Preparation methods of magnesium hydroxide.

Physical pulverization method

The physical pulverization method refers to directly pulverizing ore. Through dry coarse grinding and wet ultrafine grinding, magnesium hydroxide products of the required particle size grade are prepared. The more commonly used ore is brucite.

Ore calcination and hydration method

This method calcines ore and prepares magnesium hydroxide by hydrating the obtained magnesium oxide. It is a process of magnesium oxide dissolution and magnesium hydroxide precipitation. The dissolution of magnesium oxide is the control step. Due to different ore compositions, magnesite is more often used.

Liquid-phase precipitation method

There are two sources of raw materials for this method. One is that magnesite, dolomite, serpentine, etc. are treated by acidolysis or other methods to obtain magnesium salts, which are subjected to precipitation reaction with alkali to prepare magnesium hydroxide. The other is that magnesium salts obtained from seawater, salt lake water and well brine are subjected to precipitation reaction with alkali to prepare magnesium hydroxide.