 Graphite products are still widely used in industry and are widely used in the following fields: 1.As refractory material: graphite and its products have the characteristics of high temperature resistance and high strength.Graphite crucible is mainly used in metallurgical industry.Graphite is commonly used as a protective agent for ingot and lining of metallurgical furnace for steelmaking. 2.Conductive materials: in the electrical industry, used to manufacture graphite electrode, carbon brush, carbon rod, carbon tube, mercury rectifier anode, graphite gasket, telephone accessories, television picture tube coating, etc. 3.Graphite as wear-resisting and lubricating materials, often used as a lubricant in the machinery industry.Lubricating oil can not be used under high speed, high temperature and high pressure.Graphite wear-resistant material at 200~2000℃ without lubricating oil can achieve high-speed sliding.Many devices are used to deliver corrosive media, and graphite electrode manufacturers use the material extensively for piston cups, seals and bearings.No lubricant is required during operation.Graphite emulsion is also a good lubricant for many metal processing (wire drawing, tube drawing). 4.Graphite has good chemical stability.The specially processed graphite has the characteristics of corrosion resistance, good thermal conductivity and low permeability.Widely used in heat exchanger, reaction tank, condenser, combustion tower, absorption tower, cooler, heater, filter, pump and other equipment.Widely used in petrochemical, hydrometallurgy, acid and alkali production, synthetic fiber, papermaking and other industrial sectors, can save a lot of metal materials.
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The difference between high power graphite electrode and ultra high power graphite electrode4/18/2022 The difference between high power graphite electrode and ultra-high power graphite electrode is that graphite is mainly used in (1) arc steelmaking furnace (2) arc furnace (3) resistance furnace for preparing special-shaped graphite products (4).Graphite electrode billet can also be used to process various special shape graphite products, such as crucible, mold, container and heater. Graphite has good characteristics, so our company mainly produces graphite electrode, graphite products and graphite processing graphite foreign body.Our products reach the national qualified products and are well received by the majority of manufacturers and business partners.Here, we hope to build a commercial bridge with manufacturers from all walks of life.The difference between high power graphite electrode and ultra high power graphite electrode is mainly used to produce industrial silicon and yellow phosphorus.Its characteristic is that the lower part of the conductive electrode is buried in the charge layer, forming an arc in the charge layer, using the heat energy generated by the resistance of the charge itself to heat the charge, which requires high current density ore.The furnace needs graphite electrodes.For example, graphite electrodes consume about 100 kg per ton of silicon production and about 40 kg per ton of yellow phosphorus production.   1, what are the characteristics of needle coke? Needle coke is a kind of high quality carbon raw material, divided into coal series and oil series.The focal surface of needle has obvious stripes.When it breaks, most of it is in long, needle-like pieces.The fiber structure can be observed under the microscope, so it is called needle coke.Needle coke tends to graphitize at high temperatures above 2000 degrees.The needle coke graphite electrode has low resistivity, high volume density and low thermal expansion coefficient.It is a necessary raw material for producing ultra-high power electrode and high power electrode.Needle coke is much more expensive than ordinary coke, the current price is about 5-8 times that of ordinary coke. 2. Will the vacuum system on the eAF affect electrode consumption? The fan used in the dust collection system generates a certain negative pressure during operation, which increases the flow of air around the red-hot electrode during the preparation of steel, thus increasing the oxidation consumption of the electrode.In the process of steelmaking, a good dust removal system not only keeps a good working environment, but also makes electrode consumption stable. 3. How to avoid the increase of electrode consumption in steelmaking process? In order to avoid the increase of electrode consumption in the process of steelmaking, the following measures should be taken :(1) according to the design requirements of electric furnace, keep good power supply state, power supply within the range of electrode current intensity.(2) Prevent the arc point from immerging into the molten pool.(3) Prevent electrode from immerging in steel liquid to increase carbon.(4) Spray cooling technology should be used for electrodes if conditions permit.(5) Set the correct exhaust system.(6) Use the correct oxygen blowing system. 4. How long does the production cycle of graphite electrode take? The production process and corresponding time of a batch of ultra-high power or high power graphite electrode are as follows: pressure electrode (3 days) - baking (25 days) - impregnation (4 days) - rebaking (15 days) - graphitization (10 days) - machining, quality inspection (2 days) - finished product packaging and delivery (1 day), I, E.Production lasts up to 60 days from feed to product delivery and 90 days for electrode joints because two soaks and three bakes are required.  5. What are the characteristics of the electrode produced in series graphitization furnace?
