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 In order to make the electrode work normally at very 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 light high temperature of more than 3000 degrees. Therefore, the electrode paste occupies a very important position in the above ore thermoelectric furnace, so it is called the "heart" of this kind of electric furnace.

 　　Use process and consumption of electrode paste in terms of use characteristics, electrode paste is a continuous self baking electrode. During use, its outer layer is a cylinder made of 1-2mm thick steel plate. 　　The electrode paste is regularly added into the cylinder. With the progress of production, the electrode paste is gradually softened, melted and roasted. During roasting, a large amount of volatiles are released. After entering the conductive clip of the electrode, due to the high-temperature effect, it is from semi coking to complete coking, * and becomes a conductive carbon electrode. The electrode paste is baked into a conductive electrode by various heat of the electric furnace itself, so it is called a self baking electrode. During the working process of the electrode, a section of cylinder is connected to the top of the electrode at regular intervals, and a certain amount of electrode paste is added, and the process is repeated.

 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 the electrode has been burnt; if it is elastic, it indicates that it is normal; if it is soft, i

 　　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 of the electrode t

 　　(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

 (1) The measurement should be made twice in each shift, once during the shift, and once during the shift, and make a record. (2) The measuring position of each shift must be in the same position (inner triangle or outer triangle). (3) Each shift should decide how much electrode paste should be installed according to the height of the electrode paste. (4) The measuring personnel should be careful not to touch the two-phase electrodes at the same time to prevent electric shock. (5) The measurement must be accurate.

 Electrode accidents are common accidents in ferroalloys and calcium carbide enterprises smelted by submerged arc furnaces. The cause of electrode accidents is analyzed and judged accurately, and targeted preventive measures can be taken to reduce the occurrence of electrode accidents. However, due to the analysis of electrode accidents, it is supplied by electrode paste. The manufacturer and the electrode paste use the interference of multiple factors. To accurately determine the cause of the electrode accident requires objective evidence recognized by both parties, and the electrode section is a good objective evidence, so the analysis of the electrode section is of great significance. . 1. Electrode paste segregates, resulting in layering of aggregate and powder 1. Section status: There is obvious particle layer segregation on the section of the electrode. According to the size and cross-section of the radiant heat source for electrode baking, there are two situations, one is the ac

 Anode paste is the predecessor of preparing anodes in electrolyzers in aluminum plants. In the 40 years before 1995, the anode paste was once the largest product in China's aluminum carbon products. After 2000, this product will gradually be replaced by anode carbon blocks. It is the product with the largest output among carbon products. The anode paste is a carbon paste made of petroleum coke and pitch coke as aggregates and coal tar pitch as a binder. It is used as anode material for continuous self-baking aluminum electrolytic cell. Because of its high content of binder (more than 24%), it is paste-like before the upper part of the electrolytic cell is sintered, so it is called anode paste. The prepared anode is not only capable of good electrical conductivity, but also resistant to high temperature and corrosion, and at the same time the price is low. The resistivity of the preliminary anode is 50-70 μΩ.m, plus the lead and contact resistance, during normal aluminum electrolys

 The reason for the soft fracture of the electrode paste is quite right. Generally speaking, there are mainly the following aspects: (1) The electrode paste contains too much volatile matter. (2) The iron plate of the electrode shell is too thin or too thick. Too thin will not be able to withstand large external forces and rupture, causing the electrode iron shell to fold or leak and softly break when pressed and put; too thick will cause the iron shell and the electrode core to not contact closely and cause the core to cross. It will also cause soft disconnection. (3) Poor production of the electrode iron shell or poor welding quality will cause cracking, which will lead to leakage or soft fracture. (4) When the electrode is lowered, the load of the electric furnace is not reduced or reduced too little. After the electrode is discharged, the load increases too fast, which will also cause the electrode to softly break (except for large furnaces). (5) The electrode is lowered too freque

 The use process and consumption of the electrode paste In terms of the characteristics of use, the electrode paste is a continuous self-baking electrode. During use, the outer layer is a cylinder made of a 1-2mm thick steel plate. The electrode paste is regularly added to the cylinder. As the production progresses, the electrode paste is gradually softened-melted-baked. During roasting, a large amount of volatile matter is released. After entering the conductive clip part of the electrode, it changes from semi-coking to complete coking due to the high temperature, and finally becomes a conductive carbon electrode. The electrode paste is baked into a conductive electrode by various heat of the electric furnace itself, so it is called a self-baking electrode. During the working process of the electrode, a section of cylinder is connected to the top of the electrode at regular intervals, and a certain amount of electrode paste is added, and this is repeated.

