CN111116200A

CN111116200A - Carbon electrode with conical central hole and preparation method thereof

Info

Publication number: CN111116200A
Application number: CN201911378836.4A
Authority: CN
Inventors: 杨秀刚; 游兵; 彭革华; 罗祥明; 冯兵; 梁国龙; 罗运鹏
Original assignee: Chongqing Dongxing Carbon Material Co ltd
Current assignee: Chongqing Dongxing Carbon Material Co ltd
Priority date: 2019-12-27
Filing date: 2019-12-27
Publication date: 2020-05-08

Abstract

The invention relates to a method for preparing a carbon electrode with a conical central hole, which comprises the steps of mixing a solid mixture, raw electrode crumbs and liquid coal pitch; the solidThe mixture comprises 42-48% of graphitized massive material, 26-32% of graphitized coke and 25-30% of graphitized powdery material by weight percentage; the raw electrode fragments account for 2-3% of the mass of the solid mixture, and the liquid coal tar pitch accounts for 18.5-19.6% of the mass of the solid mixture. According to the carbon electrode with the conical central hole, the stress in the middle of the carbon electrode is small, the pitch mobility in the electrode is low during roasting, cracks are not prone to being generated, the bulging phenomenon is not prone to being generated at two ends of the electrode after forming, the yield is high, and the volume density of the obtained carbon electrode is 1.59-1.62g/cm³Resistivity is less than or equal to 32.5 u.omega.m, and flexural strength is greater than or equal to 5.7 Mpa.

Description

Carbon electrode with conical central hole and preparation method thereof

Technical Field

The invention relates to the technical field of electrodes, in particular to a carbon electrode with a conical central hole and a preparation method thereof.

Background

When the graphite carbon electrode is used, the ore furnace is used for smelting important conductive consumption materials required by metallic silicon, yellow phosphorus, iron alloy and calcium carbide. At present, large-specification carbon motors are generally produced by using a practical vertical vibration forming process, but because the specifications of electrodes produced by vertical vibration forming are too large, the carbon electrodes are easy to generate stress concentration in the motor forming process, so that the crack defect is generated at the central position of the two ends of the electrodes, and solid carbon electrode products are difficult to release due to the internal elasticity after finished products, and the crack defect is easy to generate after a period of pressure maintaining time.

The high-strength high-graphite carbon electrode with the patent number of CN200910227814.8 and the preparation method thereof are characterized in that after processed electrically calcined coal, petroleum coke and graphite fragments are screened by a vibrating screen, the graphite carbon electrode is enhanced and polymerized by yttrium oxide, so that the strength and the heat conductivity of the carbon electrode are improved. However, the high-strength and high-graphite carbon electrode prepared by the method increases the overall hardness and the cohesiveness of the carbon electrode, but still has the problem of crack defects of the carbon electrode when the carbon electrode is placed for a long time and used in a severe temperature difference environment, and the service performance of the carbon electrode is greatly influenced.

Disclosure of Invention

The invention aims to solve the problems of the prior art and provides a carbon electrode with a conical central hole and a preparation method thereof, which are used for solving the problem that the conventional carbon electrode is easy to crack.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a carbon electrode with a conical central hole, which comprises the following components: solid mixture, electrode raw meal and liquid coal tar pitch; the solid mixture comprises 42-48% of graphitized massive material, 26-32% of graphitized coke and 25-30% of graphitized powdery material by weight percentage; the raw electrode fragments account for 2-3% of the mass of the solid mixture, and the liquid coal tar pitch accounts for 18.5-19.6% of the mass of the solid mixture.

Preferably, the graphitized blocky material is unqualified after high-temperature roasting and is made of other waste materials;

preferably, the other waste materials are one or more of waste carbon anodes and carbon rods;

preferably, the liquid coal tar pitch is modified coal tar pitch;

the invention also provides a preparation method of the carbon electrode with the conical central hole, which comprises the following steps:

(1) heating and kneading: under normal pressure, adding the graphitized bulk material, the graphitized coke, the graphitized powdery material and the electrode raw meal into a kneading pot preheated to 130-;

(2) placing the mixture in the hopper into a material airing stirring cylinder preheated to 90-100 ℃, stirring and airing the material for 10-20min, and discharging the mixture from the material airing stirring cylinder when the temperature of the mixture is reduced to 115-125 ℃ to obtain paste;

