Axs d8 x ray diffractometer

The elemental analyses of raw clay are performed by X-ray fluorescence (XRF) using an Oasis 9900 spectrometer (Thermo Fisher, Waltham, MA, USA). Ignition loss is measured by calcination at 1000 °C.
The mineralogical analysis is performed using a Bruker AXS D8 X-ray diffractometer (XRD) (Billerica, MA, USA) operating on monochromatic Kα1 radiation from copper (40 kV, 40 mA, λ = 0.15406 nm). The Fourier-transform infrared (FTIR) spectra of raw clay and purified clay are recorded using a Bruker Alpha ATR (Billerica, MA, USA) spectrometer operating in the interval of 400–4000 cm⁻¹ at a resolution of 2 cm⁻¹. Potassium bromide (KBr) is used as a substance to dilute the samples. The Quantachrome instrument from Nova Instruments, Boynton Beach, FL, USA (a division of Anton Paar Quanta Tec Inc., Boynton Beach, FL, USA) is employed to generate nitrogen adsorption–desorption isotherms in order to determine the specific surface area. The data are recorded and evaluated with Quantachrome NovaWin version 11.06 software. Before conducting the analysis, all samples are subjected to vacuum degassing process at 105 °C for 12 h.

The crystalline structure and chemical composition were investigated by an X-ray powder diffraction analysis (XRD) system (Bruker-AXS D8 X-ray diffractometer, Germany). After setting the freshly mixed sealer specimens, the disc specimens were ground progressively by an agate mortar and pestle till a finer powder was obtained. An amount of 0.2 g of powder from each group was placed between two pieces of magic tape on the X-ray diffractometer. The test was conducted in continuous mode at an angle 2 range of (0–60°) with a scanning rate of 4°/minute under 30.0 mA at 40.0 kV. The attained XRD patterns were interpreted using the model pattern on the Joint Committee on Powder Diffraction Standard (JCPDS) databases [40 ].