Crystal transition device for tetragonal barium titanate nanopowder synthesized by hydrothermal method

Abstract

The invention discloses a crystal transition device for tetragonal barium titanate nanopowder synthesized by a hydrothermal method. The crystal transition device comprises a crystal transition furnace, a feeding system, a furnace body, a cyclone collector, a bag-type dust collector and a high-pressure centrifugal fan. The crystal transition furnace comprises the feeding system and the hollow furnace body, the feeding system is penetratingly arranged at one end of the bottom of the furnace body, and a feeding motor is arranged in the feeding system. The crystal transition device has advantagesthat compact structure and availability for continuous production are realized, crystal is high in near-spherical dispersity after transition, and crystal abnormal growth and impurity introduction areavoided. Especially, due to fluidized transition of the powder in the crystal transition furnace, mass transfer in a crystal transition process is effectively avoided, and accordingly crystal abnormal growth is avoided. In addition, extra crystal damages and energy consumption resulted from thin layer calcining, crystal abnormal growth and pulping, sanding and drying in a later stage in traditional crystal transition are avoided.

Description

technical field [0001] The invention relates to a chemical production device, in particular to a crystal transformation device for crystal transformation from cubic barium titanate to tetragonal barium titanate synthesized by a hydrothermal method, and belongs to the application technical field of crystal transformation devices. Background technique [0002] At present, the high-purity barium titanate nanopowder used in the electronics industry is mainly synthesized and produced by three methods: solid phase method, solution co-precipitation method and hydrothermal method. The hydrothermal barium titanate is widely used in MLCC (multilayer chip ceramic capacitor), dielectric ceramics, piezoelectric transducers and other fields because of its controllable Ba / Ti ratio, good dispersibility, and high purity. The production of barium titanate by hydrothermal method mainly utilizes titanium source (titanium hydroxide or metatitanic acid) mixed with excess barium source (barium hyd...

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Problems solved by technology

[0004] The purpose of the present invention is to solve the problem of abnormal crystal growth and mass transfer process during the crystal conversion process of the traditional calcination process, resulting in hard agglomeration of the powder, which must be dispersed by a sand mill in the later stage, and the obtained barium titanate powder or poly There are certain defects at least, and these defects are very unfavorable when applied to MLCC manufacturing, especially MLCC products with small size, high withstand voltage and high temperature stability, and seriously affect MLCC manufacturing, especially small size, high withstand voltage and high temperature. Due to the production quality problems of stable MLCC products, a crystal transformation device for synthesizing tetragonal barium titanate nanopowders by hydrothermal method is proposed

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