RAY GROUP LIMITED CO., LTD. wishes you a happy International Women’s Day!
International working women’s day, fully known as “UN women’s rights and international peace day”, also known as “March 8” women’s day in China, is a festival established by the United Nations on March 8, 1975 to celebrate the important contributions and great achievements made by women in the economic, political and social fields. On this day, women from all continents of the world, regardless of nationality, race, language, culture, economy and political differences, pay common attention to women’s human rights. After the founding of the central government of the people’s Republic of China, March 8 was officially designated as women’s day and various forms of celebrations were held.
.If you have any needs about Graphite Electrodes ,please contact us!Last,RAY GROUP LIMITED CO., LTD. wishes you a happy International Women’s Day!
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High power graphite electrode rod
Graphite electrode, which is made of petroleum coke and needle coke as raw materials and coal tar pitch as binder, is made by calcination, batching, kneading, pressing, roasting, graphitization and machining. It is a conductor that releases electric energy in the form of electric arc to heat and melt the furnace burden. According to its quality index, it can be divided into ordinary power, high power and ultra-high power.
The graphite electrode comprises:
(1) Common power graphite electrode. Graphite electrode with current density less than 17a / cm2 is allowed to be used, which is mainly used for steel making, silicon smelting, yellow phosphorus smelting, etc.
(2) Oxidation resistant coated graphite electrode. The graphite electrode coated with a layer of anti-oxidation protective layer forms a protective layer which can conduct electricity and resist high temperature oxidation, and reduces the electrode consumption in steelmaking.
(3) High power graphite electrode. Graphite electrode with current density of 18-25a / cm2 is allowed, which is mainly used in high-power EAF for steelmaking.
(4) Ultra high power graphite electrode. Graphite electrodes with current density greater than 25A / cm2 are allowed. It is mainly used in ultra-high power EAF.
1. Wet graphite electrodes should be dried before use.
2. Remove the foam protective cap on the spare graphite electrode hole and check whether the thread in the electrode hole is complete.
3. Clean the surface of spare graphite electrode and thread in hole with compressed air without oil and water; avoid cleaning with steel wire or metal brush abrasive cloth.
4. Carefully screw the joint into the electrode hole at one end of the spare graphite electrode (it is not recommended to install the joint directly into the electrode removed from the furnace) without impacting the thread.
5. Screw the electrode sling (graphite sling is recommended) into the electrode hole at the other end of the spare electrode.
6. When lifting the electrode, put a soft object under one end of the spare electrode fitting joint, so as to prevent the ground from bumping and damaging the joint; use the hook to extend into the lifting ring of the sling to lift the electrode stably, so as to prevent the electrode from loosening from the B end or colliding with other fixed devices.
7. Lift the spare electrode above the electrode to be connected, and then drop it slowly after aligning with the electrode hole; rotate the spare electrode to make the screw hook and the electrode rotate and descend together; when the end faces of the two electrodes are 10-20 mm apart, clean the exposed parts of the two electrode ends and the joint with compressed air again; when the electrode is completely lowered, it is not allowed to be too violent, otherwise the electrode hole and electrode hole will be damaged due to violent collision The thread of the joint is damaged.
8. Screw the spare electrode with a torque wrench until the end faces of the two electrodes are in close contact (the correct connection gap between the electrode and the joint is less than 0.05mm).
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Reasons for Using Graphite in Nonferrous Metal Smelting
The use of graphite mold is mainly its high temperature resistance, such as pure copper casting temperature of about 1200 degrees, graphite at this temperature is still stable, thermal barrier and cold shrinkage are very small, can be neglected. On the other hand, lubrication is relatively good, the solidification process of metal liquid is not easy to adhere to the mold. Although the heat conductivity is poor, but in the casting cooling effect is not necessarily a good thing, so this may be the advantage. Graphite mold is generally used in horizontal continuous casting, because the use of this type of casting gravity has a greater impact on solidification, lubrication is not good can not be horizontal casting.
The main disadvantage is that the general can only use 1–2 weeks, because the number of metal liquid will be in the mold residue, accumulated to a certain extent will affect the crystallization, damage to the surface quality of ingots, the removal of the graphite anode plate needs to be repaired, the actual production of some high-quality ingots even only with new plates, higher costs Most of the manufacturers rely on imports, generally in Japan and the United States, more expensive.
At present, the production of iron mold casting, but in order to improve lubrication, the general also to add lubricants such as carbon black, oil, etc., generally used only in vertical semi-continuous casting.
