Effect of agglomeration during coprecipitation: Delayed spinellization of magnesium aluminate hydrate

Soumen Pal, A. K. Bandyopadhyay, S. Mukherjee, B. N. Samaddar, P. G. Pal
2010 Bulletin of Materials Science  
Precipitation of magnesium aluminate hydrate with faster addition of ammonia at desired pH causes agglomeration. Agglomerated powder, without any further treatment, on calcination forms intermediate compounds at low temperatures (≤ 900°C). The intermediate compounds on further heat treatment (≥ 1000°C) decompose into MgO, MgAl 2 O 4 and α-Al 2 O 3 . Effect of agglomeration and absorption of foreign ions such as Cl -, SO 2 4 -, and NH + 4 in complex compounds probably cause loss of Al 3+ and Mg
more » ... ss of Al 3+ and Mg 2+ ions during heat treatment, and stoichiometry changes. Powders prepared by continuous method with better control of process parameters than batch process yields better spinellization.
doi:10.1007/s12034-010-0069-x fatcat:borkhq5mu5hghchvyhbw36a62u