Study of Carbonated Clay-Based Phosphate Geopolymer: Effect of Calcite and Calcination Temperature

This study aims to use natural carbonated Tunisian clay as an aluminosilicate precursor for the elaboration of phosphate-based geopolymers, which yields valorization this common material in Tunisia. In addition, presence calcium carbonate allows investigation associated mineral’s effect on properties geopolymeric materials. To achieve these purposes, several experimental techniques were used, namely fluorescence (FX), particle size analysis, thermogravimetric analysis (TGA), differential thermal (DTA), dilatometric X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The mechanical strength open porosity obtained samples tested by compression test standard method water absorption, respectively. findings work show that used can present attractive synthesis geopolymers. It also shows chosen calcination temperature raw considerably modifies reactivity minerals during geopolymerization and, consequently, strongly affects structure samples. These effects attributed essentially formation new crystalline phases fact, anorthite (CaAl2Si2O8) phase appears all but greater abundance those from calcined at 550 °C, brushite (CaHPO4·2H2O) only 950 °C. All are dependent state calcite clay.