Page 100 - Handbook of Thermal Analysis of Construction Materials

Section 4.0 - Synthesis of Cement Phases 83

Figure 6. DTA curves of CaO heated with various siliceous materials.

The fluorine containing compounds are added to the raw cement
mix to accelerate the formation of cement minerals. The effect of
addition of fluorides such as LiF, NaF and KF on the reactions in the system
[1]
CaCO -SiO has been followed by DTA. The results are shown in Fig. 7.
2
3
In the absence of the additions, the curve (solid line) shows a slope at about
920°C while those treated with the fluorides exhibit a slope at a temperature
of about 700°C, indicating early commencement of reactions. The effec-
tiveness of other mineralizers have also been examined by DTA. The
influence of mineralizers such as ZnO, CuO, and MnO on the formation of
2
alite from a mixture of calcium carbonate and a silica-bearing material such