Effect Of Droplet Motion Of Rare Earth Chloride On Preparation Of Rare Earth Nano-oxide

At present,the distribution of existing rare earth minerals is not very uniform geographically,and the rare earth resources with economic mining value is very few.China is a country rich in rare earth resources in the world,not only rich in mineral species,and rare earth elements are relatively complete,rare earth resources ranked first in the world.Rare-earth nanooxides have also become one of the research hotspots of scientists at home and abroad due to their unique physical and chemical properties.At present,there are many ways to prepare rare-earth nanooxides,but many methods have problems due to technological process,cost and other factors.It is difficult to precisely adjust and control the composition and size of powder.Spray pyrolysis is a process in which the precursor solution is sprayed out through the nozzle under the action of an air pump or a voltage regulator,and then atomized into small droplets.At this time,the specific surface area increases dramatically,the reactivity increases,and the reaction such as rapid pyrolysis occurs in the reactor,and finally dries into particles.In this paper,the formation of rare earth nano-oxides is controlled by spray pyrolysis with the law of droplets.In order to detect the particle size of atomized droplets,a PIV measurement technique was proposed.In addition,rare earth nano-oxides were prepared by atomizing pyrolysis experiment,and atomized droplets and product particle sizes were studied under different pressure conditions.In this paper,a cold state test bench suitable for this experiment was built,and PIV measurement technology was used to take complete pictures satisfying the processing requirements;In order to prepare rare earth nanometer cerium oxide with single phase,a hot state experiment platform was built for spray pyrolysis experiment;Image and other software are used to process the images,and the relationship between the captured droplets and the actual droplets is obtained;Taking 0.15MPa as an example,the atomization effect at different moments was studied.By analyzing the velocity vector diagram,velocity cloud diagram,flow diagram and the calculated droplet size distribution,it could be known that the atomization effect achieved a stable effect after 0.55s with the change of time;The atomization effect under six pressure conditions of 0.15MPa,0.2MPa,0.25MPa,0.3MPa,0.35MPa and 0.4MPa was studied.By studying the spray effect,spray cone Angle,velocity vector diagram,velocity cloud diagram and the law of spray flow line,it was known that the droplet size showed a trend of slowing down with the increase of pressure;The preparation of rare earth nanometer cerium oxide under different working conditions was analyzed by spray pyrolysis method.XRD phase analysis shows that the cerium oxide produced is a single phase.According to Xie Le's formula,the half-peak width is inversely proportional to the particle size,so the cerium oxide produced may have the smallest particle size around 0.25MPa;The particle size of the product of rare earth nanometer oxide was fitted to the atomized droplet D₅₀.