Milos, the minerals island and its important asset: Bentonite

Abstract

The island of Milos is an active mining site since the Antiquity. Exploitation began with the extraction of obsidian lumps and volcanic lavas and tuffs of specific type, that were used as millstones, sulphur and alum (alunite). Currently, the mining activity is focused on perlite and bentonite, even though some years ago, kaolin, silica, pozzolans and barite were also exploited. Milos bentonite is rather a specialty and not a commodity, as it has multifunctional properties, and therefore used in a wide range of industrial applications, such as foundry sand, drilling muds, lubricant oil, civil engineering structures (waterproofing and sealing, diaphragm wall construction, grouting, concrete workability additive, etc.), cat litter, iron ore pelletizing - Fe metallurgy in blast furnaces and also as “improver” for poor quality bentonites. The peculiar behaviour of Milos bentonites can be attributed to the combination of various geological and hydrogeological factors that occurred at the time of its formation from a glassy tuff precursor. Despite the continuous flourishing of tourism at the island, the mining activity does not face any threats to its existence, as both parties follow the specified regulations and environmental restrictions necessary to allow dual economic growth.