New Insight into Energy-Saving Calcination of Limestone: Preparation, Characterization, and Application of Partially Calcined Limestone

Abstract

This study presents an energy-saving calcination strategy using low temperatures and a controlled heating process for preparing partially calcined limestone. The low temperature and controlled heating ensure the high activity of the porous oxide and significantly reduce CO2 emissions and energy consumption. Reactants and products coexist in partial calcination to form a core–shell structure. Furthermore, the decarbonization of limestone is observed by multiple characterizations and interpreted visually. The prepared partially calcined limestone was used as a precursor for the cementitious materials. The compressive strength of cementitious materials with partially calcined limestone was significantly enhanced because of: (1) the increased activity of calcium oxide and (2) the presence of in situ nuclei. This is further demonstrated by the accelerated reaction heat release from the isothermal calorimetry test and the microstructure analysis. The challenges of partial calcination technology and its expanding applications are also highlighted.

Novel Carbonated Materials: The Synergistic Role of MgO in Partially Calcined Limestone

“…Low-temperature synthesis of CaO, compared to high-temperature methods, notably reduces waste gas emissions and heat loss, presenting an environmentally friendly alternative for building materials. − Despite its potential, traditional calcined limestone carbonated materials face challenges with low strength, limiting their use mainly to specific niches like cultural heritage restoration. , Addressing this, our study introduces an innovative “partial calcination technology” aimed at enhancing the strength of calcined limestone-based materials for broader applications in construction engineering. We explore the potential of adding MgO to regulate the carbonation of partially calcined limestone (PCL), aiming to improve its mechanical properties and reduce fuel consumption. − Our focus also extends to overcoming the inherent limitations in CO 2 capture efficiency due to the reduced reactivity and dense reaction layers formed during carbonation in traditionally calcined CaO. − …”