Thermal behaviour of ground and unground acid leached vermiculite

• Published in: Journal of thermal analysis and calorimetry Vol. 107; no. 2; pp. 431 - 438
• Main Authors: Perez-Maqueda, L. A., Maqueda, C., Perez-Rodriguez, J. L., Subrt, J., Cerny, Z., Balek, V.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-02-2012; Springer
• Subjects: Analysis; Analytical Chemistry; Chemistry; Chemistry and Materials Science; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Inorganic Chemistry; Measurement Science and Instrumentation; Miscellaneous; Physical Chemistry; Polymer Sciences; Silica; Vermiculite; DTA; TG; Vermiculite; Acid leaching; Emanation thermal analysis; Grinding; EGA; Gas release; Grinding(comminution); Differential thermal analysis; Gas analysis; Silicates; X ray diffraction; Leaching; Silicon Compounds; Hydrochloric acid; Mechanical treatment; Chemical treatment; Thermal analysis; Evolved gas analysis
• ISSN: 1388-6150; 1588-2926; 1572-8943
• DOI: 10.1007/s10973-011-1480-2

Acid leaching of vermiculite is an interesting procedure to prepare high surface area porous silica. Thermal behaviour of unground and ground vermiculite leached with HCl solutions has been studied by TG, DTA, ETA and high temperature XRD. Important differences have been observed in the thermal behaviour of unground and ground vermiculite after the acid treatments. Thus, for the acid-treated unground vermiculite, dehydrated vermiculite, enstatite and cristobalite were formed during the heating, while for the acid-treated ground vermiculite only iron oxides and cristobalite phases were observed. Structural modifications due to acid treatment were responsible for changes in the transport properties determined by ETA for the vermiculite samples.