Graphite means that the molecular structure of carbon products is changed and arranged regularly by high temperature or other means. This molecular arrangement makes the molecular spacing of carbon wider, which is more conducive to decomposition and nucleation in molten iron or steel. The graphite carburizers on the market now generally come from two ways, one is the cutting of waste materials of graphite electrodes, and the other is the 3000 degree graphitization of petroleum coke. There are many kinds of raw materials and production processes of carburizers. It is not said in the market that graphite powder is used for pressing molding. This production method needs to add too much binder for molding, and the carbon content generally cannot meet the requirements of high-quality carburizer. The pressed graphite powder is a solid block without a porous structure, so its absorption speed and absorption rate are not as good as those of calcined and calcined carbonaceous agents. High quality carburizers…
09-15 2022
The same chemical composition uses different melting processes, different compositions and proportions, the metallurgical quality of molten iron is completely different, and good carburization effect is obtained. The electric furnace uses carbon enhancement technology, and the anthracite carburizer has three main effects on melting. 1、 The hot metal carbonization technology can increase the graphite crystal nucleus in the smelting process, especially in the electric furnace smelting process. The addition of cupola in the iron carbide smelting process can increase the long-term nucleation of graphite solution and reduce the oxidation of hot metal. 2、 Increasing carbon emissions is the best measure to prevent or reduce the shrinkage trend of enterprises. Due to the role of graphite in the solidification process of expanded molten iron, good graphitization tends to reduce the shrinkage of molten iron. 3、 Under the condition of high carbon content, in order to obtain high-strength gray iron castings, the smelting process can adopt the all scrap steel and carburizing…
09-14 2022
The graphite heater shall be inspected and managed in the early stage before use, otherwise, the graphite heater may explode during use. The following should be done: 1. First of all, check whether the graphite heater has cracks in the early stage of work. If there are no cracks, put the graphite heater above liubaidu and dry it sufficiently; 2. There shall be no ponding around the furnace and in the pit in front of the furnace, and there shall not be too many irrelevant objects piled near the graphite heater; 3. Strictly check whether there are explosives in the charge, preheat and keep dry when adding charge, and add graphite heater slowly.
09-13 2022
The mechanical strength of electrode paste includes compressive strength, flexural strength and tensile strength The height of the electrode paste refers to the height from the upper end of the electrode clamp to the top end of the electrode paste. If the electrode paste is too high, the coarse and fine particles in the electrode paste are prone to delamination, or the electrode cylinder is expanded due to too high paste column pressure. If the electrode paste column is too low, it is difficult to obtain a dense electrode due to too low paste column pressure and poor filling. The electrode paste is consumed too fast. Proper height of electrode paste column is beneficial to improve the quality of electrode baking and reduce consumption. The mechanical strength of the electrode paste includes compressive strength, flexural strength and tensile strength. The mechanical strength of carbon products is anisotropic, that is, the composition of raw material particles of carbon products is different…
09-12 2022
Expanded graphite is a product of deep processing of graphite. Expanded graphite can be used to produce packing rings, various types of gaskets, and can also be directly pasted on various metal surfaces to effectively solve gas-phase sealing. Expanded graphite has good corrosion resistance, high and low temperature resistance, good compression resilience and high strength. Expanded graphite is very easy to adsorb oil, organic molecules and hydrophobic substances. After oil absorption, it floats on the water surface, which is easy to catch and recover. It can be reused and processed easily. Expanded graphite gasket can be widely used for static sealing of pipeline, valve, pump, pressure vessel, tower, heat exchanger, condenser, etc. It has good expansibility, high temperature resistance, heat insulation, lubricity and chemical stability.
09-11 2022
Silicon carbide is a kind of synthetic carbide with molecular formula of SiC. It is usually formed of silicon dioxide and carbon at a high temperature of 2000. D egree. Density: the particle density of various silicon carbide crystal forms is very close, which is generally considered to be 3.20g/mm3. The natural bulk density of silicon carbide abrasive is between 1.2-1.6g/mm3, which depends on the particle size number, particle size composition and particle shape. Hardness: the Mohs hardness of silicon carbide is 9.2, the Vickers microhardness is 3000-3300 kg / mm2, and the nuop hardness is 2670-2815 kg / mm2. It is higher than corundum in abrasives and second only to diamond, cubic boron nitride and boron carbide. Thermal conductivity: silicon carbide products have high thermal conductivity, small thermal expansion coefficient and high thermal shock resistance. They are high-quality refractory materials. Because of its high hardness, high wear resistance, high corrosion resistance and high temperature strength, it is used for…
09-10 2022
1. Ordinary calcined petroleum coke is a carburizer. Because it has not been calcined at high temperature, the calcination temperature may be low and the time may be short. The nitrogen content is generally about 1000ppm, and the sulfur content is also high. It is impossible to draw clear marks on white paper. 2. High temperature calcined petroleum coke carburizer, nitrogen content is 300-500ppm, sulfur is much lower than the former. Clear marks can be left on white paper. 3. The nitrogen content of coal carburizing agent varies according to the quality of coal, and is generally 2000-7000ppm, that is, 0.2-0.7%. 4. The best high-temperature calcined petroleum coke carburizer with nitrogen content of 100ppm. Sulfur is lower than the former. It can leave clear marks on white paper and feel comfortable, just like 6B pencil. 5. Graphite column particle carburizer is a kind of carburizer that uses graphite powder and binder to extrude into cylindrical particles. This kind of carburizer…
09-09 2022
