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A significant quantity of available hard coal reserves in the area of Upper Silesian Basin in the Czech Republic occurs below the areas where surface mine subsidence is unacceptable or may be only minimal. An effort is made to mine these reserves by means of a new, mining method yet not approved for the joint-stock company OKD, a.s., namely a special modification of the continuous mining method Room & Pillar. The main objective is to eliminate the mentioned surface restraints by leaving stable pillars of coal to support the overlying strata. For this reason, CSM Sever, Mining Plant 2 of OKD, a.s. realised a test run to verify the problems arising during mining at high depths, when implemented in an area where it has never been used before. The article is based on published in Journal of Mining Science in the year 2015. In the article, the authors are concerned with the description of stress-strain monitoring of pillars left after test operation, including its continuous evaluation and evaluation of important operating conditions and activities. The objective of monitoring is to gather sufficient information to assess whether the Room and Pillar extraction method can be used in areas where there is a risk of rockburst.

In this paper, the authors focused on the assessment of the individual methods to prevent coal and gas outbursts. The first part deals with a characteristic of this anomalous phenomenon and some basic methods of coal and gas outburst prevention. The second part presents the economic assessment of the costs necessary to ensure the possible prevention methods in the coalface 080 211 in the locality of the Paskov Mine, Mining Plant 3, OKD as, Czech Republic. In this coalface, a simulation method was used for calculating costs for the drift length of 100 m for the use of various prevention methods (irrigation, relief boreholes, relief blasting). The results show the cost of preventive measures during mining intended to eliminate and protect against the formation of coal and gas outbursts. The measures are compared applying the principle of the decision analysis. Four criteria are used for the mutual comparison of the methods (costs, effort, efficiency, time consumption). The comparison has shown that the optimal method to prevent coal and gas outbursts is irrigation.

No abstract

Natural ventilation in a mine is ventilation without the use of means of artificial ventilation. The flow of mine air is induced by the difference between the mass column in an intake and that in a return. The difference in mine air density is a result of difference between the temperature of intake air and that of return air. To a certain extent, the influence of differences in mine air humidity and chemical composition can act as well.Gassy mines in the Czech Republic and Ukraine are ventilated merely artificially, i.e. by means of exhaust ventilation. However, even in the case of this type of ventilation, when the total mine air flow is produced by fans, a natural current of air exists and acts in the ventilation network of the mine.Keywords: Mine ventilation, natural pressure drop, temperature, main fan Naturalna wentylacja w kopalni to wentylacja bez wykorzystania środków sztucznej wentylacji. Przepływ kolumny powietrza wymuszony jest poprzez różnicę ciśnień pomiędzy kolumną powietrza na wlocie a prądem zużytego powietrza. Różnica w gęstości powietrza kopalnianego wynika z różnicy temperatur pomiędzy powietrzem wlotowym i zużytym. W pewnym stopniu uwidacznia się także wpływ wilgotności powietrza kopalnianego i jego składu chemicznego.Kopalnie gazowe w Republice Czeskiej i na Ukrainie są przewietrzane przy użyciu sztucznej wentylacji, z wykorzystaniem instalacji wyciągowej. Jednakże nawet w przypadku zastosowania tego typu systemu wentylacyjnego w którym przepływ powietrza kopalnianego w całości generowany jest przez wentylatory, nadal istnieją naturalne prądy powietrza, których obecność i działanie ujawnia się w sieci wentylacyjnej.Słowa kluczowe: wentylacja kopalni, naturalny spadek ciśnienia, temperatura, wentylator główny * VSB