Location
Vimioso (Municipality)
Investment
2,186,389 €
2006 - 2007

Environmental Remediation of the Argozelo Mining Area

Concluded

The former mining area of Argozelo is located in the civil parish of Argozelo, municipality of Vimioso and district of Bragança, in the highest part of the topographic relief overlooking the village, where the master shaft and spoil heaps are located.

Despite the initial grant date, 1898, it was from 1958 with Minargol – Complexo Mineiro de Argozelo, SA that a more systematic method would be developed, the mining of tin and tungsten in Argozelo which, over seven floors, would reach a depth of 170 m and created an extensive network of galleries, some of which were shallow. This would lead to geotechnical difficulties that manifested themselves in the form of landslides and subsidence, with the main shaft collapsing in 1985. That same year, the mine, which employed 160 workers, was closed, and it is easy to imagine its socioeconomic importance to the region.

The former mining area of Argozelo has been the subject of two major environmental remediation operations, which consisted of the following main activities:

  • Implementation of actions defined in the Technical Cooperation Protocol between the Ministry of Cities, Territorial Planning and Environment, Vimioso City Council and the former EXMIN, to be funded by the POA and the Environment Institute. These actions were reflected primarily in the preparation of engineering projects and the completion of the works themselves, integrated into a general remediation plan;
  • Completion of a borehole for connecting the leachate collection tank to the Leitarães gallery;
  • Construction of a basin for precipitation, making use of the entire length of the Leitarães gallery. The discharge is made through a spillway located at the mouth of the gallery;
  • Construction of a limestone bed between the mouth of the gallery and the macrophyte pond to increase the pH and precipitation of the metals;
  • Construction of an excavated macrophyte pond in the area of the waterproofed spoil heap. The supporting layer of the pond consists of Typhas and Juncus;
  • Construction of a cascade between the pond spillway and the river;
  • Installation of a mine water treatment plant (MWTP).

These two contracts were awarded to the consortium Jeremias de Macedo & Cia, Lda / MT3 – Engenharia e Obras, Lda (spoil heaps and heritage) and to MT3 – Engenharia e Obras, Lda. (MWTP), for the total amount of € 1,723,333.52 and a total duration of 270 days.

The investments made were co-financed by the Environment Operational Programme (POA) under the Third Community Support Framework, and allowed the environmental liabilities resulting from mining at this location to be resolved, bringing benefits to local populations through the improvement of current conditions and use of the areas reclaimed for other ends.