Metodický postup pro stanovení emise metanu z uzavřených dolů.

Abstract

The dissertation deals with the methodical procedure for the determination of methane emissions from closed mines. Uncontrolled exits of mining gases to the surface of old mining works and of damped, liquidated and closed gaseous mines may occur in the protected deposit area, and the mining areas of the damped, disposed and closed fluent mines. This is particularly dangerous in areas with a surface build-up in contact with the subsoil and in the case of sewerage and engineering networks, where explosive or suffocating gases may accumulate in the building site and after the initiation of their potential explosion, or the displacement of oxygen from the atmosphere and the formation of an unbreathable atmosphere.

The basic explosive component of the mine gases is methane, whose explosiveness in the air mixes in the range of 5-14 %; in the presence of oxygen, it is min. 12 %. Methane contained in mine gases coming out of closed mines is generally not an explosive mixture due to oxygen deficiency. However, the explosive mixture can be mixed with the air when penetrated into enclosed building spaces.

An explosion of a gas mixture may occur provided methane is in a concentration corresponding to the explosive range, and initiation, i.e. the supply of energy to initiate a chemical reaction – i.e. an explosion. This initiation in connection with buildings can be caused primarily by electrical equipment, open fire or mechanical spark, or by other means. Another risk arising from the exits of mining gases into buildings is the formation of air with reduced oxygen content due to its displacement with outgoing gases.

The existence of a hazard resulting from uncontrollable exits of mine gases to the surface was demonstrated by a number of extraordinary events in the area of face working places of mines in the run-down phase, liquidated and closed mines, and old mining works in the OKR.