Introduction to Drying Methods for Zirconia Ceramic Powder

Drying the powder is also an important step in the preparation of zirconia ceramic powder. Only after drying the powder particles can a relatively pure zirconia ceramic powder be obtained. Below, Kezhong Ceramic Factory will introduce how it is dried.

A key problem to be solved in preparing nano ZrO2 powder using wet chemical method is how to dry the particles to eliminate or reduce the agglomeration generated by this process. The mechanism of agglomeration of powders in the drying process is that on the one hand, the smaller the particles, the greater the surface energy; on the other hand, the existence of solid-liquid interface and the effect of liquid surface tension make the liquid in the colloid prone to collapse of gel pores and aggregation and growth of particles during the volatilization process. Therefore, it is very important to adopt appropriate drying technology and process conditions.

Zirconia ceramic parts

According to the current research status, the drying methods proposed include direct high-temperature calcination method, freeze drying method, spray drying method, supercritical fluid thousand drying method, solvent displacement drying method, etc. Let's briefly introduce the first two.

(1) Direct high-temperature calcination refers to the process of placing the precipitate at high temperature and dehydrating it through drying and high-temperature calcination. Although this method is more economical and convenient, it is prone to hard agglomeration, making it difficult to obtain satisfactory nanoparticles.

(2) The freeze drying method is to freeze the gel into ice, and then sublimate and dehydrate it under low temperature and pressure, which makes full use of the relationship between the water treatment, surface energy and temperature. When water freezes into ice, its volume expands. The expansion force of water in the phase change process causes the colloidal particles that were close to each other to expand. At the same time, the formation of ice fixes the position of colloidal particles in it, which limits the Brownian movement and mutual contact of colloidal particles, thus preventing the aggregation of nanoparticles in the drying process and effectively preventing the formation of agglomeration. The powder prepared by freeze-drying method has uniform composition, no need for crushing treatment, and high purity. However, industrial equipment has high cost, high energy consumption, and low equipment efficiency, making it difficult to achieve industrialization.

After producing dry ceramic powder, Kezhong Ceramic Factory can shape the powder and perform ceramic finishing to obtain various precision ceramic parts

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