Although there is no obvious change in the changing process of the electrode paste during sintering, it can be roughly divided into various stages according to the firing temperature and position. This process is carried out without external pressure and solely on the weight of the paste itself. 1. The softening stage. At this time, the solid electrode paste melts, the resistance increases, and the strength decreases, and finally all the electrode paste becomes a liquid state. At this stage the temperature is 25. C rises to 120~200. C, about 500 mm above the conductive jaw. 2. The volatilization stage. At this time, the electrode paste is fully melted, flows along the inner section of the shell, fills the gaps, and makes the quality uniform, and at the same time, it volatilizes and becomes viscous gradually. The resistance keeps decreasing, and the volatilization becomes a paste. At this stage, the temperature changes from 120 to 200. C rises to 650~750.…
12-29 2021
The electrode paste is sintered in the electrode shell, and its heat source comes from three aspects: 1. Electric heating itself conducts heat. The temperature of the electrode tip can reach 3,500 due to arcing. About C, because the heat conducts from bottom to top, the electrode paste is heated more and more when it falls from the top to the top, and it is gradually sintered. The conduction of arc heat is the main source of heat required for firing the electrode. 2. The resistance heat generated by the current passing through the resistance itself. When the current flows through the electrode, due to the large sintering resistance of the electrode paste, part of the input power becomes resistance heat, which provides a certain amount of heat for the firing of the electrode. 3. The conduction and radiation of flame heat on the charge surface. The temperature of the stove surface is very high, generally between 500 and 600.…
12-29 2021
1. Strictly control and master the length of the working end of the electrode, and reasonably control the pressure and release time, so that the pressure and release speed is compatible with the sintering speed. When processing the material surface after every 24 hours, observe the firing of the electrode in order to better control the softness of the electrode. Hard conditions (such as finding that the surface of the lowered electrode is off-white, dark but not red or reddish, indicating that the electrode is well baked; if the surface of the lowered electrode is red, it indicates that the electrode has been overfired; if the surface is black, it indicates that the electrode is under-baked. It is also possible. Poke the electrode with round steel. If it is very hard and rebounds, it means the electrode is over-burned. If it is elastic, it means it is normal. If it is soft, it means the electrode is under-burned. The heating…
12-28 2021
1. Choose the appropriate electrode type and diameter according to the capacity of the electric furnace and the capacity of the equipped transformer. 2. In the process of loading and unloading the graphite electrode and storage, pay attention to prevent damage and dampness. The damp electrode should be used after being dried by the electric furnace, and the joint hole of the electrode and the surface thread of the joint should be protected for lifting. 3. When connecting the electrode, use compressed air to blow off the dust in the connector hole. The force used to screw the connector into the electrode connector hole must be stable and uniform, and the tightening torque must comply with the regulations. When holding the electrode with the holder, be sure to avoid the joint area and clamp it above or below the bottom of the electrode joint hole. 4. When loading charge into the electric furnace, in order to reduce the impact of…
12-28 2021
1. Natural graphite electrode. The natural graphite electrode is an electrode produced using natural flake graphite as a raw material. Adding coal pitch to natural graphite, through kneading, shaping, roasting and machining, the natural graphite electrode can be prepared. Its resistivity is relatively high, the mechanical strength is low, and it is easy to break during actual use. A small amount of small size natural graphite electrodes are used in some special occasions. 2. Artificial graphite electrode. Using petroleum coke or pitch coke as solid aggregate and coal tar pitch as binder, the artificial graphite electrode can be prepared through kneading, molding, roasting, graphitization and machining. Artificial graphite electrodes are high-temperature resistant graphite conductive materials. Carbon material companies with graphite electrodes as the main varieties constitute the metallurgical carbon material industry. 3. Graphite electrode with anti-oxidation coating. As the coating increases the price of graphite electrodes and there are some problems in its use, there is currently no widespread use…
12-27 2021
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-high power graphite electrode (UHP). Ordinary power graphite electrodes are produced from ordinary petroleum coke, with low graphitization temperature,…
12-27 2021
1. Calcining. Both petroleum coke and pitch coke need to be calcined, and the calcining temperature should reach 1350. C, to fully remove the volatile matter contained in the carbonaceous raw materials, and improve the true density, mechanical strength, and conductivity of the coke. 2. Crushing, screening and batching. The calcined carbonaceous raw material is crushed and sieved into aggregate particles of specified size, part of the coke is ground into fine powder, and then weighed according to the formula to form a dry mixture of various particles. 3. Kneading. Under the heating state, the quantitative dry mixture of various particles and the quantitative binder are stirred and mixed and kneaded to form a plastic paste. 4. Forming. Under the action of external pressure or high-frequency vibration, the paste is pressed into a green electrode with a certain shape and higher density. 5. Roasting. Put the green electrode in a special roasting furnace, and use metallurgical coke powder to fill…
12-26 2021
The anti-oxidation coating graphite electrode is a coated electrode made of graphite electrode as the substrate and sprayed with an oxidation-resistant coating on the surface of the body. The preparation process is to fuse a thin layer of aluminum-based cermet on the surface of the processed graphite electrode. The coating material, which can conduct electricity and is resistant to oxidation, is formed by the eutectic of aluminum and refractory mud with multiple components. Its characteristics and functions are as follows: 1. Provide the electrode with a high-efficiency oxygen barrier layer and a highly conductive outer surface layer, which can prevent the electrode surface from being oxidized and reduce electrode consumption, and can reduce the current density inside the electrode. 2. The anti-oxidation coating can withstand quite high temperature without melting, and the decomposition temperature of the coating is 1850. Above C. 3. The coating is well combined with the electrode surface and has a similar coefficient of linear expansion. 4.…