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Technical Requirements for Graphite Electrode Products
(1) Ordinary power graphite electrode: Allow the use of current density of less than 17a/cm 2 graphite electrode, mainly used in steelmaking, smelting silicon, refining of yellow phosphorus, such as ordinary power electric furnace.
(2) Anti-oxidation coating graphite electrode: The surface coating a layer of antioxidant protective layer of graphite electrode, forming both conductive and high-temperature oxidation protective layer, reduce the electrode consumption when steelmaking.
(3) High power graphite electrodes: Graphite electrodes, which allow the use of current density of 18~25a/cm 2, are mainly used in high power arc furnaces for steelmaking.
(4) Ultra-high power graphite electrode: Allow the use of the current density of more than 25a/cm 2 graphite electrode. Mainly used in ultra-high power steelmaking arc furnace.
The other offers a variety of small size graphite electrodes, 10-100mm between diameters, and can produce φ3-15mm, length 2-200mm graphite electrodes with small specifications.
Technical requirements for graphite electrode products:
Diameter 100-650mm resistivity: 7.0μωm connector: 4PTI flexural strength: 8–20mpa, Elastic modulus: 0 GPa, Ash 0.1–0.3%, bulk density: 1.50—1 70g/cm3, thermal expansion coefficient: 1.3-3.2 10-6 1/℃.
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Application Method of Graphite Electrode
Application Method of Graphite electrode
1. By the wet graphite electrode, before use to dry.
2. Remove the foam protective cap on the hole of the standby graphite electrode and check whether the thread is intact in the electrode hole.
3. With oil-free and water compressed air to clean up the spare graphite electrode surface and hole internal thread;
4. The connector carefully into the spare graphite electrode at one end (it is not recommended that the connector directly into the furnace to remove the electrode) in the electrode hole, no collision thread.
5. The electrode sling (the sling with graphite material is recommended) is screwed into the electrode hole of the other end of the standby graphite electrode.
6. Lifting the electrode, cushion the soft thing to the standby electrode to install the end of the connector, to prevent the ground contact damage joints, hanging hook into the sling after lifting the ring, the lifting electrode to stabilize, to prevent the electrode from the B-end loose or collision with other fixtures.
7. The standby electrode is hoisted above the electrodes to be connected, and the electrode hole is lowered slowly; rotate the standby electrode to rotate the screw hook with the electrode to decrease; when the two electrical extremes are separated from each other, the 10-20mm of the electrode two ends and the exposed part of the joint are cleaned again with compressed air. When the electrode is finally completely lowered, it can not be too strong, otherwise, because of a violent collision, the electrode hole and the thread of the joint are damaged.
8. Torque wrench to screw the standby electrode until the end of the two electrodes close contact (the correct connection between the electrode and the joint is less than 0.05mm).
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Analysis of current market situation of graphite electrode
At present, the market price of graphite electrode in China is at a relatively low level, and it is unlikely that the market will continue to decline substantially. From the beginning of June to now, the mainstream transaction prices of ultra high, medium and small specifications and super large graphite electrodes are mainly stable, and the overall market change is not big. Some low price orders are mainly affected by the furnace conditions of the bidding steel plant, and their requirements for graphite electrode performance parameters are relatively broad, so there are differences in prices, which belong to individual phenomenon.
Current situation of graphite electrode Market in China
Large capacity and high stock. The main reason for the high stock inventory, especially the ultra-high 600mm, is that affected by the market factors in 2019, the Middle East countries need to strongly lead to overproduction. In addition, affected by the epidemic situation in 2020, the demand of domestic EAF steel market and export market will weaken one after another, leading to a rapid fall in prices.
The price is lower than the cost line. If the coal tar pitch is 2270 yuan / ton and the processing cost is 12000 yuan / ton, the cost of oil-based needle coke is about 18000 yuan / ton, and that of coal-based needle coke is about 17600 yuan / ton when the coal-based needle coke is 5000 yuan / ton. However, the current domestic price of some ultra-high 600 mm graphite electrodes has been lower than the cost line.
Graphite electrode enterprises control the production rhythm, some enterprises stop production and clear inventory. At present, most of the graphite electrode enterprises control the output to the minimum to avoid ineffective production and increase inventory pressure. Some small and medium-sized graphite electrode enterprises have not started operation since, and have mainly cleaned up the inventory; others have chosen to suspend pressing and other processes to effectively clean up the online inventory.
According to the sales, lock the price. Under the influence of weak market operation, graphite electrode enterprises usually adopt the strategy of production according to sales, and make production plan according to orders on the premise of ensuring a reasonable circulation of inventory. At the same time, due to the confusion of market price, some enterprises choose to sell at lock price. If the price is lower than the enterprise cost price, they will not ship any more.
