Magnesiothermic reduction of beryllium fluoride: Reaction mechanism and kinetic study

Beryllium (Be) is mainly produced by magnesiothermic reduction of beryllium fluoride (BeF2). This research aims to improve the extraction rate of Be by investigating the reaction mechanism and kinetics during the magnesiothermic reduction of BeF2. It was found that the solid product layer composed of MgF2 and Be metal produced during the magnesiothermic reduction process is the main reason hindering the further improvement of the reduction rate. Kinetic study on the magnesiothermic reduction of BeF2 shows that it was controlled by volume diffusion. An apparent activation energy of 66.01 kJ/mol was obtained for the magnesiothermic reduction in the temperature range of 850-950 degrees C. Aiming to extract Be from BeF2 with a high efficiency, granular-shaped Mg (particle size 0.2-5 mm) and BeF2 powder (particle size < 0.83 mm) were used as raw materials for magnesiothermic reduction at 900 degrees C for 30 min, protected using Ar atmosphere. This was followed by further heating to 1300 degrees C and holding for 10 min, and the highest extraction rate of Be was achieved at 90.1 wt% with the Be purity of 94.2 wt%.