Development of Magnesium Hydroxide and 5Mg(OH)2·MgSO4·3H2O Synthetic Tuning System through Basic/Acid Catalyst

Y.J. Kim, Y.J. Yoon
KICET (Korea Institute of Ceramic Engineering & Technology,

Keywords: Mg(OH)2, brines, dolomite, nanomaterials


Magnesium hydroxide and oxide suitable for the use in basic refractories was prepared from dolomite (CaMg(CO3)2) and brine by sulfuric acid leaching, precipitation with NaOH and thermal hydrolysis. The removal of Ca2+ ions contained in dolomite and brine plays an important role in the purity of Magnesium hydroxide. CaSO4 and MgSO4 can be separated through solubility differences and pH control, and additional CaSO4 precipitation is required because CaSO4 dissolves in small amounts in water, and it is possible through ethanol and distillation. In addition, the obtained Mg ions can obtain 5Mg(OH)2·MgSO4·3H2O whisker(Mg-fiber), a functional material, through Magnesium hydroxide and pH control through a basic catalyst. We established a process system that can obtain Mg fibers by controlling the ratio of high-purity magnesium hydroxide (99.6%), sulfuric acid, and basic catalyst using brine and dolomite.