Hygroscopic properties of individual aerosol particles from aluminum smelter potrooms determined by environmental scanning electron microscopy

Abstract

Aluminum is produced by electrolysis of alumina (Al₂O₃). To decrease the melting point cryolite (Na₃AlF₆) is added. At present, the Norwegian aluminum industry uses two different technologies to produce aluminum: the so called Søderberg and Prebake processes [1]. In both cases, particles with variable composition, several gases (for example hydrogen fluorides) and aromatic hydrocarbons (PAHs) are formed. Inhalation of these pollutants leads to adverse health effects for the workers. For better understanding of the toxicological relevance of the particulate matter present in the workrooms, individual particle analysis was performed. Special emphasis was placed on the hygroscopic properties of the different particles sampled in the potrooms, as the presence of thin water films or small droplets may provide an opportunity for hydrogen fluoride (HF) to be transported deep into the lung.