Preparation Of Magnesia With Different Properties Based On Magnesite And Its Effect On Hydrated Product Magnesium Hydroxide

The preparation of Mg（OH）₂ by hydration is a green process.However,due to the physical and chemical properties of hydrated precursor Mg O,there are some phenomena that the apparent properties of Mg（OH）₂ are not ideal,such as low purity,serious agglomeration,uneven particle size and poor crystal structure.The key to the preparation of uniform hexagonal flake nano Mg（OH）₂ based on magnesite hydration is to accurately regulate the physicochemical properties of Mg O.Exploring the relationship between the preparation process conditions of Mg O,the physicochemical properties of Mg O and the apparent properties of Mg（OH）₂ is the key to realize the high-value utilization of magnesite resources.The particle size and calcination method of magnesite,the addition method and amount of light calcined powder have little influence on the physicochemical properties of Mg O,but have a certain influence on the content of iron and aluminum impurity ions in the final product.The higher the calcination temperature of Mg Cl₂·6H₂O and the longer the holding time,the Mg O will be sintered into large particle size particles,the worse the crystal structure,the larger the specific surface area and the worse the chemical activity.The particle size D₅₀of magnesite is 20.76μm.After calcining at 650℃for 4h,the obtained light calcined powder is added by reverse addition+ultrasonic.Mg Cl₂·6H₂O is prepared according to the solid-liquid ratio of light calcined powder to hydrochloric acid of 0.32:1.Finally,it is calcined at480℃for 2h.The overall physicochemical properties of Mg O are the best.MgO uses the difference of its physical and chemical properties to control the overall growth habit of Mg（OH）₂ crystal,which can change the apparent properties of Mg（OH）₂.Mg O with the best physicochemical properties can effectively promote the relative growth trend of crystal on（001）and（101）planes and improve the apparent properties of Mg（OH）₂.The relationship between the physicochemical properties of Mg O and the properties of Mg（OH）₂ was established.It provides a feasible way for the high-value and industrialization of magnesium products in China.Figure 50;Table 12;Reference 71...