Mine waste reuse and reprocessing: an important step for the implementation of the circular economy in Europe

Abstract

<p>Whereas there are growing needs for mineral resources (metals for the energy and digital transitions<br>and construction materials), the mining industry must produce them from poorer, more<br>heterogeneous and more complex deposits. Therefore, volumes of mine waste produced (including<br>tailings) are also increasing and add up to waste from mining legacy. For example in Europe (x27): 732<br>Mtons of extractive waste are generated per year and more than 1.2 Btons of legacy waste are stored<br>all over the European territory. The localisation (and potential hazards) are well known and covered<br>by the inventories carried out in EU countries under the Mining Waste Directive.<br>At the same time, Europe is implementing the circular economy approach and put a lot of emphasis<br>on the resource efficiency concept. In this context, reprocessing operation to recover both metals and<br>mineral fraction is studied with the objective of combing waste management (reducing final waste<br>storage and long-term impact) and material production from secondary resources.<br>Numerous industrial experiences of reprocessing of mine waste and tailings exist all over the world to<br>recover metals such as copper, gold or critical raw materials - CRM They concern mainly active mine<br>where both primary and secondary resources are considered in profitable operations; for example in<br>Chile, South Africa, Australia. Mineral fraction recovery is often not considered which still leaves the<br>industry with a high volume of residual minerals to store and manage.<br>In addition, legacy mining waste are potentially available for reprocessing. In this case, numerous<br>mining liabilities issues need to be managed. Some of the European legacy mining waste have residual<br>valuable metals that could be recovered but some of them have very low metal contents. In Europe,<br>classical rehabilitation operations – usually at the charge of member states and local authorities – is<br>the priority and concern the reduction of instabilities and impacts to the environment including heap<br>remodelling, covering and water management with long-term treatment. Completing this risk<br>management approach by a circular economy one is a very active R&D subject in EU27.<br>This presentation will give an overview of EU research projects which tackled the legacy mining waste<br>challenge from inventory to process development. Several process flowsheets to recover metals were<br>designed and tested on several case studies with CRM – REE, Co, W, Sb, etc. Initiatives to reuse mineral<br>fraction are also underway and should be ready for commercialisation in the coming years.<br>Resources efficiency concept and the circular economy implementation starts on mining sites. In order<br>to facilitate the implementation of this approach, the technical solutions will need to be included in<br>innovative global initiatives covering also legal (liability management), environmental (Life Cycle<br>Analysis approaches) and social (acceptance) questions.</p>