12-26 2021
70% of aluminum electrolytic cell failures occur in pre-baked anodes. Anode failures that often occur in electrolyzers include: partial overheating of the anode, uneven current distribution, anode dropout, anode long bag, anode crack fault, anode block shedding, a large amount of carbon slag falling into the electrolyte to make it carbon-containing, oxidation and combustion around the anode, and The anode is tilted and so on. These failures are mainly caused by the quality of pre-baked anodes and improper electrolysis operations. 1. The anode drops off. The pre-baked anode may cause the anode carbon block to separate from the steel claw due to the poor casting of the phosphorus pig iron or the defect of the anode carbon bowl. When this phenomenon occurs, it is necessary to remove the carbon anode from the electrolytic cell and replace it with a new pre-baked anode. When the anode carbon block has large cracks, the block will also be cracked. 2. Long anode bag.…
12-25 2021
During the operation of the electrolytic cell, carbon slag and fragments are continuously produced around the bottom of the anode carbon block, which will not only increase the carbon consumption, but the carbon slag fragments suspended in the electrolyte will destroy the normal technical conditions of electrolytic aluminum production and seriously endanger the production of aluminum electrolysis. Normal operation, even leading to an accident shutdown. The hazards of pre-baked anodized slag and cracks are mainly as follows: 1. Change the conductivity of the electrolyte, thereby affecting the normal operation of aluminum electrolysis production. 2. Make the electrolyte generate heat and generate a heat sink. The accumulation of carbon slag and the increase of electrolyte resistance result in an increase in the cell voltage and an increase in heat income, which gradually leads to the heat cell. As a result, the current efficiency decreases, and the power consumption, carbon consumption, and unit consumption of fluoride salt increase. 3. Scraping of carbon…
12-25 2021
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…
12-24 2021
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.…
12-24 2021
The graphite material is mainly composed of polycrystalline graphite. Graphite is a multi-layer laminated crystal with a hexagonal planar network structure between carbon atoms. Although graphite material is an inorganic non-metallic material, it has good thermal and electrical conductivity, and at the same time has a thermal expansion coefficient far lower than that of metal, a high melting point and chemical stability, which makes graphite materials very useful in industrial applications. High value. Graphite materials are chemically inert in non-oxidizing media and have good corrosion resistance. Except for strong acids and strong oxidizing media, graphite materials are not corroded by other acids, alkalis, and salts, and hardly react with organic compounds. . Graphite material is also a kind of high temperature resistant material. Graphite will not melt under high temperature, but at 3350 under normal pressure. C began to slowly sublimate into gas. The strength of general materials will gradually decrease at high temperatures, while graphite materials are in 2000.…
12-23 2021
Carbon materials include hundreds of varieties and thousands of specifications of products. According to materials, carbon materials can be divided into carbon products, semi-graphite products, natural graphite products and artificial graphite products. According to performance, carbon materials can be divided into graphite electrodes and graphite anodes, carbon electrodes and carbon anodes, carbon blocks, paste products, special carbon and graphite products, carbon products for mechanical and electronic industries, carbon fibers and their Composite materials and graphite chemical equipment, etc. According to service objects, carbon materials can be divided into carbon materials for metallurgical industry, carbon materials for aluminum industry, carbon materials for chemical industry, carbon materials for mechanical and electronic industries, and new carbon materials for high-tech sectors. According to the function of use, carbon materials can be divided into three categories: conductive materials, structural materials and special functional materials. (1) Conductive materials. Such as graphite electrodes for electric arc furnaces, carbon electrodes, natural graphite electrodes, electrode paste and anode paste,…
12-23 2021
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 production process, and it is necessary to adopt perfect ventilation and dust reduction and environmental protection…
12-22 2021
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 shortened the electric furnace smelting cycle, and reduced the power consumption and graphite electrode consumption. 1. Large-scale electric…
12-22 2021
As the self-baking electrode of submerged electric furnace, electrode paste has been widely used in the smelting of various products of submerged electric furnace. Although the cost of electrode paste in the production of calcium carbide, ferroalloy and other products is relatively low, the quality of the electrode paste and the firing of the electrode directly affect the stability of the operation of the submerged electric furnace. Due to the various types of submerged electric furnaces, the different furnace conditions, and the increasing capacity of electric furnaces, when the quality index of the electrode paste meets the requirements, the roasting quality plays a decisive factor, which requires us to focus on calcium carbide, ferroalloys, etc. The actual production of the product starts with the management of the electrode paste, strictly implements the operating procedures, regularly and quantitatively lowering the electrodes, and maintains the normal and stable operating parameters of the electric furnace at all times to ensure the high efficiency…
12-21 2021
The residual electrode is the part that must be replaced with a new anode from the electrolytic cell in order to prevent the steel claws from melting after the pre-baked anode has been used in the electrolytic cell for a period of time. After high-temperature roasting, the residual pole has higher mechanical strength and lower porosity than petroleum coke. Using residual pole as a raw material for the production of carbon products can improve the quality of carbon products to a certain extent. As the "heart" of the calcium carbide furnace, the electrode paste, which is called a carbon functional material, requires sufficient strength and thermal shock resistance. With the advent of the low-carbon era, it is an inevitable trend for large enclosed calcium carbide furnaces to replace small semi-closed calcium carbide furnaces and open calcium carbide furnaces. Therefore, higher requirements for the quality of electrode paste are also put forward. Rongxin Carbon has been specialized in producing electrode paste…
