Recovering Y and Eu from Waste Phosphors Using Chlorination Roasting—Water Leaching Process

Authors:
Open Access
Publisher website
Google Scholar
Abstract
Recovering Y and Eu from waste phosphors using chlorination roasting followed by a water leaching process was investigated in this study. Firstly, by chlorination roasting and water leaching, Y and Eu elements present in waste phosphors were efficiently extracted into a leach solution. Secondly, the majority of the impurities in the solution can be removed by adjusting the pH to 4.5 using a Na2S and NH3·H2O solution. Thirdly, the rare earths can be precipitated afterwards by adding a H2C2O4 solution and adjusting the pH to 2.0. Then rare earth oxides (REOs) can be obtained after calcining at 800 °C for 1 h. The characterization study of the waste phosphors and the rare earth oxide products was performed by XRD, XRF, and SEM-EDS analysis to determine the phase and morphological features. Influences of the factors, such as roasting temperatures and time, the addition of ammonium chloride on the roasting of waste phosphors, as well as the pH and the amount of oxalates on the precipitation of Y and Eu, were investigated. The maximum grade (99.84%) of mixed rare earth oxides and recovery rate (87.35%) of Y and Eu were obtained at the optimized conditions.
Funding Information
  • Key Projects in the National Science & Technology Pillar Program during the Twelfth Five-year Plan Period (2014BAC03B07)
  • Key Laboratory for Solid Waste Management and Environment Safety, Ministry of Education of China, Tsinghua University (swmes 2011-03)
  • the fundamental research funds for the central university (WUH165208005)

This publication has 10 references indexed in Scilit: