Ceramics-Silikáty 55 (2) 161-168 (2011)

Effects of RFCC Spent Catalyst on Some Physicomechanical Properties of Portland Cement Paste

A. Allahverdi, S. Vakilinia, P. Gharabeglu

Spent catalyst from Residue Fluidized Catalytic Cracking (RFCC) unit of petroleum refining processes is an important waste material that should be treated in a suitable way. The main goal of this research is to evaluate the pozzolanic activity of RFCC spent catalyst and to investigate its effects on some physic-mechanical properties of Portland cement paste. Results show that workability and setting times of fresh pastes decrease by increasing the percentage of cement substitution. A substitution of cement by spent catalyst between 15% and 20% by weight could increase the 360-day compressive strength of the paste up to 108 MPa that shows 45% increase compared to the plain cement, i.e. 75 MPa. The interesting result is that it is possible to have high substitutions up to 40% without any reduction in 28-day compressive strength compared to plain cement. The RFCC spent catalyst is therefore a high quality supplementary cementing material.

Keywords: Spent Catalyst, Portland Cement, Compressive Strength