12-21 2021
Electrode occupies an important position in submerged arc furnace. The working conditions of the electrode are bad, the current passing through is high, the temperature difference between the two ends is large, and the production is affected by the impact of mechanical, electrical and charge collapse... Mechanical strength, higher electrical resistivity, better thermal shock resistance, oxidation resistance and smaller thermal expansion coefficient. Generally speaking, the quality of electrode paste is controlled by the following five indicators: 1. Ash: Ash is the residue of electrode paste when it is burnt to constant weight at 850℃-870℃. It belongs to inorganic minerals. It has high ash resistivity, poor strength, high power consumption, and large electrode consumption. In the event of a hard breaking accident, the ash content is a very important indicator, and the lower the better. 2. Volatile matter: Volatile matter refers to the mass loss of electrode paste under the condition of heating in isolation of air. Volatile matter is generally…
12-20 2021
The following points should be paid attention to when installing the electrode paste airtight paste: 1. Do not allow debris to enter the electrode 2. Proper paste height 3. Work harder 4. Appropriate temperature 5. Prevent overhang Before filling, the electrode paste should be broken, generally broken into small pieces of 80~100mm, so that the electrode paste block can pass between the two ribs smoothly. If the particle size is too large, the electrode paste suspension failure is likely to occur; if the particle size is too small, it is easy to cause the phenomenon of spraying. Use a forklift truck or special tools to transport the electrode paste to the calcium carbide furnace, and use an electric hoist to hoist the electrode paste into the electrode bucket. Pay attention to the safety of hoisting during loading. When installing electrode paste, be careful not to scatter the electrode paste on the equipment outside the electrode barrel, so as to avoid…
12-20 2021
The liquid electrode paste flows out from the damaged part of the electrode shell, which is called leakage paste. The reasons are: (1) The welding quality of the electrode shell is not good, and the welding seam is cracked; (2) The copper tile is in partial contact with the electrode shell, and the electrode shell is burned out; (3) The load was not lowered when the electrode was discharged or the electrode case was burned through due to excessive load due to the electrode sliding down beyond the allowable lowering length. Paste leakage usually occurs soon after the electrode is lowered. At this time, the power should be cut off immediately, and the leaking parts should be found. When the leaking hole is not large and the flow is not much, plug the hole with asbestos rope or the like, press the hole in the copper tile, send power and slowly heat up. If the hole is too large to…
12-19 2021
Electrode paste is also called self-baking electrode. It is a kind of semi-finished electrode material made of electric forging coal, residual electrode, etc. as aggregate, and asphalt, tar, etc. as binder. In the process of use, the electrode paste needs to be injected into the submerged arc furnace. When it is heated to about 400 degrees, the electrode paste melts and then completes sintering to become a solid. When it is heated to 800 degrees, the arc combines with the original ore to generate huge heat to complete the ore Smelting. 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…
12-19 2021
So, is there really an electrode paste without coal tar? have! Our factory has processed 2000 tons of electrode paste without coal tar for a group of well-known companies in the industry. Coal tar is used as a binder in the manufacture of electrode paste. Although coal tar is missing, there is pitch. Of course, this is only based on the special requirements of customers. Generally speaking, the electrode paste requires coal tar. The combination of coal tar + pitch binder can make the electrode paste melt perfectly and then sintered in the submerged arc furnace. If the coal tar is missing It will affect the softening process of the electrode paste. The goose egg-shaped electrode paste, trapezoidal electrode paste, and cylindrical electrode paste produced by our factory are all formulated with coal tar. If it is nickel-iron high-standard airtight paste, the requirements for the formula are more stringent. Therefore, the standard electrode paste needs to be added with coal…
12-18 2021
Silico-manganese alloy is a common compound deoxidizer, it is also a reducing agent. High-silicon-manganese-silicon alloy is used for external reduction dephosphorization. CaSi-CaF2-CaO is used as dephosphorization agent. Under the condition of extremely low oxygen potential, the combination of calcium in the dephosphorization agent and phosphorus in the alloy generates Ca3P2, which can make The phosphorus in the alloy is removed, and the alloying elements in the alloy are not lost. The raw materials used in smelting high silicon-manganese silicon alloys are: manganese-rich slag, silica, coke, charcoal, and lime. The basic principle of reductive dephosphorization is to rely on the combination of calcium in the dephosphorizing agent and phosphorus in the alloy to generate Ca3P2 under the condition of extremely low oxygen potential, so that the phosphorus in the alloy can be removed. Adopting process methods: inverted bag method, powder spraying method. Two hot metal ladle A and B are required. A hot metal is filled with high-silicon-manganese silicon alloy smelted…
12-18 2021
The performance of the electrode paste during the sintering process can best explain the quality of the electrode paste. If the sintered electrode has transverse cracks, the next problem is most likely to be hard fracture, which is a very serious accident. The reason is that if the factors of worker operation are excluded, the greatest possibility of hard breakage is the quality of the electrode paste. We once saw an electric forged coal block as big as a fist at a hard-breaking site in a factory in Henan. After testing, the resistance of that batch of electrode paste is above 80. The occurrence of a hard-breaking accident is completely a problem of the quality of the electrode paste. The manufacture of electrode paste is a production activity with simple technology and complex process. Different furnace types have different requirements for the process raw material ratio of electrode paste. As an alloy factory, if the sintered electrode is overheated or…
12-17 2021
