Extracting Beryllium from Beryllium Fluoride by Magnesiothermic Reduction

Beryllium (Be) is an indispensable strategic metal, which is mainly produced by the magnesiothermic reduction of beryllium fluoride (BeF₂). In this study, the chemical reaction process of magnesiothermic reduction of BeF₂ has been studied, assisted with the characterization of various phases containing Be and other relevant elements present in the metal, slag, and vapor condensate. Based on thermogravimetric (TG) and differential thermal analysis (DTA), the temperature of magnesiothermic reduction of BeF₂ should be kept below 1380 K. Subsequently, Magnesium (Mg) was used as a reductant in an Ar atmosphere to extract Be from BeF₂ at a temperature in the range of 1173 K to 1323 K for 30 minutes, then heated further to 1573 K and held for 10 minutes for the separation of metal and slag. The largest extraction rate of Be metal was 68.8 wt pct. The produced Be had a purity as high as 99.5 wt pct, with Mg as the main impurity element. The slag was composed of a primary MgF₂ phase and a eutectic of BeF₂-MgF₂ after magnesiothermic reduction. The impurity elements Al and Si mainly existed in the form of Al-Si-O compounds in the slag. Characterization of the vapor condensate from magnesiothermic reduction suggested the vaporization of Mg, BeF₂, and Be during the reduction process.