Volatilization of asphalt in electrode paste
Why is there such a big gap in the volatile matter detected when the same amount of asphalt is added to the electrode paste in the production process?
First, because the electrode paste is made of different aggregate particles bonded by asphalt, the particle size leads to heterogeneity, so the sampling is difficult to be representative
Second, the thickness of powder, the error of ingredients, the length of kneading time, and the volatile of raw materials in the production process will cause volatile fluctuations
The third is the error introduced in the process of sample preparation, reduction and analysis. The combination of these kinds of errors will cause the error of volatile greater than 1%, so volatile is a range rather than a fixed value. Some manufacturers claim that volatile can be controlled at 0.5%, which is unscientific.
Too much asphalt and too much volatile will cause slow roasting of the electrode, which is easy to lead to the soft break of the electrode.
If the asphalt content is too small and the volatile content is too low, the electrode will be roasted quickly, which will easily lead to the hard break of the electrode.
The control principle of asphalt content in the production process of electrode paste generally depends on the fluidity of the paste. A slightly larger amount of asphalt within the allowable range of electrode sintering will make the paste have good fluidity, dense sintering and high strength. (see ferroalloy, issue 2, 2013. The influence of the fluidity of electrode paste on electrode roasting)