Study on Separation Experiment of Rare Earth Metal in Waste Rare Earth Fluorescent Lamps

Abstract: With the widespread use of rare earth fluorescent lamps,a large number of used rare earth fluorescent lamps are discarded by consumers in the form of solid waste. After rare earth metals and mercury,and other harmful substances in the waste rare earth fluorescent lamps go into the environment,they can pollute the environment, and enter the human body through the food chain,then can be carcinogenic, teratogenic,mutagenic,and seriously endanger human health.The study of "rare earth fluorescent lamps used in the rare earth separation experimental study" are carried out according to the features such as rare earth phosphors in the form of metal oxide and liquid extraction,using acid leaching the rare earth phosphor,and using wet liquid extraction,rare earth metals in leaching solution will be extracted.The research work will be aimed at studying the new technology which can recovery of rare earth metal from the waste rare earth phosphors instead of handling rare earth phosphors by landfill,in order to reduce waste(or waste fluorescent lamps)harmful to the environment,at the same time, recovery rare earth resources in the rare earth phosphors.The completed work are as follows:(1) study on the impact of leaching rate of waste phosphor on types of acid,the concentration of acid,dissolved temperature,dissolved speed.(2) study on the impact of leaching rate of recovery phosphor on types of acid, the concentration of acid,dissolved temperature,dissolved speed.(3) study on the impact of different acidity conditions on extraction rate of non-rare earth and rare earth elements in the acid leaching solution.(4) study on the impact of different concentrations of P507 on extraction rate of non-rare earth and rare earth elements in the acid leaching solution.The experimental results show that the waste phosphor and recovery phosphor can be dissolved by acid.The leaching rates of waste phosphor and recovery phosphor by sulfuric acid,hydrochloric acid,nitric acid are followed by sulfuric acid>nitrate acid>hydrochloric acid.Thus sulfuric acid is a good leaching agent;And with the increasing concentration of acid and leaching reaction speed,the leaching rate of rare earth metals is also significantly improved.Under the reaction conditions of 45℃and in the speed of 300r,waste Phosphor are leached by 2 mol/L solution of sulfuric acid about eight hours,then leaching rate of Y is 67.9%,leaching rate of Eu is 73.1%.Under the reaction conditions of 37℃and in the speed of 300 r,recovery Phosphor are leached by 2 mol/L solution of sulfuric acid about eight hours,then leaching rate of Y is 75.3%, leaching rate of Eu is 71.5%.Extraction rate of P507 have a significant separation effect to the rare earth elements in the leaching solution.Under the extraction conditions of 15℃, ammonification rate of 30%,rare earth in leaching solution is extracted by 2.0 mol/L P507,then it is oscillated 30 min by speed oscillator,and static stratified two-phase separation after 15 min.The results showed that when pH of the leaching solution is 5, the extraction rate of Y is 92.4%,the extraction rate of Eu is 84.5%,the extraction rate of Al is only 20.4%.So,it can be achieved rare earth separation Y and Eu from phosphor by adjusting the pH value…
Key words: rare earth phosphors; recovery; acid leaching; extraction of rare earth

This entry was posted in Master Thesis. Bookmark the permalink.