الملخص

Investigations of the nature, distribution, contents and size of free silica in the raw materials currently quarried and used at Hammam Al-Alil Cement Plant have been carried out. The raw materials are limestones and clays, being extracted from Taqtaq quarry and Mshirfa valley. Limestones and clays from Tweba and Jahuni areas have been assessed in order to be used as substitute materials for the purpose of lowering silica content, silica ratios and improving clinker properties. Chemical, mineralogical and textural examinations revealed that the silica contents are high in the currently quarried limestones and clays, while it is rather low in limestones from Tweba area. The free silica is represented as quartz and opal grains, ranging in size between (50-300) microns.