Abstract
Introduction: The emerging era of lunar exploration aims to develop a more sustainable approach, which would require careful planning, preparation, and execution of surface operations, utilising the available resources on-site efficiently while minimis-ing the impact on the local lunar environment [1]. To realise this vision, significant technological developments are taking place for lunar in situ resource utili-sation (ISRU) [2], mainly utilising terrestrial analogues. However, the aspects of lunar ISRU research could be of immediate relevance to terrestrial applications , such as in the mining sector, which faces many similar challenges. Thus, a synergistic approach involving lunar ISRU research with potential terrestrial applications could make critical contributions to areas such as raw materials and circular economy. Context: Several missions are in progress or being planned to enable the surface exploration of the Moon through human-robotic partnerships. These lunar surface operations are likely to involve extended stays for astronauts, including at locations that have never been visited by humans before (e.g., polar regions of the Moon or the far side). Regardless of the landing location, the most readily available resource at the Moon is the regolith, which could provide a feedstock for the extraction of critical elements such as hydrogen, oxygen, and other metals, besides being beneficial for construction processes such as 3D printed habitats, tools, and other structures [3,4]. Techniques are being developed to handle, process, and utilise the entirety of lunar regolith so that it produces zero waste. A comparable need exists on Earth in the mining sector where traditionally, a large amount of 'waste' is produced in extracting the target element(s), leaving a large 'footprint' that is often environmentally damaging and sometimes poses a danger to local communities. Thus, there is a tremendous potential for applying some of the techniques developed for lunar ISRU to the remediation of historic mine 'waste', and integration into current and future mining operations to improve the efficiency of mining itself while enabling cross-fertilisation of ideas between practitioners in the space sector and terrestrial mining and manufacturing industries. A new approach: Inspired by our lunar ISRU work, we have recently embarked on a project which involved a survey of legacy mine sites in north Wales, UK, which has witnessed centuries of mining activity for metals such as Cu and Zn, along with roofing material such as slates. We conducted fieldwork to collect samples of mine 'waste' from four historical mine