The thermal treatment resulted in a

The thermal treatment resulted in a change in the XRD pattern, caused by the removal of CO2 from the starting material (Figure 2). The diffraction patterns of the samples heated at temperatures 800°C displayed diffraction reflections characteristic of CaO. Samples calcined at 800°C contain CaCO3 as the major phase and CaO as a minor phase [11]. The major component of the calcined waste at 900°C for 4h was CaO species (Figure 3). The result reveals sharp XRD reflections with (1 1 1), (2 0 0), (2 2 0), (3 1 1) and (2 2 2) orientations, implying that the calcined material was well crystallized during the heat treatment process [12].