Preparation of CaO-containing carbon pellets from coking coal and calcium oxide: Effects of temperature, pore distribution and carbon structure on compressive strength in pyrolysis furnace

CaO-containing carbon pellets (CCCP) were successfully prepared from well-mixed coking coal (CC) and calcium oxide (CaO) and roasted at different pyrolysis temperatures. The effects of temperature, pore distribution, and carbon structure on the compressive strength of CCCP was investigated in a pyrolysis furnace (350-750 degrees C). The results showed that as the roasting temperature increased, the compressive strength also increased and furthermore, structural defects and imperfections in the carbon crystallites were gradually eliminated to form more organized char structures, thus forming high-ordered CC. Notably, the CCCP preheated at 750 degrees C exhibited the highest compressive strength. A positive relationship between the compressive strength and pore-size homogeneity was established. A linear relationship between the compressive strength of the CCCP and the average stack height of CC was observed. Additionally, a four-stage caking mechanism was developed.

Automated summary

The compressive strength of CaO-containing carbon pellets (CCCP) increased with the rise of pyrolysis temperature, as structural defects in carbon crystallites were gradually eliminated and more organized structures were formed. CCCP preheated at 750 degrees Celsius exhibited the highest compressive strength, with a positive correlation between compressive strength and pore-size homogeneity.