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 　　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

 　　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

　　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.

　　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 i

 　　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.

　　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 carbur

　　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 fur

 　　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 can compensate for part of the

　　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 part

 　　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

　　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 to the maximum, simplify the design of the gating system, improve the proc

 　　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 boundar

 　　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

 　　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 use effect of the carbur

 　　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. E

 　　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 the crucible with acid to dissolve th

 　　(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 an

 　　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. 　　2. The adhesion is not enough,

 　　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 select specific refract

 　　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 and the paste addition t