The development direction of graphitization furnace is internal heat series graphitization furnace.Because the current density of the connected column is the same, the resistivity difference of the electrode is very small.Second, within the string of graphitizing product on both ends of the resistivity is slightly lower than the middle (acheson graphitization furnace product resistivity is higher than the middle on both ends), beneficial to reduce the resistance of the joint, when users use slow joint overheating aglow phenomenon, make the concatenated graphitizing furnace electrode quality same as acheson furnace, electric arc furnace steelmaking is more suitable for production requirement.  Graphite electrodes are mainly used in eAF steelmaking.Electric furnace as the core steelmaking technology has obvious advantages in production efficiency, environmental protection, infrastructure investment cost, process flexibility and other aspects, electric furnace steelmaking is the use of electrode into the furnace current.A strong current will pass through the gas at the bottom of the electrode to produce an arc discharge, while releasing a large amount of heat for smelting. Graphite electrode has high quality characteristics unmatched by other components: 1.Graphite has good thermal stability, at 3550℃ when sublimation, ordinary metal has melted at this high temperature; 2.The resistance is very low, only a few ohms, smelting energy consumption is small; 3.Light weight, less than 1/4 of the density of copper, easy to transport and use, good safety, easy to clamp when melting on the furnace; 4.Raw materials for easy asphalt, petroleum coke, needle coke, etc.; 5.Good processability, 3-5 times faster than ordinary metal.  Ordinary power graphite electrode Graphite electrodes with current density less than 17A /cm2 are allowed, mainly used in steelmaking, silicon smelting, yellow phosphorus smelting, etc. Oxidation resistant coated graphite electrode ① Graphite electrode is coated with antioxidant protection (graphite electrode antioxidant).It can reduce electrode consumption (19% ~ 50%), prolong service life (22% ~ 60%), and reduce electrode power consumption.The popularization and application of this technology can bring such economic and social benefits. The single consumption of graphite electrode is less, and the production cost is reduced to a certain extent.If the one-level LF refining furnace does not stop production all year round and consumes about 35 graphite electrodes per week, 165 furnaces are refined and treated with graphite electrode anti-oxidation technology, 373 electrodes (153 tons) can be saved every year, and 2,585,700 yuan of ultra-high power electrodes can be saved per ton 16,900 yuan per year. ② The graphite electrode consumes less electricity, saving unit steelmaking power consumption, saving production cost, saving energy! ③ Due to the low number of graphite electrode replacement, the operator's labor and risk factors are reduced, and the production efficiency is improved. ④ Graphite electrode is a kind of low consumption and low pollution product.It is of great social significance in energy conservation, emission reduction and environmental protection.  High power graphite electrode
Graphite electrodes are mainly used in high-power arc furnaces for steelmaking with permissible current density of 18 ~ 25A/cm2. Ultra high power graphite electrode Graphite electrodes with current densities greater than 25A/cm2 are allowed.Mainly used for ultra high power electric arc furnace. Graphite electrode production technology Raw materials: in carbon production, the commonly used raw materials can be divided into solid carbon raw materials, binder and impregnating agent two categories.Solid carbonaceous materials include petroleum coke, bituminous coke, metallurgical coke, anthracite, natural graphite and graphite crushing.Binders and impregnators include coal pitch, coal tar, anthracene oil and synthetic resins.In addition, the production also used quartz sand, metallurgical coke powder, coke powder and other auxiliary materials.Other special materials are used to produce some special carbon and graphite products (such as carbon fiber, activated carbon, pyrolytic carbon and pyrolytic graphite, glass carbon). Calcination: the process of heat treatment of carbon raw materials in isolated air at high temperature (1200≤1500℃) is called calcination.Calcination is the first heat treatment process in carbon production.As a result of calcination, the structure and physicochemical properties of various materials containing carbon have undergone a series of changes. Anthracite and petroleum coke contain a certain amount of volatile, need to calcination.Asphaltene coke and metallurgical coke coking temperature is higher (more than 1000℃), equivalent to the temperature of the calciner in the carbonization plant.It can't burn any more. Just dry it out.However, if asphalt coke and petroleum coke are mixed before calcination, they should be fed into the calcination furnace together with petroleum coke.Natural carbon black and graphite do not need to be calcined. Screening: Kneading: The purpose of kneading is to obtain a uniform, plastic paste.However, due to the change of some factors, the kneading quality will change greatly, resulting in the instability of product quality.The test shows that when the softening point of hard asphalt is 80 ~ 90℃, the temperature of paste should be raised to 168 ~ 174℃.In this temperature range, the best improvement of wettability and bonding property of dry materials by asphalt is that the paste obtained has good plasticity and extrusion properties.Mix dry for 30 minutes, wet for 40 minutes.If the stirring time is too long, the large particles will be destroyed, the original particle composition will be destroyed, so that the volume density of the product is reduced, the plasticity becomes poor, the porosity increases, the mechanical strength decreases Graphite electrode. PNG Molding: extrusion molding, vibration molding and molding.Our factory adopts 3500T extruder molding.Before forming, the resulting paste was reduced from 168-174℃ to 116℃ in the cooler.The cooling time should not be less than 8 minutes.After the heat preservation platform is kept for 20 minutes, put the heat preservation paste into the extruder barrel body, and the pressure is generally not less than 25MPa.The product is extruded through a mouth installed in front of the extruder. The extruder is usually produced intermittently. The production is divided into three stages.In the second stage, the electrode density increases gradually as the indenter continues to apply pressure.When the density reaches a certain value, the pressure continues to increase and the density increases slowly.In the third stage, the pressure reaches the limit value and the density tends to be uniform.The electrode is then extruded from the nozzle Roasting: Roasting is a heat treatment process in which the pressed product is heated at a certain rate in the protective medium in the heating furnace under the condition of air isolation. The purpose of roasting is: The main results are as follows :(1) the release of volatiles after calcination of products using coal pitch as binder is about 10%.Therefore, the roasting yield is generally less than 90%. （2）Coking raw materials are roasted according to certain technological conditions, the binder is coking, and the coke network is formed between the aggregate particles, so that the aggregates with different particle sizes are firmly connected together, and the products have certain physical and chemical properties.Under the same conditions, the higher the coke rate, the better the product quality.The residual carbon content of medium-temperature asphalt is about 50% (3) During the roasting process, the products with fixed geometry softened and the binder migrated.As the temperature increases, a coking network forms, making the product hard.Therefore, the shape does not change with increasing temperature  What can not be done in the use of graphite electrode?  1、The graphite electrode manufacturer indicates that the connector should be carefully screwed into the hole of the spare graphite electrode (it is not recommended to install the connector directly into the electrode taken out of the furnace).No thread will collide.
