solid graphite block

Pubdate: 08-17 2021

How to better reduce the consumption of electric furnace solid graphite block and improve the quality of solid graphite block?

solid graphite blocksolid graphite block

The solid graphite block is mainly used as a conductive material in the field of electric furnaces. Compared with other conductive materials, solid graphite block material has the advantages of good conductivity, good toughness, resistance to high current impact, high temperature non-softening, non-melting, etc., and has been widely used in the field of high-temperature electric furnace steelmaking. The steel-making electric arc furnace uses it as a conductive material, and transfers heat energy to the charge to melt the scrap through arc discharge.

In recent years, the proportion of electric furnace steel in total steel output has increased year by year, and has now exceeded 40%. The output of electric furnace steel increased rapidly from 14.57 million tons in 2000 to 41.79 million tons in 2005, and the production of solid graphite blocks required 1.9 million tons per year. The cost of solid graphite block consumption generally accounts for 15%-30% of the total cost. However, the current consumption of solid graphite blocks in my country is very large. The consumption of solid graphite blocks in large steel mills is about 1 million T/A. With the continuous strengthening of the macro economy and the rapid development of the steel industry, the development trend of consumption of large electric arc furnaces and solid graphite blocks in China will become faster and faster.

Therefore, research to reduce the consumption of solid graphite block and improve the quality of solid graphite block is an urgent problem that electric arc furnace metallurgical experts and enterprises need to solve. Therefore, exploring the consumption mechanism of solid graphite block, effective measures to reduce the consumption of solid graphite block, and reducing production costs have become an important aspect of the cost and energy saving of electric arc furnace steelmaking. Especially in today’s rapid development of the steel industry, the rapid development of electric arc furnace steelmaking, the demand for solid graphite block is also increasing. However, due to the constraints of capital, energy, production technology and other conditions, the development of graphite carbon products is still difficult to meet the special needs of electric arc furnace steelmaking. There is still a considerable gap between solid graphite block consumption indicators and foreign countries, the quality is not high, and the contradiction between supply and demand is prominent. For example, most of the solid graphite blocks used in UHV electric arc furnaces in large domestic steel mills are imported from Japan and other countries. Therefore, reducing the consumption of solid graphite blocks has become one of the important issues considered by electric arc furnace steelmaking companies, that is, energy saving and consumption reduction. The implementation of the national development “Eleventh Five-Year Plan” put forward the prospect of energy saving and consumption reduction in my country’s iron and steel enterprises in the new period, and it is also an important way to reduce the production cost of electric furnace steel and improve the core competitiveness of enterprises. Research on consumption mechanism The solid graphite block is the last part of the short network. The short network generates a strong electric arc melting furnace through the ends of two connected graphitized solid graphite blocks. The material and heating molten steel, the solid graphite block, is the central hub for converting electrical energy into heat. When the solid graphite block works, it will be affected by high temperature, furnace gas oxidation and collapsed materials. In particular, the connection between the two solid graphite blocks is more corrosion-resistant than other places, has low conductivity, and is easy to trip, oxidize, fall off, and break, resulting in high consumption of the solid graphite block, prolonging the smelting time and reducing the output. In the steelmaking process, due to the high temperature environment, the surface of the solid graphite block reacts with oxygen, resulting in carbon and oxygen consumption. The solid graphite block is stable at low temperature and easily oxidized at high temperature.

In general, carbon products in the air begin to oxidize at about 450°C. Graphite products with a high degree of graphitization begin to oxidize at about 600°C. After 750°C, the oxidation increases sharply, and increases with the increase in temperature. Oxidize when heated to 900℃ in steam. In other words, the main influencing factor is the high temperature oxidation atmosphere of the solid graphite block, which is the oxidation consumption of the solid graphite block. Especially with the successive application of new technologies such as furnace door oxygen lance, oil-oxygen booster, EBT cluster oxygen lance, furnace wall oxygen lance, the intensity of oxygen supply in the furnace increases, the oxidizing atmosphere increases, and the consumption of solid graphite block further increases.

Since the end of the solid graphite block is in direct contact with the arc, the end of the solid graphite block is sublimated and consumed; because the solid graphite block is partly in contact with the molten pool, the carbon element is absorbed by the molten pool as erosion consumption; due to electromagnetic force, mechanical force and solid impact The role of force is the raw material, solid graphite block breaks and collapses during operation. The consumption of electric arc furnace solid graphite block can be divided into chemical consumption and physical consumption: physical loss The physical loss of solid graphite block mainly refers to the front and side loss of solid graphite block, which is mainly caused by external mechanical force and electromagnetic force. For example, the solid graphite block joint is loose and broken, solid graphite block cracks, and the joint thread part falls off. The reason is that the solid graphite block itself is of poor quality, such as low strength; in terms of equipment, the diameter of the solid graphite block is improperly selected, the solid graphite block holder, and the lifting The control device is not good, etc.; the scrap during the melting process such as improper loading, large area collapse, impact on the solid graphite block, loose connection of the two solid graphite blocks, etc.

Chemical loss mainly refers to the consumption of the solid graphite block surface, including the consumption of the end of the solid graphite block and the consumption of the circumference. The local heating at the end of the solid graphite block sublimes the graphite, and the end of the solid graphite block contacts the molten steel. The consumption of absorbed graphite at the tip of the solid graphite block is mainly caused by the sublimation of graphite at high temperature and the melting of graphite in steel slag. Under normal working conditions, the needle tip consumption can reach 50% of the total consumption of solid graphite block. Secondary consumption is the main cause of oxidation of solid graphite block, accounting for 40% of the total consumption.

The oxidation reaction rate is closely related to the temperature. 1) In the range of 550°C to 750°C, the oxidation rate is controlled by the solid graphite block itself. The graphite quality and temperature have a greater impact on the consumption of the solid graphite block than air. 2) When the temperature is higher than 800°C, the air flow rate starts to control the reaction. The influence of air flow and air pressure on the consumption of the solid graphite block is greater than the influence of temperature and the quality of the solid graphite block. The larger the contact area of the solid graphite block with air, the greater the intensity of the oxidation reaction and the greater the consumption. The solid graphite block’s circumference is in contact with steel slag and furnace gas, causing oxidation loss. If you are interested, please go to the official website for consultation.


Get the Quote

Send Mail Get Quote