CaCl2 as a Mineralizing Agent in Low-Temperature Recycling of Autoclaved Aerated Concrete: Cl-Immobilization by Formation of Chlorellestadite

The suitability of CaCl2 as a mineralizing agent in the synthesis low-temperature C2S-cement clinker from wastes autoclaved aerated concrete was investigated. As chlorellestadite is potential host mineral for immobilization chlorine, formation conditions highest joint content and C2S were studied samples with different sulfate contents. Oven experiments conducted at temperatures between 700 1200 °C. analyzed by X-ray diffraction combination chemical thermal analysis Raman spectroscopy. Calculation yield ellestadite all proves optimum temperature range C2S-ellestadite 950 to 1000 At lower temperatures, carbonate-rich halogenide melt promotes crystallization significant amount spurrite expense C2S. Ellestadite mainly depends on lesser extent temperature. However, higher ternesite another coexists sulfate-rich ellestadite. In addition, distinct evidence non-stoichiometry carbonate substitution structure found. Low leads Ca10[Si2O7]3Cl2 temperatures. treated above °C chlorine loss starts. Its decreases increasing content.