Spray Drying Of Slurry Research Articles

Estimation of Diameter of Granule Prepared by Spray Drying of Slurry with Fast and Easy Evaporation.

In our previous report, a hollow granule model was proposed as a basis of spray drying granulation of slurry in case of fast and easy evaporation. In the present research, the compatibility of the model was examined by comparing the granule diameters obtained from the model with those from granulation experiments. The granules were prepared with slurry of 0.3 μm mono-dispersed silica particles without binder and dispersant by means of a spinning disk. As a result, it was confirmed that the calculated values from the model suited well with the experimental ones, and thus the granule diameter increases with lower rate of disk rotation and higher particle volume concentration of the slurry.

特集 ニューコンポジット材料 アルミナ‐ジルコニア系複合材料の製造プロセスとその評価

In the design of ceramic composites, composition is usually determined by mechanical properties. However, in order to promote industrialization of the composites, it is very important to consider the handling of particles. In this study, first composite particles with high dispersion of two components were formed by spray-drying of slurry, which rate of components was varied. And then we pressed and sintered to obtain A1203-Zr02 composite. If the rate of Zr02 was relative high to give the composites tenacity, particles became light and rough, and ability of packing into mold remarkably went down. As a result, its handling must be harder, and then shrinkage increased in sintering. Besides the dispersion state of each component on the surface of sintered body could be quantitatively evaluated by X-ray elementary analysis.

Effect of mixing state of raw materials in the preparation of Mg 2B 2O 5 whiskers

We have studied various ways of preparing acicular magnesium pyroborate (Mg 2B 2O 5). We formed acicular Mg 2B 2O 5 from the reaction of an MgO-H 3BO 3-KCl mixture (2:3:5 mole ratio) at 850°C. The product, however, contained agglomerates derived from large MgO particles. In a variation, finely mixed raw material was prepared by the spray drying of slurry. The slurry was made by dissolving MgCl 2, H 3BO 3 and KCl in hot water and neutralizing it with KOH. The reaction was again driven at 850°C. The product was acicular Mg 2B 2O 5 without agglomerate, but the crystal length did not exceed 10μm. Finally, Mg 2B 2O 5 crystals 20-40 μm long and 1-3 μm thick were obtained by seeding the slurry with small Mg 2B 2O 5 crystals.