Disposal of the abandoned mine workings of uranium mines - Case study of Rožná I mine, Czech Republic

Abstract

Having abandoned mine workings, the closure strategy of mine working openings is important in terms of maintaining long-term stability. The paper describes the process of closing the mine workings in the uranium deposit Rožná using unconsolidated backfill. Before backfilling, it is vital to carry out preparatory work underground for ecological, technological or economic reasons. The mine workings backfilling using unconsolidated backfill is preceded by calculations to determine the quantity of the backfill. The stability of the mine workings opening is achieved using a closing sinking platform made of reinforced concrete. The abandonment procedure is framed within the legislation of the Czech Republic, grounded in the handbook by the National Coal Board of Great Britain (NCB, 1982), and has been gradually amended according to the experience with disused mine workings. The Czech legislation dealing with mine abandonment is very advanced and may be applied to modify foreign legislation. The abandonment procedure based on Decree 52 (1997) proposed in this paper is complemented by safety features such as micropilots in the sinking platform or shaft lining check-up before the backfill. The proposed method is applicable in mines with analogous specific conditions, such as mines free of gas hazards and coal dust. The paper concludes with an analysis of risks likely to occur due to incorrect mine closures.