Preparation of Plate-shape Nano-Mg(OH)2 Powder from Magnesite Tailing

For comprehensive utilization of the magnesite tailing as a new kind of resource, research is done on the magnesite tailing used as raw material in the preparation of plate-shape nano-Mg(OH)2 powder. The powder can be obtained through the calcinations of magnesite tailing, the preparation of magnesia sulphate solution by the reaction of the sulfuric acid and MgO, and the preparation of plate-shape nano-Mg(OH)2 powder. The process of magnesia sulphate solution preparation is to mix the MgO powder with water, and then react the solution with acid. It is important to control the pH value between 5 and 6. Then, the slurry should be filtrated. The process parameters for the preparation of plate-shape nano-Mg(OH)2 powder are: initial concentration of Mg2+ at 22.75 g/L, reaction temperature at 50 °C, 5 min of reaction time, and organotitanate YB-502 used as reagent of in-situ surface modification with a dosage of 1.5% of the mass of nano-Mg(OH)2 powder. This study shows good crystallization of Mg(OH)2 powder with the particle in plate-shape with a diameter of about 100 nm and nanometer grade with a thickness of 10 nm. There is obvious agglomeration of the powder and the size of the agglomerated particle is d50 = 0.95 μm, d97 = 3.53 μm.