The traditional smelting method is similar to cupola smelting, which uses pig iron, recycled materials, scrap steel, ferroalloy, etc. as metal furnace materials; The new synthetic cast iron production process uses scrap steel as furnace charge, and uses carburizing agent to adjust the carbon equivalent of molten iron. The latter is easier to ensure high-quality molten iron, and greatly reduces the cost by using less or replacing pig iron with scrap steel. There are many sources and forms of carburizers, and the price varies greatly according to their processing technology and composition. First, the stirring degree of molten iron increases the contact surface area between the carburizer and molten iron. The absorption rate is fast and high. Therefore, under normal circumstances, the carburizing agent should be added before smelting, and the effect of adding on the surface of molten iron or ladle is very ideal. In addition, the superheat temperature of molten iron is generally more than 1420 degrees, so…
09-08 2022
In order to avoid the slow melting and heating time of graphite carburizer, scrap steel and carburizer are added in batches during the batching process, and the melting time of each batch of furnace materials is about 15 minutes. In the early stage of chemical feeding, low power is used to avoid the burning loss of graphite carburizer caused by excessive temperature. In the later stage, the temperature rises rapidly after the molten iron paste is formed. It cannot be effectively combined with molten iron and the temperature is too high, resulting in serious burning loss. Similarly, the amount added in the last time should be relatively small, so as to avoid adding graphite carburizer into molten iron in large quantities, resulting in incomplete absorption of graphite carburizer in molten iron and production delay. The absorption rate of graphite carburizing agent can be effectively improved by combining mechanical mixing with manpower. The specific gravity of graphite carburizing agent is small.…
09-07 2022
1. Reduce the amount of scrap steel to reduce the amount of nitrogen brought in. In addition, increasing the carbon equivalent will also reduce the equilibrium nitrogen content. 2. Electric furnace melting is adopted. 3. Increase pouring temperature. As the temperature of molten iron decreases, the nitrogen contained in the molten iron will precipitate and form bubbles of a certain size after aggregation. At this time, if the pouring temperature is increased, the bubbles will escape from the molten iron under the pressure established by themselves. If it is poured at a lower temperature, the bubbles formed cannot escape and stay in the inspection platform and cast iron plate, forming nitrogen pores. What level of carburizer is selected, the nitrogen content inside is also different. Low nitrogen carburizers should be selected, and the harmful substances inside will also be reduced. The titanium content in molten iron is very low, and it will not consume a lot of nitrogen, which is…
09-06 2022
Carburizer is an indispensable additive in steel smelting. Its use can save a lot of iron ore, increase the use of scrap steel and iron, reduce production costs, and save non renewable resources. Carbon and sulfur are important elements that determine the quality of steel specifications. Iron products with carbon content higher than 1.7% are called cast iron, iron products with carbon content lower than 1.7% are called steel, steel with carbon content higher than 0.6% is called high carbon steel, steel with carbon content between 0.25-0.6% is called medium carbon steel, steel with carbon content less than 0.25% is called low carbon steel, and steel with carbon content less than 0.04% is called industrial pure iron. Carbon plays an important role in the performance of steel. With the increase of carbon content, the hardness and strength of steel will also increase, but the plasticity and toughness will decrease. Conversely, with the decrease of carbon content, the hardness and strength…
09-05 2022
There are many coarse hypereutectic graphite in pig iron. This kind of coarse graphite is hereditary. The melting temperature is low, and the coarse graphite is not easy to be eliminated. The coarse graphite is inherited from the liquid to the solid cast iron structure. On the one hand, it reduces the mechanical properties that the cast iron can achieve. On the other hand, the existence of the coarse graphite weakens the expansion effect of graphitization precipitation that should have occurred in the solidification process, The shrinkage tendency of molten iron during solidification will be increased. In addition, the coarse graphite will easily fall off during subsequent processing, forming surface pits and affecting the surface finish of the casting. And there are many impurity elements in pig iron. For example, a small amount of ti.p.v, B, etc. will have a negative impact on the casting and deteriorate the matrix structure and graphite morphology. Therefore, during electric furnace smelting, the amount…
08-31 2022
In short, coal carburizing agent is an additive used for reducing and carburizing in the process of steel smelting, and is often used in the process of steel casting. In the face of different smelting processes, the ways of adding coal carburizing agent are also different. Can be added to the middle and lower part of the electric furnace according to the proportion or carbon equivalent requirements, and the recovery rate can reach more than 95%. If the carbon content is insufficient to adjust the carbon content, the slag in the furnace shall be cleaned first, and then the carburizing agent shall be added; If low temperature is used Graphite powder is used as carburizing agent. Nitrogen is generally used as the carrier for carbon addition of jet graphite powder, but it is more convenient to use compressed air under industrial production conditions. The chemical reaction heat of the carbon oxide produced by the combustion of oxygen in compressed air…
08-31 2022
The characteristics of carburizing agent are that pure carbon containing graphitization material is selected to reduce excessive impurities in pig iron, and proper selection of carburizing agent can reduce the production cost of castings. There are many kinds of raw materials and production processes of carburizing agent. It is not said in the market that graphite powder is pressed and formed. This production method needs to add too much binder to form, and the carbon content generally cannot meet the requirements of high-quality carburizing agent. The pressed graphite powder is a solid block without a porous structure, so the absorption rate and absorption rate are not as good as those of calcined and calcined carburizers. The use of carburizing agent in casting can greatly increase the amount of scrap steel, reduce the amount of pig iron or not use pig iron. At present, most of the carburizers are suitable for electric furnace smelting, and a small number of carburizers with…
