Alternative ways to supply Rare Earth Elements: extractive waste recovery.

Abstract

Rare Earth Elements (REE) are considered to be highly "critical" by the European Commission because the concentration of global supply and their use in a wide range of emerging technologies (e.g. smart phones, electric cars and wind turbines) and this at a time of increasing geopolitical tensions. According to the European Commission’s assessment, the demand for rare earth elements is expected to increase more than fivefold by 2030. Today, Europe is dependent on imports of these minerals, where China completely dominates the market, a factor which increases the vulnerability of European industry. Alternative sources of REE in Europe, such as recovery of quarrying and processing waste, are being considered. This research, part of an italian project NODES, wich has received funding (PNRR) from the EU, about circular economy and recovery of mineral waste, focuses on the possibility to recover REE from extractive waste. The investigated area cover Piedmont Region in northern Italy. Waste materials from gneisses and granites (ranging from blocks up to residual sludge) used as dimension stones were characterized for volume, chemistry, mineralogy, and texture. Based on the first analyses carried out, the most interesting contexts are those related to gneisses in Luserna Stone and Verbano Cusio Ossola quarrying area and to quartzites of Monte Bracco quarrying area. Thanks to a proper treatment activity (grinding, screening and magnetic separation), these materials, present in past extractive waste facilities and in extractive waste coming from exploitation and working activities, could be used to recovery of REE. After the first phase, connected to “waste” characterisation, the following activities will be linked to processing of the richest samples to exploit (at Laboratory level) REE, and to economic issues. An additional step will include leaching extraction tests (always at laboratory scale) to identify the best and most sustainable technique to extract and separate REE from the sampled extractive waste.   Key words: Rare Earth Elements, Critical Raw Materials, Supply-chain, extractive waste, mining waste, leaching, magnetic separation.