阅读说明：本技术 一种熔炼石英用超长再生石墨电极的生产工艺 (Production process of ultra-long regenerated graphite electrode for smelting quartz ) 是由 薛喜利 刘长青 薛明虎 张锐琦 于 2021-01-21 设计创作，主要内容包括：本发明公开了一种熔炼石英用超长再生石墨电极的生产工艺,包括以下步骤：S1、配料：将石墨粉、硅粉加入煤沥青在搅拌锅中进行搅拌,使其混合均匀；S2、混捏：S3、晾料；S4、成型：S5、焙烧；本发明生产工艺简单,通过对原料的重新配伍,并对生产工序进行严格的控制,使得产品长度长达4.9米,使用寿命较长、成本低廉、高密度同时也具备耐高温、耐腐蚀的性能,有利于大规模生产。(The invention discloses a production process of an ultra-long regenerated graphite electrode for quartz smelting, which comprises the following steps: s1, batching: adding graphite powder and silicon powder into coal tar pitch, and stirring in a stirring pot to uniformly mix; s2, kneading: s3, airing the materials; s4, molding: s5, roasting; the invention has simple production process, long product length up to 4.9 meters, long service life, low cost, high density, high temperature resistance and corrosion resistance by re-compatibility of the raw materials and strict control of the production process, and is beneficial to large-scale production.)

1. A production process of an ultra-long regenerated graphite electrode for smelting quartz is characterized by comprising the following steps:

s1, batching:

adding graphite powder and silicon powder into coal tar pitch, and stirring in a stirring pot to uniformly mix;

s2, kneading:

uniformly stirring and mixing the ingredients in the step S1 and a proper amount of binder, and kneading the mixture into a plastic paste;

s3, airing: placing the kneaded paste in a paste cooling machine for 3-10min for cooling;

s4, molding:

the forming process comprises the following steps: feeding → sealing → vacuumizing → pressure maintaining → vacuum breaking → pressure relief → discharge molding;

s5, roasting:

the roasting production period is 22-36 days.

2. The production process of the overlength regeneration graphite electrode for smelting quartz as claimed in claim 1, wherein the mass ratio of the graphite powder, the silicon powder and the coal pitch in S1 is as follows: 62:5-10:30-33.

3. The process for producing an ultra-long regenerated graphite electrode for melting quartz as claimed in claim 1, wherein the heating temperature at the kneading in S2 is a high temperature of 180 ± 20 ℃.

4. The process for producing an ultra-long regenerated graphite electrode for fused quartz according to claim 1, wherein the dry mixing is carried out for 10 to 20 minutes and then the wet mixing is carried out for 30 to 50 minutes at the time of kneading in S2.

5. The process for producing an extra-long regenerated graphite electrode for melting quartz as claimed in claim 1, wherein the feeding system is opened at the time of feeding in S4, the feeding is stopped when the material in the chamber approaches the upper edge of the piston, the main cylinder is pushed forward again until the pressure of the sub-cylinder reaches 5MPA, the main cylinder is pushed backward and rapidly, and the operation is repeated until the material is completely fed or the chamber is full.

6. The process for producing an ultra-long regenerated graphite electrode for fused quartz according to claim 1, wherein the sealing time in S4 is 3 to 10 min.

7. The process for producing an ultra-long regenerated graphite electrode for fused quartz according to claim 1, wherein when the pressure is released in S4, the main cylinder is stopped from being fed and the pressure is released to 0.5 to 1.5 MPa.

Technical Field

The invention relates to the technical field of regenerated graphite electrodes, in particular to a production process of an ultra-long regenerated graphite electrode for quartz smelting.

Background

At present, a graphite electrode is a high-temperature resistant graphite conductive material prepared by using petroleum coke and pitch coke as aggregates and coal pitch as an adhesive through the steps of raw material calcination, crushing and grinding, blending, kneading, molding, roasting, impregnation, graphitization and machining, and is called an artificial graphite electrode (graphite electrode for short) and is different from a natural graphite electrode prepared by using natural graphite as a raw material.

The existing graphite electrode is formed by integrally pressing, the length of the electrode produced by the graphite electrode is constant, and therefore, if the graphite electrodes with different lengths are needed, a plurality of sets of dies are needed to produce the graphite electrodes with different lengths, so that the manufacturing cost can be increased, and in the actual construction, when the graphite electrodes with longer lengths are needed, the graphite electrodes are very easy to break.

Loss of electrode breakage, surface flaking and chipping can be collectively referred to as abnormal consumption. The problem of electrode breakage can occur in the production process of smelting quartz, and besides electrode loss, consumption increase and cost increase are directly generated, more importantly, production interruption can be caused, and production loss is caused by furnace shutdown and mis-production.

