INVESTIGATION OF FREE CALCIUM OXIDE IN PORTLAND CEMENT CLINKER

Abstract

Free calcium oxide (free CaO) is a critical quality parameter in Portland cement clinker. This study investigates the determination of free CaO in laboratory-prepared clinker samples using the ethylene glycol extraction method followed by titration with benzoic acid. Three clinker compositions were analyzed: limestone–slag–clay, limestone–slag, and limestone–clay–coal ash. The results demonstrate that raw mix composition significantly influences free lime content and clinker quality.