After publishing two reports about black shale properties in Estonian territory, our efforts are continued from different perspectives.
Data describing the characteristics of black shale is being gathered into a digital database that will contain information about the shale’s geological, geochemical as well as calorific properties. Previous efforts of this kind were aimed to characterise the whole occurrence are of black shale, but the focus is now shifted towards phosphorite deposit areas. This interest is initiated from the fact that black shale might become a valuable by-product of phosphate production. Namely, black shale immediately overlies phosporite in most of the deposits in Estonia, and thus those two might represent a double-resource.
GSE is also starting a drilling campaign in NE part of the country, where the highest grades of V, Mo, and U in the black shale strata are previously known to occur. The primary aim of the drilling is to verify some of the existing information, but the knowledge base will also be significantly improved because the most up-to-date analytical methods will be applied. GSE currently holds the permits to drill 10 black shale and 9 phosphorite wells.
One of the key questions in the possible exploitation of black shale is the applicability of its processing. It is not adequate to state that there has been no processing research performed in Estonia, taking into consideration the works of Ello Maremäe and her co-authors. Besides, production of uranium took place in Sillamäe in the end of the 1940s from Estonian black shale, albeit with low recoveries as well as poor economic performance. In recent years, research of the bioleaching of black shale has been active (see more: http://biotatec.com/ ). In order to set the understanding of the state of the art of black shale processing technologies into perspective, we are compiling a review article on this subject.
- Johannes Vind