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- CN104016334B CN104016334B CN201410231292.XA CN201410231292A CN104016334B CN 104016334 B CN104016334 B CN 104016334B CN 201410231292 A CN201410231292 A CN 201410231292A CN 104016334 B CN104016334 B CN 104016334B
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Abstract
The invention belongs to material purification techniques field, disclosed graphite purification method, comprises the following steps: implement broken and grinding to the micro crystal graphite raw ore that fixed carbon content is 82%-95% (weight) successively, obtain powdered graphite raw ore; Described powdered graphite raw ore is paved in electron beam furnace, forms powdered graphite raw ore layer; Single heating-surface area in order to be not more than Electron Beam Focusing area utilizes electron beam progressively heat described powdered graphite raw ore layer and vacuumize described electron beam furnace, and the vacuum tightness of described electron beam furnace is at least 1 × 10
-4mmhg, single heat-up time is 30min-120min, and maximum heating temperature is 3500 DEG C-4500 DEG C.The graphite purity that graphite purification method provided by the invention obtains can reach 99.99%, and solves the problem that observable index is comparatively large, cost compare is high of current pyroprocess purification graphite existence.
Description
Technical field
The present invention relates to technical field of graphite purification, more specifically, relate to a kind of graphite purification method.
Background technology
Graphite is one of crystalline mineral of carbon, is widely used in various fields owing to having the premium propertiess such as oilness, chemical stability, high thermal resistance, electroconductibility, thermal conductivity, plasticity-, coating.Graphite is main in metallurgical industry is used as refractory materials, is used as the material producing carbon pole, electrode carbon-point and battery in electrical industry.The aquadag that graphite is made can be used as television picture tube coating, and the carbon product that graphite is made can be used for all many-sides such as generator, electric motor, Communication Equipment.Graphite can be used as the lubricant of the high speed conveyer tools such as aircraft, steamer, train in mechanical industry; For the manufacture of various anticorrosive vessel and equipment in chemical industry; In the industry as the neutron moderator in reactor and protective material etc.; Rocket motor nozzle larynx lining is can be used as, the dedicated radio link signal on heat insulation, the heat-stable material of rocket, guided missile and man-made satellite and the material of conductive structure in space industry.In addition, the polishing agent of glass and papermaking in graphite or light industry and rust-preventive agent are also the raw materials manufacturing pencil, prepared Chinese ink, pitch-dark, ink and man-made diamond.Along with modern science and technology and industrial expansion, the Application Areas of graphite is also constantly being widened, and has become the important source material of advanced composite material in high-tech area, has important effect in national economy.
In the process of some application above-mentioned, graphite needs higher purity.But there is not pure graphite in nature.The graphite that nature exists is often containing SiO
2, Al
2o
3, FeO, CaO, P
2o
5, the impurity such as MgO, and these impurity exist with mineral shapes such as quartz, mica, feldspar, carbonate usually.In addition, above-mentioned graphite also has water, CO
2, H
2, CH
4, N
2deng gaseous impurities.Therefore, graphite purification is seemed particularly necessary.
At present, for the method for graphite purification primarily of flotation process, alkali acid system, hydrogen fluoride, chlorinating roasting, pyroprocess etc.The advantage of flotation process is that energy consumption and reagent consumes least, cost are minimum.Use the raising that the grade of graphite can only be made to reach limited during flotation process purification graphite, for flaky graphite, adopt multistage grinding not only by its complete monomer dissociation, and the large scale protecting graphite cannot be unfavorable for.Therefore, adopt flotation process purification graphite both uneconomical also not science, and be difficult to obtain the high purity graphite that carbon content reaches 99%.
Alkali acid system, hydrogen fluoride and chlorinating roasting are the method for chemical purification graphite.Wherein, the shortcoming of alkali acid system purification graphite is to need high-temperature calcination, and energy expenditure is large, and the long reaction time of purifying.This method is comparatively serious to the corrosion of equipment, and does not reach 99.9% by the graphite purity that this method obtains.
The states such as hydrogen fluoride is a kind of method of purification preferably, realizes suitability for industrialized production in the nineties in 20th century, American-European use more general than China.But this method is large to equipment corrosion, and strong toxicity, and production process must have strict safety precaution and Waste Water Treatment.
Chlorinating roasting have energy-conservation, purification efficiency is high (at least reaching 98%), rate of recovery advantages of higher.Toxicity, the factor such as severe corrosive and serious environment pollution of chlorine limit applying of chlorizing calcination process to a certain extent.Certainly this technique is also difficult to the high purity graphite of production more than 99.99%.
All there is the shortcomings such as, strong toxicity large to equipment corrosion in the method for above-mentioned chemical purification graphite, and is difficult to reach 99.99% to the purification of graphite.Pyroprocess extracts graphite can by graphite purification to 99.99%, and the shortcoming such as large to equipment corrosion, strong toxicity.But current pyroprocess extracts in the process of graphite, is usually placed in purifying furnace by the crucible that graphite is housed, by heating and then reach the object of graphite in crucible in indirect heating purifying furnace to purifying furnace.We know, the boiling point of graphite higher than impurity boiling point this be the theoretical basis that pyroprocess extracts graphite, but at present pyroprocess to purifying furnace carry out heating need to add heat very large, cause observable index larger, cost compare is high, and the mode of this indirect heating requires higher to the resistance to elevated temperatures of equipment, further increases cost for purification.
Summary of the invention
The invention provides a kind of graphite purification method, under ensureing that the graphite purity after purifying reaches the prerequisite of 99.99%, solve the problem that observable index is comparatively large, cost compare is high that current pyroprocess purification graphite exists.
In order to solve the problems of the technologies described above, the invention provides following technical scheme:
Graphite purification method, comprises the following steps:
Successively broken and grinding are implemented to the micro crystal graphite raw ore that fixed carbon content is 82%-95% (weight), obtain powdered graphite raw ore;
Described powdered graphite raw ore is paved in electron beam furnace, forms powdered graphite raw ore layer;
Utilize electron beam progressively heat described powdered graphite raw ore layer and vacuumize described electron beam furnace with the single heating-surface area being not more than Electron Beam Focusing area, the vacuum tightness of described electron beam furnace is at least 1*10
-4mmhg, single heat-up time is 30min-120min, and maximum heating temperature is 3500 DEG C-4500 DEG C.
Preferably, in above-mentioned graphite purification method, in described single heat-up time and described micro crystal graphite raw ore, fixed carbon content and maximum heating temperature are inversely proportional to, and described powdered graphite raw ore equal thickness stall with goods spread out on the ground for sale is layered in described electron beam furnace.
Preferably, in above-mentioned graphite purification method, utilize electron beam progressively to described powdered graphite raw ore layer heating with the single heating-surface area being not more than Electron Beam Focusing area, comprise the following steps:
Described powdered graphite raw ore layer is heated to the first design temperature, keeps the first setting-up time;
Continuing heats up to described powdered graphite raw ore layer is heated to described maximum heating temperature, keeps the second setting-up time, and described first setting-up time and the second setting-up time sum are described single heat-up time.
Preferably, in above-mentioned graphite purification method, the micro crystal graphite raw ore being 80%-95% (weight) to fixed carbon content successively also comprises after implementing broken and grinding:
To described powdered graphite raw ore screening, obtaining granularity is 100-1000 object powdered graphite raw ore.
Preferably, in above-mentioned graphite purification method, also comprise before described powdered graphite raw material is paved in electron beam furnace:
By chemical purification, preliminary pre-purification is implemented to described powdered graphite raw ore;
Dehydration and drying treatment is implemented successively to through preliminary pre-described powdered graphite raw ore of purifying.
