Structural alterations and thermal behaviour of mechanically activated alunite ore

• Published in: Journal of thermal analysis and calorimetry 2014-11, Vol.118 (2), p.883-889
• Main Authors: Tunç, Tuğba, Apaydin, Fatih, Yildiz, Kenan
• Format: Article
• Language: English
• Subjects: Activated; Alunite; Analysis; Analytical Chemistry; Chemistry; Chemistry and Materials Science; Dehydration; Differential thermal analysis; Diffraction; Infrared spectroscopy; Inorganic Chemistry; Measurement Science and Instrumentation; Mechanical activation; Physical Chemistry; Polymer Sciences; Thermal analysis; X-rays
• ISSN: 1388-6150; 1588-2926; 1572-8943
• DOI: 10.1007/s10973-014-3918-9

Alunite, a potassium alum, was activated mechanically in a planetary ball mill, and the effects of mechanical activation on the structure of alunite have been studied by particle size analysis, scanning electron microscopy, X-ray diffraction and the Fourier transform infrared spectroscopy. The results show that the activation procedure led to amorphisation and structural disordering in the alunite structure. Thermal decompositions of both non-activated and activated alunite samples have been studied by thermogravimetry (TG) and differential thermal analysis (DTA). In non-activated alunite, the dehydration reaction starts after 500 °C. On the contrary, the dehydration of mechanically activated alunite was started after 100 °C. It is observed by X-ray diffraction analysis and thermal analysis that dehydration and desulphation temperatures of alunite decreased with mechanical activation, owing to amorphisation and structural disordering in alunite.