(3) filling the paste into a mold: preheating an upper pressure head, a lower pressure head and a die of a molding press by using heat conduction oil, stabilizing the temperature at 90-100 ℃, horizontally fixing the lower pressure head and the die on a vibrating table in an upward manner, slowly adding a paste into the die, and flattening while feeding by using the vibrating table;

(4) pressurizing and vibrating in two directions: putting down the upper pressure head, pressurizing the paste, starting a four-axis amplitude modulation vibration table and an additional vibration motor to vibrate at the same time, continuously maintaining the pressure, and maintaining the pressure for natural cooling for 90-100 min;

(5) molding: after the pressurization and cooling are stopped, heating the die to 80 ℃, lifting the upper pressure head, turning over the oil cylinder to lay the die in parallel, pushing the electrode from the die to a cooling tray by the lower pressure head, putting the electrode into cooling water for cooling for 12-24h, and obtaining a carbon electrode green body after the cooling is finished;

(6) roasting: under the conditions of vacuum and protective medium, a ring-type roasting furnace is adopted to roast the electrode green body into a carbon electrode;

(7) and (3) machining: and (4) processing the excircle, the male head and the female hole of the roasted carbonaceous electrode.

Preferably, the feeding and leveling time in the step (4) is 2-3min, and the paste is pressurized to 3-5kg/cm 2.

Preferably, the roasting mode in the step (6) is variable temperature roasting, the roasting time is 740 hours, and the roasting maximum temperature of the external filler is 900-.

Compared with the prior art, the invention has the following beneficial effects:

according to the carbon electrode with the conical central hole, the stress in the middle of the carbon electrode is small, the pitch mobility in the electrode is low during roasting, cracks are not prone to being generated, the bulging phenomenon is not prone to being generated at two ends of the electrode after forming, the yield is high, and the volume density of the obtained carbon electrode is 1.59-1.62g/cm³Resistivity is less than or equal to 32.5 u.omega.m, and flexural strength is greater than or equal to 5.7 Mpa. Meanwhile, the carbon electrode preparation method with the conical central hole, provided by the invention, is characterized in that the central rod is additionally arranged at the central position of the lower pressing head of the die, and the direction from the lower pressing head to the upper pressing head has larger taper, so that the stripping efficiency of the carbon electrode is increased, the stress concentration phenomenon of the middle part in the carbon electrode forming process is reduced, and the influence of the elastic after-effect on the electrode after the electrode is stripped is reduced; the variable-temperature roasting can effectively avoid the overlarge temperature inside and outside the electrode in the roasting process, and avoid the expansion of the electrode of the formed product to cause the defect or waste judgment of the electrode.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the functions of the invention clearer and easier to understand, the invention is further described by combining the following specific embodiments:

the invention provides a carbon electrode with a conical central hole and a preparation method thereof, wherein two groups of 6000L high-capacity kneading pots and a paste cooling system are adopted in the process of die pressing of raw materials, the purpose of producing a support electrode by using one pot of raw materials is achieved, a central rod is arranged in the center of a lower pressing head of a die, the diameter of the central rod is divided into two stepped sections, the direction from the lower pressing head to an upper pressing head has larger taper, the friction force between the electrode and the central rod during die stripping is favorably reduced, the conical central hole is formed in the carbon electrode along the center, and the problems of cracking and bulging of the carbon electrode caused by the expansion of the interior of the carbon electrode can be effectively avoided.

When the paste is added into a die, the paste is flattened while being added, one surface of the paste flows freely, asphalt smoke is discharged from the other surface of the paste, and the generation of a bulge phenomenon in the carbon electrode die pressing process can be reduced. Meanwhile, the paste is pressurized to 3-5kg/cm2, so that the subsequent electrode sintering density can be effectively ensured, the condensation reaction is facilitated, and the strength of the carbon electrode is improved.