Preferably, in above-mentioned graphite purification method, the fixed carbon content of described micro crystal graphite raw ore is 82%, and described single heat-up time is 120min, and described vacuum tightness is 3*10
-4mmhg, described maximum heating temperature is 3500 DEG C.
Preferably, in above-mentioned graphite purification method, the fixed carbon content of described micro crystal graphite raw ore is 85.5%, and described single heat-up time is 90min, and described vacuum tightness is 2.5*10
-4mmhg, described maximum heating temperature is 3500 DEG C.
Preferably, in above-mentioned graphite purification method, the fixed carbon content of described micro crystal graphite raw ore is 89%, and described single heat-up time is 60min, and described vacuum tightness is 2*10
-4mmhg, described maximum heating temperature is 3800 DEG C.
Preferably, in above-mentioned graphite purification method, the fixed carbon content of described micro crystal graphite raw ore is 92.5%, and described single heat-up time is 45min, and described vacuum tightness is 1.5*10
-4mmhg, described maximum heating temperature is 4200 DEG C.
Preferably, in above-mentioned graphite purification method, the fixed carbon content of described micro crystal graphite raw ore is 95%, and described single heat-up time is 30min, and described vacuum tightness is 1*10
-4mmhg, described maximum heating temperature is 4500 DEG C.
Compared to background technology, graphite purification method provided by the invention takes full advantage of high-melting-point, the high boiling point feature of graphite, adopts electron beam type of heating that the impurity gasification in micro crystal graphite raw ore is discharged, and then obtains highly purified graphite.The graphite high purity 99.990% obtained by method of purification provided by the invention, and the electron beam type of heating adopted progressively can heat powdered graphite raw ore layer with less area, and can not whole purification furnace be heated, this can reduce energy consumption and the cost of graphite purification, and electron beam type of heating can reach a high temperature in the short period of time, and then can realize carrying out graphite purification expeditiously.Meanwhile, the Heating temperature of electron beam type of heating is very high, is at least 3500 DEG C, can realize the gasification finish of impurity quickly, improves graphite purification efficiency further.
Accompanying drawing explanation
In order to be illustrated more clearly in the technical scheme in the embodiment of the present invention, below the accompanying drawing used required in describing embodiment is briefly described, apparently, for those of ordinary skills, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.
Fig. 1 is the schematic flow sheet of the graphite purification method that the embodiment of the present invention one provides;
Fig. 2 is the schematic flow sheet of the graphite purification method that the embodiment of the present invention two provides;
Fig. 3 is the schematic flow sheet of the graphite purification method that the embodiment of the present invention three provides;
Fig. 4 is the schematic flow sheet of the graphite purification method that the embodiment of the present invention four provides;
Fig. 5 is the schematic flow sheet of the graphite purification method that the embodiment of the present invention five provides.
Embodiment
Embodiments provide a kind of graphite purification method, under ensureing that the graphite purity after purifying reaches the prerequisite of 99.99%, solve the problem that observable index is comparatively large, cost compare is high that current pyroprocess purification graphite exists.
Technical scheme in the embodiment of the present invention is understood better in order to make those skilled in the art person, and enable the above-mentioned purpose of the embodiment of the present invention, feature and advantage become apparent more, below in conjunction with accompanying drawing, the technical scheme in the embodiment of the present invention is described in further detail.
Embodiment one
Please refer to the flow process that accompanying drawing 1, Fig. 1 shows the graphite purification method that the embodiment of the present invention one provides.
Flow process shown in Fig. 1, comprises the following steps:
S101, to fixed carbon content be 82% micro crystal graphite raw ore implement broken.
In the present embodiment one, the raw material of graphite purification is micro crystal graphite raw ore.Because the granularity of micro crystal graphite raw ore is comparatively large, in order to make the impurity in subsequent heat process in micro crystal graphite raw ore more easily gasify, and then improve graphite purification effect, step S101 implements broken to micro crystal graphite raw ore.The broken particle diameter that can reduce micro crystal graphite raw ore, increases the specific surface area of micro crystal graphite raw ore simultaneously, and then the precipitation of foreign gas when being conducive to subsequent heat.Usually, step S101 is realized by crusher.
In the present embodiment one fixed carbon content be 82% micro crystal graphite raw ore refer to the micro crystal graphite raw ore that fixed carbon weight ratio is 82%.
In addition, the fixed carbon content of the micro crystal graphite raw ore in step S101 is 82%.This high-grade micro crystal graphite raw ore fixed carbon content is higher, the micro crystal graphite raw ore lower compared to fixed carbon content, and what can alleviate the heating load of subsequent step S104 and step S105 vacuumizes dynamics, and then reduces purification energy consumption.
S102, to after fragmentation micro crystal graphite raw ore implement grinding, obtain powdered graphite raw ore.
In order to reduce the granularity of micro crystal graphite raw ore further, in step S102, grinding is implemented to the micro crystal graphite raw ore after fragmentation, obtain powdered graphite raw ore, the granularity of micro crystal graphite raw ore can be reduced further and increase the specific surface area of micro crystal graphite raw ore, and then the precipitation of gaseous impurities when being more conducive to subsequent heat, be finally conducive to improving graphite purity.Usually, step S102 is realized by ball mill.
More preferred, can also comprise after step s 102 the screening of powdered graphite raw ore, obtaining granularity is 100-1000 object powdered graphite raw ore.The object of screening makes the particle diameter of powdered graphite raw ore more even.Granularity is that 100-1000 object powdered graphite raw ore ensures that powdered graphite raw ore has larger specific surface area, is unlikely to again granularity meticulous and make the vacuum pumping of step S105 take part graphite out of electron beam furnace simultaneously.
S103, powdered graphite raw ore is paved in electron beam furnace, form powdered graphite raw ore layer.
The powdered graphite raw ore that step S102 obtains by step S103 paves in electron beam furnace, forms powdered graphite raw ore layer, so that the electron beam in Subsequent electronic bundle stove heats powdered graphite raw ore layer.Preferably, powdered graphite raw ore equal thickness stall with goods spread out on the ground for sale is layered in electron beam furnace.The various piece thickness of powdered graphite raw ore layer is equal, can to improve in step S104 electron beam to the heating uniformity of powdered graphite raw ore layer, and then can obtain the more balanced graphite of purity.
Electron beam furnace is the heat energy utilizing high-velocity electrons kinetic energy to change, and heating object is carried out to the vacuum smelting equipment of heat (Heating temperature is at least 3500 DEG C).Electron beam furnace is generally used for the purification of refractory metal, and the high-power electron beam of tens to hundreds of kilowatts can be focused on 1cm by its electron beam gun
2in the focus of left and right, produce the high temperature of more than 3500 DEG C and 3500 DEG C, and then make to be discharged by the impurity gasification in smelting metal, finally reach the object of purification.
S104, employing electron beam heat powdered graphite raw ore layer.
Utilize electron beam progressively to the heating of powdered graphite raw ore layer with the single heating-surface area being not more than Electron Beam Focusing area in step S104, and then the impurity in powdered graphite raw ore is separated out with the form of gas.In this step, the maximum heating temperature of heating is 3500 DEG C, and heat-up time is 120min.
Under normal circumstances, micro crystal graphite raw ore contains low-melting impurities and the volatile impurity such as silicon, aluminium, calcium, magnesium, iron.The fusing point of these low-melting impurities is different, will certainly increase purification energy consumption if heated under same high temperature all the time.
In order to head it off, step S104 can comprise the following steps:
A
1, powdered graphite raw ore layer is heated to the first design temperature, keep the first setting-up time.
A
2, continue to powdered graphite raw ore layer heat up be heated to maximum heating temperature, 3500 DEG C namely in the present embodiment one, keep the second setting-up time, the first setting-up time and the second setting-up time sum are single heat-up time.