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RAY GROUP LIMITED CO., LTD. wishes you a happy Lantern Festival
Lantern Festival is a traditional festival in China. The formation of the custom of Lantern Festival has a long process, which is rooted in the ancient custom of turning on lights and praying for blessings. Turning on the lights and praying for blessings usually begins on the 14th night of the first month. On the 15th night, it is called “positive lights”. People want to light lights, also known as “sending lights” to worship gods and pray for blessings. The introduction of Buddhist culture in the Eastern Han Dynasty also played an important role in promoting the formation of the custom of the Lantern Festival.
During the reign of emperor Yongping of the Han and Ming Dynasties, in order to carry forward the Dharma, Emperor Han and Ming ordered to “light a lamp to show the Buddha” in the palace and temple on the 15th night of the first month. Therefore, the custom of lighting lanterns on the 15th night of the first month gradually expanded in China with the expansion of the influence of Buddhist culture and the later addition of Taoist culture. During the northern and Southern Dynasties, lantern lighting became a common practice. Emperor Wu of the Liang Dynasty believed in Buddhism, and lights were lit at the 15th National Day of the first month in his palace. During the Tang Dynasty, cultural exchanges between China and foreign countries were closer, Buddhism flourished, and officials and people generally “lit lamps for Buddha” on the 15th day of the first month, so Buddhist lights were all over the people. Since the Tang Dynasty, lantern lighting has become a legal matter.
The 15th day of the first lunar month is the Lantern Festival, also known as Shangyuan Festival, Yuanye and Lantern Festival. The first month is the first month of the lunar calendar. The ancients called night “Xiao”, so they called the fifteenth day of the first month “Lantern Festival”. [9] With the changes of society and times, the customs of the Lantern Festival have changed greatly, but it is still a traditional Chinese folk festival. When the Lantern Festival was formed in the early stage, it was only called the fifteenth day of the first month, the first half of the first month or the hope of the month. After the Sui Dynasty, it was called the new year’s Eve or the new year’s Eve. Influenced by Taoism at the beginning of the Tang Dynasty, it was also called Shangyuan, and it was occasionally called yuanxiao at the end of the Tang Dynasty. But since the Song Dynasty, it has also been called Lantern Festival. In the Qing Dynasty, it was also called Lantern Festival. In foreign countries, the Lantern Festival is also known as the Lantern Festival. On the evening of the 15th day of the first lunar month, Chinese people have a series of traditional folk activities, such as appreciating lanterns, eating dumplings, eating Lantern Festival, guessing lantern riddles, setting off fireworks and so on.
At Ray Group, our engineers have been in these industries since 1990. It is combining research, development, production and sales. Backed with expertise garnered from their days at major chemical research institutes, they can offer you the technical understanding you need to get your projects done right.If you have any needs about Graphite Electrodes ,please contact us!
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Performance of graphite electrode
Graphite has good chemical stability. After special processing, graphite has the characteristics of corrosion resistance, good thermal conductivity and low permeability, so it is widely used to make heat exchanger, reaction tank, condenser, combustion tower, absorption tower, cooler, heater, filter and pump equipment. Widely used in petrochemical, hydrometallurgy, acid and alkali production, synthetic fiber, paper and other industrial sectors, can save a lot of metal materials.
Graphite and its products have the properties of high temperature resistance and high strength. They are mainly used to make graphite crucible in metallurgical industry. In steelmaking, graphite is often used as the protector of ingot and the lining of metallurgical furnace. 2. As conductive material: used in the electrical industry as the positive pole of electrode, brush, carbon rod, carbon tube, mercury positive current device, graphite washer, telephone parts, TV picture tube coating, etc.
The high-power graphite electrode is allowed to use the graphite electrode with the current density of 18-25a / cm2, which is mainly used in the high-power arc furnace of steel making. Graphite electrode for EDM, also known as copper worker. Graphite electrode is easy to process, and the processing speed is faster than copper electrode. For example, when using milling technology to process graphite, its processing speed is 2-3 times faster than that of other metals, and no additional manual treatment is needed, while copper electrode needs manual grinding. Similarly, if high-speed graphite machining center is used to make electrodes, the speed will be faster, the efficiency will be higher, and there will be no dust problem. In these processes, choosing proper hardness tools and graphite can reduce the wear loss of tools and the damage of copper. If the milling time of graphite electrode is compared with that of copper electrode, graphite is 67% faster than that of copper electrode. In general, the machining speed of graphite electrode is 58% faster than that of copper electrode. In this way, the processing time is greatly reduced, and the manufacturing cost is also reduced.
