Benefication of Estonian phosphate ore by flotataion

Sole active mining phosphate operation in European Union (EU) is in Finland Siilinjärvi with limited resources available for approximately next 20-30 years [1]. In this context it is important that Estonia holds the largest unused sedimentary phosphate rock reserve in EU. Estonian phosphate is a sedimentary rock composed of variegated sandstone that contains abundant remains (detritus) of (biogenic) phosphatic brachiopod shells [2]. Phosphate enriched beds occur stratigraphically at the transition between Cambrian and Ordovician and the phosphatic sandstones belong to Kallavere formation. The biogenic phosphate is dominated by francolite mineral phase. The P2O5 content of the sandstone beds is quite low varying between 6–20% [3]. However, the brachiopod shells and detritus contain up to 35–37% of P2O5 and sandstone is weakly cemented that allows rather efficient enrichment of the phosphate ore. Despite of its economical and, perhaps, political importance, Estonian phosphate rock is currently not mined or explored due to concerns over the ecological impact of phosphate rock mining. The main concern is on the environmental effects of the rock mining in the inhabited area with numerous settlements and intensive agricultural use. Please download the file below for full content