Spent FCC catalyst for preparing alkali-activated binders: an opportunity for a high-degree valorization

Spent FCC catalyst is a waste from the petrochemical industry which has excellent pozzolanic properties, containing more than 90% silica and alumina. Its similarity to metakaolin creates interesting prospects for its use in the production of alkali-activated binders. In this study, the alkali activation of this residue, spent FCC catalyst, through mixtures with alkali hydroxide and silicate solutions (both sodium and potassium) has been carried out. The alkali cation had an important role in the nature of AA-FCC pastes: some differences in the mass loss in the thermogravimetric tests and in the X-ray mineral characterization were found. No significant differences in compressive strength were observed for mortars cured for 3 days in several conditions: room temperature and 65ºC. Prepared AA-FCC mortars had a compressive strength of about 65-70 MPa. Microstructural studies showed that an amorphous, dense and compact microstructure was obtained, independent of the activating solution and curing condition.Mitsuuchi Tashima, M.; Soriano Martinez, L.; Akasaki, JL.; Castaldelli, V.; Monzó Balbuena, JM.; Paya Bernabeu, JJ.; Borrachero Rosado, MV. (2014). Spent FCC catalyst for preparing alkali-activated binders: an opportunity for a high-degree valorization. Key Engineering Materials. 600:709-716. doi:10.4028/www.scientific.net/KEM.600.709709716600WBCSD – World Business Council for Sustainable Development, Cement industry energy and CO2 performance – Getting numbers right, WBCSD editor, (2009).S. Berger, C.C.D. Coumes, P. le Bescop, D. Damidot, Influence of a thermal cycle at early age on the hydration of calcium sulphoaluminate cements with variable gypsum contents, Cem. Concr. Res. 41-3 (2011) 149-160.I. García-Díaz, J.G. Palomo, F. Puertas, Belite cements obtained from ceramic wastes and the mineral pair CaF2/CaSO4, Cem. Concr. Comp. 33-10 (2011) 1063-1070.M.M. Tashima, L. Soriano, M.V. Borrachero, J. Monzó, C.R. Cheeseman, J. Payá, Alkali activation of vitreous calcium aluminosilicate derived from glass fiber waste, J. Sust. Cem-Based Mater. 1-3 (2012) 83-93.J. Payá, M.V. Borrachero, J. Monzó, L. Soriano, M.M. Tashima, A new geopolymeric binder from hydrated-carbonated cement, Mater. Lett. 74 (2012) 223-225.C. Shi, A. Fernández-Jiménez, A. Palomo, New cements for the 21st century: The pursuit of an alternative to Portland cement, Cem. Concr. Res. 41 (2011) 750-763.P. Duxson, A. Fernández-Jiménez, J.L. Provis, G.C. Lukey, A. Palomo, J.S.J. van Deventer, Geopolymer technology: the current state of the art, J. Mater. Sci. 42 (2007) 2917-2933.A. Fernández-Jiménez, A. Palomo, M. Criado, Microstructure development of alkali-activated fly ash cement: a descriptive model, Cem. Concr. Res. 35 (2005) 1204-1209.J. Payá, J. Monzó, M.V. Borrachero, Fluid catalytic cracking catalyst residue (FC3R) An excellent mineral by-product for improving early-strength development of cement mixtures, Cem. Concr. Res. 29 (1999) 1773-1779.J. Payá, M.V. Borrachero, J. Monzó, L. Soriano, Estudio del comportamiento de diversos residuos de catalizadores de craqueo catalítico (FCC) en cemento Portland, Mat. Construc. 59-296 (2009) 37-52.M.M. Tashima, J.L. Akasaki, V.N. Castaldelli, L. Soriano, J. Monzó, J. Payá, M.V. Borrachero, New geopolymeric binder based on fluid catalytic cracking catalyst residue (FCC), Mater. Lett. 80 (2012) 50-52.A.V. McCormick, A.T. Bell, The solution chemistry of zeolite precursors, Catal. Rev. Sci. Eng. 31 (1989) 97-127