08-30 2022
Because of its high carbon and low sulfur, the carburizing agent can be fully absorbed without slag inversion, reducing the cost of spheroidization and slag removal, shortening the melting cycle, and saving energy consumption. It not only meets your requirements for carbon content, but also effectively controls the amount of sulfur element, so that most of the microscopic forms of carbon element in the casting appear as A-type graphite, obtaining fine and uniform graphite, promoting the spheroidization process and effectively improving the production of iron graphite system. So many advantages of using carburizing agent make more and more manufacturers buy it. When the carbon content is insufficient to adjust the carbon content, the slag in the furnace is cleaned first, and then the carburizing agent is added. The carbon is dissolved and absorbed by heating the molten iron, electromagnetic stirring or manual stirring, and the recovery rate can be about 90%. If the low-temperature carburizing process is adopted, that is,…
08-30 2022
The slag remover is a kind of volcanic ash from the pre geological period, which is a naturally produced expanded material due to geological changes. Due to its high expansion property, it has a strong ability to clean the scum in steel and molten iron, thicken and increase the viscosity of the slag, easily collect and scrape the scum in steel and molten iron, purify the molten iron and steel, and generally can be used for scraping the slag in the furnace and ladle. It is precisely because the slag remover has the advantages of low dosage, strong slag gathering ability, easy to pick up slag and does not affect the composition of molten iron, and convenient operation. Therefore, the use of slag remover is to reduce the content of macro and micro slag and other inclusions in the casting, improve the quality and processing performance of the casting, purify the molten metal, make it play the role of inoculation…
08-29 2022
The crystal structure of C in the carburizing agent can be divided into amorphous structure and crystal structure. According to the morphology of C in the carburizing agent, it can be divided into graphite carburizing agent and non graphite carburizing agent. Graphite carburizers generally include non graphite carburizers that break the atomic structure of the original carburizers at high temperature and then rearrange the atomic covalent bonds. The graphitized carburizers form a layered hexagonal crystal structure. Moreover, C in the carburizing agent is mainly dissolved in the molten iron through dissolution and diffusion. The graphite in the graphite carburizing agent can be directly dissolved in the molten iron, while the direct melting phenomenon of the non graphite carburizing agent basically does not exist. As time goes on, C gradually diffuses and dissolves in the molten iron. The dissolution of C in molten iron is controlled by the mass transfer of C in the liquid boundary layer on the surface of…
08-29 2022
The pretreatment agent is a kind of casting additive added during the melting process of molten iron. It contains a certain amount of deoxidizing elements and composite elements, which can provide more and stable crystal nuclei for the precipitation and growth of graphite through the treatment of molten iron before tapping or during tapping. ● solve the negative impact of high-temperature standing of molten iron in electric furnace, enhance the graphite nucleation ability and increase the graphite core, effectively solve the incubation recession, promote and stabilize the nucleation, alleviate the ablation of graphite core during long-time high-temperature standing of molten iron, effectively compensate the lost graphite core, and thus improve the overall metallurgical quality of molten iron. ● it has strong deoxidizing effect, purifies molten iron, and reduces slag inclusion and pore defects; ● improve the morphology and distribution of graphite, reduce the white tendency and improve the cutting performance of castings. ● increase the fluidity, reduce the sensitivity of…
08-28 2022
Expanded graphite is the product of deep processing of graphite. Expanded graphite can be used to produce strips, packing rings, packing and various gaskets, and can also be directly pasted on various metal surfaces to effectively solve gas phase sealing. The long strip can be directly used to make packing and spiral wound gasket. Expanded graphite has good corrosion resistance, high and low temperature resistance, good compression resilience and high strength. Expanded graphite is very easy to absorb oil, organic molecules and hydrophobic substances. After oil absorption, it floats on the water surface and is easy to catch and recover. It can be reused and processed easily. What are the advantages of expanded graphite? 1. It has strong pressure resistance, flexibility, plasticity and self lubrication; 1. It has strong pressure resistance, flexibility, plasticity and self lubrication; 2. Extremely strong resistance to high and low temperature, corrosion and radiation; 3. Extremely strong seismic characteristics; 4. Extremely strong conductivity; 5. Extremely strong…
08-27 2022
For the analysis of trace impurities in high-purity flake graphite, the sample is usually pre ashed or wet digested to remove carbon, the ash is dissolved with acid, and then the impurity content in the solution is determined. The ashing method does not need to use ultra pure acid to dissolve the ash, thus avoiding the risk of introducing the elements to be measured, so it is used more. It is also very difficult to detect the ash content of high-purity flake graphite, because the enriched ash needs to be burned at high temperature, and it is difficult to separate the ash from the sample boat at high temperature, which makes it impossible to accurately determine the composition and content of impurities. The existing methods all take advantage of the characteristic that the platinum crucible does not react with acid, use the platinum crucible to burn the high-purity flake graphite to enrich ash, and then directly heat the sample in…
08-27 2022
The preparation process of high-purity graphite is briefly as follows: first, water is added to natural graphite to make it paste. In addition, strong oxidant is added and heated and stirred. Finally, filter, wash to neutral and dry. The liquid phase method is simple to produce high-purity graphite and has no strict requirements on raw materials. It is suitable for processing raw materials with 10000 mesh to 20 mesh and fixed carbon of more than 80%. Through this process, high-purity natural flake graphite with a purity of 99.9% - 99.998% can be obtained, which can meet the needs of atomic energy and aerospace industry, with low cost and stable quality.