After step s 104, can also comprise and progressively powdered graphite raw ore layer is down to envrionment temperature from maximum heating temperature.
Above-mentioned type of heating is stepped heating mode.Adopt lower than maximum heating temperature the first design temperature to powdered graphite raw ore layer heating, make the impurity of low melting point in powdered graphite raw ore layer take the lead in gasification discharge.After adopting the first design temperature heating maintenance first setting-up time, continuing heats up to powdered graphite raw ore layer heats, and makes it reach maximum heating temperature, and keeps the second setting-up time.While adopting stepped heating mode to reach same effect in the present embodiment, can avoid adopting maximum heating temperature to the heating of powdered graphite raw ore layer from start to finish, and then reduce the energy consumption of graphite purification.In addition, step S104 can also adopt more multi-level type of heating step by step to the heating of powdered graphite raw ore layer, and then reaches meticulousr heating temperatures adjustment, finally reaches reduction energy consumption further, improves the object of purification efficiency.
Adopt progressively cooling method, that is, make the powdered graphite raw ore after heating progressively be down to envrionment temperature, temperature after purifying can be avoided directly to be down to the impact of this temperature jump of envrionment temperature on graphite mechanics or chemical property by maximum heating temperature.Envrionment temperature in the present embodiment one refers to the atmospheric temperature in graphite purification place.
It should be noted that, in the present embodiment one, first design temperature, the first setting-up time and the second setting-up time, dopant species all with contained in micro crystal graphite raw ore is relevant with foreign matter content, those skilled in the art specifically can set the first design temperature, the first setting-up time and the second setting-up time after mode checked for impurities kind by experiment and foreign matter content, and the present embodiment one does not do concrete restriction to above-mentioned parameter.
S105, electron beam furnace to be vacuumized.
Electron beam furnace is vacuum heating apparatus, and step S104 heating makes the impurity in graphite separate out with the form of gas.Electron beam furnace is vacuumized, the impurity of these gaseous states can be discharged electron beam furnace, and then reach the object of purification & isolation.In addition, the vacuum tightness of electron beam furnace, except the purity affecting graphite, also can affect the transmitting of electron beam, this is because the low vacuum of electron beam furnace is in 10
-4during mmhg, then easily there is glow discharge and then device current is transshipped, affecting the heating to graphite., in step S105, electron beam furnace is vacuumized for this reason, make the vacuum tightness of electron beam furnace be 3*10
-4mmhg.
It should be noted that, step S105 can occur before step S104, realized preparing in advance of vacuum tightness environment, can certainly occur after step s 104, also can occur with step S104 simultaneously.
Obviously, in the graphite purification method that the present embodiment one provides, the material purity of purification more high being more conducive to obtains more highly purified graphite, and can shorten the working hour of electron beam furnace.The shortening of electron beam furnace working hour can reduce energy consumption further, improves purification efficiency simultaneously.For this reason, in the graphite purification method that the present embodiment one provides, can also comprise the following steps before step S103:
B
1, by chemical purification, preliminary pre-purification is implemented to powdered graphite raw ore.
Step B
1in can implement preliminary to purify in advance by the chemical purification methods such as alkali acid system, hydrogen fluoride, chlorinating roasting to powdered graphite raw ore.
B
2, implement dehydration and drying treatment successively to through preliminary pre-powdered graphite raw ore of purifying.
Step B
2in implement dehydration and drying treatment successively to through preliminary pre-powdered graphite raw ore of purifying, to prepare for paving in step S103, dried powdered graphite raw ore is convenient to pave more, can improve the operation efficiency paved.
The graphite purification method that the present embodiment one provides takes full advantage of high-melting-point, the high boiling point feature of graphite, adopts electron beam type of heating that the impurity gasification in micro crystal graphite raw ore is discharged, and then obtains highly purified graphite.Compared to background technology, the graphite high purity 99.990% that the method for purification that the present embodiment one provides obtains.And the electron beam type of heating adopted progressively can heat powdered graphite raw ore layer with less area, and can not whole purification furnace be heated, this can reduce energy consumption and the cost of graphite purification, and electron beam type of heating can reach a high temperature in the short period of time, and then graphite purification expeditiously can be realized.Meanwhile, the Heating temperature of electron beam type of heating is very high, is at least 3500 DEG C, can realize the gasification finish of impurity quickly, improves graphite purification efficiency further.
Embodiment two
Please refer to the flow process that accompanying drawing 2, Fig. 2 shows the graphite purification method that the embodiment of the present invention two provides.
Flow process shown in Fig. 2, comprises the following steps:
S201, to fixed carbon content be 85.5% micro crystal graphite raw ore implement broken.
In the present embodiment two, the raw material of graphite purification is micro crystal graphite raw ore.Because the granularity of micro crystal graphite raw ore is comparatively large, in order to make the impurity in subsequent heat process in micro crystal graphite raw ore more easily gasify, and then improve graphite purification effect, step S201 implements broken to micro crystal graphite raw ore.The broken particle diameter that can reduce micro crystal graphite raw ore, increases the specific surface area of micro crystal graphite raw ore simultaneously, and then the precipitation of foreign gas when being conducive to subsequent heat.Usually, step S201 is realized by crusher.
In the present embodiment two fixed carbon content be 85.5% micro crystal graphite raw ore refer to the micro crystal graphite raw ore that fixed carbon weight ratio is 85.5%.
In addition, in step S201, the fixed carbon content of micro crystal graphite raw ore is 85.5%.This high-grade micro crystal graphite raw ore fixed carbon content is higher, the micro crystal graphite raw ore lower compared to fixed carbon content, and what can alleviate the heating load of subsequent step S204 and step S205 vacuumizes dynamics, and then reduces purification energy consumption.
S202, to after fragmentation micro crystal graphite raw ore implement grinding, obtain powdered graphite raw ore.
In order to reduce the granularity of micro crystal graphite raw ore further, in step S202, grinding is implemented to the micro crystal graphite raw ore after fragmentation, obtain powdered graphite raw ore, the granularity of micro crystal graphite raw ore can be reduced further and increase the specific surface area of micro crystal graphite raw ore, and then the precipitation of gaseous impurities when being more conducive to subsequent heat, be finally conducive to improving graphite purity.Usually, step S202 is realized by ball mill.
More preferred, can also comprise after step S202 the screening of powdered graphite raw ore, obtaining granularity is 100-1000 object powdered graphite raw ore.The object of screening makes the particle diameter of powdered graphite raw ore more even.Granularity is that 100-1000 object powdered graphite raw ore ensures that powdered graphite raw ore has larger specific surface area, is unlikely to again granularity meticulous and make the vacuum pumping of step S205 take part graphite out of electron beam furnace simultaneously.
S203, powdered graphite raw ore is paved in electron beam furnace, form powdered graphite raw ore layer.
The powdered graphite raw ore that step S202 obtains by step S203 paves in electron beam furnace, forms powdered graphite raw ore layer, so that the electron beam in Subsequent electronic bundle stove heats powdered graphite raw ore layer.Preferably, powdered graphite raw ore equal thickness stall with goods spread out on the ground for sale is layered in electron beam furnace.The various piece thickness of powdered graphite raw ore layer is equal, can to improve in step S204 electron beam to the heating uniformity of powdered graphite raw ore layer, and then can obtain the more balanced graphite of purity.
