Effect of ZnO; ZrO2 y B2O 3. Part II. Phase separation and clinker phase distribution

This study is a continuation of previous research which established the effect of the oxides ZnO, ZrO2 and B2O3, both separately and jointly, on clinkerization processes, as well as on clinker phase composition and morphology. A knowledge of the distribution of these elements in mineral phases is requisite to understanding which phases they affect and how. The present study aimed, then, to develop a suitable methodology for the selective separation of clinker phases and to ascertain how ZnO, ZrO2 and B2O3 are distributed in these phases when added to the raw mix in proportions of up to 2%. The optimal conditions for separating clinker phases with selective solutions (KOH-sucrose and CH3OHsalicylic acid) were established. These selective treatments proved to be insufficient in and of themselves to determine the distribution of ZnO and ZrO2 in the clinker phases. Consequently, the original clinkers had to be analyzed with SEM/BSE/EDX techniques to complete the study. The findings showed that ZnO and ZrO2 were fixed primarily in the C3A and C4AF present in the clinker, while B2O3 was taken up by the silicate phases.