Composition and performance analysis of electrode paste
Electrode paste, also known as self-baking electrode, anode paste or electrode carbon paste, is a material that is self-baked into a conductor in a mineral heat furnace.It is mainly composed of a mixture of petroleum coke (or bituminous coke, electric calcined anthracite), coal asphalt and other raw materials, and an electrode with good electrical conductivity is formed by high temperature sintering.This material is widely used in ferroalloy electric furnaces and calcium carbide furnaces because of its simple process and low cost.
Composition
The main components of electrode paste include：
Petroleum coke (or bituminous coke, electro-calcined anthracite): These are aggregates of electrode paste, which provide the basic structure and electrical conductivity of the electrode.Petroleum coke and bituminous coke have high carbon content and good electrical conductivity, while electro-calcined anthracite coal has lower ash content and higher purity.
Coal asphalt: As a binder, coal asphalt binds aggregate particles together to form a uniform electrode structure.The softening point and adhesion of coal asphalt have an important influence on the forming and sintering properties of electrode paste.
In addition, the electrode paste may also contain other additives, such as coal tar asphalt and other binders, to improve its processing performance and final performance.
Performance analysis
The performance of the electrode paste directly affects the conductivity, oxidation resistance and durability of the electrode.The following is the analysis of the main properties of the electrode paste：
Electrical conductivity: The main purpose of electrode paste is as a conductive material, so its electrical conductivity is essential.The electrical conductivity of the electrode paste mainly depends on its fixed carbon content and resistivity.The higher the fixed carbon content, the better the conductivity of the electrode paste.At the same time, the lower resistivity also means that the electrode paste has good electrical conductivity.
High temperature resistance: The electrode paste needs to work at high temperature for a long time, so it must have good high temperature resistance.The high temperature resistance of the electrode paste mainly depends on its fixed carbon content and ash content.The higher the fixed carbon content, the better the high temperature resistance of the electrode paste; and the lower the ash content, the higher the purity and conductivity of the material, which also helps to improve the high temperature resistance.
Mechanical strength: The electrode paste needs to withstand a certain mechanical pressure during the forming and sintering process, so it must have a certain mechanical strength.The mechanical strength of the electrode paste can be evaluated by indicators such as compressive strength and flexural strength.The higher these strength indicators, the better the durability of the electrode paste.
Coefficient of thermal expansion: The electrode paste will change in size when the temperature changes. The lower coefficient of thermal expansion helps to avoid cracking or deformation of the electrode during use.
Adhesion and plasticity: The adhesion and plasticity of the electrode paste have an important impact on its molding and sintering properties.Good adhesion can ensure that the electrode paste remains stable during the molding process, while plasticity helps to form a uniform and dense electrode structure during the molding process.
Inspection and quality control
In order to ensure the quality and performance of the electrode paste, it needs to be thoroughly tested.These tests include the determination of fixed carbon content, ash content, volatile content, sulfur content, particle size, softening point, adhesion, moisture content, compressive strength, flexural strength, coefficient of thermal expansion, thermal conductivity, resistivity and conductivity and other indicators.Through these testing items, the quality and performance of the electrode paste can be comprehensively evaluated to ensure its effectiveness and stability in different application scenarios.
At the same time, the selection and upgrading of raw materials is also an important way to improve the quality of electrode paste.For example, the use of high-quality raw materials such as electro-calcined anthracite coal, calcined petroleum coke and modified coal asphalt can significantly improve the performance of electrode paste.
As an important conductive material, electrode paste plays an important role in ferroalloy electric furnaces and calcium carbide furnaces.Through reasonable selection of raw materials and comprehensive quality inspection, the electrode paste can be ensured to have excellent chemical, physical, mechanical, thermal and electrical properties, thereby significantly improving the service life and conductive efficiency of the electrode.This kind of comprehensive testing not only provides a strong guarantee for the quality control of electrode paste, but also provides important technical support for process optimization and product development.
