Põlevkivi kaevise allmaarikastuse jääkide ladestamine Uus-Kiviõli kaevanduses [Bakalaureusetöö. Juhendaja: E. Väli]

There are two outputs of oil shale ore enrichment: commercial stone and tailings. The enrichment residue – mainly limestone – is the by-product of oil shale mining, but its use as a building material has not become very popular in Estonia, because its quality does not meet the established standards. That is why most of the oil shale tailings are currently stored in above-ground repositories. However, this is not the most practical way to protect the environment.

When planning the Uus-Kiviõli mine (to be opened in the coming years), larger-scale reuse of tailings should definitely be considered. One way to do this is to fill in the mined areas.

The aim of this bachelor's thesis is to offer the optimal technical solution and logistic scheme for the storage of tailings from the underground enrichment process in an operating underground harvesting department. The harvesting department has three working chamber blocks, where the tailings using the right storage technologies can be deposited.

Based on this goal and after analysing various possibilities, the author of the dissertation suggests different transport and storage schemes and the corresponding equipment.

At the time of writing, the author belonged to the research team of TalTech Department of Geology working on the project KIK19022 “Underground enrichment of oil shale ore and storage of tailings” and, in addition to technical parameters obtained from the two mining companies, had the opportunity to use reports and other necessary materials provided by the Department.

The drawings and explanatory diagrams provided by AS VKG Kaevandused and EE Kaevandused contributed greatly to the successful completion of the work. On the basis of these materials the author was able to draw his own graphic diagrams given in the Appendices of this work.

Professor Emeritus Enno Reinsalu's calculation models on the enrichment of oil shale ore have been used to derive the number of vehicles needed and to calculate the approximate quantities of tailings.

Based on the analysis performed with the help of real source data obtained from technologists in VKG Ojamaa and Eesti Energia Enefit mines, the author of the dissertation selected the three most suitable options for tailings disposal: storage with a loader, storage with a countinuous loader and a tipper with a push box, storage with a loader and a filler.

After thorough analysis and calculations by the author, the combination of a loader truck and a filler turned out to be the best solution. With this method, it is possible to fill the chambers most efficiently and over the entire height of the chamber.

The analysis of three different schemes showed that the loader alone fills the smallest part of the chamber height, the combination of a tipper and continuous loader can store more than half the chamber height due to the tipper's push box, but cannot store tailings to the full chamber height. 

Tähtajalise juurdepääsupiiranguga lõputöö. Täistekst avalikustatakse 01.07.2025