08-26 2022
1. Artificial graphite: among the carburizers, the best quality is artificial graphite. Artificial graphite is calcined petroleum coke, added with asphalt as binder, and then added with other auxiliary materials. After high-temperature graphitization at 2500-3000 ℃, the ash content, sulfur content and gas content are greatly reduced. Artificial graphite is expensive, so the general carburizing agent is made by using the cutting particles used in the manufacture of electrodes or by grinding the waste electrodes. In addition, the tail material of negative electrode material is also a good source of carburizing agent. The most important indicator of artificial graphite is that the sulfur content is very low, between 0.01-0.07. 2. Petroleum coke: calcined petroleum coke is a widely used carburizing agent. The raw petroleum coke is calcined at 1200-1350 ℃ to become calcined petroleum coke that can be used as a carburizing agent. The sulfur content of calcined petroleum coke is between 0.02-3%, and the calcined petroleum coke that can…
08-26 2022
What is the carburizing agent: it is a product of black or gray particles or lumps of coke with high carbon content, which is added to the metal smelting furnace to improve the carbon content in the molten iron. On the one hand, it can reduce the oxygen content in the molten iron, and on the other hand, it is more important to improve the mechanical properties of the smelting metal or castings. Poor quality of carburizing agent will bring great losses to the enterprise, with slow absorption, low absorption rate and increased cost; Cause unnecessary waste, and other harmful elements will affect product quality and cause losses. According to the raw materials and production process of the carburizing agent, the price also varies greatly. How to choose raw materials to produce professional carburizing agents? The content of fixed carbon, sulfur, nitrogen and ash in the general carburizing agent will directly affect the quality of the carburizing agent and the…
08-25 2022
Performance: it has the performance of high-quality natural flake graphite, and has special oxidation resistance under high temperature conditions. Self lubricating and plastic, with good conductivity, heat conduction and adhesion. Purpose: (1) Used as mold release lubricant in catalyst production of fertilizer industry. (2) High temperature resistant lubricant base material, corrosion-resistant lubricant base material. (3) Powder metallurgy release agent and metal alloy raw materials. (4) Used for making carbon film resistance, conductive dry mold and preparing conductive liquid. (5) It can be used as filler or performance improver for rubber, plastic and various composite materials to improve the wear resistance, compression resistance or conductivity of materials.
08-25 2022
Different carburizers have different quality. For example, there are graphite carburizers and coal carburizers. Although they are all carburizers, they are different in basic characteristics, absorption coefficient, price, advantages and disadvantages. It is not very large, but if it is not properly applied, it will also affect their carburizing effect. 1. The raw materials of the two kinds of carburizing agents are different: the graphite carburizing agent is made of 2830 degree graphitized artificial graphite, and the coal carburizing agent is made of anthracite. 2. The basic characteristics of the two kinds of carburizers are different: graphite carburizers have the advantages of low sulfur, low nitrogen, low phosphorus, high temperature resistance and good conductivity. High quality coal carburizing agent can not achieve ideal carburizing effect. 3. The absorption coefficient is different: the absorption coefficient of graphite carburizing agent is above 90%, and the absorption coefficient of coal carburizing agent is basically about 70%. This is the reason why graphite carburizers…
08-25 2022
Carburizing agent is more and more popular now, mainly because of its low price, good quality and wide application. At present, there are a variety of carburizing agents in the ferroalloy market. Therefore, as a purchasing manufacturer, it is necessary to know what elements are contained in the carburizing agent so as to better select the appropriate carburizing agent products and make better use of the carburizing agent. In the smelting process, due to improper materials or preparation, excessive decarburization and other reasons, the carbon content of the steel sometimes cannot meet the requirements of the normal standard, so it is necessary to add carbon to the steel. Commonly used carburizing agents include carburized pig iron, electrode powder, petroleum charcoal powder, charcoal powder and coke powder. When smelting medium and high carbon steel in converter, petroleum coke carburizing agent with less impurities is used. The requirements of carburizing agent for top blowing steelmaking are high fixed carbon, low ash, volatile,…
08-24 2022
The process development of pretreatment agent can be effectively divided into two stages to a certain extent, namely, traditional pretreatment process and modern pretreatment process. In the process of operation, the traditional pretreatment process is usually to effectively add its graphite carburizing agent or SiC into the furnace, so that the new core of these substances can be effectively used to effectively improve the metallurgical quality of molten iron. Modern pretreatment technology can effectively control w (o) in molten iron at a low level by adding pretreatment agent before inoculation. Through tests and comparison, some enterprises producing high-end castings (cylinder block and cylinder head) show that their use effect is obviously better than that of metallurgical grade silicon carbide. Therefore, the pretreatment agent based on SiC is favored and applied by foundry factories. Advantages of using pretreatment agent: 1. Reduce the amount of spheroidizing agent by about 10%. 2. Improve the absorption rate of Mg. 3. Increase the number of…
08-24 2022
Natural graphite, as its name implies, is naturally formed graphite in nature. It generally occurs in graphite schist, graphite gneiss, graphite containing schist and metamorphic shale. Graphite belongs to the complex hexagonal biconical crystal type, which is in the form of hexagonal plate crystal. The common single form includes parallel double sides, hexagonal biconical and hexagonal column, but the intact crystal form is rare, generally in the form of flake or plate, and the aggregate is in the form of dense block, earth or spherical. The natural graphite minerals are iron black and steel gray, and the stripes are bright black; Metallic luster, cryptocrystalline aggregate is dull and opaque; The hardness is anisotropic, the vertical cleavage plane is 3-5, and the parallel cleavage plane is 1-2; It is soft, with a density of 2.09-2.23g/, with a feeling of greasiness and easy to pollute the fingers. Natural graphite is rarely pure and often contains impurities, including SiO2, A12O3, FeO, Cao, P2O5,…
08-23 2022
Isostatic pressing graphite refers to the graphite material produced by isostatic pressing and is a graphite material developed on the basis of "three high graphite". Isostatic graphite is also known as "isotropic" graphite because of its excellent properties, such as large molding size, uniform billet structure, high density, high strength and isotropy (the characteristics are independent of size, shape and sampling direction) due to the uniform and constant pressure of liquid pressure during the molding process. The main raw materials for producing isostatic pressure graphite are petroleum coke, asphalt coke and coal tar pitch. Some overseas enterprises use mesophase carbon microspheres. Due to technical barriers, no domestic enterprise has chosen mesophase carbon microspheres as raw materials. Its downstream applications are distributed in semiconductor industry, atomic energy industry, EDM, continuous casting metallurgy industry, photovoltaic and other production fields. The production of isostatic pressing graphite in China is mainly cold isostatic pressing technology, and its raw materials are petroleum coke and asphalt…
08-23 2022
