Characterization of Mg(OH)2 powders produced from real saltworks bitterns at a pilot scale

<p>The growing demand for a reliable supply of minerals has pushed the European Union toward seeking novel<br>mineral sources. In the present work, the recovery of magnesium, in the form of magnesium hydroxide, Mg<br>(OH)2, from saltworks bitterns was investigated at a pilot scale. The natural bittern collected from Margi saltworks<br>(Trapani, Italy) was treated with synthetic sodium hydroxide (NaOH) solutions. The influence of different<br>reactant concentrations, flow rates and pH environments, on Mg(OH)2 particle sizes, filtration characteristics,<br>Mg2+ extraction performance and the Mg(OH)2 solid purity was thoroughly assessed. The presence of additional<br>dissolved salts in NaOH solutions was also analyzed. The pH environment was found to be the most crucial<br>parameter. On the one hand, high pH values ensured high Mg2+ recovery and powder purities, i.e. &gt; 98%, with<br>boron content complying with market requirements. On the other hand, filtration characteristics considerably<br>worsened due to the lyosorption phenomenon.</p>