2、Remove the foam cover from the spare graphite electrode hole.Check integrity of thread in electrode hole. 3、Dry the wet graphite electrode before use. 4 Rotate the electrode coater (graphite coater recommended) into the electrode hole at the other end of the spare electrode. 5 when lifting the electrode, the joint should be prevented from damage;Cushion loose material at the end of the connector at the spare electrode.The lifting electrode should be stable.After entering the lifting ring with the hook, lift the lifting ring to prevent the electrode end B from loosening or colliding with other fixing devices. 6、Clean the surface and threaded holes of the spare graphite electrode with oil-free and water-free compressed air.Avoid using steel wire or metal brush to clean emery cloth. 7 Hang the standby electrode above the electrode to be connected, align the standby electrode with the electrode hole, and slowly lower the standby electrode.After the electrode is completely lowered, do not apply too much, otherwise it will be damaged by violent collision.Rotate the spare electrode so that the spiral hook rotates downward with the electrode;When the tops of the two electrodes are 10-20 mm apart.Then clean the end faces and exposed parts of the connector with compressed air, which may damage the electrode holes and the connector threads. 8 Tighten the spare electrode with a torque wrench until the top surfaces of the two electrodes are in close contact (the correct connector between electrode and connector is less than 0.05mm). In fact, carbon electrode is mainly composed of carbon elements, compared with graphite electrode, it has the characteristics of electric conductivity, heat conduction, heat resistance, chemical corrosion resistance, high mechanical strength, easy processing and forming, carbon electrode is mainly used in metallurgy, chemical and other fields, electrochemical and other industries, such as arc furnace electrode, electrolytic electrode, battery electrode and so on.  The carbon electrode is carbonized from asphalt coke, petroleum coke and adhesive.The degree of graphitization is not high, and the conductivity is not as good as artificial graphite.Can be used for aluminum and magnesium electrolytic electrode, battery electrode, etc.Special carbon electrode refers to the electrode made of special carbon material, mainly based on carbon fiber porous carbon electrode, can be used for fuel cells, etc.Glass carbon electrodes made from carbonization of thermosetting resin, with high purity and chemical resistance, can be used for analysis.
Although, graphite electrode has been widely used in the market by virtue of its own strength, and gradually occupied the dominant position in the market.The performance of graphite electrode is undeniable, but the quality of graphite electrode must be up to standard.But the types, brands and prices of graphite electrodes on the market vary.Therefore, special care should be taken to avoid the purchase of substandard graphite electrodes.
Graphite electrode materials can be divided into different grades according to their particle size.Of course, for the user, the choice of graphite electrode material is very critical, because it directly affects the speed of electromachining.Therefore, it is necessary to select good graphite electrode materials according to different technological conditions.Graphite electrode melting point is high, because of its high heat resistance, can improve the current value, reduce electrode loss, further improve the production efficiency;When the current value is very low, the electrode loss will increase.When the area and pulse width remain unchanged, the peak current will reach a certain value and continue to increase, resulting in the phenomenon of machining instability.Arc burns can occur during electrode and machining process, which will greatly reduce production efficiency. The larger the graphite electrode current, the larger the pits.Therefore, as the peak current increases, the surface becomes rougher and rougher.In the beginning, the chip electrode is in almost point contact with the workpiece, and the small electrode cannot withstand too much current and is easily damaged.Therefore, at the beginning, the current should be lowered, and then gradually increase the peak current until the discharge is stable and the processing speed is fast.
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