A study of the particle size effect on the pozzolanic activity of an equilibrium catalyst

Abstract

A study by thermogravimetry was done to evaluate the influence of the particle size on the pozzolanic activity of a residual equilibrium catalyst from a fluid catalytic cracking unit of a Brazilian refinery. For this purpose, cement type II pastes with the same substitution degree containing coarse, medium, and fine fractions of the residual catalyzer were evaluated after 28 days of setting. Using thermogravimetric and derivative thermogravimetric analysis, the contents of total combined water and calcium hydroxide were determined. Comparing the results on initial cement mass basis of each sample with those of a control paste without any residual catalyst addition, it can be seen that the coarse and medium fractions present similar pozzolanic activity and the fine one presents a higher activity than the others due to its specific area and composition.