This article uses ion exchange resin and electrochemical methods to prepare high -purity ultra -fine hydroxide magnesium.According to the preparation methods of nano -hydroxide magnesium hydroxide, urea, sodium hydroxide, ammonia, etc. are used as precipitants. The advantages of using these sesame agents are low cost, easy chemical measurement, and high precipitation rate of magnesium, but this uses this.At the same time of synthesizing magnesium hydroxide hydroxide, the remaining anion in the solution is difficult to wash. On the one hand, it may affect the purity of the product. On the other hand, it produces a large amount of cleaning wastewater, polluting the environment, and wasting water resources.
In this paper, anionic Ion-exchange resin was used as precipitating agent to replace interfering ions on the resin while precipitating, which solved the problem of anion elution in the past precipitation method, and reduced the water consumption and cost. In this paper, high purity ultrafine Magnesium hydroxide was prepared by agitation in a water bath using Ion-exchange resin as the exchange medium and MGCL2 as the raw material, the structure, morphology and purity of the Magnesium hydroxide were characterized by differential thermal balance, scanning electron microscopy (SEM) and X-ray diffraction (XRD) .
The optimal reaction temperature for the preparation of ultrafine Magnesium hydroxide was determined to be 60 ° C by changing the reaction temperature, the reaction time and the concentration of the reaction solution, respectively, while keeping the other reaction conditions unchanged, the optimal reaction time and concentration for the preparation of ultrafine Magnesium hydroxide were determined to be 16 h and 0.1 Magnesium hydroxide respectively. The ultrafine Magnesium hydroxide prepared under the optimal reaction conditions were characterized. The results showed that the prepared Magnesium hydroxide had good dispersion, regular morphology and regular polygonal lamellar structure, the average grain size is about 18 nm. The thermal decomposition temperature of the prepared Magnesium hydroxide is above 300 ° C, which is suitable for making flame retardant materials.
In this paper, the reaction conditions of preparing high purity ultrafine Magnesium hydroxide by electrochemical method were also studied. In this method, a self-made electrolytic reactor with cross-arrangement of cathode and anode was used to directly synthesize ultrafine Magnesium hydroxide with D113 macroporous weak acid resin as template and magnesium chloride as raw material under the action of an applied electric field. By controlling the reaction current and voltage, it was determined that the hexagonal flake ultrafine Magnesium hydroxide with high purity and regular shape could be prepared at the current of 4A and the voltage of 20V.