Spray Drying of Ferrite Powders and the Characteristics of the Granule

,; ,; ,; ,; ,; ,

J. Korean Ceram. Soc. > Volume 32(5); 1995 > Article

Journal of the Korean Ceramic Society 1995;32(5): 549.

페라이트 분말의 분무건조와 제조된 과립의 특성

변순천, 제해준¹, 홍국선

서울대학교 무기재료공학과
¹한국과학기술연구원 세라믹스연구부

Spray Drying of Ferrite Powders and the Characteristics of the Granule

ABSTRACT

Mn-Zn ferrite granules were prepared by spray drying of the slurry containing different kinds and concentration of binders at various spray drying temperatures and atomizing pressures. The characteristics of the spraydried granules were analyzed according to the processing variables of spray drying and the slurries containing different solid loading and kinds and concentration of binders. Typical shape of the spray dried granules was spherical. The granules spray dried at 15$0^{circ}C$ were more spherical and containing lower hollow percentage than any other granules prepared at higher temperature. The granules prepared at higher atomizing pressures were more spherical and become smaller in size. The granules prepared using slurry containing higher solid loading were larger in size and less defective in shape. As increasing the concentration of binder the number of donut-shaped granules was increased and the size distribution become broader. The granules prepared using the slurry containing PVA 205 were more spherical than those containing PVA 217 and PVA 117. As the amount of granules which were donut-shaped or dimpled increased the compaction response were less effective. The hollows were not fractured completely even at hight pressures and remained after sintering.

Key words: Spray drying, Ferrite, Granule, Compaction, Binder