Jenni Lie, Hardy Shuwanto, Hairus Abdullah, Felycia Edi Soetaredjo, Suryadi Ismadji, Christian Julius Wijaya, Chintya Gunarto
The optimization study of rare earth elements (REEs) leaching from electronic waste is imperative for industrial-scale development with cost- and energy-efficient processing. Response surface methodology (RSM) with the principle of central composite design (CCD) was utilized to optimize the Y and Eu leaching process from waste cathode ray tube (CRT) phosphor in subcritical water extraction. The analysis of variance (ANOVA) demonstrated that acid concentration and leaching temperature had a significant effect on the leaching efficiency of Y and Eu in subcritical water extraction. The obtained optimum conditions of Y and Eu leaching from waste CRT phosphor were 1.15 mol/L H2SO4 solution as the leaching agent, 166 ± 1 °C, for 27 min in subcritical water at a 20 g/L of solid to liquid (S/L) ratio. The experiment under optimum conditions resulted in 99.07 % and 99.62 % leaching efficiency of Y and Eu, respectively, which had a relative error of less than 1 % from the value predicted by the model. Selective separation of Y and Eu from the leaching solution was carried out as well and it resulted in 87.72 % and 95.11 % recovery of Y and Eu, respectively. The recovery product consists mainly of REE(PO4). This study could be the alternative process for electronic waste utilization as the secondary resources of valuable rare metals promoting the circular economy. © 2024 Elsevier Ltd
Department of Chemical Engineering, Widya Mandala Surabaya Catholic University, Kalijudan 37, Surabaya, 60114, Indonesia; Collaborative Research Center for Zero Waste and Sustainability, National Research and Innovation Agency, Indonesia; Science and Technology Innovation Center for Circular Economy and Green Innovative Resources, Taiwan; Department of Industrial Engineering, Universitas Prima Indonesia, Medan, Indonesia