Electron beam furnace is the heat energy utilizing high-velocity electrons kinetic energy to be converted to, and heating object is carried out to the vacuum smelting equipment of heat (Heating temperature is at least 3500 DEG C).Electron beam furnace is generally used for the purification of refractory metal, and the high-power electron beam of tens to hundreds of kilowatts can be focused on 1cm by its electron beam gun
2in the focus of left and right, produce 3500 DEG C and above high temperature, and then make to be discharged by the impurity gasification in smelting metal, finally reach the object of purification.
S204, employing electron beam heat powdered graphite raw ore layer.
Utilize electron beam progressively to the heating of powdered graphite raw ore layer with the single heating-surface area being not more than Electron Beam Focusing area in step S204, and then the impurity in powdered graphite raw ore is separated out with the form of gas.In this step, the maximum heating temperature of heating is 3500 DEG C, and heat-up time is 90min.
Under normal circumstances, micro crystal graphite raw ore contains low-melting impurities and the volatile impurity such as silicon, aluminium, calcium, magnesium, iron.The fusing point of these low-melting impurities is different, will certainly increase purification energy consumption if heated under same high temperature all the time.
In order to head it off, step S204 can comprise the following steps:
A
1, powdered graphite raw ore layer is heated to the first design temperature, keep the first setting-up time.
A
2, continue to powdered graphite raw ore layer heat up be heated to maximum heating temperature, 3500 DEG C namely in the present embodiment two, keep the second setting-up time, the first setting-up time and the second setting-up time sum are single heat-up time.
After step s 204, can also comprise:
Progressively powdered graphite raw ore layer is down to envrionment temperature from maximum heating temperature.
Above-mentioned type of heating is stepped heating mode.Adopt lower than maximum heating temperature the first design temperature to powdered graphite raw ore layer heating, make the impurity of low melting point in powdered graphite raw ore layer take the lead in gasification discharge.After adopting the first design temperature heating maintenance first setting-up time, continuing heats up to powdered graphite raw ore layer heats, and makes it reach maximum heating temperature, and keeps the second setting-up time.While adopting stepped heating mode to reach same effect in the present embodiment, can avoid adopting maximum heating temperature to the heating of powdered graphite raw ore layer from start to finish, and then reduce the energy consumption of graphite purification.In addition, step S204 can also adopt more multi-level type of heating step by step to the heating of powdered graphite raw ore layer, and then reaches meticulousr temperature adjustment, finally reaches reduction energy consumption further, improves the object of purification efficiency.
Adopt progressively cooling method, that is, make the powdered graphite raw ore after heating progressively be down to envrionment temperature, temperature after purifying can be avoided directly to be down to the impact of this temperature jump of envrionment temperature on graphite mechanics or chemical property by maximum heating temperature.Envrionment temperature in the present embodiment two refers to the atmospheric temperature in graphite purification place.
It should be noted that, in the present embodiment two, first design temperature, the first setting-up time and the second setting-up time, dopant species all with contained in micro crystal graphite raw ore is relevant with foreign matter content, those skilled in the art specifically can set the first design temperature, the first setting-up time and the second setting-up time after mode checked for impurities kind by experiment and foreign matter content, and the present embodiment two does not do concrete restriction to above-mentioned parameter.
S205, electron beam furnace to be vacuumized.
Electron beam furnace is vacuum heating apparatus, and step S204 heating makes the impurity in graphite separate out with the form of gas.Electron beam furnace is vacuumized, the impurity of these gaseous states can be discharged electron beam furnace, and then reach the object of purification & isolation.In addition, the vacuum tightness of electron beam furnace, except the purity affecting graphite, also can affect the transmitting of electron beam, this is because the low vacuum of electron beam furnace is in 10
-4during mmhg, then easily there is glow discharge and then device current is transshipped, affecting the heating to graphite., in step S205, electron beam furnace is vacuumized for this reason, make the vacuum tightness of electron beam furnace be 2.5*10
-4mmhg.
It should be noted that, step S205 can occur before step S204, realized preparing in advance of vacuum tightness environment, can certainly occur after step s 204, also can occur with step S204 simultaneously.
Obviously, in the graphite purification method that the present embodiment two provides, the material purity of purification more high being more conducive to obtains more highly purified graphite, and can shorten the working hour of electron beam furnace.The shortening of electron beam furnace working hour can reduce energy consumption further, improves purification efficiency simultaneously.For this reason, in the graphite purification method that the present embodiment two provides, can also comprise the following steps before step S203:
B
1, by chemical purification, preliminary pre-purification is implemented to powdered graphite raw ore.
Step B
1in can implement preliminary to purify in advance by the chemical purification methods such as alkali acid system, hydrogen fluoride, chlorinating roasting to powdered graphite raw ore.
B
2, implement dehydration and drying treatment successively to through preliminary pre-powdered graphite raw ore of purifying.
Step B
2in implement dehydration and drying treatment successively to through preliminary pre-powdered graphite raw ore of purifying, to prepare for paving in step S203, dried powdered graphite raw ore is convenient to pave more, can improve the operation efficiency paved.
The graphite purification method that the present embodiment two provides takes full advantage of high-melting-point, the high boiling point feature of graphite, adopts electron beam type of heating that the impurity gasification in micro crystal graphite raw ore is discharged, and then obtains highly purified graphite.Compared to background technology, the graphite high purity 99.992% that the method for purification that the present embodiment two provides obtains, and adopt electron beam type of heating progressively can heat powdered graphite raw ore layer with less area, and can not whole purification furnace be heated, this can reduce energy consumption and the cost of graphite purification, and electron beam type of heating can reach a high temperature in the short period of time, and then graphite purification expeditiously can be realized.Meanwhile, the Heating temperature of electron beam type of heating is very high, is at least 3500 DEG C, can realize the gasification finish of impurity quickly, improves graphite purification efficiency further.
Embodiment three
Please refer to the flow process that accompanying drawing 3, Fig. 3 shows the graphite purification method that the embodiment of the present invention three provides.
Flow process shown in Fig. 3, comprises the following steps:
S301, to fixed carbon content be 89% micro crystal graphite raw ore implement broken.
In the present embodiment three, the raw material of graphite purification is micro crystal graphite raw ore.Because the granularity of micro crystal graphite raw ore is comparatively large, in order to make the impurity of micro crystal graphite raw ore in subsequent heat process more easily gasify, and then improve graphite purification effect, step S301 implements broken to micro crystal graphite raw ore.The broken particle diameter that can reduce micro crystal graphite raw ore, increases the specific surface area of micro crystal graphite raw ore simultaneously, and then the precipitation of foreign gas when being conducive to subsequent heat.Usually, step S301 is realized by crusher.
In the present embodiment three, fixed carbon content be 89% micro crystal graphite raw ore refer to the micro crystal graphite raw ore that fixed carbon weight ratio is 89%.
In addition, in the micro crystal graphite raw ore in step S301, fixed carbon content is 89%.This high-grade micro crystal graphite raw ore fixed carbon content is higher, the micro crystal graphite raw ore lower compared to fixed carbon content, and what can alleviate the heating load of subsequent step S304 and step S305 vacuumizes dynamics, and then reduces purification energy consumption.
S302, to after fragmentation micro crystal graphite raw ore implement grinding, obtain powdered graphite raw ore.
In order to reduce the granularity of micro crystal graphite raw ore further, in step S302, grinding is implemented to the micro crystal graphite raw ore after fragmentation, obtain powdered graphite raw ore, the granularity of micro crystal graphite raw ore can be reduced further and increase the specific surface area of micro crystal graphite raw ore, and then the gasification of impurity is separated out when being more conducive to subsequent heat, be finally conducive to improving graphite purity.Usually, step S302 is realized by ball mill.