Nickel-iron electrode paste has always been regarded as a high-end product in the electrode paste market. For a long time, the formula of nickel-iron electrode paste has been a mystery. At present, there are only a few electrode paste factories that can produce high-standard sealed electrode pastes that meet the needs of ferronickel production. The formula of the nickel-iron high-standard airtight paste is the same as that of the ordinary national standard electrode paste, and the raw material ratio is different. The terminal price of the electrode paste processed by our factory for a trading company to one of the largest alloy plants in Asia in Jiangsu is close to 4,000 yuan/ton. The price of ordinary electrode paste is only between 3000-3500. The raw materials of nickel-iron smelted electrode paste are indeed a little higher than the cost of ordinary electrode paste. Regarding the amount of electrode paste, our factory's high-standard sealed paste reaches 8-10kg/ton of nickel-iron alloy finished product.…
12-17 2021
Heat source and sintering process for electrode paste sintering. 1. Heat source for electrode paste sintering. The electrode has a high carbon content, and its own electrical and thermal conductivity is excellent; the resistance heat generated by the current passing through the electrode itself (the resistance of the ferrosilicon electrode paste is generally around 70, and the resistance of the nickel-iron electrode paste is slightly lower at about 65. In sub-fields, this resistance is still relatively high. You must know that the resistance of the graphite electrode is about 5.); The conduction and radiation of the furnace surface flame (the domestic submerged arc furnace is submerged arc operation, and this operation makes the contact surface more generated. Large heat, then this heat can be conducted by the electrode paste after sintering.) 2. The process of electrode paste sintering. The boundary of the change process of electrode paste during sintering is not very obvious, but in order to facilitate research and…
12-16 2021
Product introduction of standard submerged arc furnace and closed semi-closed submerged arc furnace One principle use Submerged arc furnace is mainly used to reduce raw materials such as smelting ore, carbonaceous reducing agent and solvent. It mainly produces ferrosilicon, ferromanganese, ferrochromium, tungsten, silicomanganese and other ferroalloys, which are important industrial raw materials in the metallurgical industry and calcium carbide and other chemical raw materials. Its working characteristic is to use carbonaceous or magnesia refractory materials as furnace lining and self-cultivation electrodes. The electrode** charge is submerged arc operation. It uses the energy and current of the arc to pass through the charge. The energy is generated due to the resistance of the charge to smelt the metal. It is an industrial electric furnace with continuous feeding and intermittent tapping of iron slag. Two structural characteristics Submerged arc furnace is a kind of industrial electric furnace that consumes huge power. Mainly consists of furnace shell, fume hood, furnace lining, short net,…
12-16 2021
The cylindrical electrode paste is an electrode paste product exclusively for the Muslim market. Our factory has processed more than 10,000 tons of cylindrical electrode paste for South Africaian customers. Its diameter is 600mm, length is 1000mm, resistance is generally less than 80 or 75, and ash content is less than 5. Such a process is a very common indicator for our company. Difficulty. After Rongxin Carbon completed its automation transformation in 2008, it can achieve a production capacity of 600 tons per day. What is the concept of 500 tons. The 15,000 silico-manganese alloy furnace needs about 80 tons of Rongxin carbon electrode paste per month. Then, the daily output of Rongxin Carbon Factory can meet the monthly demand of six 15,000 silico-manganese alloy furnaces. Rongxin Carbon can meet the large-volume procurement needs of alloy factories.
12-15 2021
Goose egg-shaped electrode paste is Rongxin Carbon’s largest shipment of electrode paste products, with an annual shipment of more than 100,000 tons. The goose egg-shaped electrode paste can be applied to most types of submerged arc furnaces and has the greatest applicability. Our company's egg-shaped electrode paste products are exported to Yunnan, Guizhou, Mongolia, Shandong, and also exported to South Africa, Indonesia and other countries and regions. There is no difference in the formula between the egg-shaped electrode paste and the trapezoidal electrode paste, but it will be different in the mold forming stage. Electrode pastes of different shapes are also to meet the different needs of customers. There are 500 electrode paste production enterprises nationwide. Among so many electrode paste production factories, why does Rongxin Carbon do better in terms of production scale and reputation? This starts with the product layout of Rongxin Carbon. Since 1992, Rongxin Carbon has been producing forged petroleum coke as its main business. In…
12-15 2021
Feeding, power distribution and material level management during the start-up process of the silicon-aluminum-iron alloy electrode paste electric arc furnace Feeding After the electrode paste electric furnace is completed, start to gradually add materials to the furnace. During the opening of the furnace, all activities, whether it is feeding, level management, or power distribution, must be carried out around raising the furnace temperature. For the first feeding, the three electrode columns must be buried, and the feeding amount is large. Therefore, the raw materials are mixed evenly, and the feeding should be evenly thrown around the click. Partial feeding is strictly prohibited. The material level management should be in place in time, and the material should be discharged in time according to the smelting situation. Since the furnace temperature is low when the furnace is turned on, it is most likely to cause three-phase disconnection, which will cause difficulties for the first iron discharge. Therefore, after blanking, sprinkle a layer…
12-14 2021
Application of High-standard Sealed Paste Electrode Paste in the Process of Smelting Nickel Pig Iron In China, laterite ore is a better technology choice for producing ferronickel (nickel pig iron) in a closed paste submerged arc furnace. At present, the most suitable process route is considered to be laterite ore-after drying, crushing and agglomeration-closed paste smelting in an electric furnace with coke and solvent-production of crude nickel pig iron-energy reduction of C, SI, S, P, etc. Impurities are refined in a converter to obtain nickel and iron granulation, or liquid iron can be directly smelted into stainless steel. The above-mentioned process of using laterite ore to directly process stainless steel products has been realized by enterprises such as Inner Mongolia Mingtuo Company and Guangxi Beihai De Nickel Industry. In terms of production process, resource conditions, product quality, etc., the process technology of pyro-electrode paste ferronickel smelting is varied. At present, there are blast furnace method, electric furnace thermal reduction method,…
12-14 2021
