Low temperature synthesis of cement from ladle slag and fly ash

Abstract

This study investigates the feasibility of producing environmentally friendly cement exclusively from industry wastes: ladle slag fines and fly ash. A low temperature clinkering process was implemented to produce a cement material capable of gaining early strength by carbonation and late strength by hydration. The optimum uses of fly ash and clinkering temperature were determined by undergoing meticulous parametric studies. The results of this investigation demonstrate that the higher the clinkering temperatures used, the higher the carbonation and hydration reactivity of the cement. The optimal fly ash ratio and temperature for synthesizing cement was found as 30% and 1250 °C, respectively. The composite action generated by calcium carbonates and calcium silicate hydrates eventually plays an important role in gaining the strength. Production of cement with ladle slag and fly ash at low temperature can reduce the energy consumption, the natural resources consumption, landfills disposal cost, and the total CO₂ emission.

Keywords:

• low temperature synthesis
• cement
• ladle slag
• fly ash
• carbonation activation
• CO₂ emission

Acknowledgments

Financial support by Fonds Québécois de la Recherche sur la Nature et les Technologies (FQRNT) is gratefully acknowledged. The authors are also thankful to Quebec Rio Tinto Iron & Titanium (RTIT) for ladle slag and to EPCOR for fly ash.

Disclosure statement

No potential conflict of interest was reported by the authors.