Investigation of perlite particles heat treatment in fluidized bed of inert medium

Results on perlite particles expansion into inert medium fluidized bed apparatus are presented in this paper. Narrow fractions were subjected to expansion of material from the Berehove deposits in Ukraine. In some experiments, raw material was preliminary heated in order to remove bound structural water. As a result of such thermal treatment the content of bound water, which is an expanding agent, was regulated within the range 5.2-1.5%. Processed experimental data allow observation of a significant eff ect of residual bound water onto expanding of particles. For particles larger than 160 μm a reduction of bound water can increase an expansion factor. For each particle size there is an own value of bound water content which provides a maximum expansion factor. Upon reaching the maximum expansion factors the spherical particles with transparent thin wall (so-called microspheres) were obtained. Thus, due to preheating about 3% of the all particles of original size deqv = 358 μm with bound water content were transformed to hollow glass microspheres up to 1000 μm size and bulk density 82 kg/m3. © 2013 by Begell House, Inc.