Magnesium Hydroxide Production at a Pilot Scale: Exploitation of Different Mg2+-containing Solutions

Abstract

Today water scarcity and the lack of minerals are two challenges to face. This work investigates the recovery of magnesium, in the form of magnesium hydroxide, from waste saline solutions, by-products of the desalination industry. Two solutions were tested: (i) a seawater reverse osmosis brine and (ii) a concentrated one resulting from the evaporative process of the reverse osmosis brine in evaporative ponds. Magnesium hydroxide was synthesized using an innovative pilot-scale prototype patented by ResourSEAs company. Magnesium recovery was always higher than 98%. In addition, Mg(OH)2 powder purity was 90% and >98% in samples produced from reverse osmosis brines and those obtained after the evaporation process, respectively.