The measures to prevent electrode soft break during the use of electrode paste can be divided into the following points: 1. Strictly control and master the length of the working end of the electrode, reasonably control the pressing time, so that the pressing speed is compatible with the sintering speed. When the material surface is processed every 24 hours, Observe the baking condition of the electrode so as to control the hardness and softness of the electrode (if it is found that the surface of the laid down electrode is gray white, dark but not red or slightly red, it indicates that the electrode is well roasted; if the surface of the laid down electrode is red, it indicates that the electrode has been burnt; if the surface is black, it indicates that the electrode is not baked enough. You can also use round steel to poke the electrode. If it is hard, it can bounce back to indicate that…
08-18 2022
The measures to prevent electrode soft break during the use of electrode paste can be divided into the following points: 1. Strictly control and master the length of the working end of the electrode, reasonably control the pressing time, so that the pressing speed is compatible with the sintering speed. When the material surface is processed every 24 hours, Observe the baking condition of the electrode so as to control the hardness and softness of the electrode (if it is found that the surface of the laid down electrode is gray white, dark but not red or slightly red, it indicates that the electrode is well roasted; if the surface of the laid down electrode is red, it indicates that the electrode has been burnt; if the surface is black, it indicates that the electrode is not baked enough. You can also use round steel to poke the electrode. If it is hard, it can bounce back to indicate that…
08-18 2022
The main problem perplexing the electrode paste manufacturers is that the baking speed of the electrode paste is too slow, so some manufacturers adopt the method of reducing the use of asphalt. This method is effective to a certain extent, but the too low asphalt content causes poor fluidity of the electrode paste, and the electrode paste is not easy to be filled in the electrode barrel. The poor compactness after sintering is easy to cause hard fracture. Another method is to reduce the softening point of the asphalt and improve the electrode sintering speed. However, the softening point of the asphalt can not be reduced without limitation, because the asphalt with too low softening point reduces the coking rate of the asphalt, The strength of the electrode should also be reduced, or the hard break phenomenon should occur. Therefore, in addition to properly mastering the above two methods, the production of electrode paste should also improve the sintering speed…
08-17 2022
(I) principle and purpose Submerged arc furnace is also called electric arc furnace or resistance electric furnace. It is mainly used for reducing smelting ore, carbonaceous reductant, solvent and other raw materials. It mainly produces ferrosilicon, ferromanganese, ferrochromium, ferrotungsten, silicon manganese alloy and other ferroalloys. It is an important industrial raw material in the metallurgical industry and chemical raw materials such as calcium carbide. Its working characteristics are that carbon or magnesium refractory materials are used as furnace lining and self-cultivation electrodes (electrode paste or sealed paste) are used. The electrode is inserted into the charge for submerged arc operation. It is an industrial electric furnace that uses the energy and current of the arc to pass through the charge and the energy generated by the resistance of the charge to smelt the metal. It is continuously fed and intermittently discharged with iron slag. Main categories and uses of submerged arc furnace Industrial waste heat refers to a large amount…
08-17 2022
The length of the working end of the electrode and the depth of entering the furnace shall be strictly controlled in accordance with the process operation requirements. After each shift, the measurement shall be carried out accurately. The measurement times of each phase of the electrode shall not be less than three times. If the deviation is large, the measurement shall be carried out several times. The average value of the three times with small deviation shall be taken as the length of the working end of the electrode. Only when the length of the working end of the electrode and the depth of entering the furnace are accurately mastered can the operation scheme of the shift be determined, and the pressing length Times As the molten pool of submerged arc furnace not only bears strong high-temperature effect, but also is eroded and mechanically scoured by furnace charge, high-temperature furnace gas, molten iron and high-temperature slag, it is necessary to…
08-16 2022
Study on the effect of different coal tar pitch content and additives on the plasticity of electrode paste The electrode paste is consumed while baking (sintering in the electrode barrel made of steel plate) in the submerged arc furnace, so it is also called continuous self baking electrode. The unique baking and use mode of the electrode paste put forward very high requirements for its plasticity. If the plasticity is too poor, the electrode paste does not have enough fluidity during the process of heating and softening, and cannot fully fill the inside of the electrode barrel to form a dense whole. After baking, there are many holes in the electrode, which is prone to "hard breaking" accidents; If the plasticity is too good, during the softening process of the electrode paste, under the pressure generated by its own weight and volatilization, the asphalt is easy to migrate, resulting in paste flow and segregation, and easily leading to "soft break"…
08-16 2022
The control items of electrode paste include fixed carbon, volatile, ash and water. Generally, the four items can be calculated by analyzing the volatile, ash and water. Volatile matter shall be controlled within a certain range, otherwise the following results will be caused. 1. If the volatiles are too high, the following adverse results will be caused: 1 it is not easy to sinter, with poor strength and easy to break. 2. Large shrinkage and poor strength, and hard fracture may occur. 3 fast oxidation and fast consumption of electrode paste. 4. It is easy to be layered and sintered into special shape. Besides the difficulty of lowering the electrode, it is also easy to be broken. 5. When discharging the electrode, the load is reduced much and the load is increased slowly, which affects the output. 2. If the volatile is too low, the following adverse results will be caused: 1 premature sintering, poor strength and easy hard fracture.…
08-15 2022
The electrode paste shall be stored in a special closed warehouse. The ground for storage shall be hardened with concrete, and the dust and sundries stacked on the ground shall be cleaned. Enterprises without conditions * suggest purchasing electrode paste packed in ton bags and covering it with tarpaulin after stacking on the clean ground to prevent dust and sundries from polluting the electrode paste, prevent the electrode paste from being exposed to the sun and change the performance of the electrode paste; Bulk electrode paste is not stored in the warehouse. It should be stacked in a clean place on the ground and covered with a tarpaulin. During the transfer and addition of electrode paste, secondary pollution shall be prevented. All tools and appliances shall be clean. The measurement and addition of electrode paste column shall be in the charge of a specially assigned person. It is recommended that the measurement shall be no less than once per shift…
08-15 2022
Application of high strength electrode paste on self baking electrode of large submerged arc furnace The application test of high strength electrode paste in 20 MVA submerged arc furnace shows that it can effectively prevent electrode accidents and play a key role in improving smelting economic indicators. At the same time, the key factors affecting the use of high-strength electrode paste and the change of input power of three-phase electrode were studied. According to the electricity consumption of each phase of the electrode, it is beneficial to use the high-strength electrode paste by determining the electrode discharge amount, reducing the conductive area of the electrode shell, and properly increasing the secondary voltage.
