Phase evolution and pulverization mechanism of self-pulverizing carbonatable clinkers

This paper investigates the phase evolution and pulverization mechanism of a self-pulverizing carbonatable clinker (SPCC) with a variety of raw material compositions. The particle size, mineral phases, and microstructure of SPCC, produced by sintering at 1400°C for 3 h, were systematically studied by laser particle size testing, XRD/QXRD and SEM/EDS. Results show that clinkers sintered by raw materials with low-Ca/low-Al (Ca/Si 2O3  2.6; Al2O3 ≈ 10 wt.%) are non-pulverized after cooling. The mineral phases of C2AS, CA, and C12A7 are considered to facilitate clinker pulverization at low γ-C2S contents. With the increase of Al2O3 content in raw materials, SPCC is refined in particle size, accompanied by the significant decrease in the content of calcium silicates. Based on the results, guidelines for producing SPCC are proposed. © 2022 The American Ceramic Society.