| 摘要 |
PURPOSE:To obtain high purity Mg(OH)2 having very low CaO and B2O3 contents by bringing light burned magnesia into contact with an acidic soln., carrying out solid-liq. separation, and bringing the solid matter into contact with an alkaline soln. to convert it into Mg(OH)2. CONSTITUTION:MG(OH)2 contg. impurities such as CaO and B2O3 manufactured from seawater is burned at 600-1,200 deg.C, and the resulting light burned magnesia is put in an acidic soln. such as hydrochloric acid or nitric acid of <=3pH. They are stirred, and solid-liq. separation is carried out by settling, filtration or other method. The solid matter is put in an alkaline soln. such as an NaOH soln. of >=12pH, and they are stirred to manufacture high purity Mg(OH)2 having very low CaO and B2O3 contents. This Mg(OH)2 is suitable for use as a starting material for high density magnesia clinker or as a starting material for magnesia clinker for magnesia brick with high strength at high temp.
|
