Endotherms located at 782–862 C are due to the decomposition of sodium and calcium carbonates.
Fig. 3b shows XRD diffractograms of calcium carbonate (CC) and dry activator powders (NC9, NC14, NC19); the
intensities of CH, SC and P peaks increase from NC9 NC14 and NC9. This is due to that the amount of calcium carbonate
decreases in the opposite direction as shown in Table 2.