Elaboration of nanometric amorphous silica from quartz-based minerals using the fluorination method

A method of elaboration of nanometric amorphous silica is proposed using a rational processing of quartz-based ores with the help of a fluorination method. The different steps of the process are described, including the kinetics of the interaction mechanism of ammonium bifluoride with the initial raw materials, the sublimation of ammonium fluorosilicate and the formation of nanometric amorphous silica. Rate constants and activation energy of the chemical reactions are calculated.

A rational elaboration of amorphous silica from quartz-based ores is proposed with the help of the ammonium bifluoride method. The different steps of the process are described, which allows the preparation of high quality nanometric silica (as shown on the TEM photograph). Reaction mechanisms are proposed.Figure optionsDownload as PowerPoint slideHighlights
► In this study high purity nanometric silica is synthesized via fluoridation method.
► The pristine silica is obtained from quartz-based ores.
► Morphology, surface area, composition, thermal stability, are fully characterized.
► Reaction mechanisms are explained.