Low-energy cements — their production and utilization

Term “low-energy cements” describes cements that can replace ordinary Portland cement in at least some applications and can also reduce energy consumption during the production process. An expansion of these cements could lead in both lower costs of binders production and lower emissions, CO₂ especially. Belite cements are part of low-energy cements. Pure belite clinkers with interstitial matter comprising C3A and C4AF are not produced, since they yield materials with insufficient strength. Currently, sulfoaluminate-belite cements, low-energy cements doped with fluorine and chlorine as well as undoped high-belite cements are produced in limited volumes in China. Results of hydraulic activation of high-belite clinker by sulfate anions are also given in this work. A principle of activation is the preparation of belite clinker with increased Ca:Si ratio in the structure of dicalcium silicate at substitution of SiO₄^2– by SO₄^2–. Cements prepared from these high-belite content clinkers with alite content up to 25 % that were burned at 1350°C display the same technological properties including early strengths as ordinary alite Portland cements.

Author: T. Stanek, M. Bohac

Section: Science and production

Keywords: low-energy cement, belite clinker, hydraulic activation, sulfate anion