The occurrence of electrode body breakage is mainly due to the following aspects:

firstly, the screw hole of the electrode body has quality defects;

volume density and strength of the electrode body are not enough;

the electrode body is not matched with the joint indexes and the processing precision;

fourthly, the deep cracks generated at the end part of the electrode body are caused by poor thermal shock resistance of the electrode; :

the longer the length, the larger the volume, the density and strength are not easy to be mastered, so that the prior art is difficult to produce the graphite electrode with longer length which is not easy to break.

Disclosure of Invention

The invention aims to provide an ultralong regenerated graphite electrode which has ultralong specification, low cost and high density, and also has high temperature resistance and corrosion resistance aiming at the defects in the prior art.

In order to solve the technical problems, the invention provides the following technical scheme:

a production process of an ultra-long regenerated graphite electrode for smelting quartz comprises the following steps:

preparing materials: adding graphite powder and silicon powder into coal tar pitch according to a proportion, and stirring in a stirring pot to uniformly mix the graphite powder and the silicon powder;

kneading: the quantitative carbon granules and powder with various granularities and a proper amount of binder are stirred and mixed evenly at a certain temperature, and kneaded into the plastic paste.

Preferably, the heating temperature is at an elevated temperature of about 180 ℃, e.g., 180 ± 20 ℃.

Kneading process: dry mixing (10-20min) and wet mixing (30-50min)

The purpose of kneading:

during dry mixing, various raw materials are uniformly mixed, and simultaneously, solid carbonaceous materials with different particle sizes are uniformly mixed and filled, so that the compactness of the mixture is improved;

secondly, after adding the coal tar pitch, uniformly mixing the dry materials and the pitch, uniformly coating and infiltrating the surface of the particles with the liquid pitch to form a pitch bonding layer, bonding all the materials together, and further forming a homogeneous plastic paste, which is beneficial to forming;

thirdly, partial coal tar pitch permeates into the internal gaps of the carbonaceous material, so that the density and the cohesiveness of the paste are further improved.

Airing materials: the kneaded paste was placed in a hopper of a paste cooling machine and cooled.

And (3) cooling: placing in a cooling machine (3-10 min).

The cooling effect is as follows: the paste is allowed to fall to a temperature at which it can be formed, preventing the paste from caking.

Molding: and (3) plastically deforming the kneaded carbonaceous paste under the external acting force applied by a forming device to finally form a green body (or a green product) with certain shape, size, density and strength.

The forming process comprises the following steps: feeding → sealing → vacuumizing → pressure maintaining → vacuum breaking → pressure releasing → discharge molding

Feeding: and starting the feeding system, stopping feeding when the material in the material chamber approaches the upper edge of the piston, then pushing the main cylinder forwards, pushing the auxiliary cylinder backwards and quickly when the pressure of the auxiliary cylinder reaches 5MPA, and repeating the operation until the material completely enters or the material chamber is full.

The sealing time is usually 3-10 min.

Vacuumizing: and starting a vacuum pump to ensure that the negative pressure in the tank reaches a certain value and then starting vacuumizing.

Pre-pressing and pressure maintaining: and starting the main cylinder to work in advance to reach the set pressure maintaining time.

Breaking vacuum: the vacuum in the feed chamber was broken.

Pressure relief: the main cylinder stops working, and the pressure is released to the main cylinder pressure (0.5-1.5 MPa).

Discharging: the main cylinder worker advances after the material receiving vehicle is ready, automatic discharging is carried out after the discharging length is set, the shear shank advances to cut after the discharging length is reached, the material receiving vehicle receives the material and retreats to the rear limit, and the discharging forming is completed by turning the material receiving vehicle.

Roasting: under the protection of filler, the green body of carbon product is placed into a specially designed heating furnace to make high-temperature heat treatment so as to make the coal pitch in the green body be carbonized. The pitch coke formed after the coal pitch is carbonized consolidates the carbonaceous aggregate and the powder particles together, and the roasted carbon product has higher mechanical strength, lower resistivity, better thermal stability and chemical stability.

The roasting production period is 22-36 days, and the roasting quality of the green body has certain influence on the quality of the finished product and the production cost.

Secondly, the coal tar pitch in the green body is coked in the roasting process, about 10% of volatile matters are discharged, meanwhile, the volume is contracted by 2-3%, and the mass is reduced by 8-10%. The physical and chemical properties of the carbon blank are also obviously changed, the volume density is reduced from 1.80g/cm3 to 1.74g/cm3 due to the increase of porosity, the resistivity is reduced to 14-18 omega.m, and the mechanical strength of the baked blank is also greatly improved.

