Nº03 – The Phosphorite Mine of la Constanza

ATTRACTIONS OF THE VISIT

The phosphorites of Logrosán were made known by the Irish mining engineer William Bowles, who worked in Spain in the 1750s. The Costanaza mine was exploited sporadically from the late 19th century until its closure in 1944, when it was 210 m deep and had 14 levels; some 200,000 tons of ore had been extracted for the manufacture of superphosphate fertilisers that were exported to much of Europe. The number of parallel galleries in the mine is enormous, but only the upper two have been conditioned for visiting. Inside we can contemplate the mineralised lode of phosphorite, gap areas and fault mirrors, geodes, springs, stalactites, folds, mining support arches, and a workshaft of masonry. Outside we can view installations that still retain their original mining structure in perfect condition, such as the factory of fine aggregates, the factory of superphosphates, the pyrite kiln, and the laboratory, which houses the Interpretation Centre of the Costanaza Mine.

The mine is equally rich in intangible values and elements of our mining heritage, such as the mining support arches of masonry, the pipe vault, the exploitation chamber, the María shaft, and the Calle shaft. During the visit explanations are given of the details of the mining and the extraction method, which was known as “top hole” because the miners gradually extracted the lode from upper layers they could not see. Mention is also made of what the miners were like and their working conditions, the humidity, the very primitive equipment, and the lamps, which were initially traditional Badajoz oil lamps and subsequently carbide lamps. Some of these items decorate the walls of the mine.