Particle size control method of ceramic powder prepared by wet chemical method

Abstract

The invention discloses a particle size control method of ceramic powder prepared by a wet chemical method. The particle size control method comprises the following steps: adding a combustible to initial powder prepared by a wet chemical method, uniformly mixing, drying, and calcining so as to obtain the ceramic powder, wherein the combustible is a solid particle combustible which can be completely burned off at a temperature which is below calcination temperature and is free of fusion and remained ash. The particle size control method is simple, convenient, easy to operate, economical and practicable; and the sintering degree among nano-powder particles in a calcination process can be controlled by adding the combustible, so as to reduce and control agglomeration particle sizes of nano-powder, so that the nanometer ceramic powder with uniform compositions and controlled particle sizes is realistically and effectively obtained.

Description

technical field [0001] The invention relates to the technical field of ceramic powder preparation, in particular to a method for controlling the particle size of the initial ceramic powder prepared by a wet chemical method during the sintering process. Background technique [0002] Wet chemical method refers to the method of preparing materials through chemical reaction with the participation of liquid phase. It is a commonly used preparation method in modern powder engineering, especially nano-ceramic powder. Wet chemical methods mainly include homogeneous precipitation method, sol-gel method, hydrothermal method, microemulsion method, reverse microemulsion method, organic matter assisted combustion method, etc. In addition to the hydrothermal method, other methods first obtain the initial powder through chemical reaction (here, the initial powder refers to the precipitation obtained by filtration for the homogeneous precipitation method; the sol-gel method refers to the pr...

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Problems solved by technology

[0003] (1) The drying process can easily lead to powder agglomeration

[0004] In the solution stage, even if the initial powder with a particle size of about 5-30nm can be obtained by controlling the reaction conditions, solution properties, and adding a dispersant; but in the drying stage, due to the existence of the liquid phase, the formed surface tension makes the resulting powder Severe agglomeration between initial powders

Although the agglomeration can be reduced to a certain extent by reducing the surface tension of the solvent and adding a dispersant (for example, the preparation of nano-zirconia powder by homogeneous precipitation, the chloride ions are removed by multiple washings, and finally the precipitate is washed with ethanol as a solvent. , to reduce the surface tension between powder particles), but obviously, these methods not only increase the process difficulty and preparation cost, but also cause environmental pollution to a certain extent

[0005] (2) The calcination process leads to hard agglomeration of the powder

If the hard agglomeration is reduced by lowering the calcination temperature, a longer processing time is required, and it is easy to cause some hydroxides to be incompletely converted

[0007] Although the hydrothermal method does not require calcination, this method requires specific high-pressure equipment; and because the production is intermittent and the production efficiency is low, it has not been widely promoted in actual production

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