The invention has the following beneficial effects: the invention has simple production process, long product length up to 4.9 meters, long service life, low cost, high density, high temperature resistance and corrosion resistance by re-compatibility of the raw materials and strict control of the production process, and is beneficial to large-scale production.

Detailed Description

The following description of the preferred embodiments of the present invention is provided for the purpose of illustration and description, and is in no way intended to limit the invention.

Examples

A production process of an ultra-long regenerated graphite electrode for smelting quartz comprises the following steps:

preparing materials: graphite powder (62%) and silicon powder (5% -10%) are added into coal tar pitch (30% -33%) according to a certain proportion, and stirred in a stirring pot, so that the mixture is uniformly mixed.

Kneading: the quantitative carbon granules and powder with various granularities and a proper amount of binder are stirred and mixed evenly at a certain temperature, and kneaded into the plastic paste. Preferably, the heating temperature is at a high temperature of about 180 ℃.

Kneading process: dry mixing (10-20min) and wet mixing (30-50min)

The purpose of kneading:

during dry mixing, various raw materials are uniformly mixed, and simultaneously, solid carbonaceous materials with different particle sizes are uniformly mixed and filled, so that the compactness of the mixture is improved;

secondly, after adding the coal tar pitch, uniformly mixing the dry materials and the pitch, uniformly coating and infiltrating the surface of the particles with the liquid pitch to form a pitch bonding layer, bonding all the materials together, and further forming a homogeneous plastic paste, which is beneficial to forming;

thirdly, partial coal tar pitch permeates into the internal gaps of the carbonaceous material, so that the density and the cohesiveness of the paste are further improved.

Airing materials: the kneaded paste was placed in a hopper of a paste cooling machine and cooled.

And (3) cooling: placing in a cooling machine (3-10 min).

The cooling effect is as follows: the paste is allowed to fall to a temperature at which it can be formed, preventing the paste from caking.

Molding: and (3) plastically deforming the kneaded carbonaceous paste under the external acting force applied by a forming device to finally form a green body (or a green product) with certain shape, size, density and strength.

The forming process comprises the following steps: feeding → sealing → vacuumizing → pressure maintaining → vacuum breaking → pressure releasing → discharge molding

Feeding: and starting the feeding system, stopping feeding when the material in the material chamber approaches the upper edge of the piston, then pushing the main cylinder forwards, pushing the auxiliary cylinder backwards and quickly when the pressure of the auxiliary cylinder reaches 5MPA, and repeating the operation until the material completely enters or the material chamber is full.

Sealing (3-10 min).

Vacuumizing: and starting a vacuum pump to ensure that the negative pressure in the tank reaches a certain value and then starting vacuumizing.

Pre-pressing and pressure maintaining: and starting the main cylinder to work in advance to reach the set pressure maintaining time.

Breaking vacuum: the vacuum in the feed chamber was broken.

Pressure relief: the main cylinder stops working, and the pressure is released to the main cylinder pressure (0.5-1.5 MPa).

Discharging: the main cylinder worker advances after the material receiving vehicle is ready, automatic discharging is carried out after the discharging length is set, the shear shank advances to cut after the discharging length is reached, the material receiving vehicle receives the material and retreats to the rear limit, and the discharging forming is completed by turning the material receiving vehicle.

Roasting: under the protection of filler, the green body of carbon product is placed into a specially designed heating furnace to make high-temperature heat treatment so as to make the coal pitch in the green body be carbonized. The pitch coke formed after the coal pitch is carbonized consolidates the carbonaceous aggregate and the powder particles together, and the roasted carbon product has higher mechanical strength, lower resistivity, better thermal stability and chemical stability.

The roasting production period is 22-36 days, and the roasting quality of the green body has certain influence on the quality of the finished product and the production cost.

Secondly, the coal tar pitch in the green body is coked in the roasting process, about 10% of volatile matters are discharged, meanwhile, the volume is contracted by 2-3%, and the mass is reduced by 8-10%. The physical and chemical properties of the carbon blank are also obviously changed, the volume density is reduced from 1.80g/cm3 to 1.74g/cm3 due to the increase of porosity, the resistivity is reduced to 14-18 omega.m, and the mechanical strength of the baked blank is also greatly improved. The compression strength and the breaking strength of the baked blank are respectively 30Mpa and 13.5Mpa, which are greatly improved compared with the prior art.

The length of the finally prepared ultra-long regenerated graphite electrode is as long as 4.9 meters, the service life is ultra-long, and the specific data is as follows:

as can be seen from the above table, the existing regenerated graphite electrode has poor conductivity, insufficient length and short service life, and cannot support the consumption of a large-scale quartz stone smelting furnace for a long time.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.