Analysis of particles size distributions in Mg(OH)2 precipitation from highly concentrated MgCl2 solutions

Magnesium is a raw material of great importance, which attracted increasing interest in the last years. A promising
route is to recover magnesium in the form of Magnesium Hydroxide via precipitation from highly concentrated
Mg2+ resources, e.g. industrial or natural brines and bitterns. Several production methods and
characterization procedures have been presented in the literature reporting a broad variety of Mg(OH)2
particle sizes. In the present work, a detailed experimental investigation is aiming to shed light on the
characteristics of produced Mg(OH)2 particles and their dependence upon the reacting conditions. To this
purpose, two T-shaped mixers were employed to tune and control the degree of homogenization of reactants.
Particles were analysed by laser static light scattering with and without an anti-agglomerant treatment based
on ultrasounds and addition of a dispersant. Zeta potential measurements were also carried out to further assess
Mg(OH)2 suspension stability.