The electrification of the Almadén mercury mine: causes and consequences.

The Almadén mercury mine, located in Ciudad Real province, South-Central Spain, has been the World’s largest producer of this element worldwide. During its continuous activity of 2000 years, it has provided some one third of the total human production of this element. Many different technologies have been used to perform the mining exploitation of this singular mine, of underground typology, and centred in a complex cinnabar (HgS) orebody, with some 650 m. depth and some 500 m. length.

Mercury is an element which importance for mankind has been diverse in different moments of history: Romans considered its ore, cinnabar, a critical resource, producing the important red stain; Arabs were highly interested on the alchemy concerns affecting this unique liquid metal; during the conquest of America, the discovery of the possibilities of amalgamation in silver recovery produced an intense traffic of this element from Europe to the new discovered continent; during the early 20^th century, the use of Hg fulminate in ammunition also made of this element an important war resource. However, the catastrophic Hg-related poisoning in Minamata (Japan) and Iraq caused the acute decline of the importance of this element, due to the high toxicity of most of its compounds.

In this work we present the results of a heritage-based research of a critical historic moment of the mine exploitation, concerning the transformation of a technically obsolete mining facility in a mine equipped with the latest advances that the use of electrical energy allowed. Besides, this research has allowed to cover an important documentary gap, concerning a period of time that had not been addressed in any previous research work.