Analysis of the volatilization stage during the sintering process of electrode paste
The volatilization stage is a crucial step in the sintering process of electrode paste, which directly affects the final quality and performance of the electrode. This stage occurs within the temperature range of 200 ℃ to 600 ℃, which is a transitional period for the electrode paste to gradually transition from a molten state to a solid state. This article will provide a detailed analysis of the volatilization stage during the sintering process of electrode paste.
Overview of volatilization stage
The volatilization stage follows closely after the softening stage, at which point the electrode paste has fully melted and filled the pores between the electrode cylinder and the paste block. As the temperature continues to rise, the binder in the electrode paste begins to decompose, accompanied by the release of a large amount of volatile substances. This process has a significant impact on the sintering quality, conductivity, and mechanical strength of the electrode.
The relationship between volatile emissions and temperature
During the volatilization stage, the binder such as asphalt in the electrode paste gradually decomposes, releasing a large amount of volatile substances. The emission rate of these volatile compounds reaches its peak at 300 ℃ to 500 ℃, especially at around 400 ℃. The discharge of volatile substances not only reduces the viscosity of the electrode paste, but also promotes further solidification and densification of the electrode paste.
The main pathways of volatile emissions
Volatile compounds are mainly discharged from the electrode through the following pathways:
Discharge from the weld seam of the electrode shell: During the production and assembly process of the electrode shell, there may be small gaps at the weld seam, which become one of the channels for the discharge of volatile substances.
Discharging from the gap between the electrode and the iron shell: With the sintering of the electrode and the shrinkage of its volume, a certain gap will be formed between the electrode and the iron shell, which becomes the main pathway for the discharge of volatile substances.
Discharging from the upper opening of the electrode shell: In the case of low cooling air flow of the electrode, components with lower gasification temperature may be discharged from the upper opening of the electrode shell. However, this situation is relatively rare, and the main discharge route is still the gap between the electrode and the iron shell.
The influence of volatilization stage on electrode performance
The volatilization stage has a significant impact on the final performance of the electrode. On the one hand, the discharge of volatile substances helps to solidify and densify the electrode paste, improving the mechanical strength and conductivity of the electrode. On the other hand, if the volatile matter is discharged too quickly or the electrode pressure release speed is improper, it may lead to accidents such as electrode burnout or soft breakage.
In order to ensure the smooth progress of the volatilization stage, operators need to closely monitor the sintering situation of the electrode, and reasonably control the pressing speed of the electrode and the temperature inside the furnace. At the same time, it is necessary to regularly check the sealing and weld quality of the electrode shell to prevent volatile substances from being discharged from unexpected sources.
