Recycling of rare earths from lamp phosphor waste: Enhanced dissolution of LaPO4:Ce3+,Tb3+ by mechanical activation

摘要: Abstract With the promoted use of compact fluorescent lamps and increasing amount stockpiled lamp waste, phosphors are becoming an interesting secondary source for critical metals (yttrium, europium terbium). This paper explores on mechanism a new potential hydrometallurgical route to improve recovery efficiency rare-earth elements from green phosphor LaPO4:Ce3+,Tb3+ using mechanical activation as pretreatment step prior leaching. By applying intense frictional action, leaching yields were enhanced 0.9% 81% at room temperature, consequence change in energy. The shrinking core model was employed modelling kinetics calculate decreasing apparent energy unmilled milled samples (from 68 kJ mol−1 1.4 kJ mol−1). difference can be explained by physicochemical changes, including structural decomposition, specific surface area increase particle size reduction, which related corresponding pattern. optimized procedure successfully applied containing mix different phosphors. After sequential removal halophosphate red YOX phosphor, 99.0%, 87.3% 86.3% La, Ce Tb present could dissolved. These observations provide more insight process may contribute sustainable alternative element recycling industry.