Mineral Phase and Microstructure Behaviors on Burning Condition of Domestic Low-grade Limestone

Natural hydraulic lime (NHL) is produced by burning a form of low-grade limestone containing silica and alumina which, above certain temperatures, combine with calcium oxide. The resulting silicates and aluminates impart hydraulic properties to the product. This study aims to determine the calcined characteristics of NHL using domestic low-grade limestone with maximized hydraulic properties. Six types of low-grade limestone containing SiO2 were selected and experiments were carried out with different burning temperatures and holding times. The burning temperature and holding time as the most suitable burning conditions were 1,200oC to 1,300oC and 3 to 7 h, respectively, for the manufacturing of NHL from domestic low-grade limestone. These results demonstrate the feasibility of NHL using domestic low-grade limestone to produce NHL.