 Electrode paste is called self-baking electrode in the smelting industry. It is called self-baking electrode because the process of baking into electrode is completed in submerged arc furnace by the heat of electric current. Because of its uniform composition, low melting point, fast melting rate, and shortening of smelting time, electrode paste is receiving more and more attention from steelmaking enterprises and is hailed as a new type of material in the 21st century. It is mainly used for smelting in submerged arc furnaces. Pre-melted multifunctional refining slag has been used maturely in foreign countries, such as South Korea, Japan, Europe and the United States, etc., and has gradually attracted the attention and application of the domestic metallurgical industry. The electrode paste produced by our factory is melted in an electric furnace, open hearth furnace, and cupola, with few impurities, stable and uniform composition, and can also be produced according to the chemical com

 The so-called airtight paste is only for the type of submerged arc furnace. Submerged arc furnace is divided into closed type, semi-closed type and open type. These different types of submerged arc furnaces use electrode pastes. Because of the different furnace types, over time, the electrode pastes applied to closed submerged arc furnaces are called closed electrode pastes, or closed pastes for short; they are used in open or semi-closed furnaces. The electrode paste on the closed submerged arc furnace is called standard electrode paste or just electrode paste. The airtight paste itself is a kind of electrode paste. Of course, generally speaking, the quality of the sealed electrode paste is one grade higher than that of the ordinary electrode paste. Resistance and ash content should perform better.

 The development of electric furnace steelmaking technology has continuously put forward requirements for the variety and performance of graphite electrodes. The use of high-power and ultra-high-power electric furnaces for steelmaking can shorten the melting time of the charge, increase production efficiency, reduce power consumption and reduce the consumption of graphite electrodes . According to the transformer capacity per ton of furnace capacity, electric arc steelmaking furnaces can be divided into ordinary power furnaces, high power furnaces, and ultra-high power furnaces. According to the classification of the electric power level of electric furnace steelmaking, and according to the difference of the raw materials used to produce the electrode and the difference of the physical and chemical indexes of the finished electrode, the corresponding ginger graphite electrode is divided into 3 varieties: ordinary power graphite electrode (RP), high power graphite electrode (HP) , Ultra

 1. Raw materials. The pre-baked anode adopts low-ash raw materials. Petroleum coke and residual electrode are used as aggregates. The impurity content is generally not more than 0.5%. The binder is coal tar pitch. Pre-baked anode production has widely used modified pitch or high-temperature pitch as a binder. 2. Calcination. Use rotary kiln or tank calciner at 1250. The petroleum coke is calcined at a high temperature of about C. 3. Crushing and screening. The forged petroleum coke and residual pole are crushed, sieved and ground into different strength materials according to the requirements of the formula, and then put into their respective silos. 4. Ingredients. The ingredients are set by the formula I set. There are two types of pre-baked anode formulas: large particle formula and small particle formula. The maximum particle size of the aggregate is 12mm~15mm. The amount of coal tar pitch varies according to the dry material formula and molding process. Generally, It is 16%~18%. 5

 The main problem that plagues electrode paste manufacturers is that the electrode paste baking speed is too slow. Some manufacturers adopt methods to reduce the amount of asphalt used. This method is effective to a certain extent, but too low amount of pitch causes the fluidity of the electrode paste to deteriorate, and the electrode paste is not easy to be filled in the electrode cylinder, and the density after sintering is poor and it is easy to cause hard fracture. Another method is to lower the softening point of the pitch and increase the sintering speed of the electrode. However, the softening point of the pitch cannot be reduced indefinitely, because the pitch with a too low softening point reduces the coking rate of the pitch, and the strength of the electrode should also be reduced. There is a hard break phenomenon. Therefore, in addition to properly mastering the above two methods in the production of electrode paste, the sintering speed of the electrode must be improved thr

 In the early 1960s, major changes occurred in electric furnace steelmaking technology, especially the adoption of ultra-high-power electric arc furnace technology, which clarified the technical direction for improving the production efficiency of electric furnaces. From the 1960s to the mid-1980s, the electric furnace smelting cycle was shortened from 3 hours. By 4 hours, the acceleration of the continuous casting rhythm has promoted the improvement of the production efficiency of electric furnace steelmaking, that is, increasing the capacity of the electric furnace, increasing the energy input to the electric furnace per unit time, and shortening the electric furnace smelting cycle. On the basis of ultra-high-power power supply, the international community has focused on the development of modern electric furnace smelting technologies that increase heat energy, such as enhanced oxygen supply, scrap preheating, and hot metal smelting. The development of these technologies has greatly

1. Long production cycle. The production cycle of ordinary power graphite electrodes is about 45 days, the production cycle of ultra-high power graphite electrodes is more than 70 days, and the production cycle of graphite electrode joints that require multiple dipping is longer. 2. High energy consumption. The production of 1t of ordinary power graphite electrode requires about 6000kw·h of electricity, thousands of cubic meters of gas or natural gas, and about 11t of metallurgical coke particles and metallurgical coke powder. 3. Many production processes. The production process includes raw material calcination, crushing and grinding, batching, kneading, molding, impregnation, graphitization and mechanical processing. Its production requires a lot of special mechanical equipment and kilns with special structures, the construction investment is relatively large, and the investment recovery period is relatively long. 4. A certain amount of dust and harmful gases are generated during the