E-waste mining and the transition toward a bio-based economy: The case of lamp phosphor powder

Replacement of conventional hydrometallurgical and pyrometallurgical process used in E-waste recycling to recover metals can be possible. The metallurgical industry has been considered biohydrometallurgical-based technologies for E-waste recycling. Biorecovery of critical metals from phosphor powder from spent lamps is an example of transition to a bio-based circular economy. E-waste contains economically significant levels of precious, critical metals and rare-earth elements (REE), apart from base metals and other toxic compounds. Recycling and recovery of critical elements from E-waste using a cost-effective technology are now among the top priorities in metallurgy due to the rapid depletion of their natural resources. This paper focuses on the perceptions of recovery of REE from phosphor powder from spent fluorescent lamps regarding a possible transition toward a bio-based economy. An overview of the worldwide E-waste and REE is also demonstrated to reinforce the arguments for the importance of E-waste as a secondary source of some critical metals. Based on the use of bioprocesses, we argue that the replacement of conventional steps used in E-waste recycling by bio-based technological processes can be possible. The bio-recycling of E-waste follows a typical sequence of industrial processes intensely used in classic pyro- and hydrometallurgy with the addition of bio-hydrometallurgical processes such as bioleaching and biosorption. We use the case study of REE biosorption as a new technology based on biological principles to exemplify the potential of urban biomining. The perspective of transition between conventional processes for the recovery of valuable metals for biohydrometallurgy defines which issues related to urban mining can influence the mineral bioeconomy. This assessment is necessary to outline future directions for sustainable recycling development to achieve United Nations Sustainable Development Goals.