Sorbents Sludge samples from two domestic WWTPs in Hong

Hamilton et al., 1989 and Pownceby and Patrick, 2000 reported the formation temperature of the SFCA phase as around 1050 °C. From the DSC curve in Fig. 2, it AMG-458 can be seen that the formation temperature of the SFCA phase in the PRM was below 1115 °C. In the 1100 °C thermally treated PRM sample, the SFCA phase was clearly identified in the XRD data, and this was generally consistent with the previous results. Compared to the red mud samples used in the other studies, the higher calcium content in the PRM (Table 1) may have benefited the crystallization of the SFCA phase, as substantial calcium is coprolites required to form SFCA. In addition, the intermediate gehlenite phase generated from the process of heat-treating PRM may also have facilitated the reactions with hematite, andradite and the Ca–Al–Si-containing amorphous content for the formation of the SFCA phase as follows:
Ca–Al–Si-containing amorphous content + Hematite + Gehlenite → SFCAAndradite+Gehlenite+Hematite→SFCAAndradite+Gehlenite+Hematite→SFCA