08-14 2022
Most of the problems in the use of electrode paste are caused by the overlapping of multiple factors. Among them, there are many U-turns. Here, two situations are not discussed for the time being. 1; Operational factors during use (e.g., carbon deficiency, silkworm erosion, etc.) II; Loopholes in the production process (such as different batches, inclusions, etc.) Starting from the rationality of process formulation design, we focus on the following situations: Let's start with a phenomenon in our daily life. I think everyone has experienced such a thing; In the cold winter, we take a cold glass and pour boiling hot water into it. What happens? Why? The result is well known. If it is light, the glass wall becomes cracked; Most importantly, the bottom of the glass is completely detached. In fact, this is because when the glass is subjected to thermal stress, the heated bottom of the glass and the non heated wall of the glass will produce…
08-14 2022
The raw material of electrode paste is composed of solid carbon material and bonding material. The quality of electrode paste is related to the raw material formula and preparation process. Solid materials include calcined anthracite, metallurgical coke, petroleum coke and graphite electrode debris. Anthracite is dense and has high carbon content, which can improve the thermal stability, electrical conductivity and mechanical strength of the electrode; The binder of the electrode paste includes asphalt and refining tar. Tar is added to adjust the softening point. During the sintering process of the electrode paste, the binder is decomposed and the volatiles are removed, and then it is transformed into coke to play the role of coking, so that the electrode line becomes a hard whole. The formulation of electrode paste should consider the proportion of various solid materials, particle size composition, softening point and amount of binder.
08-13 2022
As for the classification and performance of electrode paste, electrode paste can be divided into standard paste and sealed paste due to different uses. The former is mostly used in semi closed submerged arc furnace; The latter is commonly used in closed electric furnace and large capacity semi closed electric furnace due to its low roasting temperature and easy sintering. Most of the solid materials in the standard paste are anthracite and metallurgical coke, while the solid materials in the closed paste need a large amount of graphite chips and petroleum coke. The binder in the standard paste is mostly medium temperature asphalt, while the binder in the sealed paste uses a large amount of tar and graphite chips. As a special sealed electrode paste favored by ferronickel smelting enterprises in submerged arc furnace, the blending amount of tar and graphite chips is obviously increased. The high price of graphite chips and tar is the main reason for the high…
08-13 2022
Under the basic conditions such as the performance and quality standard of electrode paste, the technical innovation and formula innovation of high-quality sealed electrode paste with waste carbon material as the main material were analyzed in detail. The theoretical research and experimental results show that the overall design scheme, formula and technological process of producing high-quality sealed electrode paste from waste carbon materials are feasible and reasonable, with good quality effects of energy saving, consumption reduction and environmental protection.
08-12 2022
People pay attention to the ash content first in the index inspection of electrode paste, and should be updated to pay attention to the specific resistance first. Because the purpose of the electrode paste is to make conductive materials, the specific resistance should be paid attention to first when examining the indicators of conductive materials. Although there is a certain correlation between ash content and specific resistance, it is not always positive. The relationship between ash content and specific resistance is affected by many factors, such as material itself, ash content, processing temperature, material ratio, product density, etc. That is, the same material (the same ash content) also has different specific resistance at different temperatures. Electrode paste is a relatively simple product in the production of carbon products, but their production links are basically the same from the calcination of raw materials to crushing, screening and the front-end of ingredients. Moreover, it is very important to directly affect the output…
08-12 2022
Carbon and graphite materials are non-metallic solid materials mainly composed of carbon elements. Carbon materials are basically non-carbon products, which can be divided into graphite electrodes, carbon blocks, graphite anodes, carbon electrodes and electrode pastes according to product uses Carbon rods are made of graphite and carbon. 1. It can be used as the electrode of electrical appliances. 2. Painting tools. Also known as carbon strips, they are mainly black and brown, and can be divided into cylindrical and rectangular shapes. Electrode paste is a conductive material for ferroalloy furnace, calcium carbide furnace and other electric furnace equipment. It can withstand high temperature and has a small coefficient of thermal expansion. It has a relatively small resistance coefficient, which can reduce the loss of electric energy. With small porosity, the heated electrode can be oxidized slowly. With high mechanical strength, the electrode will not break due to the influence of mechanical and electrical loads.