In the process of roasting by adopting the ring furnace, the ring furnace has the advantages of continuous production, high production efficiency, favorable roasting temperature control, easy mechanization of charging and discharging, and the like, and meanwhile, the quality of the carbon electrode can be influenced because the vertical temperature difference and the horizontal temperature difference in a furnace chamber in the ring furnace are large. Therefore, a variable-temperature roasting mode is adopted, firstly, redundant moisture in the material is discharged through low-temperature roasting, then, high-temperature roasting is carried out, the reaction in the paste is promoted, finally, the temperature is gradually reduced, the internal structure of the carbon electrode is stabilized, the internal bulge or crack of the carbon electrode caused by variable temperature is avoided, and the mechanical property of the carbon electrode is stabilized. And the roasting furnace and the carbon electrode are isolated and heated through the filler, and the difference between vertical and horizontal temperature difference in the ring furnace is reduced by utilizing the mass transfer effect of the filler, so that the consistency of the carbon electrode in all directions is ensured. The filling material selects metallurgical coke particles as roasting filling material, the metallurgical coke has various use requirements of the filling material, a flue at the bottom of the furnace is not easy to block, and the coke powder has small harm to workers when being loaded and discharged.

Example 1:

selecting a solid mixture according to parts by weight: 42 parts of graphitized massive materials, 26 parts of graphitized coke, 25 parts of graphitized powdery materials, and liquid coal pitch which is crushed by the electrode accounting for 2% of the mass of the solid mixture and accounts for 18.5% of the mass of the solid mixture. Preheating a kneading pot to 130 ℃, adding the graphitized massive material, the graphitized coke, the graphitized powdery material and the electrode raw pieces into the kneading pot to be heated to 130 ℃ under normal pressure, carrying out dry mixing for 40min, discharging the moisture in the mixture material, adding the fully-standing liquid coal tar pitch, carrying out wet mixing for 30min, and then discharging the mixture into a hopper; putting the mixture in the hopper into a preheated material airing stirring cylinder with the temperature of 90 ℃, airing the material after stirring for 10min, and taking out the paste when the temperature of the mixture is 115 ℃. Preheating an upper pressure head, a lower pressure head and a die of a molding press by using heat conduction oil, stabilizing the temperature at 90 ℃, horizontally fixing the lower pressure head and the die on a vibrating table in an upward manner, adding a paste material into the die, flattening the material while feeding, enabling one surface of the paste material to flow freely, and discharging asphalt smoke from the other surface of the paste material. And putting down the upper pressure head, pressurizing the paste, and starting a four-axis amplitude modulation vibration table and an additional vibration motor to vibrate. Keeping the pressure and cooling for 90 min. After the pressurization and cooling are stopped, heating the die to 80 ℃, lifting the upper pressure head, turning over the oil cylinder to lay the die in parallel, pushing the electrode out of the die onto a cooling tray by using the lower pressure head, putting the electrode into cooling water for cooling for 12 hours, and obtaining a carbon electrode green body after the cooling is finished; then, a ring-type roasting furnace is adopted, the electrode green body is isolated from air under a protective medium, and the electrode green body is roasted at variable temperature for 740 hours to obtain a carbonaceous electrode; and processing the excircle, the male head and the female hole of the roasted carbonaceous electrode to obtain the carbon electrode A.

Example 2:

selecting a solid mixture according to parts by weight: 45 parts of graphitized massive materials, 28 parts of graphitized coke, 28 parts of graphitized powdery materials, and liquid coal pitch which is crushed by the electrode accounting for 2.5 percent of the mass of the solid mixture and accounts for 19 percent of the mass of the solid mixture. Preheating a kneading pot to 135 ℃, adding the graphitized massive material, the graphitized coke, the graphitized powdery material and the electrode raw pieces into the kneading pot to be heated to 135 ℃ under normal pressure, carrying out dry mixing for 50min, discharging the water in the mixture material, adding the fully-standing liquid coal tar pitch, carrying out wet mixing for 35min, and then discharging the mixture into a hopper; placing the mixture in the hopper into a preheated material airing stirring cylinder with the temperature of 95 ℃, airing the material after stirring for 15min, and taking out the paste when the temperature of the mixture is 118 ℃. Preheating an upper pressure head, a lower pressure head and a die of a molding press by using heat conduction oil, stabilizing the temperature at 95 ℃, horizontally fixing the lower pressure head and the die on a vibrating table in an upward manner, adding a paste material into the die, flattening the material while feeding, enabling one surface of the paste material to flow freely, and discharging asphalt smoke from the other surface of the paste material. And putting down the upper pressure head, pressurizing the paste, and starting a four-axis amplitude modulation vibration table and an additional vibration motor to vibrate. The pressure was maintained continuously and the cooling was carried out for 95 min. After the pressurization and cooling are stopped, heating the die to 80 ℃, lifting the upper pressure head, turning over the oil cylinder to lay the die in parallel, pushing the electrode out of the die onto a cooling tray by using the lower pressure head, putting the electrode into cooling water for cooling for 18 hours, and obtaining a carbon electrode green body after the cooling is finished; then, a ring-type roasting furnace is adopted, the electrode green body is isolated from air under a protective medium, and the electrode green body is roasted at variable temperature for 740 hours to obtain a carbonaceous electrode; and processing the excircle, the male head and the female hole of the roasted carbonaceous electrode to obtain a carbon electrode B.