Raw materials analysis and market conditions of nickel-iron submerged arc furnace using high-standard closed paste electrode paste The domestic nickel oxide ore resources are extremely limited. At present, the domestic laterite resources for the production of nickel pig iron and ferronickel with high-standard airtight electric furnaces come from South Pacific island countries such as Indonesia and the Philippines. Enterprises purchase nickel ore from the market according to suitable production processes and equipment conditions. Laterite Dewatering The purchased laterite ore usually contains about 33% of the physical water and crystal water. It is extremely uneconomical to directly charge nickel ore into a high-standard closed paste electric furnace to smelt ferronickel. Inefficient and useless to use large amounts of heat. At present, the domestic enterprises engaged in smelting ferronickel with electrode paste electric furnaces almost all dry laterite ore. It is more economical to bake laterite ore with the waste heat of a closed paste electric furnace to remove the physical water…
12-13 2021
Application of submerged electric furnace using high-standard closed paste electrode paste (self-baking electrode) in ferronickel production Production and capacity development The main equipment for smelting closed paste nickel pig iron using laterite mines in my country is the electrode paste submerged arc furnace. Next is the blast furnace. In 2012, the output of nickel-containing pig iron physical alloys has reached 5.201 million tons according to private statistics. The output of medium and high nickel pig iron solid alloys with high-standard closed paste nickel pig iron containing more than 4% nickel was 3.95 million tons. The ferroalloy electrode paste submerged thermal equipment produced in my country is undergoing a large-scale transition from a capacity of 6300kva to a capacity of 25000-66000kva. At present, most of the electrode paste electric furnaces with a capacity of 12500-33000kva are used. The profit situation of the recent production of ferronickel products is extremely uneven; some good companies with favorable times and places may make a…
12-13 2021
The nickel pig iron base material produced by the nickel-iron electric furnace has made an important contribution to the development of stainless steel. In the production of submerged arc furnaces in 2012, nearly 3.95 million tons of high-grade ferronickel base materials were continuously sent to stainless steel plants, ensuring a substantial increase in stainless steel output by 11.69%. In recent years, TISCO and Baosteel have used nickel metal in the total nickel pig iron, and the market has accounted for 30%-50% of the total nickel metal consumption. The high-standard sealed electrode paste produced by Rongxin Carbon in Gongyi City can ensure the long-term continuous and stable operation of the nickel submerged arc furnace. The physical and chemical indexes of Rongxin Carbon Special Airtight Paste in Gongyi City project Product name Special paste for ferronickel 1# electrode paste 2# electrode paste 3# electrode paste 4# electrode paste Ash content (%,m/m)≤ 3 4 5 7 9 True specific gravity (g/cm3) 2.02 2.02 2.02 2.02 2.02 Resistivity (uΩ·m)≤…
12-12 2021
Crushing and screening Laterite ore has low nickel content and uneven lumpiness. The particle size is finer, and there are also large blocks with a particle size of more than 100 millimeters. It is necessary to consider the installation of cone, jaw crusher or counter-roll crusher and screening equipment, so that the high-standard closed paste electric furnace ore and other charge can meet the technical requirements of use. Pre-drying Laterite ore imported from Indonesia and the Philippines usually contains 32-40% moisture. About 20% of the physical water should be dried at 120°C for 2 hours to remove. Use closed paste submerged arc furnace, hot blast stove, rotary furnace hot flue gas to dry laterite, blast furnace or closed submerged arc furnace gas or to strengthen production equipment (7-8% crystalline water, decomposed and removed at 400℃, after half an hour.) Block The powdered red clay is sintered, pelletized, and briquetted into the electrode paste submerged arc furnace, which can improve the…
12-12 2021
The electrode is the only channel for the electric furnace to input electric energy, and it can also be said to be the heart of the electric furnace. Therefore, making the electrode have good working conditions is the key to the successful opening of the furnace. Large-scale submerged arc furnaces generally use self-baking electrodes. Self-baking electrodes use anthracite, pitch, etc. as raw materials to make electrode paste at a certain temperature, and then put the electrode paste into the installed electrode shell and then sinter and coke. . Therefore, to make a reasonable oven system, it is necessary to understand the sintering characteristics of the electrode paste. Sintering process of Rongxin carbon electrode paste self-baking electrode The self-baking electrode sintering process is a process in which the binder decomposes and gradually discharges volatiles as the temperature increases. The sintering of the electrode can be roughly divided into three stages. The first stage: the temperature rises from outdoor air temperature to…
12-11 2021
It is more difficult to smelt silicon-aluminum-ferroalloy in a closed electrode paste submerged arc furnace, and only a good start can make the future smelting road smoother. Therefore, adequate preparation, high-quality raw materials, careful operation, and excellent technology are all necessary guarantees for opening the furnace. The ferrosilicon-aluminum alloy produced by the submerged thermal method, as a steelmaking deoxidizer, has been gradually recognized by major steel mills and more and more manufacturers because of its good deoxidizing effect and can effectively reduce steelmaking costs. At present, the types of furnaces for the production of ferrosilicon-aluminum alloys are mostly concentrated in the range of 1800KVa to 6300kVA. Its production capacity accounts for more than 80% of all submerged arc furnaces producing silicon-aluminum-ferroalloys, and its smelting technology in small furnaces is also becoming more mature. However, the rise in electricity prices and the pressure of industrial policies have prompted the production of silicon-aluminum-ferroalloy furnaces to gradually become larger. Everyone knows that more…
12-11 2021
Build a furnace The main aluminum refractory material is high-alumina brick masonry. Three layers of graphite carbon bricks are built on the bottom of the furnace, and one layer of graphite carbon bricks are built on the walls of the furnace. A layer of electrode paste is knotted at the bottom of the furnace before starting the furnace, with an average thickness of 200mm. Raw material preparation Bauxite Content: AL2O3 55%-90% SIO2 20%-30%. Granularity: 30-120mm Rinse clean Bituminous coal Compared with other alloys in the smelting of silicon-aluminum-iron alloy submerged arc furnace electrode paste smelting, the application of the original agent is the most unique. Among the reducing agents used, bituminous coal accounts for more than 80%. Composition: 15%-25% volatile, less than 20% ash, less than 55% fixed carbon, good slagging performance. Silica In fact, the normal smelting of silicon-aluminum-ferroalloy does not have high requirements for silica. We have used it from 90% to 99% of the SiO2 content, and…