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RAY GROUP LIMITED CO., LTD. wishes you a happy Spring Festival!
The Spring Festival is the beginning of the year and the traditional festival. It is commonly known as new year, new year, new year’s day and so on. The Spring Festival has a long history, which evolved from the worship of praying for new year in ancient times. All things are based on heaven and people are based on ancestors. Praying for the new year, offering sacrifices to heaven and worshiping the ancestors are the same. The origin of the Spring Festival contains profound cultural connotation, which carries rich historical and cultural heritage in the process of inheritance and development. During the Spring Festival, all kinds of celebrations are held all over the country, with strong regional characteristics. These activities are mainly about the old and new cloth, the exorcism, the worship of gods, the blessing of the year, and the rich and colorful forms, which are the essence of Chinese traditional culture.
In the early age of observing and timing, the beginning of spring is the beginning of all things and the meaning of all rebirth, which means that a new reincarnation begins. In the traditional farming society, the beginning of spring is of great significance, which has derived a large number of popular culture related to it. In the historical development, although the calendar is used differently and the date of the first festival is different, its festival framework and many folk customs are inherited. In modern times, people set the Spring Festival on the first day of the first month of the lunar calendar, but it usually ends at least on the fifteenth day of the first month. The Spring Festival is a folk festival integrating worship of gods and ancestors, praying for blessings and ward off evil spirits, family reunion, celebration, entertainment and diet.
The Spring Festival is the most grand traditional festival of the Chinese nation. Influenced by Chinese culture, some countries and regions in the world also have the custom of celebrating the new year. According to incomplete statistics, nearly 20 countries and regions have designated Chinese Spring Festival as a legal holiday for the whole or some cities under their jurisdiction. Spring Festival, Qingming Festival, Dragon Boat Festival and Mid Autumn Festival are known as China’s four traditional festivals. With the approval of the State Council, the Spring Festival folk custom has been listed in the first batch of national intangible cultural heritage list.
.If you have any needs about Graphite Electrodes ,please contact us!Last,RAY GROUP LIMITED CO., LTD. wishes you a happy New Year’s Day!
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Graphite Electrode Quality Index
The main indicators of the quality and performance of graphite electrodes include: bulk density db, resistivity ρ, flexural strength, elastic modulus E, thermal expansion coefficient α and ash content A%. According to the differences between these indicators and different national standards and manufacturing processes, graphite electrodes are divided into three types: ordinary power graphite electrodes (RP), high power graphite electrodes (HP), and ultra-high power graphite electrodes (UHP). On the basis of national standards, each company has its own corporate standards, and customers will make their own quality standards when ordering. The relative volume density is the ratio of the quality management of the graphite electrode material sample to its volume. The unit is g/cm3. The larger the volume density is, the denser the working electrode is, which is positively related to the strength and the performance of the anti-oxidation system. Generally speaking, the greater the effect of the same variety of electrode volume density, the lower the resistivity.
Resistivity is a parameter that measures the conductivity of an electrode. It refers to the resistance of the conductor to the current when the current passes through the conductor. In value, it is equal to the resistance of the conductor with a length of 1m and a cross-sectional area of 1m2 at a certain temperature, which reduces consumption in use.
Flexural strength is a parameter that characterizes the performance of the mechanical system of graphite structural materials. It is also called flexural strength. It means that when the external force is perpendicular to the axis of the object, the object bends to the momentary limit after being subjected to external force, which can resist the risk. The unit is MPa. High-strength electrodes and joints are less likely to be broken in the use of the network.
Elastic modulus is an important aspect of mechanical properties, an index to measure the elastic deformation capacity of materials, and refers to the stress-strain ratio within the elastic deformation range. The larger the elastic modulus, and the greater the required stress to deform elastically, it is simply, the greater the elastic modulus of brittle materials, the smaller the elastic modulus of flexible materials.
The thermal expansion coefficient of graphite as an electrode is a very important thermal performance parameter. The lower the value, the stronger the thermal stability of Chinese products and the higher the oxidation resistance, which can reflect the less fracture and lower consumption.
Ash refers to other elements in solid products other than carbon graphite. Graphite is used as ash in the electrode and is mainly affected by the ash content of the raw materials used. The ash content of petroleum coke needle coke is low, so the ash content of graphite passing through the electrode generally does not exceed 0.5%, and the ash content within 1% has no effect on steelmaking. Obviously, the impurity elements in the ash will reduce the anti-oxidation system performance of the working electrode and so on.
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