Mineral Transition and Chemical Reactivity Evolution of a Low-Lime Calcium Aluminate Clinker with MgO and NaSO Codopants.

The mineral formation-transition mechanism, microstructure evolution, crystal structure, pulverization property, and chemical reactivity of the CaO-AlO-SiO clinker with MgO and NaSO dopants during the sintering process at 1300 °C for 2.0 h were systematically studied using CaO, AlO, SiO, MgO, and NaSO as raw materials when the molar ratio of CaO to AlO is 1.4, the mass ratio of AlO to SiO is 3.0, and the mass percentage of MgO and NaSO is 2%. The MgO dopant could result in 12CaO·7AlO and γ-2CaO·SiO, transform into 20CaO·13AlO·3MgO·3SiO, restrain the crystal transformation of 2CaO·SiO from β to γ, and then deteriorate the pulverization and alumina leaching property corresponding to parts of Al, Si, and Mg atoms occupying the same lattice positions of the crystal structure. MgO and NaSO codoped could promote transformation of 20CaO·13AlO·3MgO·3SiO into 3CaO·3AlO·CaSO as well as some 2CaO·AlO·SiO, while 3CaO·3AlO·CaSO has good alumina leaching property in the NaCO-NaOH solution. The ultrasonic assistant mainly could promote the diffusion of reactive samples, enhance the separation of agglomeration, and then accelerate the chemical reaction of the sintered clinker with NaCO-NaOH.