| 摘要 |
Hydrometallurgical method for the preparation of layered magnesium hydroxide with a narrow particle distribution (d50=0,5-1,5 m, d90=3-10 m) and high crystallinity (specific surface less than 15m2/g), especially suitable for use as a combustion retardant in polymers. The said method relates to the hydration of deadburned magnesia having specific physical properties (specific weight greater than 3,37 g/cm3) and particle distribution (2-75 m with d50=15-20 m) at multiple stages under atmospheric pressure and in the presence of a system of magnesium salts (MgX, wherein X = Cl-, CH3COO-, etc.). The said processleads to the removal of specific accompanying components of the starting material and in combination with the use of further enrichment procedures (e.g. removal of a certain fraction and washing withwater) allows the use of magnesia of natural origin with relatively high content of accompanying components, in contrast to other methods. |
