Chemical reaction mechanism of electrode paste in steelmaking process
Electrode paste, as an indispensable and important material in modern electric furnace steelmaking, its chemical reaction mechanism during the steelmaking process is of great significance for understanding the entire steelmaking process, improving steelmaking efficiency and product quality. This article will delve into the chemical reaction mechanism of electrode paste, starting from its composition, properties, and specific applications in steelmaking.
Basic composition and properties of electrode paste
Electrode paste is mainly made by mixing, shaping, and roasting carbon raw materials such as petroleum coke, asphalt coke, and graphitized coke with coal tar pitch. The selection and ratio of these raw materials play a decisive role in the performance of electrode paste. Coal tar pitch, as a binder, not only tightly binds various raw materials, but also endows electrode paste with excellent heat resistance and chemical stability. In addition, electrode paste also has good conductivity, thermal stability, and self baking electrode properties, making it a key material for maintaining electrode height and ensuring stable current transmission in the electric furnace steelmaking process.
The role of electrode paste in steelmaking
In the process of electric furnace steelmaking, electrode paste serves as the main raw material for self baking electrodes, and through continuous consumption and self baking process, it supplements and maintains the height of the electrodes in the furnace. Electrode paste not only has good conductivity in high temperature environments, but also maintains a stable shape, ensuring effective current transmission and smooth steelmaking process. At the same time, the electrode paste undergoes a series of chemical reactions with the furnace atmosphere at high temperatures, which play an important role in adjusting the composition of the molten steel, controlling the temperature, and removing impurities.
Analysis of Chemical Reaction Mechanisms
1. Oxidation reaction of carbon
The carbon raw material in the electrode paste undergoes oxidation reaction with oxygen in the furnace at high temperature, producing carbon monoxide and carbon dioxide. This reaction not only provides necessary heat for the steelmaking process, but also regulates the furnace atmosphere by controlling the oxygen supply, thereby affecting the decarburization and alloying process of the molten steel.
2. Decomposition and carbonization of coal tar pitch
Coal tar pitch undergoes decomposition reactions at high temperatures, producing volatile matter and fixed carbon. Volatile matter is discharged with the furnace gas, while fixed carbon remains in the electrode paste, enhancing the structural strength and conductivity of the electrode paste. In addition, the decomposition of coal tar pitch also promotes the sintering process of electrode paste, making it denser and more stable.
3. Impurity removal and alloying
Impurities in electrode paste may react with other substances in the furnace at high temperatures, forming compounds that are easy to discharge, thereby purifying the molten steel. Meanwhile, certain elements in the electrode paste may also participate in the alloying process of molten steel, improving its properties. For example, elements such as silicon and manganese in electrode paste may enter the molten steel and form beneficial alloying elements.
4. Current and heat transfer
Electrode paste, as a conductive medium, transmits current and generates heat during the steelmaking process. The Joule heating generated when current passes through electrode paste is one of the main heat sources in the steelmaking process. Meanwhile, the heat exchange between the electrode paste and the molten steel also promotes the heating and melting process of the molten steel.