08-11 2022
Electrode paste is an important consumable conductive material for the production of calcium carbide and ferroalloy. In terms of its use nature, it is a "self baking electrode". At present, the thermoelectric furnace consumes about 45kg electrode paste for each ton of ferrosilicon containing 75% Si, and about 30kg electrode paste for each ton of calcium carbide. The main raw materials for producing electrodes are anthracite, metallurgical coke and coal and coal tar pitch, which can be divided into two categories according to different formulas: 1) standard and non-standard electrode pastes: standard electrode pastes are mainly used in open ferroalloy furnaces and medium and small calcium carbide furnaces, and medium temperature asphalt is used as binder; Non standard electrode paste is mainly used in large open calcium carbide furnace. Its dry material particle composition is the same as that of standard electrode paste. However, in order to appropriately improve the sintering speed of electrode paste, a small amount of tar…
08-10 2022
Why is electrode paste an excellent conductor material? Let me explain to you: Electrode paste is a conductive material for ferroalloy furnace, calcium carbide furnace and other electric furnace equipment. The electrode paste can withstand high temperature and has a small coefficient of thermal expansion. It has a relatively small resistance coefficient, which can reduce the loss of electric energy. With small porosity, the heated electrode can be oxidized slowly. With high mechanical strength, the electrode will not break due to the influence of mechanical and electrical loads.
08-10 2022
The production formula of electrode paste should not be changed easily, and the formula should be changed for many times. Small calcium carbide furnace or ferroalloy furnace can all use metallurgical coke or asphalt coke plus a small amount of natural graphite electrode paste, but the consumption is larger. For large or medium calcium carbide furnaces and ferroalloy furnaces, anthracite and metallurgical coke should be used to prepare their electrode paste. Adding a small amount of natural graphite or graphitized metallurgical coke to the electrode paste formula is conducive to improving the conductivity and thermal conductivity of the electrode paste. However, the preparation of earthy graphite for small and medium-sized factories should be strictly controlled. It should be noted that too much asphalt will make the sintering speed of the electric paste unable to keep up with the consumption, which is easy to cause soft fracture. The electrode paste with too much binder has high porosity and low strength after…
08-09 2022
Electrode paste is a conductive material for ferroalloy furnace, calcium carbide furnace and other electric furnace equipment. It can withstand high temperature and has a small coefficient of thermal expansion. It has a relatively small resistance coefficient, which can reduce the loss of electric energy. With small porosity, the heated electrode can be oxidized slowly. With high mechanical strength, the electrode will not break due to the influence of mechanical and electrical loads. The current is smelted by the electric arc generated by the electrode input into the furnace. The electrode plays a very important role in the whole electric furnace. Without it, the electric furnace cannot play a role. In order to make the electrode work normally under the temperature generated by the arc, it needs to have a high degree of oxidation resistance and conductivity, which is only possible for the electrode made of carbon material, because the carbon electrode can withstand the arc temperature of 3500 ℃…
08-09 2022
In the process of producing carbide, ferrosilicon, ferromanganese and other ferroalloys, the smelting temperature needs to be increased, which can meet the production requirements only by inputting a strong current into the furnace through special electrodes. In order to make the electrode work normally at high temperature in the electric arc furnace, the electrode itself needs to have good conductivity, oxidation resistance and thermal shock resistance. Only the electrode paste produced with carbon raw materials can meet the harsh smelting requirements under continuous arc high temperature above 3000 degrees. Therefore, electrode paste plays an important role in the above-mentioned thermoelectric furnaces, so it is called the "heart" of this kind of electric furnace. The electrode paste is a kind of "continuous self baking electrode" in terms of its use method and properties. In the process of use, the outer layer of the continuous self baking electrode is a cylinder made of 1-2 mm thick steel plate. The electrode paste is…
08-08 2022
Determination of specific resistance during baking of electrode paste Place the corundum crucible containing the electrode paste sample in the silicon carbide rod electric furnace, raise the temperature at the rate of 100 ℃ per hour, measure the resistance value of the electrode paste at the corresponding temperature through a pair of metal plates pre processed into the electrode paste with an electric bridge, calculate and correct with the container coefficient calibrated with 0.1N potassium chloride standard solution in advance, and then * the specific resistance value of the electrode paste at this temperature. Through this experiment, we can see the following problems: (1) In the past, although it was known that the conductivity of electrode paste was poor before burning, it was still used to regard electrode paste as a conductor. Conclusions can be drawn from the measurement results; Electrode pastes before 400 ℃ are basically insulators. Taking standard pastes and special pastes as examples, their specific resistance at…
08-08 2022
Discussion on the performance characteristics of anthracite Anthracite is the main raw material of electrode paste. The performance of anthracite is related to the performance of electrode paste. Therefore, it is necessary to understand and discuss the performance of anthracite to ensure the quality of electrode paste. Anthracite coal in China is mainly distributed in Shanxi, Ningxia and Guizhou. Shanxi is the origin of anthracite, which is mainly produced in Yangquan City and Jincheng city. Anthracite is an indispensable raw material for carbon industry. It is mainly used in semi graphite cathode carbon block, electric furnace carbon block, blast furnace carbon block, carbon electrode and various pastes. Studying and discussing various properties of anthracite is very beneficial to improve the quality of carbon products.
