The competitive adsorption of HF and soj on smelter grade alumina

Abstract

Smelter grade alumina (SGA) is the preferred agent for recovering HF from aluminum smelter ventilation gas streams since the alumina also serves as feed to the electrolysis cells, thereby allowing return of the recovered fluoride to the process. This alumina-based recovery loop includes sulfur, since S02 evolved from cells is in fact adsorbed on the SGA. This paper explores the competitive adsorption/reaction behavior of S02 and HF and on smelter grade alumina as well as the impact of increasing HF exposure on the surface area and porosimetry of SGA.