SiC is a Silicon Carbide material in powder form which was formed in the require shape. The addition is a Al2O3-SiO2 spinel, also in powder form (around 10-20% wt.) which is a high temperature binder for Silicon Carbide.

Dear Mehrdad Rashidzadeh thank you for posting this interesting technical question. In this context please have a look at the following potentially useful link which might help you in your analysis:

Production Of Silicon Carbide Sagger

https://mastere.com.pl/Oct/07-31215.html

For more general information about the silicon carbide (SiC) production process please also see the following article:

Silicon Carbide Production Process

https://www.fiven.com/world-of-silicon-carbide/sic-production-process/

More details can also be found in this patent:

Sagger and composition of sagger containing silicon carbide for manufacturing positive, negative electrode active material of secondary battery

https://patents.google.com/patent/KR101223032B1/en

Unfortunately only the Abstract is in English, but it already contains the most important details about the raw materials composition.

Good luck with your work!