ZHENGSHAN TECHNOLOGY

In the operation of a mineral thermal electric furnace, electrode paste is a crucial conductive material, and its performance directly affects the stable operation and product quality of the furnace. Today, I will share with you the detection methods for various indicators of electrode paste to help you better understand this important industrial material.
1、 Basic Overview of Electrode Paste
Electrode paste, also known as self baking electrode, is a conductive material made by mixing, shaping, and baking carbon raw materials such as petroleum coke, asphalt coke, and graphitized coke with coal tar pitch. It is widely used in fields such as electric furnace steelmaking, electrolytic aluminum, and ferroalloy smelting, and is an essential material for modern electric furnace steelmaking. The quality of electrode paste depends not only on the selection and ratio of raw materials, but also closely related to its preparation process.
2、 Main technical indicators and detection methods of electrode paste
1. Ash content
Ash content refers to the percentage of residual material of electrode paste burned to constant weight at 850 ℃± 20 ℃ in the original sample. The determination method of ash content usually includes the following steps:
Sampling: Take a uniform sample from the production batch, crush it to the appropriate particle size, and sieve it.
Drying: Dry the sample continuously for 1 hour at a temperature not exceeding 50 ℃ until the mass change does not exceed 0.1%.
Burning: Place the dried sample in a high-temperature furnace and burn it at 850 ℃± 10 ℃ for 3 hours until it reaches a constant weight.
Weighing: After burning, remove the sample from the high-temperature furnace, cool it to room temperature, and weigh it to calculate the ash content.
2. Volatile matter
Volatile matter is calculated by heating a certain amount of sample at a specified temperature and time in the absence of air, based on the difference between the total mass loss and the loss of evaporated water. The methods for determining volatile matter mainly include:
Sampling: Similar to ash content determination, uniform sampling is required from the production batch.
Heating: Place the sample in a muffle furnace and heat it at 900 ℃± 20 ℃ for a certain period of time to ensure complete evaporation of volatile matter.
Weighing: After heating, remove the sample from the muffle furnace, cool it to room temperature, and weigh it to calculate the volatile content.
3. Bulk density
The bulk density is determined by weighing and measuring the volume after heating the electrode paste and placing it into a mold, pressing it into shape. This indicator reflects the density of the electrode paste and has a significant impact on the conductivity and mechanical strength of the electrode.
Molding: Heat the electrode paste to an appropriate temperature and place it into a mold for pressure molding.
Measurement: After forming, weigh and measure the volume of the sample to calculate its bulk density.
4. Plasticity
Plasticity refers to the ability of electrode paste to not segregate in liquid state and to have good compressibility. This indicator is crucial for the stable use of electrode paste in electric furnaces.
Heating: Slowly heat the cylindrical electrode paste to a certain temperature.
Measurement: At the end of heating, measure the diameter change of the sample and express its plasticity as a percentage change in diameter.
5. Flow coefficient
The flow coefficient reflects the fluidity of electrode paste at a specific temperature. The testing method involves placing a certain amount of electrode paste in a container and measuring the average diameter of the paste cake formed by its flow under constant temperature conditions.
Preparation: Place the electrode paste into a container and set a constant temperature condition (such as 250 ℃± 10 ℃).
Measurement: After a certain period of constant temperature, measure the average diameter of the paste cake formed by the electrode paste flowing onto the iron plate below the container, and calculate the flow coefficient.
6. Compressive strength, flexural strength, and tensile strength
These indicators reflect the mechanical strength of the electrode paste and have a significant impact on the stability and durability of the electrode in the electric furnace. These strength measurements usually require specialized testing machines to measure the compressive, flexural, and tensile strength of electrode paste by applying different forces.
3、 Summary
As the "heart" of a mineral thermal electric furnace, the detection of various indicators of electrode paste is crucial for ensuring the stable operation and product quality of the furnace. Through strict sampling, drying, burning, weighing, forming, heating, and measuring steps, we can accurately determine key indicators such as ash content, volatile matter, bulk density, plasticity, flow coefficient, and mechanical strength of electrode paste. The implementation of these detection methods not only helps us understand the performance of electrode paste, but also provides strong technical support for the production and use of electrode paste.