Example 3:

selecting a solid mixture according to parts by weight: 48 parts of graphitized blocky materials, 32 parts of graphitized coke, 30 parts of graphitized powdery materials, crushed electrodes accounting for 3% of the mass of the solid mixture, and liquid coal pitch accounting for 19.6% of the mass of the solid mixture. Preheating a kneading pot to 140 ℃, adding the graphitized massive material, the graphitized coke, the graphitized powdery material and the electrode raw pieces into the kneading pot to be heated to 140 ℃ under normal pressure, carrying out dry mixing for 60min, discharging water in the mixture material, adding fully-standing liquid coal tar pitch, carrying out wet mixing for 40min, and then discharging the mixture into a hopper; placing the mixture in the hopper into a preheated material airing stirring cylinder with the temperature of 100 ℃, airing the material after stirring for 20min, and taking out the paste when the temperature of the mixture is 125 ℃. Preheating an upper pressure head, a lower pressure head and a die of a molding press by using heat conduction oil, stabilizing the temperature at 100 ℃, horizontally fixing the lower pressure head and the die on a vibrating table in an upward manner, adding a paste material into the die, flattening the material while feeding, enabling one surface of the paste material to flow freely, and discharging asphalt smoke from the other surface of the paste material. And putting down the upper pressure head, pressurizing the paste, and starting a four-axis amplitude modulation vibration table and an additional vibration motor to vibrate. Keeping the pressure and cooling for 100 min. After the pressurization and cooling are stopped, heating the die to 80 ℃, lifting the upper pressure head, turning over the oil cylinder to lay the die in parallel, pushing the electrode out of the die onto a cooling tray by using the lower pressure head, putting the electrode into cooling water for cooling for 24 hours, and obtaining a carbon electrode green body after the cooling is finished; then, a ring-type roasting furnace is adopted, the electrode green body is isolated from air under a protective medium, and the electrode green body is roasted at variable temperature for 740 hours to obtain a carbonaceous electrode; and processing the excircle, the male head and the female hole of the roasted carbonaceous electrode to obtain a carbon electrode C.

Example 4:

selecting a solid mixture according to parts by weight: 42 parts of graphitized massive materials, 26 parts of graphitized coke, 25 parts of graphitized powdery materials, and liquid coal pitch which is crushed by the electrode accounting for 2% of the mass of the solid mixture and accounts for 18.5% of the mass of the solid mixture. Preheating a kneading pot to 135 ℃, adding the graphitized massive material, the graphitized coke, the graphitized powdery material and the electrode raw pieces into the kneading pot to be heated to 135 ℃ under normal pressure, carrying out dry mixing for 50min, discharging the water in the mixture material, adding the fully-standing liquid coal tar pitch, carrying out wet mixing for 35min, and then discharging the mixture into a hopper; placing the mixture in the hopper into a preheated material airing stirring cylinder with the temperature of 95 ℃, airing the material after stirring for 15min, and taking out the paste when the temperature of the mixture is 120 ℃. Preheating an upper pressure head, a lower pressure head and a die of a molding press by using heat conduction oil, stabilizing the temperature at 95 ℃, horizontally fixing the lower pressure head and the die on a vibrating table in an upward manner, adding a paste material into the die, flattening the material while feeding, enabling one surface of the paste material to flow freely, and discharging asphalt smoke from the other surface of the paste material. And putting down the upper pressure head, pressurizing the paste, and starting a four-axis amplitude modulation vibration table and an additional vibration motor to vibrate. The pressure was maintained continuously and the cooling was carried out for 95 min. After the pressurization and cooling are stopped, heating the die to 80 ℃, lifting the upper pressure head, turning over the oil cylinder to lay the die in parallel, pushing the electrode out of the die onto a cooling tray by using the lower pressure head, putting the electrode into cooling water for cooling for 18 hours, and obtaining a carbon electrode green body after the cooling is finished; then, a ring-type roasting furnace is adopted, the electrode green body is isolated from air under a protective medium, and the electrode green body is roasted at variable temperature for 740 hours to obtain a carbonaceous electrode; and processing the excircle, the male head and the female hole of the roasted carbonaceous electrode to obtain a carbon electrode D.

