The role of Li2O, MgO and CuO on SO3 activated clinkers

Clinkers activated by SO3 and modified by Li2O, CuO and MgO were prepared from industrial raw materials and burned at 1350 degrees C. The role of dopants on the burnability of the raw mix was monitored by TG-DTA and heating microscopy. The phase composition of the clinker was characterized by light microscopy, scanning electron microscopy, and X-ray powder diffraction. Predominance of M1 over M3 C3S was determined in all combinations of dopants. Hydration of cement pastes was followed by isothermal calorimetry during the first 48 h and strength development of cement mortars during 365 days of curing. The content of SO3 incorporated in clinker silicates is lower in the presence of Li2O and CuO due to the enrichment of interstitial matter. Thermal analysis shows that Li2O and CuO in combination with SO3 are strong mineralizers and fluxes during clinkering process.