More preferred, can also comprise after step S302 the screening of powdered graphite raw ore, obtaining granularity is 100-1000 object powdered graphite raw ore.The object of screening makes the particle diameter of powdered graphite raw ore more even.Granularity is that 100-1000 object powdered graphite raw ore ensures that powdered graphite raw ore has larger specific surface area, is unlikely to again granularity meticulous and make the vacuum pumping of step S305 take part graphite out of electron beam furnace simultaneously.
S303, powdered graphite raw ore is paved in electron beam furnace, form powdered graphite raw ore layer.
The powdered graphite raw ore that step S302 obtains by step S303 paves in electron beam furnace, forms powdered graphite raw ore layer, so that the electron beam in Subsequent electronic bundle stove heats powdered graphite raw ore layer.Preferably, powdered graphite raw ore equal thickness stall with goods spread out on the ground for sale is layered in electron beam furnace.The various piece thickness of powdered graphite raw ore layer is equal, can to improve in step S304 electron beam to the heating uniformity of powdered graphite raw ore layer, and then can obtain the more balanced graphite of purity.
Electron beam furnace is the heat energy utilizing high-velocity electrons kinetic energy to change, and heating object is carried out to the vacuum smelting equipment of heat (Heating temperature is at least 3500 DEG C).Electron beam furnace is generally used for the purification of refractory metal, and the high-power electron beam of tens to hundreds of kilowatts can be focused on 1cm by its electron beam gun
2in the focus of left and right, produce 3500 DEG C and above high temperature, and then make to be discharged by the impurity gasification in the metal of melting, finally reach the object of purification.
S304, employing electron beam heat powdered graphite raw ore layer.
Utilize electron beam progressively to the heating of powdered graphite raw ore layer with the single heating-surface area being not more than Electron Beam Focusing area in step S304, and then the impurity in powdered graphite raw ore is separated out with the form of gas.In this step, the maximum heating temperature of heating is 3800 DEG C, and heat-up time is 60min.
Under normal circumstances, micro crystal graphite raw ore contains low-melting impurities and the volatile impurity such as silicon, aluminium, calcium, magnesium, iron.The fusing point of these low-melting impurities is different, will certainly increase purification energy consumption if heated under same high temperature all the time.
In order to head it off, step S304 can comprise the following steps:
A
1, powdered graphite raw ore layer is heated to the first design temperature, keep the first setting-up time.
A
2, continue to powdered graphite raw ore layer heat up be heated to maximum heating temperature, 3800 DEG C namely in the present embodiment three, keep the second setting-up time, the first setting-up time and the second setting-up time sum are single heat-up time.
After step S304, can also comprise and progressively powdered graphite raw ore layer is down to envrionment temperature from maximum heating temperature.
Above-mentioned type of heating is stepped heating mode.Adopt lower than maximum heating temperature the first design temperature to powdered graphite raw ore layer heating, make the impurity of low melting point in powdered graphite raw ore layer take the lead in gasification discharge.After adopting the first design temperature heating maintenance first setting-up time, continuing heats up to powdered graphite raw ore layer heats, and makes it reach maximum heating temperature, and keeps the second setting-up time.While adopting stepped heating mode to reach same effect in the present embodiment, can avoid adopting maximum heating temperature to the heating of powdered graphite raw ore layer from start to finish, and then reduce the energy consumption of graphite purification.In addition, step S304 can also adopt more multi-level type of heating step by step to the heating of powdered graphite raw ore layer, and then reaches meticulousr heating temperatures adjustment, finally reaches reduction energy consumption further, improves the object of purification efficiency.
Adopt progressively cooling method, that is, make the powdered graphite raw ore after heating progressively be down to envrionment temperature, temperature after purifying can be avoided to be down to the impact of this temperature jump of envrionment temperature on graphite mechanics or chemical property by maximum heating temperature.Envrionment temperature in the present embodiment three refers to the atmospheric temperature in graphite purification place.
It should be noted that, in the present embodiment three, first design temperature, the first setting-up time and the second setting-up time, dopant species all with contained in micro crystal graphite raw ore is relevant with foreign matter content, those skilled in the art specifically can set the first design temperature, the first setting-up time and the second setting-up time after mode checked for impurities kind by experiment and foreign matter content, and the present embodiment three does not do concrete restriction to above-mentioned parameter.
S305, electron beam furnace to be vacuumized.
Electron beam furnace is vacuum heating apparatus, and step S304 heating makes the impurity in graphite separate out with the form of gas, vacuumizes electron beam furnace, the impurity of these gaseous states can be discharged electron beam furnace, and then reach the object of purification & isolation.In addition, the vacuum tightness of electron beam furnace, except the purity affecting graphite, also can affect the transmitting of electron beam, this is because the low vacuum of electron beam furnace is in 10
-4during mmhg, then easily there is glow discharge and device current is transshipped, affect the heating to graphite., in step S305, electron beam furnace is vacuumized for this reason, make the vacuum tightness of electron beam furnace be 2*10
-4mmhg.
It should be noted that, step S305 can occur before step S304, realized preparing in advance of vacuum tightness environment, can certainly occur after step S304, also can occur with step S304 simultaneously.
Obviously, in the graphite purification method that the present embodiment three provides, the material purity of purification more high being more conducive to obtains more highly purified graphite, and can shorten the working hour of electron beam furnace.The shortening of electron beam furnace working hour can reduce energy consumption further, improves purification efficiency simultaneously.For this reason, in the graphite purification method that the present embodiment three provides, can also comprise the following steps before step S303:
B
1, by chemical purification, preliminary pre-purification is implemented to powdered graphite raw ore.
Step B
1in can implement preliminary to purify in advance by the chemical purification methods such as alkali acid system, hydrogen fluoride, chlorinating roasting to powdered graphite raw ore.
B
2, implement dehydration and drying treatment successively to through preliminary pre-powdered graphite raw ore of purifying.
Step B
2in implement dehydration and drying treatment successively to through preliminary pre-powdered graphite raw ore of purifying, to prepare for paving in step S303, dried powdered graphite raw ore is convenient to pave more, can improve the operation efficiency paved.
The graphite purification method that the present embodiment three provides takes full advantage of high-melting-point, the high boiling point feature of graphite, adopts electron beam type of heating that the impurity gasification in micro crystal graphite raw ore is discharged, and then obtains highly purified graphite.Compared to background technology, the graphite high purity 99.993% that the method for purification that the present embodiment three provides obtains.And the electron beam type of heating adopted progressively can heat powdered graphite raw ore layer with less area, and can not whole purification furnace be heated, this can reduce energy consumption and the cost of graphite purification, and electron beam type of heating can reach a high temperature in the short period of time, and then graphite purification expeditiously can be realized.Meanwhile, the Heating temperature of electron beam type of heating is very high (be at least 3500 DEG C, top temperature is 3800 DEG C), can realize the gasification finish of impurity quickly, improves graphite purification efficiency further.
Embodiment four
Please refer to the flow process that accompanying drawing 4, Fig. 4 shows the graphite purification method that the embodiment of the present invention four provides.
Flow process shown in Fig. 4, comprises the following steps:
S401, to fixed carbon content be 92.5% micro crystal graphite raw ore implement broken.
In the present embodiment four, the raw material of graphite purification is micro crystal graphite raw ore.Because the granularity of micro crystal graphite raw ore is comparatively large, in order to make the impurity in subsequent heat process in micro crystal graphite raw ore more easily gasify, and then improve graphite purification effect, step S401 implements broken to micro crystal graphite raw ore.The broken particle diameter that can reduce micro crystal graphite raw ore, the specific surface area simultaneously increasing micro crystal graphite raw ore increases, and then the precipitation of foreign gas when being conducive to subsequent heat.Usually, step S401 is realized by crusher.
