The hydrothermal synthesis of a mcallisterite (Mg 2 (B 6 O 7 (OH) 6 ) 2 · 9(H 2 O)) mineral at low temperatures was characterized. For this purpose, several reaction temperatures (0–70°C) and reaction times (30–240 min) were studied. Synthesized minerals were subjected to X-ray diffraction (XRD), fourier transform infrared (FT-IR), and Raman spectroscopies and scanning electron microscopy (SEM). Additionally, experimental analyses of boron trioxide (B 2 O 3 ) content and reaction yields were performed. Furthermore, thermal gravimetry and differential thermal analysis (TG/DTA) were used for the determination of thermal dehydration kinetics. According to the XRD results, mcallisterite, which has a powder diffraction file (pdf) number of “01-070-1902,” was formed under certain reaction parameters. Pure crystalline mcallisterite had diagnostic FT-IR and Raman vibration peaks and according to the SEM analysis, for the minerals which were synthesized at 60°C and 30 min of reaction time, particle size was between 398.30 and 700.06 nm. Its B 2 O 3 content and reaction yield were 50.80±1.12 % and 85.80±0.61 %, respectively. Finally, average activation energies (conversion values (α) that were selected between 0.1 and 0.6) were calculated as 100.40 kJ/mol and 98.31 kJ/mol according to Ozawa and Kissinger-Akahira-Sunose (KAS) methods, respectively.
Moroydor Derun, E., & Senberber, F. T. (2014). Characterization and thermal dehydration kinetics of highly crystalline mcallisterite, synthesized at low temperatures. The Scientific World Journal, 2014. https://doi.org/10.1155/2014/985185