Testing new technology and a new way of conducting exploration surveys in the Neves-Corvo Copper and Zinc Mine in Portugal at a 600 m level below surface, is a big milestone for the Smart Exploration Project funded by EU’s Horizon 2020 programme. The outside-of-the-box thinking and the simultaneous exploration survey in the mine tunnels and surface level in a semi 3-D manner is a great leap forward for the European deep mines as well as worldwide.
The Smart Exploration Project, whose partners include Somincor, a subsidiary of Lundin Mining who operates the Neves-Corvo mine, has seen success in the development of new technologies aimed at assisting mining operations in procuring a greater yield of raw materials while also drastically reducing environmental impacts. The latest development saw viable data acquired by using two new prototypes and utilizing mining infrastructures.
The new prototypes, Electric Shaker (developed by Seismic Mechatronics) and GPS time system (developed jointly by Uppsala University and Mic Nordic) were tested in real mine conditions, operating in exploration tunnels and mine as well as on the surface, over the course of two weeks. Somincor/Lundin Mining and LNEG facilitated the logistics of this first challenging field test of the technology.
Nelson Pacheco, Chief Mine Geologist of Somincor/Lundin Mining has been a lead advocate for using existing mining infrastructure, such as tunnels, for exploration and mine planning purposes, rather than only for drilling. He believes that “if we keep doing things in the same way over and over, we will not reach different results. We need to try new ways so that we can reach different and better results”. These tests represent a step in that direction.
Simplistically, the seismic shakers are used to vibrate the ground and thus allowing to map the subsurface using echoes to create visuals, in a manner similar to ultrasound technologies, albeit a bit more complicated, as it was, like a pregnant woman. The new shaker is fully electric and broadband in frequency, making the images more accurate and higher resolution. This technique can be used, among other geophysical methods, to detect faults, dikes and in suitable conditions mineral deposits as well as guiding exploration programs.
The project also developed a new GPS synchronisation system and the project believes that this will be a breakthrough for seismic data acquisition in deep mines to allow utilizing mining infrastructures for exploration and mine planning.
The operation was not confined only to the mine tunnels. While the underground team was acquiring data at depth 600m in the exploration tunnels, the surface team was also harvesting data recorded from the shots generated by the shaker in the tunnels but rather in a peaceful condition. The latest tech to acquire data on the surface without a source on the surface is an evidence of project’s innovative thinking. Sources were later generated on the surface while receivers in the tunnels were still utilized for data recording.
The successful testing of these new prototypes at Neves-Corvo in such set-up represents the latest achievement of the project and its state-of-art vision. “Through instrumenting mining infrastructures using an advanced synchronized in time array of ~1000 receivers (mixed 1C and 3C), Smart Exploration team will explore the down dip and the surrounding mining tunnels by populating seismic receivers synchronized in a manner similar to MRI scanning technology. This should allow resolving structures that often difficult to see using only surface seismic surveys providing also much higher resolution images than ever provided before.” said Project’s Coordinator Alireza Malehmir, Professor of Applied Geophysics at Uppsala.
**This article first appeared in Mining Weekly and in Minex Forum in March 2019.