12-10 2021
Electrode paste is also called self-baking electrode. It relies on the heat in the submerged arc furnace to complete the roasting. Therefore, matching the consumption speed of the electrode with the roasting speed is the key to the use of electrode paste. Due to the development of submerged arc furnace technology, it is gradually becoming large With the development of the electrode in the sintering process from open furnace to closed furnace, the heat obtained by the electrode from the furnace is greatly reduced, which requires the improvement of the sintering performance of the electrode paste to make up for this deficiency. Hard fracture is caused by insufficient strength of the electrode paste after sintering; soft fracture is that the electrode sintering speed is not as fast as the consumption rate, and the lowering is too fast. The electrode is not completely sintered and cannot withstand the stretching and lateral impact of the lower part of the electrode, causing fracture.…
12-10 2021
Requirements for the use of electrode paste The process method of producing ferroalloy by electric furnace is the most important process technology. In my country, the number of alloys produced by submerged arc furnaces in electric furnace equipment exceeds 80% of the total output of ferroalloys. Submerged arc furnace is the main equipment furnace type. Submerged arc furnace is also called submerged arc reduction electric furnace. The process technology for the production of ferroalloys uses electric energy as the main heat source, uses carbonaceous reductant to reduce ore, and produces deoxidizers and alloying agents required for steel production. It is the main method for producing ferroalloys. The high temperature and thermal energy required by the ferroalloys produced are usually converted by sending electrical energy into the electric furnace through self-baking electrodes. The self-baking electrode is an indispensable central link in submerged arc furnace equipment, and is the basic condition and prerequisite for the existence of smelting ferroalloy production technology. In…
12-09 2021
Raw material for preparing electrode paste The raw material for making electrode paste is composed of solid carbon material and binding material. The quality of the electrode paste is closely related to the raw material formula and preparation process. Solid materials include calcined anthracite, metallurgical coke, petroleum coke and graphite electrode scraps. Anthracite is dense and has a high carbon content, which can improve the thermal stability, conductivity and mechanical strength of the electrode; the binder of the electrode paste includes pitch and coal tar, and tar is added to adjust the softening point. The binder is decomposed during the sintering process of the electrode paste and the volatiles are discharged and then converted into coke, so that the electrode forms a hard whole. The formula of electrode paste should consider various factors such as the ratio of various aggregates, particle size composition, softening point of the binder, and the amount of addition. Classification and performance of electrode paste The…
12-09 2021
At present, when domestic submerged arc furnaces are used to produce ferrosilicon, manganese and chromium ferroalloys, standard electrode pastes are usually used. With the widespread use of large-capacity submerged arc furnaces and closed electric furnaces, the number of large-scale electric furnaces has continued to increase; and the output of ferroalloys has increased significantly, many silico-manganese alloy submerged arc furnaces are gradually switching to closed electrode pastes. In order to ensure that the self-baking electrode can be sintered early. There are also some silicomanganese alloy manufacturers, which are electric furnace nickel-iron manufacturers. According to the needs of our factory, they usually prefer to choose high-standard sealed electrode paste that is more suitable for them. Among them, the main point is that the high-standard electrode paste is easy to bake, has stable performance and quality, and can ensure the baking quality of the electrode, so as to prevent the occurrence of soft short, hard broken, and U-turn events. A nickel-iron alloy plant…
12-08 2021
Firewood The main purpose of wood baking is to dry the moisture in the furnace and to initially bake the electrodes. Compared with coke and electric baking, wood baking has a larger baking area but a lower temperature, so the time is longer, generally lasting three to five days. Before the firewood is baked, the electrode paste is cushioned with refractory bricks to prevent adhesion. In the early stage of wood baking, the flame height does not exceed the furnace mouth. In the later stage, the electrode is baked with a high fire to make the wood burn evenly and violently. Burnt Before the coke is baked, a circle of flower wall with clay bricks is used to hold the coke around the electrode, and the height is lower than that of the furnace mouth. A layer of 100mm thick coke powder is placed on the bottom of the furnace to prevent oxidation at the bottom of the furnace. During…
12-08 2021
The height of the electrode paste refers to the height from the upper end of the electrode clip to the top of the electrode paste. If the electrode paste is too high, the coarse and fine particles in the electrode paste are prone to stratification, or the electrode cylinder will be swollen due to too much pressure of the paste column. If the electrode paste column is too low, the pressure of the paste column is too small and the filling is poor, and it is difficult to obtain Dense electrodes. The electrode paste is consumed too quickly. The proper height of the electrode paste column is beneficial to improve the quality of electrode firing and reduce consumption. Electrode paste is the conductive electrode of various submerged electric furnaces, and it is an indispensable product in industrial production. We at Rongxin Carbon have read many domestic and foreign materials, but we have not found any materials that specifically discuss the…
12-07 2021
The so-called oven is an operation in which the furnace lining and electrodes are gradually adapted to the feeding smelting by heating, and its main purpose is to dry the furnace lining and baking the electrodes. The quality of the oven will not only affect the service life of the furnace lining, but also directly affect whether the electric furnace can be put into production smoothly. Therefore, the furnace system should be formulated in detail in the furnace opening plan and strictly implemented. Coke oven In the first stage of the oven process, there are three methods of wood baking, oil baking and coke baking. This article focuses on the focus on the focus baking. As the name implies, coke baking is a method of oven using the combustion heat of coke. Large metallurgical coke with less ash content should be used to make fuel (particle size> 150 mm). During the baking of the electrode, the coke should be burned…
