How to monitor the working status of the electrode paste in the electric furnace?
As the core raw material of the mine thermal power furnace, the quality and performance of electrode paste directly affect the operating efficiency and safety of the electric furnace.The working state of the electrode paste is not only related to production efficiency, but also to production safety.Therefore, regular monitoring of the working status of the electrode paste in the electric furnace is a key step to ensure the smooth progress of production.
1. The composition and performance of electrode paste
The electrode paste is mainly composed of fixed carbon, ash, volatile content, sulfur content, particle size, softening point, adhesion, moisture content and other components.These components directly affect the conductivity, high temperature resistance, mechanical strength and other key performance indicators of the electrode.
Fixed carbon: The main component in the electrode paste. The higher the content, the better the conductivity and high temperature resistance of the electrode.
Ash content: The lower the content of non-carbon residues in the electrode paste, the higher the purity and conductivity of the material.
Volatile components: Components that will evaporate at high temperatures. Moderate volatile components contribute to the bonding and forming of electrodes, but excessive volatile components may cause pores and electrode cracks.
Sulfur content: A harmful impurity that may cause the electrode to become brittle at high temperatures and needs to be strictly controlled.
Particle size: It affects the uniformity of the electrode paste in the electrode forming process and the density of the final electrode.
Softening point: Determines the forming and sintering properties of the electrode paste.
Adhesion: Evaluating the cohesion of the electrode paste and the adhesion to the electrode skeleton are the key properties in the electrode forming and sintering process.
Moisture content: It affects the storage stability and molding quality of the electrode paste.
2. Monitoring method
To monitor the working status of the electrode paste in the electric furnace, it is necessary to synthesize a variety of testing methods and indicators to ensure a comprehensive evaluation of the performance of the electrode paste.
sampling
The samples should be representative and reflect the overall quality of the production batch.
Samples should be stored in a dry and ventilated environment to avoid moisture and pollution.
The quantity of samples should be determined according to the requirements of the test item, generally not less than 500g.
Volatile content detection
Volatile components are substances that volatilize during the heating process of the electrode paste, and their content is too high, which will affect the conductivity and stability of the electrode paste.
A volatile content tester is used for testing, the sample is heated at a certain temperature for a certain period of time, and then the content of volatile components is measured.
Fixed carbon detection
Fixed carbon is the non-volatile carbon content in the electrode paste. The higher the content, the better the conductivity and heat resistance of the electrode paste.
A fixed carbon analyzer is used for testing, the sample is burned at high temperature, and then the content of fixed carbon is measured.
Ash detection
Ash is a non-burning substance in the electrode paste, and its content is too high, which will affect the conductivity and stability of the electrode paste.
An ash analyzer is used for testing, the sample is burned to a constant weight at a high temperature, and then the ash content is measured.
Resistivity detection
The resistivity is the electrical conductivity index of the electrode paste. The lower the value, the better the electrical conductivity of the electrode paste.
A resistivity tester is used for testing, the sample is made into an electrode of a certain shape, and then its resistivity is measured.
Mechanical strength test
The mechanical strength evaluates the compressive and flexural resistance of the electrode paste after forming and in use.
The compressive strength testing machine and the three-point bending testing machine were used to determine the compressive strength and flexural strength of the electrode paste respectively.
Coefficient of thermal expansion detection
The coefficient of thermal expansion is a measure of the ability of the electrode paste to change in volume under temperature changes.
A thermal expansion meter is used to measure the expansion rate of the electrode paste sample during the heating process and calculate its thermal expansion coefficient.
Chemical composition detection
It includes the determination of the content of carbon, sulfur, nitrogen and other elements in the electrode paste.
An elemental analyzer or X-ray fluorescence spectrometer (XRF) is used to detect the main chemical components in the sample to ensure that it meets specific process requirements.
3. Application of monitoring results
By monitoring the working status of the electrode paste in the electric furnace, the quality problems of the electrode paste can be discovered in time, and corresponding measures can be taken to deal with them to ensure the normal progress of production.For example：
If the volatile content of the electrode paste is found to be too high, the production process can be adjusted to reduce the volatile content and improve the conductivity and stability of the electrode.
If the fixed carbon content of the electrode paste is found to be insufficient, a better quality electrode paste can be replaced to ensure the conductivity and high temperature resistance of the electrode.
If the ash content of the electrode paste is found to be too high, the screening and purification of raw materials can be strengthened, the content of inorganic impurities can be reduced, and the chemical stability and electrical conductivity of the electrode can be improved.
4. Conclusion
Monitoring the working status of the electrode paste in the electric furnace is an important measure to ensure the production efficiency and safety of the electric furnace.Through the synthesis of various testing methods and indicators, the performance of the electrode paste can be comprehensively evaluated, quality problems can be found and dealt with in time, and the normal production can be guaranteed.At the same time, strengthening the quality control of electrode paste and improving the quality and performance of electrode paste are also the key to improving the production efficiency and safety of electric furnaces.