Example 5:

selecting a solid mixture according to parts by weight: 42 parts of graphitized massive materials, 26 parts of graphitized coke, 25 parts of graphitized powdery materials, and liquid coal pitch which is crushed by the electrode accounting for 2% of the mass of the solid mixture and accounts for 18.5% of the mass of the solid mixture. Preheating a kneading pot to 140 ℃, adding the graphitized massive material, the graphitized coke, the graphitized powdery material and the electrode raw pieces into the kneading pot to be heated to 140 ℃ under normal pressure, carrying out dry mixing for 60min, discharging water in the mixture material, adding fully-standing liquid coal tar pitch, carrying out wet mixing for 40min, and then discharging the mixture into a hopper; placing the mixture in the hopper into a preheated material airing stirring cylinder with the temperature of 100 ℃, airing the material after stirring for 20min, and taking out the paste when the temperature of the mixture is 125 ℃. Preheating an upper pressure head, a lower pressure head and a die of a molding press by using heat conduction oil, stabilizing the temperature at 100 ℃, horizontally fixing the lower pressure head and the die on a vibrating table in an upward manner, adding a paste material into the die, flattening the material while feeding, enabling one surface of the paste material to flow freely, and discharging asphalt smoke from the other surface of the paste material. And putting down the upper pressure head, pressurizing the paste, and starting a four-axis amplitude modulation vibration table and an additional vibration motor to vibrate. Keeping the pressure and cooling for 100 min. After the pressurization and cooling are stopped, heating the die to 80 ℃, lifting the upper pressure head, turning over the oil cylinder to lay the die in parallel, pushing the electrode out of the die onto a cooling tray by using the lower pressure head, putting the electrode into cooling water for cooling for 24 hours, and obtaining a carbon electrode green body after the cooling is finished; then, a ring-type roasting furnace is adopted, the electrode green body is isolated from air under a protective medium, and the electrode green body is roasted at variable temperature for 740 hours to obtain a carbonaceous electrode; and processing the excircle, the male head and the female hole of the roasted carbonaceous electrode to obtain a carbon electrode E.

Example 6:

selecting a solid mixture according to parts by weight: 45 parts of graphitized massive materials, 29 parts of graphitized coke, 28 parts of graphitized powdery materials, and liquid coal pitch which is crushed by the electrode accounting for 2.5 percent of the mass of the solid mixture and accounts for 19 percent of the mass of the solid mixture. Preheating a kneading pot to 130 ℃, adding the graphitized massive material, the graphitized coke, the graphitized powdery material and the electrode raw pieces into the kneading pot to be heated to 130 ℃ under normal pressure, carrying out dry mixing for 40min, discharging the moisture in the mixture material, adding the fully-standing liquid coal tar pitch, carrying out wet mixing for 30min, and then discharging the mixture into a hopper; putting the mixture in the hopper into a preheated material airing stirring cylinder with the temperature of 90 ℃, airing the material after stirring for 10min, and taking out the paste when the temperature of the mixture is 115 ℃. Preheating an upper pressure head, a lower pressure head and a die of a molding press by using heat conduction oil, stabilizing the temperature at 90 ℃, horizontally fixing the lower pressure head and the die on a vibrating table in an upward manner, adding a paste material into the die, flattening the material while feeding, enabling one surface of the paste material to flow freely, and discharging asphalt smoke from the other surface of the paste material. And putting down the upper pressure head, pressurizing the paste, and starting a four-axis amplitude modulation vibration table and an additional vibration motor to vibrate. Keeping the pressure and cooling for 90 min. After the pressurization and cooling are stopped, heating the die to 80 ℃, lifting the upper pressure head, turning over the oil cylinder to lay the die in parallel, pushing the electrode out of the die onto a cooling tray by using the lower pressure head, putting the electrode into cooling water for cooling for 12 hours, and obtaining a carbon electrode green body after the cooling is finished; then, a ring-type roasting furnace is adopted, the electrode green body is isolated from air under a protective medium, and the electrode green body is roasted at variable temperature for 740 hours to obtain a carbonaceous electrode; and processing the excircle, the male head and the female hole of the roasted carbonaceous electrode to obtain a carbon electrode F.