12-07 2021
1.Poor paste quality of electrode paste , too much volatile matter 2. The electrode paste shell iron sheet is too thin or too thick.It is too thin to withstand the larger external force and break, causing the electrode paste cylinder to fold or leak paste and soft break when pressing;Too thick will cause the iron shell and electrode paste core contact is not close and string core, will also cause soft break. 3.electrode pastes are pressed frequently, the interval time is too short, or the electrode paste is too long after the electrode paste is put down, resulting in soft break. 4. If the carbon electrode paste is not added in time and the position of the electrode paste paste is too high or too low, it will also cause the soft break of the electrode paste. 5. The electrode paste block is too large, and the paste is careless, and it can be put on the ribs and suspended,…
12-06 2021
The pore structure of semi coke l is an important indicator of the adsorption performance of semi coke l. Someone has used nitrogen isotherm adsorption method to study the influencing factors of the pore structure of semi coke l. The purpose of the research is to influence the pore structure of semi coke l by atmospheric pressure and pressurized gasification. influences. The results of the research on several samples show that the specific surface area, pore specific surface area and specific pore volume of semi coke l are significantly increased compared with raw coal. The production purposes of coal gasification and coking are different. The former aims to produce as much gas as possible under certain energy consumption conditions, while the latter aims to produce semi coke l that meets the requirements of product quality standards by controlling the process parameters of the coking process. . High-quality semi coke l requires less ash and moisture, and volatile content should not…
12-05 2021
The working temperature of the ferronickel furnace is relatively low, so it is necessary to use the high-standard sealed electrode paste which is easy to roast and produced by Gongyi Rongxing Carbon. Rongxing Carbon can make the furnace stable and less accidents.The consumption of electrode paste is about 10kg per ton of iron, which can save 50% compared with the general standard electrode paste, which can reduce the production cost of ferronicke and make the enterprise benefit better.Production-oriented enterprises pay special attention to the stable operation of the furnace for a long time, and would rather spend more money to buy high-quality electrode paste, so as to ensure the production of peace of mind. For a long time, the customers are very satisfied with the quality and service of Rongxing carbon high standard sealed paste, which is called as "special paste for ferronickel electric furnace" by many nickel production enterprises. It is understood that other ferronickel plant ton consumption of…
12-04 2021
The electrode paste broken into pieces in advance is regularly added above the cylinder (500-1500mm in diameter) welded by steel plate. The electrode paste in the cylinder begins to soften and melt under the action of heat, and then the binder coal tar pitch is thermally decomposed to release volatile matter until it is roasted into carbonaceous electrode with good conductivity and high mechanical strength, Depending on the roasted electrode, the current (current density is generally 3 ~ sifcm2) is introduced into the ore thermal power furnace. Due to high temperature oxidation and chemical reaction of furnace charge, the lower end of the electrode is consumed continuously. Therefore, the whole electrode barrel should be lowered regularly, and the upper part of the electrode barrel should be connected with a new barrel timely and the electrode paste should be added. The self baking process of electrode paste can be divided into three stages (1) Soften and melt. The temperature of electrode…
12-03 2021
At present, standard electrode paste is usually used in the production of ferro-silica, manganese series and chromium series ferroalloys in submerged arc furnace. With the wide use of large capacity submerged arc furnace and closed electric furnace, the number of large electric furnace is increasing; As well as a large increase in the production of ferroalloy, many silicon manganese furnace, is gradually converted to the use of closed electrode paste. In order to ensure that the self-baking electrode can finish sintering in advance. There are some silicon manganese alloy manufacturers, especially the electric furnace for ferro-nickel manufacturers, according to the needs of the factory, usually preferred to choose more suitable for their own high standard closed electrode paste. Among them, the main focus is that the high-standard electrode paste is easy to roast, stable performance and quality, and can ensure the quality of the roasting of the electrode, so as to prevent the occurrence of soft short, hard break and…
12-02 2021
In the equipment of calcium carbide furnace, the electrode is the "heart" of calcium carbide furnace. The quality of the electrode directly affects the production of calcium carbide. The electrode is baked by the calcium carbide producer with the electrode paste as the main raw material. The quality of the electrode paste and the operation level of the calcium carbide producer jointly affect the quality of the electrode. The electrode plays the role of conducting current and converting electric energy into heat energy in the calcium carbide furnace. In the production of calcium carbide, the current is input into the furnace through the electrode to generate arc, which mainly uses the arc energy to release heat and produce calcium carbide products at high temperature. The production and operation effect of calcium carbide furnace directly depends on whether the electrode is in normal working state. If there are problems with the electrode, such as hard break, soft break, too short, too…
12-01 2021
In the process of producing semi coke, the different raw coal and technological process and technological conditions have certain influence on the properties of semi coke 1. The yield of blue carbon during coal pyrolysis decreases with the increase of pyrolysis temperature, and is affected by the volatile content of raw coal. The coal with high volatile content has a low yield. 2. The volatiles of semi coke decreased with the increase of pyrolysis temperature, and the volatiles of semi coke of different coals tended to be the same at high temperature.The volatile content of semi coke produced from coal with high silky content is higher than that from raw coal. 3. The calorific value of semi coke is the highest when the pyrolysis temperature is 550~600℃.It is significant to produce blue carbon with high calorific value by pyrolysis of high moisture, low metamorphism lignite and long flame coal. 4, the sulfur content of semi coke with different pyrolysis temperature…
12-01 2021