08-07 2022
At present, the diameter of the electrode of the large closed calcium carbide furnace to be developed is relatively large, and the working length is relatively long. The tensile force generated by its own weight is larger, which requires high mechanical strength, and it also needs to re regulate the new compressive strength control index; Now energy conservation has become a national policy. The national standard for the energy consumption index of large closed calcium carbide furnace is quite strict, so the electrode paste should have a relatively small resistance coefficient to reduce the loss of electric energy. Therefore, the original control index of the electrode paste needs to be changed. The height of electrode paste refers to the height from the upper end of electrode clip to the top of electrode paste. If the electrode paste is too high, the coarse and fine particles in the electrode paste are prone to delamination, or the electrode cylinder is swollen due…
08-07 2022
Electrode paste is used for ferroalloy, calcium carbide, silicon and manganese The submerged arc furnace is a conductive material for self-cultivation electrode Conductive materials used in electric furnace equipment such as calcium carbide furnace. It can withstand high temperature and has a small coefficient of thermal expansion. It has a relatively small resistance coefficient, which can reduce the loss of electric energy. With small porosity, the heated electrode can be oxidized slowly. With high mechanical strength, the electrode will not break due to the influence of mechanical and electrical loads. The current is smelted by the electric arc generated by the electrode input into the furnace. The electrode plays a very important role in the whole electric furnace. Without it, the electric furnace cannot play a role. In order to make the electrode work normally under the temperature generated by the arc, it needs to have a high degree of oxidation resistance and conductivity, which is only possible for the…
08-06 2022
Requirements for measuring electrode paste height (1) The measurement shall be carried out twice per shift, once after shift handover and once during shift, and records shall be made. (2) The measurement position of each shift should be in the same position (inner triangle or outer triangle). (3) Each shift should decide how much electrode paste to install according to the height of electrode paste. (4) The measuring personnel should be careful not to contact the two-phase electrodes at the same time to prevent electric shock. (5) The measurement shall be accurate.
08-06 2022
Distribution of current between electrode shell and electrode paste On the basis of the above data, it is not difficult to calculate the distribution law of current between the electrode shell and the electrode paste. The electrode paste is basically non-conductive before 450 ℃, and all current passes through the electrode shell. At 500 ℃, the current through the electrode paste gradually increases. After 800 ℃, more than 50% of the current flows through the electrode paste. As the temperature continues to rise, the resistance increases sharply with the oxidation and ablation of the electrode shell, while the resistance of the electrode paste decreases accordingly, and all the current is borne by the electrode paste. The effect of using electrode paste on the current distribution law at the same temperature is not obvious. For example, when using standard paste at 500 ℃, 0.82% of the current passes through the electrode paste, which is increased to 2.34% with special paste. At…
08-05 2022
The electrode paste has high temperature resistance and low coefficient of thermal expansion. It has a relatively small resistance coefficient, which can reduce the loss of electric energy. With small porosity, the heated electrode can be oxidized slowly. With high mechanical strength, the electrode will not break due to the influence of mechanical and electrical loads. The current is smelted by the electric arc generated by the electrode input into the furnace. The electrode plays a very important role in the whole electric furnace. Without it, the electric furnace cannot play a role. In order to make the electrode work normally under the temperature generated by the arc, it needs to have a high degree of oxidation resistance and conductivity, which is only possible for the electrode made of carbon material, because the carbon electrode can withstand the arc temperature of 3500 ℃ and only oxidize slowly.
08-05 2022
Less electrode operation accidents, choose electrode paste The core problem of long-term stable operation of ferroalloy electric furnace is whether the electrode column can work normally. People often regard electrodes as the "heart" of submerged arc furnaces. The problem is the quality of electrode sintering to ensure long-term stable operation and less accidents. In fact, in the production cost of ferroalloy, the cost factor of electrode paste consumption only accounts for a small share. The primary responsibility of the operators and organizers of the production is to ensure the normal operation of the production equipment. Once an accident occurs to the electrode of the electric furnace, the loss will be huge and catastrophic, which is almost difficult to repair. For this reason, sometimes it is better to choose electrode paste with some margin in performance and quality to prevent electrode accidents in case. Is wise. 3. Electric furnace smelting ferronickel Technology Laterite mine submerged arc furnace is a better technical…
08-04 2022
Market dynamics of electrode paste: Recently, the price of domestic electrode paste tends to decline steadily, and the market transaction atmosphere is flat. Downstream industries such as calcium carbide and ferroalloy are still in a weak consolidation stage, and electrode paste lacks solid demand support. The market situation of electrode paste continues to be depressed, and the sales volume has not been guaranteed for a long time. Downstream calcium carbide enterprises are still on the sidelines, with prices rising and falling, which is the primary drag on the demand for electrode paste. Moreover, under the situation of unstable support of electrode paste raw materials, users such as calcium carbide have a high price depression mentality, and the price of electrode paste is quite stable and declining. On the other hand, the acceptance sales model brings great pressure to the production and operation of enterprises, and the capital circulation bears a great test. At present, the downstream operating rate has not…
08-04 2022
The electrode paste has high temperature resistance and low coefficient of thermal expansion. It has a relatively small resistance coefficient, which can reduce the loss of electric energy. With small porosity, the heated electrode can be oxidized slowly. With high mechanical strength, the electrode will not break due to the influence of mechanical and electrical loads. The current is smelted by the electric arc generated by the electrode input into the furnace. The electrode plays a very important role in the whole electric furnace. Without it, the electric furnace cannot play a role. In order to make the electrode work normally under the temperature generated by the arc, it needs to have a high degree of oxidation resistance and conductivity, which is only possible for the electrode made of carbon material, because the carbon electrode can withstand the arc temperature of 3500 ℃ and only oxidize slowly.
08-03 2022
Electrode paste is a conductive material used for electric furnace equipment such as ferroalloy furnace and calcium carbide furnace. It is not energy, but material. Energy refers to the substances that provide energy conversion to nature, such as wind energy, hydropower and solar energy. So electrode paste is not energy.
08-03 2022