Example 7:

selecting a solid mixture according to parts by weight: 45 parts of graphitized massive materials, 29 parts of graphitized coke, 28 parts of graphitized powdery materials, and liquid coal pitch which is crushed by the electrode accounting for 2.5 percent of the mass of the solid mixture and accounts for 19 percent of the mass of the solid mixture. Preheating a kneading pot to 140 ℃, adding the graphitized massive material, the graphitized coke, the graphitized powdery material and the electrode raw pieces into the kneading pot to be heated to 140 ℃ under normal pressure, carrying out dry mixing for 60min, discharging water in the mixture material, adding fully-standing liquid coal tar pitch, carrying out wet mixing for 40min, and then discharging the mixture into a hopper; placing the mixture in the hopper into a preheated material airing stirring cylinder with the temperature of 100 ℃, airing the material after stirring for 20min, and taking out the paste when the temperature of the mixture is 125 ℃. Preheating an upper pressure head, a lower pressure head and a die of a molding press by using heat conduction oil, stabilizing the temperature at 100 ℃, horizontally fixing the lower pressure head and the die on a vibrating table in an upward manner, adding a paste material into the die, flattening the material while feeding, enabling one surface of the paste material to flow freely, and discharging asphalt smoke from the other surface of the paste material. And putting down the upper pressure head, pressurizing the paste, and starting a four-axis amplitude modulation vibration table and an additional vibration motor to vibrate. Keeping the pressure and cooling for 100 min. After the pressurization and cooling are stopped, the mould is heated to 80 ℃, the upper pressure head is lifted, the mould is placed in parallel by turning the oil cylinder, the electrode is pushed out of the mould to a cooling tray by using the lower pressure head, the electrode is placed in cooling water for cooling for 24 hours, and the cooling is carried out

Obtaining a carbon electrode green body after completion; then, a ring-type roasting furnace is adopted, the electrode green body is isolated from air under a protective medium, and the electrode green body is roasted at variable temperature for 740 hours to obtain a carbonaceous electrode; and processing the excircle, the male head and the female hole of the roasted carbonaceous electrode to obtain a carbon electrode G.

Example 8:

selecting a solid mixture according to parts by weight: 48 parts of graphitized blocky materials, 32 parts of graphitized coke, 30 parts of graphitized powdery materials, crushed electrodes accounting for 3% of the mass of the solid mixture, and liquid coal pitch accounting for 19.6% of the mass of the solid mixture. Preheating a kneading pot to 130 ℃, adding the graphitized massive material, the graphitized coke, the graphitized powdery material and the electrode raw pieces into the kneading pot to be heated to 130 ℃ under normal pressure, carrying out dry mixing for 40min, discharging the moisture in the mixture material, adding the fully-standing liquid coal tar pitch, carrying out wet mixing for 30min, and then discharging the mixture into a hopper; putting the mixture in the hopper into a preheated material airing stirring cylinder with the temperature of 90 ℃, airing the material after stirring for 10min, and taking out the paste when the temperature of the mixture is 115 ℃. Preheating an upper pressure head, a lower pressure head and a die of a molding press by using heat conduction oil, stabilizing the temperature at 90 ℃, horizontally fixing the lower pressure head and the die on a vibrating table in an upward manner, adding a paste material into the die, flattening the material while feeding, enabling one surface of the paste material to flow freely, and discharging asphalt smoke from the other surface of the paste material. And putting down the upper pressure head, pressurizing the paste, and starting a four-axis amplitude modulation vibration table and an additional vibration motor to vibrate. Keeping the pressure and cooling for 90 min. After the pressurization and cooling are stopped, heating the die to 80 ℃, lifting the upper pressure head, turning over the oil cylinder to lay the die in parallel, pushing the electrode out of the die onto a cooling tray by using the lower pressure head, putting the electrode into cooling water for cooling for 12 hours, and obtaining a carbon electrode green body after the cooling is finished; then, a ring-type roasting furnace is adopted, the electrode green body is isolated from air under a protective medium, and the electrode green body is roasted at variable temperature for 740 hours to obtain a carbonaceous electrode; and processing the excircle, the male head and the female hole of the roasted carbonaceous electrode to obtain a carbon electrode H.