With high quality anthracite, coke, graphite as raw materials made of carbon block. Used as cathode of aluminium electrolytic cell. It is built at the bottom of the electrolytic cell, also known as the bottom carbon block. The cathode carbon block plays a dual role of conducting electricity and forming the inner lining of the electrolytic cell. The cathode carbon block is required to have high temperature resistance in aluminum electrolysis production, resistant to molten salt erosion, good electrical and thermal conductivity, high mechanical strength, good thermal shock resistance and strong corrosion resistance of sodium, which is conducive to energy saving and tank life improvement in the production of aluminum electrolysis. According to the quality requirements of the products, the raw materials selected and the technological conditions used, the cathode carbon blocks in China are basically divided into three categories: ordinary cathode carbon blocks, semi-graphitic carbon blocks and graphitic carbon blocks. Anthracite calcined at 1250 ~ 1350℃ is used as…
12-01 2021
With high quality anthracite, coke, graphite as raw materials made of carbon block. Used as cathode of aluminium electrolytic cell. It is built at the bottom of the electrolytic cell, also known as the bottom carbon block. The cathode carbon block plays a dual role of conducting electricity and forming the inner lining of the electrolytic cell. The cathode carbon block is required to have high temperature resistance in aluminum electrolysis production, resistant to molten salt erosion, good electrical and thermal conductivity, high mechanical strength, good thermal shock resistance and strong corrosion resistance of sodium, which is conducive to energy saving and tank life improvement in the production of aluminum electrolysis. According to the quality requirements of the products, the raw materials selected and the technological conditions used, the cathode carbon blocks in China are basically divided into three categories: ordinary cathode carbon blocks, semi-graphitic carbon blocks and graphitic carbon blocks. Anthracite calcined at 1250 ~ 1350℃ is used as…
11-28 2021
Graphite electrode prices have been running steadily this week. Although the price of low-sulfur coke has fallen more recently, the rising trend of coal pitch prices has remained unchanged. Needle coke is also strong, and the supply of imported needle coke is in short supply in the later period, so the raw materials are facing The graphite electrode support still exists. In addition, the production cycle of graphite electrodes is long, and the products currently on the production line are produced with high-priced raw materials in the early stage, and the pressure of high-cost early-stage is always present. Electric furnace steel is currently operating at a high level. In terms of export, European economic recovery and anti-dumping investigations are affecting corporate procurement inquiries. Under the Indian epidemic, Southeast Asia may increase the demand for Chinese electrodes, and the demand for graphite electrodes has performed well. According to surveys, some companies have slightly lowered the prices of individual specifications of electrodes,…
06-11 2021
As shown in the figure below, the price of China’s needle coke market continues to rise from January to May 2021 Needle coke price trend 20210607 As of May 31, China’s needle coke electrode coke market price index was 9077, which was 5.34% higher than the same period last month, 53.99% higher than the beginning of the year, and 19.53% higher than the same period last year; The negative coke market price index is 5250, which is stable from the same period last week, up by 4.76% from the same period last month, up by 22.09% from the beginning of the year, and down by 16.00% from the same period last year. It is reported that the main reasons are: Coal pitch: From January to May of 2021, coal tar pitch prices continue to rise. As of May 31, the coal tar pitch price index has reached 5,412 yuan/ton, an increase of 2,151 yuan/ton from the beginning of the year,…
06-11 2021
Needle coke is a high-quality variety vigorously developed in carbon materials, and its appearance is a porous solid with a silver-gray and metallic luster. Its structure has an obvious flowing texture, with large and few pores and a slightly elliptical shape. The particles have a large aspect ratio, and some have fibrous or needle-like textures. It has a lubricating texture when touched by hand. Classification of needle coke According to different raw materials, needle coke can be divided into oil-based needle coke and coal-based needle coke. The United States takes petroleum residue as raw material and produces needle coke as oil-based needle coke. Japan is the representative of coal tar pitch and its fractions as raw materials, and the needle coke produced is coal-based needle coke. The use of needle coke Graphite Electrode Needle coke is the raw material for the production of high-end carbon products such as ultra-high power electrodes, special carbon materials, carbon fibers, and composite materials. It…
06-11 2021
What is petroleum coke? Petroleum coke is a product of crude oil that is distilled to separate light and heavy oils, and the heavy oils are then thermally cracked. From the appearance, the coke is black lumps (or particles) with irregular shapes and different sizes. ), with a metallic luster, the coke particles have a porous structure, the main element is carbon, which occupies more than 80%, contains 1.5%-8% hydrogen, and the rest are oxygen, nitrogen, sulfur, and metal elements. Petroleum coke belongs to the category of easily graphitized carbon, which has unique physical, chemical, and mechanical properties. The non-volatile carbon, volatile matter, and mineral impurities (sulfur, metal compounds, water, ash, etc.) in the heating part determine the coke Chemical nature. Petroleum coke classified according to the heat treatment temperature Petroleum coke classified by heat treatment can be divided into petroleum coke before calcining (green coke) and petroleum coke after calcining (calcined coke). Specializes in sieving calcined petroleum coke of…
06-11 2021
The consumption of graphite electrodes in electric furnace steelmaking is mainly related to the quality of the electrode itself, as well as the condition of the steelmaking furnace (such as new and old furnaces, whether there is a mechanical failure, whether continuous production, etc.) and steelmaking operations (such as smelting steel types, blowing steel, etc.). Oxygen time, charge conditions, etc.) are very important. Here only discuss the consumption of the graphite electrode itself, its consumption mechanism has the following aspects: End consumption Including the sublimation of the graphite material caused by the high temperature of the arc and the loss of the chemical reaction between the electrode end and the molten steel and slag. The high-temperature sublimation rate of the end mainly depends on the current density through the electrode, and secondly is related to the diameter of the side of the electrode after oxidation, and the end consumption is also related to whether the electrode is inserted into the…
06-11 2021
