| Magnesium hydroxide is a widely used chemical product, which is widely used in the field of environment, medicine, materials, etc. As a natural magnesium hydroxide, brucite can not satisfy the applications in some high quality field. Therefore, a lot of researches on preparing high-quality magnesium hydroxide through brucite have been done by researchers. However, the application of this method, to a certain, has been limited due to the high cost of the process. For the present situation of Liaoning province abundanting in the brucite resources, the market of magnesium hydroxide has a good future. This paper is aim that how to resolve the major problems of magnesium hydroxide produced and effectively manufacture. The one step method is used to prepare high quality magnesium hydroxide through the direct transformation of inducer with brucite as raw materials. The main research contents and results are as follows:(1) Preparation of magnesium hydroxide through direct conversion in which brucite was induced by magnesium lactate. The dosage of inducer, reaction time and the addition amount of PEG10000 were investigated; and the peak intensity ratio(I001/I101) was used as indicator to explore the experimental conditions. The results show that the change of concentration ratio, hydrothermal time and the amount of PEG10000 can effectively improve the surface polarity of magnesium hydroxide, while it can not significantly improve morphology of products. Taking magnesium lactate and brucite as raw material, the conversion of crystal through direct hydrothermal within 48 hours can not achieve.(2) Preparation of magnesium hydroxide through direct conversion in which brucite/MgO was induced by magnesium lactate. The dosage of MgO, reaction time and reaction temperature were investigated to carry on single factor experiment. The results show that the addition of light magnesium oxide in the brucite is beneficial for transformation of the lattice structure of brucite, and the crystal lattice structure of the brucite while be changed when MgO takes 30% and more in total amount of Mg, the lattice structure changes will occur. MgO will react with deionized water to produce magnesium hydroxide firstly in the reaction process, which plays a role of crystal seed and as a result, the crystal lattice structure of the brucite will be changed. The extension of reaction time is beneficial for a complete transformation of lattice structure, while increase of temperature is beneficial for decrease of the surface polarity. Magnesium hydroxide was prepared when the amount of magnesium oxide is 30% and the reaction time and temperature is 36 h and 200℃ respectively, which shows six party sheet evenly arranged.(3) Preparation of magnesium hydroxide through direct conversion in which activated brucite was induced by sodium p-toluene sulfonate. The single factor experiment was performed to investigated the reaction time, reaction temperature and NaOH solution concentration. The function of the inducer and the performance of the cycle were explored. The results show that the sodium p-toluene sulfonate is benefit of nucleation and growth of the crystals, which plays a similar "crystal orientation agent" role on the morphology of Mg(OH)2. When the reaction conditions are as follows: the mole ratio of sodium p-toluene sulfonate and brucite powder was 1:20, the filling 70%, the hydrothermal time 12 h, the hydrothermal temperature 200℃, the concentration of NaOH solution 5 mol·L-1. The nano magnesium hydroxide produced was six piece of uniform rules. The process of brucite preparation of magnesium hydroxide was effectively shorten by the method that sodium p-toluene sulfonate induced the activation of brucite directly into preparing magnesium hydroxide. The repeated use of sodium p-toluene sulfonate has good performance, which greatly reduce the cost of production. |
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