Synthesis and processing of Ca-PSZ pellets by a spray-drying method

Parameters for spray drying ZnO nanopowders as spherical granules

“…The synthesis of the ZnO nanopowders by spray drying of Zn(OH) 2 precipitate was performed first time in our previous study 5 although other oxide powders were produced in literature. [34][35][36][37][38][39][40][41][42][43][44] It is not possible always to synthesize the nanopowders in a spherical granule form by spray dryer. 5,34,44 This is even more difficult for ZnO.…”

“…5,38,45 Spray drying method in the production of ZnO nanopowders was recently introduced into the literature. 5 Spray drying is found to be an efficient production technique in obtaining ZnO nanopowders 5 and the other oxides [34][35][36][37][38][39][40][41][42][43][44][45] by eliminating the requirement of grinding, as the synthesized ZnO nanopowders have a very high SSA and crystalline structure. The conventional drying or calcination of the powders at high temperature is an inevitable requirement to obtain the powders in a crystalline structure for the other production methods such as precipitation and solgel.…”

“…47,48 The transform of the precursor droplets in an aqueous aerosol form of solutions, emulsions, suspension or slurries into solid powders can be carried out by concurrent atomizing, drying and rapid evaporation of the aerosol droplets in a hot air flow at a certain temperature and pressure. [34][35][36][37][38][39][40][41][42][43][44][45] There are many techniques to obtain finely atomized droplets, for example flame spray reactor, 28 ultrasonic atomizer systems, 26,27,30 spray dryer with a nozzle, electrostatic sprayer, or rotary head. [34][35][36][37][38][39][40][41][42][43][44][45] Spray dryers represent considerable importance for sample preparation at manufacturing of high technology ceramic materials.…”

“…The atomization, drying, coating and granulation steps are very critical to obtain easily dispersible powders in soft and spherical granule form having a nano size with high specific surface area (SSA). [34][35][36][37][38][39][40][41][42][43][44][45] These properties of ZnO powders play a significant role on the complete wetting process of particle surfaces during working conditions to prevent the porosity formation in a sintering process and/or adverse properties of ZnO in other applications. Therefore, shape, morphology, agglomerate structure, crystallinity, particle size and distribution, and SSA of the powders are very crucial for all kinds of ZnO applications.…”

“…Thus, there are several spray dryer applications to synthesize the oxide powders. [26][27][28][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48] In this study, the ZnO nanopowders were synthesized by combination of precipitation and spray drying processes. The research focuses on the optimization of process parameters of the spray dryer under different experimental working conditions to obtain ZnO nanopowders in spherical granule form.…”