EFFECT OF NaF AND SnO[sub 2] ON PORTLAND CEMENT CLINKER FABRICATION

Abstract

The paper aimed at studying the effect of NaF and SnO2 employed as mineralisers on Portland cement clinker fabrication. In order to do this, the raw mix included in turn 0.5% NaF, 0.5% SnO2, and a combination of 0.5% NaF and 0.5% SnO2, all expressed as weight percentages of the raw mix. The effects of the presence of NaF and SnO2 mineralisers on the raw mix were studied by investigations of the loss on ignition at 700 °C and 800 °C with calculating the corresponding decarbonation ratio of the raw mix, determination of free lime and XRD analysis. NaF was found to have a positive effect both during the decarbonation of the raw mix and during the formation of minerals in clinker. On the other hand, SnO2 has but a little effect on the decarbonation process. Finally, the combined use of NaF and SnO2 modifies the kinetics of binding the free lime to the effect of accelerating the process as compared to the separate use of each mineraliser.