Abstract
Magnesium chloride is often a byproduct of hydrochloric acid-leach of metal ores or concentrates. It can be processed for the production of the magnesium metal (more capital intensive) or magnesium oxide. This paper provides an industry update of the MgO production route, with emphasis on the environmentally responsible recovery of the hydrochloric acid lixiviant, and the efficient energy usage (minimum fuel and electrical power) during the pyro-hydrolysis transformation of MgCl2 to MgO and HCl. Specifically, the spray roaster and the fluid bed technologies will be discussed in their overall process and mechanical design features, and how those have evolved from the originally installed plants of last century to the current state and future opportunities.