Particles size distribution analysis in Mg(OH)2 precipitation from highly concentrated MgCl2 solutions

Since 2011, European Union has identified and updated a list of high-supply risk “Critical Raw Materials” (CRMs) for the development of the European economy. In this context, a growing concern has been placed on the seek for sustainable CRMs alternative mining routes.

Magnesium is a raw material of great importance, which can be extracted from seawater or brines as magnesium hydroxide, Mg(OH)2, via reactive crystallization. Products will have to comply with market requirements, e.g particle size distribution or purity, to supersede typical mineral mining manufactured goods.

The webinar presents the results of a detailed experimental investigation on the effect of reactants mixing on Mg(OH)2 particle size distributions precipitated from highly concentrated magnesium chloride solutions.

Two T-mixers devices were employed to tune and control reactants mixing degree. A methodical analytical procedure for the characterization of the produced Mg(OH)2 particles was followed. The Mastersizer 2000 and Zetasizer instruments were employed for particle size distributions and particle stability assessments, respectively. Mg(OH)2 nanoparticles measurements were obtained after varying the material refractive index to decrease data-weighted residuals.

The experimental campaign shed light on the interaction between precipitation and mixing phenomena, and on the crucial role of an effective particles’ treatment before analysis. The optimal operating conditions for the industrial production of attractive Mg(OH)2 nanoparticles are also highlighted.