La Zarza project

The La Zarza deposit was exploited by open-pit and inland mining for the extraction of crude pyrite, which was transported by rail to the port of Corrales, in Huelva, where it was shipped to various sulphuric acid production centres.

The mining operation began in the middle of the 19th century and ceased its activity in 1991, having produced more than 38 Mt of pyrite. Since then, there have been several investigations aimed at researching a type of mineral called "silicate" which, unlike the "massive" mineral, was not exploited, and the reopening of the activity, with a view to processing metals such as gold and copper. The most important of these are those carried out by the company Ormonde España in the period 2004-2012, in which they defined, through drilling research, mineral resources with more than 11 Mt in the JORC category with interesting Cu and Au contents, particularly in the silicate type of ore, also opening the door to the expansion of these resources in the massive ore, with relevant zinc and copper contents.
1853 – 1866

Discovery of the site by Ernest Deligny. Foundation of the French company Compagnie des Mines de Cuivres d'Huelva.

1853 – 1866
1879 – 1888

The concessions are leased to T.O.S. and work begins on the Corta de los Silos in parallel with the interior work in the eastern area (Algaida).

1879 – 1888
1913 – 1965

Diversification and intensification of mining activity. Extraction winches no. 3 and 4 were built. A few years later, the well-known winch no. 5 and its crushing plant were built.

1913 – 1965
1970 – 1991

The mine went into a long decline that ended in 1991 with the closure of the mine, although water pumping continued until 1995, allowing the cut to be flooded.

1970 – 1991
1991 – 1997

Bureau de Recherches Géologiques et Minières (BRGM), makes researches under a joint venture along with Nueva Tharsis

1991 – 1997
2005-2013

After a series of changes in ownership, further investigations are carried out and an exploitation project is submitted to the administration but never developed.

2005-2013

Project development

In 2023, the second borehole investigation phase was completed with 13 new boreholes (6383 m in total), point load tests (585 tests) and densimetry (467 samples) and sampling for analysis (2346 samples).

The drill cores, in the different campaigns, have been witnessed and photographed with a high resolution camera, prior to their geological and geotechnical witnessing and the sampling and execution of the different tests.
Five of the boreholes were investigated with acoustic and other multi-parameter probes.

With this investigation, the consultancy CSA-Global has defined resources in the JORC category of 107 Mt for the deposit, of which 63% would correspond to the Measured+Indicted Resources category.

In addition, it considers 21.6 Mt of potential resources, which are not included in the JORC category, as they need further investigation.

With the ore obtained from the drill holes, a sample composed of the massive ore and another of the silicate-type ore has been prepared for metallurgical tests to complement those carried out in the past by the Ormonde company. The results of the studies are expected in 2024-2025. With these results, the pre-feasibility study of the deposit can be undertaken.

In pursuit of the extension of known mineralisation and the discovery of new masses, the study of geophysical anomalies is progressing, taking into account both proprietary and historical information, in order to define possible mineral extensions and new exploration targets.

News

Latest news and developments

{"cpt":"blog","style":"3","columns":"3","show":3,"order":"DESC","orderby":"DESC"}
en_GBEnglish (UK)