A precipitation reactor for producing ultrafine cerium carbonate

Abstract

The invention relates to liquid-liquid mixing reaction precipitation devices, and in particular relates to a precipitation reactor for producing ultra-fine cerium carbonate. A main body of a kettle body is a cylinder body, wherein the lower end of the cylinder body is closed to form an inverse truncated cone shape, and the central part of a seal head at the bottom of the kettle body adopts an internal cone shape. According to the precipitation reactor disclosed by the invention, fluids in upper and middle areas form axial circulation, and the fluid in a bottom area of a crystallizer forms radial circulation so as to ensure that the crystallizer is large in internal circulation quantity and relatively short in mixing time, the shearing rate can be significantly increased, and micro-mixing and micro mass transfer of liquid-liquid phase reaction materials can be enhanced; areas with poor mixing cannot exist, deposited dead angles cannot be formed at the bottom, and precipitation particles are high in suspension efficiency and relatively uniform in distribution of solid hold-up; and good stirring effects can be achieved under relatively small stirring power, and the energy consumption can be reduced. Cerium carbonate prepared by using the precipitation reactor disclosed by the invention is relatively fine in particle size, narrow in particle size distribution range and relatively low in cost, and is suitable for industrial application.

Description

technical field [0001] The invention relates to the technical field of a liquid-liquid mixing reaction precipitation device, in particular to a stirred tank type precipitation reactor for producing ultrafine cerium carbonate. Background technique [0002] At present, the preparation methods of ultrafine cerium carbonate powder are divided into physical method and chemical method, and precipitation method is the most widely used in chemical method. The reaction precipitation process is a complex mass transfer process, which is a process of producing insoluble or insoluble solid substances by means of chemical reactions, usually accompanied by secondary crystallization processes such as crystal aging, coalescence and fragmentation. Cerium carbonate is usually prepared by adding soluble cerium salt to a precipitant such as ammonium bicarbonate and other precipitating agents for rapid reaction and precipitation. Control factors such as the addition method and mixing state of the...

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Problems solved by technology

And prior art devices, such as a kind of rare earth oxalate precipitation reaction device disclosed in Chinese patent CN203782211, its typical structure is as follows Image 6 , in order to improve the stirring intensity, three sets of inclined-blade paddle stirrers are installed on the stirring shaft. Although the stirring circulation speed has been increased, it is still a large axial circulation flow, and the shear rate and shear stress are not significantly increased. Stirring However, the power consumption is greatly increased, and there is still a dead zone in the bottom flow, which is prone to the deposition of solid grains, making the generated oxalate larger in size and uneven in size distribution

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