Research On The Preparation Technology Of Magnesium Oxysulfate Whiskers

In this paper, the technology of preparing magnesium oxysulfate whisker (153MOS) was researched. The effects of processing parameters on preparing magnesium oxysulfate whisker in the course of experiment were discussed. The new technology and some conditions benefit to industry were researched.In the process of preparing magnesium oxysulfate whisker by hydrothermal treatment, the effects of magnesium sulfate, match of raw materials, reaction time, reaction temperature and stirring velocity on whisker pattern were discussed. The powder was characterized by SEM, XRD and TG. The growth of whisker was investigated by whisker structure and theory of growth. The feasibility of aggrandizing ratio of length to diameter was researched by adding some organic acid into the materials. The different systems of materials were compared in order to probe simple, feasible and applied method of magnesium oxysulfate whisker products. Magnsium oxysulfate whisker producd by stirred semi-batch reactor (SSBR) -hydrothrmal treatment or produced rotor-stator reactor (RSR) -hydrothermal treatment were compared.The results of research indicated(1) The effect factors of preparing magnesium oxysulfate whisker: the ratio of raw materials > reaction temperature > stirring velocity > reaction time.(2) The ratio of length to diameter could be aggrandized by adding some organic acid.(3) Compared to the whisker prepared by stirred semi-batch reactor -hydrothermal treatment, the whisker prepard by rotor-stator reactor -hydrothermal treatment has a lot of advantages of good dispersibility, high-quantity and high ratio of length to diameter.The proer conditions of preparing magnesium oxysulfate whiskers were obtained.(1) The proper operational conditions of preparing magnesium oxysulfate whiskers by stirring-hydrothermal reaction making magnesium sulfate and sodium hydroxide as materials. The concentration of magnesium sulfate: 1.2 mol·L^-1; the concentration of sodium hydroxide: 4mol·L^-1; the reaction temperature: 160℃; the stirring velocity: 600rpm; the reaction time: 6h. The magnesium oxysulfate whiskers (153MOS) with a length of 20-40μm and a diameter of 0.5-1.0μm were obtained.(2) The proper operational conditions of preparing magnesium oxysulfate whiskers by rotor-stator reactor (RSR)-hydrothermal reaction making magnesium sulfate and sodium hydroxide as materials. The concentration of magnesium sulfate: 1.2mol·L^-1; the concentration of sodium hydroxide: 8 mol·L^-1; the rotating velocity of the rotor-stator reactor: 800rpm; circulating flow: 400L·h^-1 The proper conditions of preparing magnesium oxysulfate whiskers in the autoclave were written. The reaction temperature: 160℃; the stirring velocity: 600rpm; the reaction time: 6h. The magnesium oxysulfate whiskers (153MOS) with a ratio of length to diameter of 50 and a high concentration of 50g·L^-1 were obtained.