Robots to explore old flooded mines in Europe
An autonomous robot will be developed in Europe to scout for minerals in flooded underground mines, which could lead to some being reopened, as the EU looks to secure supply for critical minerals.
The four-year UNEXMIN project, led by the University of Miskolc, Hungary, has secured €5m through Horizon 2020 to develop the robot and the first meeting of the 13-member consortium was held in late February 2016.
The robotic explorer, known as the UX-1, will be tested on four mines, concluding with a multi-robot test at the former Deep Ecton copper mine, UK. Testing starts at the Kaatiala feldspar mine in Finland, then moves on to Urgeiri?a uranium mine in Portugal, followed by Slovenia’s Idrija mercury mine.
Ecton is considered the ‘final and most ambitious’ project, where the consortium will look to prove the system’s scalability by increasing the number of deployed drones to prove their ability to navigate and communicate using real-time data from on-board sensors. This is planned for 2018.
A new software developer collective, 4dcoders, is a project partner. VMine developer Steve Henley (Resources Computing International) is the coordinator of the group, which includes three other coders – Mike McLoughlin (Rockmate), Hilco van Moerkerk (Georeka) and James Tweedie (GeoMEM). The team will operate the post-processing software that will make sense of the data the drones collect.
Henley said drone exploration could provide early data that would help to determine whether to undertake more expensive exploratory drilling and eventually dewatering. ‘If you can send in a robot to explore, it gives the information that you need to decide whether you are going to do anything more. It also gives you access to these deep levels – the robot, as we are designing it, is going to go down to a depth of up to 500m, and drilling to those depths is expensive.’
This will be the first time autonomous robots have been developed to scout underground mines. It will use technology so far only seen in space and deep-sea exploration. Deep-sea drones, such as the Bluefin-21, have been used to search for the crashed aeroplane MH370 and the designs of these vehicles are constantly being improved by research bodies worldwide, including the National Oceanography Centre, UK.
However, the UNEXMIN robot will be more constrained by size than its deep-sea counterparts, which measure metres in length. It will be spherical, with a diameter of 50cm, and in that space will fit its motors plus sensing equipment that includes optical systems, natural gamma ray sensor, ion-selective sensors and a depressurising measurement cell.
Construction of the first prototype will follow component validation, with post-processing and data analysis tools developed in parallel.
John Barnatt, Senior Survey Archaeologist at the Peak District National Park Authority, said geologists have ‘long bemoaned’ the inability to reach a full understanding of the mineralisation caused by the folding of the carboniferous limestone at Ecton. What is known of the hundreds of metres of underground passages at the mine is based on 2D mine elevations from the 19th Century and surviving mine accounts. ‘Plotting of the chamber walls underwater should make a significant contribution to our knowledge,’ Barnatt said. ‘Much could be learned of their configuration from modern exploration.’
Urgeirica uranium mine, Portugal
Mined from 1913 to 1992, ore processing facilities closed in 2001. Six shafts reach a maximum depth of around 500m. There were 60 deposits exploited around the area, in central-northern Portugal near the city of Viseu, with Urgeirica including four of them. There is still 15 Mt of tailings at the mine.
Kaatiala quartz mine, Finland
A pegmatite quarry mined for quartz in the 19th Century. Later, Kaatiala was mined from 1942 to 1968 for mainly potash feldspar. The production amounted to 160,000 tonnes of feldspar and 30,000 tonnes of quartz. Additional production included muscovite (700 tonnes), columbite (5 tonnes), l?llingite (5 tonnes) and 18 tonnes of beryl.
Idrija mercury mine, Slovenia
Discovered in 1492 and closed in 1995, the UNESCO World Heritage Listed mine was the second-largest mercury mine in the world at its peak, behind the Almad?n mine in Spain. It is estimated that, during its 500-year life, 107,700 tonnes of mercury was extracted.
Deep Ecton copper mine, UK
Mined from the Bronze Age to the 1890s, the mine was at its peak in 1786, when it produced 4,000 tonnes of copper. Shafts go as deep as 411m below river level.