In the present embodiment four, fixed carbon content be 92.5% micro crystal graphite raw ore refer to the micro crystal graphite raw ore that fixed carbon weight ratio is 92.5%.
In addition, in the micro crystal graphite raw ore in step S401, fixed carbon content is 92.5%.This high-grade micro crystal graphite raw ore fixed carbon content is higher, the micro crystal graphite raw ore lower compared to fixed carbon content, and what can alleviate the heating load of subsequent step S404 and step S405 vacuumizes dynamics, and then reduces purification energy consumption.
S402, to after fragmentation micro crystal graphite raw ore implement grinding, obtain powdered graphite raw ore.
In order to reduce the granularity of micro crystal graphite raw ore further, in step S402, grinding is implemented to the micro crystal graphite raw ore after fragmentation, obtain powdered graphite raw ore, the granularity of micro crystal graphite raw ore can be reduced further and increase the specific surface area of micro crystal graphite raw ore, and then the precipitation of gaseous impurities when being more conducive to subsequent heat, be finally conducive to improving graphite purity.Usually, step S402 is realized by ball mill.
More preferred, can also comprise after step S402 the screening of powdered graphite raw ore, obtaining granularity is 100-1000 object powdered graphite raw ore.The object of screening makes the particle diameter of powdered graphite raw ore more even.Granularity is that 100-1000 object powdered graphite raw ore ensures that powdered graphite raw ore has larger specific surface area, is unlikely to again granularity meticulous and make the vacuum pumping of step S405 take part graphite out of electron beam furnace simultaneously.
S403, powdered graphite raw ore is paved in electron beam furnace, form powdered graphite raw ore layer.
The powdered graphite raw ore that step S402 obtains by step S403 paves in electron beam furnace, forms powdered graphite raw ore layer, so that the electron beam in Subsequent electronic bundle stove heats powdered graphite raw ore layer.Preferably, powdered graphite raw ore equal thickness stall with goods spread out on the ground for sale is layered in electron beam furnace.The various piece thickness of powdered graphite raw ore layer is equal, can to improve in step S404 electron beam to the heating uniformity of powdered graphite raw ore layer, and then can obtain the more balanced graphite of purity.
Electron beam furnace is the heat energy utilizing high-velocity electrons kinetic energy to change, and heating object is carried out to the vacuum smelting equipment of heat (Heating temperature is at least 3500 DEG C).Electron beam furnace is generally used for the purification of refractory metal, and the high-power electron beam of tens to hundreds of kilowatts can be focused on 1cm by its electron beam gun
2in the focus of left and right, produce 3500 DEG C and above high temperature, and then make to be discharged by the impurity gasification in the metal of melting, finally reach the object of purification.
S404, employing electron beam heat powdered graphite raw ore layer.
Utilize electron beam progressively to the heating of powdered graphite raw ore layer with the single heating-surface area being not more than Electron Beam Focusing area in step S404, and then the impurity of powdered graphite raw ore is separated out with the form of gas.In this step, the maximum heating temperature of heating is 4200 DEG C, and heat-up time is 45min.
Under normal circumstances, micro crystal graphite raw ore contains low-melting impurities and the volatile impurity such as silicon, aluminium, calcium, magnesium, iron, and the fusing point of these low-melting impurities is different under normal circumstances, will certainly increase purification energy consumption if heated under same high temperature all the time.
In order to head it off, step S404 can comprise the following steps:
A
1, powdered graphite raw ore layer is heated to the first design temperature, keep the first setting-up time.
A
2, continue to powdered graphite raw ore layer heat up be heated to maximum heating temperature, 4200 DEG C namely in the present embodiment four, keep the second setting-up time, the first setting-up time and the second setting-up time sum are single heat-up time.
After step S404, can also comprise and progressively powdered graphite raw ore layer is down to envrionment temperature from maximum heating temperature.
Above-mentioned type of heating is stepped heating mode.Adopt lower than maximum heating temperature the first design temperature to powdered graphite raw ore layer heating, make the impurity of low melting point in powdered graphite raw ore layer take the lead in gasification discharge.After adopting the first design temperature heating maintenance first setting-up time, continuing heats up to powdered graphite raw ore layer heats, and makes it to maximum heating temperature, and keeps the second setting-up time.While adopting stepped heating mode to reach same effect in the present embodiment, can avoid adopting maximum heating temperature to the heating of powdered graphite raw ore layer from start to finish, and then reduce the energy consumption of graphite purification.In addition, step S404 can also adopt more multi-level type of heating step by step to the heating of powdered graphite raw ore layer, and then reaches meticulousr heating temperatures adjustment, finally reaches reduction energy consumption further, improves the object of purification efficiency.
Adopt progressively cooling method, that is, make the powdered graphite raw ore after heating progressively be down to envrionment temperature, temperature after purifying can be avoided to be down to the impact of this temperature jump of envrionment temperature on graphite mechanics or chemical property by maximum heating temperature.Envrionment temperature in the present embodiment four refers to the atmospheric temperature in graphite purification place.
It should be noted that, in the present embodiment four, first design temperature, the first setting-up time and the second setting-up time, all relevant with foreign matter content with the dopant species contained by micro crystal graphite raw ore, those skilled in the art specifically can set the first design temperature, the first setting-up time and the second setting-up time after mode checked for impurities kind by experiment and foreign matter content, and the present embodiment four does not do concrete restriction to above-mentioned parameter.
S405, electron beam furnace to be vacuumized.
Electron beam furnace is vacuum heating apparatus, and step S404 heating makes the impurity in graphite separate out with the form of gas, vacuumizes electron beam furnace, the impurity of these gaseous states can be discharged electron beam furnace, and then reach the object of purification & isolation.In addition, the vacuum tightness of electron beam furnace, except the purity affecting graphite, also can affect the transmitting of electron beam, this is because the low vacuum of electron beam furnace is in 10
-4during mmhg, then easily there is glow discharge and device current is transshipped, affect the heating to graphite., in step S405, electron beam furnace is vacuumized for this reason, make the vacuum tightness of electron beam furnace be 1.5*10
-4mmhg.
It should be noted that, step S405 can occur before step S404, realized preparing in advance of vacuum tightness environment, can certainly occur after step S404, also can occur with step S404 simultaneously.
Obviously, in the graphite purification method that the present embodiment four provides, the material purity of purification more high being more conducive to obtains more highly purified graphite, and can shorten the working hour of electron beam furnace.The shortening of electron beam furnace working hour can reduce energy consumption further, improves purification efficiency simultaneously.For this reason, in the graphite purification method that the present embodiment four provides, can also comprise the following steps before step S403:
B
1, by chemical purification, preliminary pre-purification is implemented to powdered graphite raw ore.
Step B
1in can implement preliminary to purify in advance by the chemical purification methods such as alkali acid system, hydrogen fluoride, chlorinating roasting to powdered graphite raw ore.
B
2, implement dehydration and drying treatment successively to through preliminary pre-powdered graphite raw ore of purifying.
Step B
2in implement dehydration and drying treatment successively to through preliminary pre-powdered graphite raw ore of purifying, to prepare for paving in step S403, dried powdered graphite raw ore is convenient to pave more, can improve the operation efficiency paved.
The graphite purification method that the present embodiment four provides takes full advantage of high-melting-point, the high boiling point feature of graphite, adopts electron beam type of heating that the impurity gasification in micro crystal graphite raw ore is discharged, and then obtains highly purified graphite.Compared to background technology, the graphite high purity 99.994% that the method for purification that the present embodiment four provides obtains.And the electron beam type of heating adopted progressively can heat powdered graphite raw ore layer with less area, and can not whole purification furnace be heated, this can reduce energy consumption and the cost of graphite purification, and electron beam type of heating can reach a high temperature in the short period of time, and then graphite purification expeditiously can be realized.Meanwhile, the Heating temperature of electron beam type of heating is very high (be at least 3500 DEG C, top temperature is 4200 DEG C), can realize the gasification finish of impurity quickly, improves graphite purification efficiency further.