Example 9:

selecting a solid mixture according to parts by weight: 48 parts of graphitized blocky materials, 32 parts of graphitized coke, 30 parts of graphitized powdery materials, crushed electrodes accounting for 3% of the mass of the solid mixture, and liquid coal pitch accounting for 19.6% of the mass of the solid mixture. Preheating a kneading pot to 135 ℃, adding the graphitized massive material, the graphitized coke, the graphitized powdery material and the electrode raw pieces into the kneading pot to be heated to 135 ℃ under normal pressure, carrying out dry mixing for 50min, discharging the water in the mixture material, adding the fully-standing liquid coal tar pitch, carrying out wet mixing for 35min, and then discharging the mixture into a hopper; placing the mixture in the hopper into a preheated material airing stirring cylinder with the temperature of 95 ℃, airing the material after stirring for 15min, and taking out the paste when the temperature of the mixture is 120 ℃. Preheating an upper pressure head, a lower pressure head and a die of a molding press by using heat conduction oil, stabilizing the temperature at 95 ℃, horizontally fixing the lower pressure head and the die on a vibrating table in an upward manner, adding a paste material into the die, flattening the material while feeding, enabling one surface of the paste material to flow freely, and discharging asphalt smoke from the other surface of the paste material. And putting down the upper pressure head, pressurizing the paste, and starting a four-axis amplitude modulation vibration table and an additional vibration motor to vibrate. The pressure was maintained continuously and the cooling was carried out for 95 min. After the pressurization and cooling are stopped, heating the die to 80 ℃, lifting the upper pressure head, turning over the oil cylinder to lay the die in parallel, pushing the electrode out of the die onto a cooling tray by using the lower pressure head, putting the electrode into cooling water for cooling for 18 hours, and obtaining a carbon electrode green body after the cooling is finished; then, a ring-type roasting furnace is adopted, the electrode green body is isolated from air under a protective medium, and the electrode green body is roasted at variable temperature for 740 hours to obtain a carbonaceous electrode; and processing the excircle, the male head and the female hole of the roasted carbonaceous electrode to obtain a carbon electrode I.

Testing the resistivity of the carbon electrode according to GB 242530-2009 (carbon material resistivity measuring method), and measuring the density and breaking strength data of the carbon electrode as follows:

the carbon electrodes obtained by the method have the volume density of 1.59-1.62, the resistivity of less than or equal to 32.5 u.omega.m and the breaking strength of more than or equal to 5.7Mpa, meet the YB/4226-.

Finally, the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all of them should be covered in the claims of the present invention.

Claims

1. A carbon electrode with a conical central hole is characterized by comprising the following components: solid mixture, electrode raw meal and liquid coal tar pitch; the solid mixture comprises 42-48% of graphitized massive material, 26-32% of graphitized coke and 25-30% of graphitized powdery material by weight percentage; the raw electrode fragments account for 2-3% of the mass of the solid mixture, and the liquid coal tar pitch accounts for 18.5-19.6% of the mass of the solid mixture.

2. The carbon electrode with the conical central hole as claimed in claim 1, wherein the graphitized bulk material is unqualified electrode after high temperature roasting and other waste materials.

3. The carbon electrode with the conical central hole as claimed in claim 2, wherein the other waste materials are one or more of waste carbon anodes and carbon rods.

4. The carbon electrode with the tapered central hole according to claim 1, wherein the liquid coal pitch is upgraded coal pitch.

5. A method for preparing a carbon electrode with a tapered central hole according to any one of claims 1 to 4, comprising the steps of:

6. The method for preparing a carbon electrode with a tapered central hole according to claim 5, wherein the time for feeding and leveling in step (4) is 2-3min, and the paste is pressurized to 3-5kg/cm 2.

7. The method for preparing the carbon electrode with the tapered central hole as claimed in claim 5, wherein the baking manner in the step (6) is variable temperature baking, the baking time is 740 hours, and the baking maximum temperature of the external filler is 900-950 ℃.