Active low-energy belite cement

The term ‘low-energy cement’ is used for cements that can be in some applications used instead of OPC, and which are produced with less energy. A more extensive utilization of these cements would lead to the lowering of expenses on production of binders as well as a reduction of undesirable emissions. The belite-rich cement belongs to this group. Pure belite clinkers with interstitial matter consisting of C3A and C4AF have not been produced, as they have insufficient strength. This work describes the results of hydraulic activation of belite-rich clinkers with sulfate anions. The principle of activation is used for the preparation of belite-rich clinkers with an increased Ca:Si ratio in the structure of dicalcium silicate and partial substitution of SiO44−  by SO42−. Cements, prepared from these belite-rich clinkers, containing up to 20% of alite, which are burned at 1350 °C, have the same technological properties, including early strengths, as OPC.