Author: Besperstov V.E.
Prevention of endogenic fires in explosive seams
A lot of scientists for over 100 years have been working on the examination of the nature of spontaneous coal combustion. However, the initial stage of the spontaneous combustion process is practically unexplored [1].
The fact, that the coal-seam inclined to spontaneous combustion is not equally inclined to combustion within the limits of the whole mine field, has been definitely proved. This, we can speak about the selectivity, zonal character of combustion danger [2].
It is known that some coal-seam are simultaneously inclined to outbursts of gas and coal as well as to combustion. According to the theory "coal-oxygen" in such seams after outburst because of finer graining and extension of the area (surface) of the contact of discharge coal with air, the incubation period of spontaneous combustion must become shorter, leading to forming of centers of endogenic fires. However, during underground mining of such seams the absence of endogenic fires after outburst is also observed. So, some additional physical and chemical activity is needed to fine graining of coal and presence of oxygen in air.
These discrepancies have led to creation of a new hypothesis of the nature of spontaneous coal combustion. The hypothesis is based on the expermentally found characteristic of the mined roch (including coal) to "return" the parent water from pores more than 10-7m during discharge [2,3]. The development of deformation of genetic return is accompanied by emitting from the mined coal of compounds, moistering the products of the caved coal massif, which can be active to coal chemical agents, rock compounds and can be accompanied by emittion of heat which conditions the locality of endogenic fires denger [3].
Obviously chemical composition of the parent water differs absolutely irregularly. That`s why first of all attention should be paid to chemical compounds, interaction with coal of which favours the emission of heat energy, origin of self-heating (spontanious heating).
Skochinskogo mine is one of the foremost enterprises in Donetsk region.
It mines (develops) the seam h'6, which is coal and gas outburst dengerous. In recent years spontaneous coal combustion has been registrated. However, combustion centers appear not in the seam, but in the developed roch after high-intensity outbursts. Outbursts at Skochinskogo mine happen in lower parts of faces adjoined to the coal massif. At low-intensity outbursts endogenic fires do not happen, because fine outburst coal is quickly loaded on the conveyer. At high-intensity outburts (500-1000 t) coal, being in the working for a long time, comdusts, as it is impossible to load it quickly.
Thus it would be expedient to use inhibitor mixtures, which do not contain water [2], and to have a substantial stoch of first facilities for fire extinguishing to eliminate the fire actively at the initial stage.
Literature
- Oxidation and spontaneous combustion of hard fuel / V.I.Saranchuk, A.D.Ruschev, V.K.Semenenko and others // Kiev, 1994. - p.264
- Nikolin V.I., Malyev N.V., Yavruyan A.Y. A new hypothesis of the nature of coal spontaneous combustion, based on development of deformation of genetic return during discharge // Mine resculing: Collection of scientific works / NIIGD - Donetsk, 2004. - p.160-167
- Decrease of traumatism from mine pressure manifestation / V.I.Nikolin, S.V.Podkopaev, A.V.Agafonov and others. - Donetsk, 2005. - p.316