Study On Preparation Of Li₂CO₃ In A Rotating Packed Bed Reactor

The demand of lithium carbonate?Li₂CO₃?in batteries expanded significantly in recent years due to the fast development of battery and single crystal industries.Material synthesis processes using Li₂CO₃ always include a time-consuming ball-milling step to pulverize powders for providing a uniform reactants mixture.So it is of great significance to prepare Li₂CO₃ with high purity,small size and low cost.A rotating packed bed?RPB?reactor was introduced to prepare well-dispersed fine Li₂CO₃ powders by LiHC03 pyrolysis in this work.Since there is seriously adhesion phenomenon of Li₂CO₃ during the process of pyrolysis,anti-fouling packing is investigated firstly.With usage of the anti-fouling packing,the paper deals with the preparation of ultrafine Li₂CO₃ by the method of LiHC03 directly pyrolysis in a rotating packed bed reactor.The main research contents are listed on the following:?1?Study on anti-fouling packing used in a rotating packed bed reactorThe anti-fouling packing used in a rotating packed bed reactor is optimized through analysis of material and surface property as well as mesh model which conclude 9 kinds of modified and unmodified packing samples and 5 kinds of wire mesh size.It turns out that the packing of ss304-PTFE?stainless steel 304 with surface coating of polytetrafluoroethylene?with the size of 10 meshes can prevent Li₂CO₃ fouling in some degree.Thus,the optimal packing is used in a rotating packed reactor in the following Li₂CO₃ preparation.?2?Study on preparation of Li₂CO₃ by gas-liquid directly pyrolysis method in a rotating packed reactorEffects of operating parameters on particles size and distribution are examined in a rotating packed bed reactor with modified packing by using LiHC03 solution as feed solution and water steam as heating medium under the condition of adding dispersant and not adding dispersant,respectively.Results indicated that prismatic micro Li₂CO₃ powders are obtained under the two kinds of process and the size of Li₂CO₃ particles are sensitive to rotational speed and preheating temperature of LiHCO₃ solution,while the effects of liquid flow rate and steam mass flow rate are limited.The size of Li₂CO₃ particles are effectively decreased to 3?m with the usage of ethanol as dispersant,while it is 9 ?m when there is none of dispersant.?3?Study on preparation of Li₂CO₃ by liquid-liquid directly pyrolysis method in a rotating packed reactor.Effects of operating parameters on particles size and distribution are examined in a rotating packed reactor with modified packing by using LiHCO₃ solution as feed solution and heated ethanol as heating medium.The results showed that the obtained Li₂CO₃ particles are prismatic crystals with the average size of 3 ?m and the size of them is decreased with the increase of the temperature of heated ethanol,flow rate of heated ethanol,the temperature of LiHC03 solution,rotational speed and is decreased then increased slightly with the flow rate of LiHCO₃ solution.