Zinc oxide in cement clinkering: part 1. Systems CaO—ZnO—Al₂O₃ and CaO—ZnO—Fe₂O₃

The systems CaO—ZnO—Al₂O₃ and (C—Z—A) and CaO—ZnO—Fe₂O₃ (C—Z—F) have been studied and their phase relationships established. Two hitherto unreported phases, Ca₃ZnAl₄O₁₀ (C₃ZA₂) and Ca₆Zn₃A1₄O₁₅ (C₆Z₃A₂) were characterized in the system C—Z—A: their X ray diffraction patterns were obtained and indexed. No new phases were discovered in the system C—Z—F Phase coexistence has been established in both systems. C₆Z₃A₂ is of particular interest to clinkering because it coexists with alite, belite and a c~lnker liqUid phase: This. is confirmed both by laboratory experiment and its identification in white and grey clinkers, made from industrial raw meals doped with 1·0 and 2·0 wt% of zinc oxide.