Parameters for spray drying ZnO nanopowders as spherical granules

Abstract

Spray drying is a versatile method to perform atomization, drying, and granulation.Spray dryers enable agglomeration of particles into a spherical granule form with a nano-meter size and thus very high specific surface areas (SSA). For this, the synthesized Zn(OH) 2 precipitate should be concurrently atomized and dried under desired spray drying conditions. The drying process has many complex and critical parameters. In order to obtain ZnO nanopowders in a spherical granule form the inlet temperature and the flow rate of the hot air, the feeding rate and the solid- 114 m 2 Ág À1 (average particle size: 9-51 nm according to the SSA analyses) depending on the drying process parameters. The ZnO nanopowders have a soft granule structure according to the SSA analyses. Therefore, there is no need to grind the powders. They can be easily processed at all of the mixing and forming steps. In addition, they do not contain any contamination coming from grinding. K E Y W O R D Satomization, spherical granule form, spray dryer, ZnO nanopowders

Partial flocculation for spray drying of spherical mixed metal oxide particles

“…Many current efforts explore the use of particle reactors for STWS due to high surface area relative to monolith structures and for the ability to flow around a system. Spray drying is commonly employed to make high‐performance, fluidizable particles for chemical looping combustion and other applications …”

“…Many groups have found that the composition and properties of the feed solution/slurry has a significant impact on final particle properties . Feed suspensions comprise micrometer sized particles and thus can be considered a colloidal dispersion .…”