Embodiment five
Please refer to the flow process that accompanying drawing 5, Fig. 5 shows the graphite purification method that the embodiment of the present invention five provides.
Flow process shown in Fig. 5, comprises the following steps:
S501, to fixed carbon content be 95% micro crystal graphite raw ore implement broken.
In the present embodiment five, the raw material of graphite purification is micro crystal graphite raw ore, because the granularity of micro crystal graphite raw ore is larger, in order to make the impurity in subsequent heat process in micro crystal graphite raw ore more easily gasify, and then improve graphite purification effect, step S501 implements broken to micro crystal graphite raw ore.Broken to reduce the particle diameter of micro crystal graphite raw ore, the specific surface area increase of micro crystal graphite raw ore can be increased simultaneously, and then the precipitation of foreign gas when being conducive to subsequent heat.Usually, step S501 is realized by crusher.
In the present embodiment five fixed carbon content be 92% micro crystal graphite raw ore refer to the micro crystal graphite raw ore that fixed carbon weight ratio is 92%.
In addition, in the micro crystal graphite raw ore in step S501, fixed carbon content is 95%.This high-grade micro crystal graphite raw ore fixed carbon content is higher, the micro crystal graphite raw ore lower compared to fixed carbon content, and what can alleviate the heating load of subsequent step S504 and step S505 vacuumizes dynamics, and then reduces purification energy consumption.
S502, to after fragmentation micro crystal graphite raw ore implement grinding, obtain powdered graphite raw ore.
In order to reduce the granularity of micro crystal graphite raw ore further, in step S502, grinding is implemented to the micro crystal graphite raw ore after fragmentation, obtain powdered graphite raw ore, the granularity of micro crystal graphite raw ore can be reduced further and increase the specific surface area of micro crystal graphite raw ore, and then the precipitation of gaseous impurities when being more conducive to subsequent heat, be finally conducive to improving graphite purity.Usually, step S502 is realized by ball mill.
More preferred, can also comprise after step S502 the screening of powdered graphite raw ore, obtaining granularity is 100-1000 object powdered graphite raw ore.The object of screening makes the particle diameter of powdered graphite raw ore more even.Granularity is that 100-1000 object powdered graphite raw ore ensures that powdered graphite raw ore has larger specific surface area, is unlikely to again granularity meticulous and make the vacuum pumping of step S505 take part graphite out of electron beam furnace simultaneously.
S503, powdered graphite raw ore is paved in electron beam furnace, form powdered graphite raw ore layer.
The powdered graphite raw ore that step S502 obtains by step S503 paves in electron beam furnace, forms powdered graphite raw ore layer, so that the electron beam in Subsequent electronic bundle stove heats powdered graphite raw ore layer.Preferably, powdered graphite raw ore equal thickness stall with goods spread out on the ground for sale is layered in electron beam furnace.The various piece thickness of powdered graphite raw ore layer is equal, can to improve in step S504 electron beam to the heating uniformity of powdered graphite raw ore layer, and then can obtain the more balanced graphite of purity.
Electron beam furnace is the heat energy utilizing high-velocity electrons kinetic energy to change, and heating object is carried out to the vacuum smelting equipment of heat (Heating temperature is at least 3500 DEG C).Electron beam furnace is generally used for the purification of refractory metal, and the high-power electron beam of tens to hundreds of kilowatts can be focused on 1cm by its electron beam gun
2in the focus of left and right, produce 3500 DEG C and above high temperature, and then make to be discharged by the impurity gasification in smelting metal, finally reach the object of purification.
S504, employing electron beam heat powdered graphite raw ore layer.
Utilize electron beam progressively to the heating of powdered graphite raw ore layer with the single heating-surface area being not more than Electron Beam Focusing area in step S504, and then the impurity in powdered graphite raw ore is separated out with the form of gas.In this step, the maximum heating temperature of heating is 4500 DEG C, and heat-up time is 30min.
Under normal circumstances, micro crystal graphite raw ore contains low-melting impurities and the volatile impurity such as silicon, aluminium, calcium, magnesium, iron, and the fusing point of these low-melting impurities is different, if heated under same high temperature all the time, will certainly increase purifies consumes.
In order to head it off, step S504 can comprise the following steps:
A
1, powdered graphite raw ore layer is heated to the first design temperature, keep the first setting-up time.
A
2, continue to powdered graphite raw ore layer heat up be heated to maximum heating temperature, 4500 DEG C namely in the present embodiment five, keep the second setting-up time, the first setting-up time and the second setting-up time sum are single heat-up time.
After step S504, can also comprise and progressively powdered graphite raw ore layer is down to envrionment temperature from maximum heating temperature.
Above-mentioned type of heating is stepped heating mode.Adopt lower than maximum heating temperature the first design temperature to powdered graphite raw ore layer heating, make the impurity of low melting point in powdered graphite raw ore layer take the lead in gasification discharge.After adopting the first design temperature heating maintenance first setting-up time, continuing heats up to powdered graphite raw ore layer heats, and makes it reach maximum heating temperature, and keeps the second setting-up time.While adopting stepped heating mode to reach same effect in the present embodiment, can avoid adopting maximum heating temperature to the heating of powdered graphite raw ore layer from start to finish, and then reduce the energy consumption of graphite purification.In addition, step S504 can also adopt more multi-level type of heating step by step to the heating of powdered graphite raw ore layer, and then reaches meticulousr heating temperatures adjustment, finally reaches reduction energy consumption further, improves the object of purification efficiency.
Adopt progressively cooling method, that is, make the powdered graphite raw ore after heating progressively be down to envrionment temperature, temperature after purifying can be avoided to be down to the impact of this temperature jump of envrionment temperature on graphite mechanics or chemical property by maximum heating temperature.Envrionment temperature in the present embodiment five refers to the atmospheric temperature in graphite purification place.
It should be noted that, in the present embodiment five, first design temperature, the first setting-up time and the second setting-up time, all relevant with foreign matter content with the dopant species contained by micro crystal graphite raw ore, those skilled in the art specifically can set the first design temperature, the first setting-up time and the second setting-up time after mode checked for impurities kind by experiment and foreign matter content, and the present embodiment five does not do concrete restriction to above-mentioned parameter.
S505, electron beam furnace to be vacuumized.
Electron beam furnace is vacuum heating apparatus, and step S504 heating makes the impurity in graphite separate out with the form of gas.Electron beam furnace is vacuumized, the impurity of these gaseous states can be discharged electron beam furnace, and then reach the object of purification & isolation.In addition, the vacuum tightness of electron beam furnace, except the purity affecting graphite, also can affect the transmitting of electron beam, this is because the low vacuum of electron beam furnace is in 10
-4during mmhg, then easily there is glow discharge and then device current is transshipped, affecting the heating to graphite., in step S505, electron beam furnace is vacuumized for this reason, make the vacuum tightness of electron beam furnace be 1*10
-4mmhg.
It should be noted that, step S505 can occur before step S504, realized preparing in advance of vacuum tightness environment, can certainly occur after step S504, also can occur with step S504 simultaneously.
Obviously, in the graphite purification method that the present embodiment five provides, the material purity of purification more high being more conducive to obtains more highly purified graphite, and can shorten the working hour of electron beam furnace.The shortening of electron beam furnace working hour can reduce energy consumption further, improves purification efficiency simultaneously.For this reason, in the graphite purification method that the present embodiment five provides, can also comprise the following steps before step S503:
B
1, by chemical purification, preliminary pre-purification is implemented to powdered graphite raw ore.
