Browsing by Subject "closure of mine"

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Access status: Open Access ,
Application of stabilizing highly thickened slurries for filling of flooded shafts
(Wydawnictwa AGH, 2005) Kleta, Henryk; Plewa, Franciszek; Strozik, Grzegorz
The paper presents the results of research on the use of highly thickened slurries for closure of abandoned shafts. Two fill slurry compositions were considered, i.e. mixtures of slag, fly ash, cement and water, one of them containing 15 and the other 30% of cement by mass. In the case of closure of a partially flooded shaft, the fill material or mixture of materials should possess the ability to solidify in a water environment, and after solidification must be proof against soaking and secondary liquefaction. The solidified fill material should also remain stable under the loads resulting from subsequent batches of fill material placed in the shaft. The laboratory test results and analyses showed that strength and strain parameters of the fill material depend not only on the composition of the mixture, but also on the way of transport (transport in stagnant water) and the curing environment - water or dry air environment. Numerical calculations of stress and strain state in the shaft plug performing the function of a revetment plug, conducted for increasing strengths of the fill material and increasing loads exerted on the plug by the thickening column of fill material poured in the shaft, allowed to determine the strength requirements and the technology of solidifying backfill utilized for shaft closures.
Access status: Open Access ,
Problems associated with closing underground mines for economic reasons
(Wydawnictwa AGH, 2005) Dvořaček, Jaroslav
This contribution deals with the economic development of underground coal mines in the last phase of their service life in conditions of the Ostrava part of the Ostrava-Karvina District. The question of alternative development of these mines from the economic point of view is presented here.