PRECIPITATION OF MG(OH)(2) BY THE REACTION OF MG(NO3)(2) WITH AMMONIAIN A FLOW REACTOR

The influence of ammonia content and of the retention time on the crys tal size distribution of magnesium hydroxide prepared by the precipita tion from Mg(NO3)(2) solutions in a flow reactor was investigated. The temperature of the reacting mixture was 80 degrees C. It was found th at the higher is the content of ammonia and/or its surplus with respec t to the stoichiometric demand, the larger are the Mg(OH)(2) crystals. The longer is the retention time, the lower is the fraction of the pa rticles smaller than 24 mu m in the product. When the retention time o f Mg(OH)(2) in the reactor is shorter than 3 min, irregular agglomerat es of Mg(OH)(2) with sharp edges are formed while at the retention tim e longer than 5 min the aggregates have a round shape.