Step B
1in can implement preliminary to purify in advance by the chemical purification methods such as alkali acid system, hydrogen fluoride, chlorinating roasting to powdered graphite raw ore.
B
2, implement dehydration and drying treatment successively to through preliminary pre-powdered graphite raw ore of purifying.
Step B
2in implement dehydration and drying treatment successively to through preliminary pre-powdered graphite raw ore of purifying, to prepare for paving in step S503, dried powdered graphite raw ore is convenient to pave more, can improve the operation efficiency paved.
The graphite purification method that the present embodiment five provides takes full advantage of high-melting-point, the high boiling point feature of graphite, adopts electron beam type of heating that the impurity gasification in micro crystal graphite raw ore is discharged, and then obtains highly purified graphite.Compared to background technology, the graphite high purity 99.996% that the method for purification that the present embodiment five provides obtains.And the electron beam type of heating adopted progressively can heat powdered graphite raw ore layer with less area, and can not whole purification furnace be heated, this can reduce energy consumption and the cost of graphite purification, and electron beam type of heating can reach a high temperature in the short period of time, and then can realize carrying out graphite purification expeditiously.Meanwhile, the Heating temperature of electron beam type of heating is very high (be at least 3500 DEG C, maximum heating temperature is 4500 DEG C), can realize the gasification finish of impurity quickly, improves graphite purification efficiency further.
Above-described embodiment one-embodiment five is some specific embodiments that the present invention announces, between each embodiment distinct portions only otherwise contradiction, arbitrary combination can form new embodiment, and these new embodiments are all in category disclosed in the embodiment of the present invention.
In above-described embodiment one-embodiment five, in single heat-up time and micro crystal graphite raw ore, fixed carbon content and maximum heating temperature are inversely proportional to, and that is the purity of raw material is higher, and temperature is higher, then need the time of heating relatively to lack, namely heat-up time is fewer.
In the embodiment of the present invention one-embodiment five, to be not more than the single heating-surface area of Electron Beam Focusing area to the heating of powdered graphite raw ore layer, each part can be made to be heated to.Preferably, between two heating zone adjacent in the process progressively heated, coincidence district should be had, to ensure that powdered graphite raw ore layer is all heated, and can not make to exist between any two heating zone to omit.
Above-described embodiment of the present invention, does not form limiting the scope of the present invention.Any amendment done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within protection scope of the present invention.
Claims (9)
1. graphite purification method, is characterized in that, comprises the following steps:
Successively broken and grinding are implemented to the micro crystal graphite raw ore that fixed carbon content is 82%-95% (weight), obtain powdered graphite raw ore;
Described powdered graphite raw ore is paved in electron beam furnace, forms powdered graphite raw ore layer;
Utilize electron beam progressively heat described powdered graphite raw ore layer and vacuumize described electron beam furnace with the single heating-surface area being not more than Electron Beam Focusing area, the vacuum tightness of described electron beam furnace is at least 1*10
-4mmhg, single heat-up time is 30min-120min, and maximum heating temperature is 3500 DEG C-4500 DEG C;
Utilize electron beam progressively to described powdered graphite raw ore layer heating with the single heating-surface area being not more than Electron Beam Focusing area, comprise the following steps:
Described powdered graphite raw ore layer is heated to the first design temperature, keeps the first setting-up time;
Continuing heats up to described powdered graphite raw ore layer is heated to described maximum heating temperature, keeps the second setting-up time, and described first setting-up time and the second setting-up time sum are described single heat-up time.
2. graphite purification method according to claim 1, it is characterized in that, in described single heat-up time and described micro crystal graphite raw ore, fixed carbon content and maximum heating temperature are inversely proportional to, and described powdered graphite raw ore equal thickness stall with goods spread out on the ground for sale is layered in described electron beam furnace.
3. graphite purification method according to claim 1, is characterized in that, the micro crystal graphite raw ore being 80%-95% (weight) to fixed carbon content successively also comprises after implementing broken and grinding:
To described powdered graphite raw ore screening, obtaining granularity is 100-1000 object powdered graphite raw ore.
4. graphite purification method according to claim 1, is characterized in that, also comprises before paving in electron beam furnace by described powdered graphite raw material:
By chemical purification, preliminary pre-purification is implemented to described powdered graphite raw ore;
Dehydration and drying treatment is implemented successively to through preliminary pre-described powdered graphite raw ore of purifying.
5. according to the graphite purification method in claim 1-4 described in any one, it is characterized in that, the fixed carbon content of described micro crystal graphite raw ore is 82%, and described single heat-up time is 120min, and described vacuum tightness is 3*10
-4mmhg, described maximum heating temperature is 3500 DEG C.
6. according to the graphite purification method in claim 1-4 described in any one, it is characterized in that, the fixed carbon content of described micro crystal graphite raw ore is 85.5%, and described single heat-up time is 90min, and described vacuum tightness is 2.5*10
-4mmhg, described maximum heating temperature is 3500 DEG C.
7. according to the graphite purification method in claim 1-4 described in any one, it is characterized in that, the fixed carbon content of described micro crystal graphite raw ore is 89%, and described single heat-up time is 60min, and described vacuum tightness is 2*10
-4mmhg, described maximum heating temperature is 3800 DEG C.
8. according to the graphite purification method in claim 1-4 described in any one, it is characterized in that, the fixed carbon content of described micro crystal graphite raw ore is 92.5%, and described single heat-up time is 45min, and described vacuum tightness is 1.5*10
-4mmhg, described maximum heating temperature is 4200 DEG C.
9. according to the graphite purification method in claim 1-4 described in any one, it is characterized in that, the fixed carbon content of described micro crystal graphite raw ore is 95%, and described single heat-up time is 30min, and described vacuum tightness is 1*10
-4mmhg, described maximum heating temperature is 4500 DEG C.
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| CN107522197A (en) * | 2017-09-15 | 2017-12-29 | 福建翔丰华新能源材料有限公司 | The method of the preparation high-purity of economy, the micro crystal graphite of high graphitization degree |
| CN108069422A (en) * | 2017-12-25 | 2018-05-25 | 凯盛石墨碳材料有限公司 | A kind of method of graphite purification |
| CN110255553B (en) * | 2019-07-17 | 2021-03-09 | 钢研晟华科技股份有限公司 | Method for preparing high-purity graphite in vacuum at high temperature |
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| CN1336325A (en) * | 2001-04-26 | 2002-02-20 | 李明远 | High-vacuum electronic beam purifying system for producing semiconductor level material |
| US6692718B1 (en) * | 1999-05-27 | 2004-02-17 | Futaba Corporation | Method for preparing nano-size particulate graphite |
| CN102689895A (en) * | 2010-12-30 | 2012-09-26 | 王宏晓 | Preparation method and application of high-purity high-fineness graphite powder |
| CN103265016A (en) * | 2013-05-15 | 2013-08-28 | 武汉理工大学 | Graphite purification furnace with medium/high frequency pulse electric induction heating |
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| US6692718B1 (en) * | 1999-05-27 | 2004-02-17 | Futaba Corporation | Method for preparing nano-size particulate graphite |
| CN1336325A (en) * | 2001-04-26 | 2002-02-20 | 李明远 | High-vacuum electronic beam purifying system for producing semiconductor level material |
| CN102689895A (en) * | 2010-12-30 | 2012-09-26 | 王宏晓 | Preparation method and application of high-purity high-fineness graphite powder |
| CN103265016A (en) * | 2013-05-15 | 2013-08-28 | 武汉理工大学 | Graphite purification furnace with medium/high frequency pulse electric induction heating |
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