The study of the nature of gas distribution in the quarry at stable and unstable states of the atmosphere allows to establish “the actual amount of air ventilating the quarry, taking into account certain atmospheric conditions.On the nature of gas distribution in quarries in the literature there is no information. The main factor of natural ventilation of quarries V.S. Nikitin considers wind energy. This is at variance with our experimental data.

Air exchange in quarries is formed under the action of wind energy and convective flows resulting from the temperature heterogeneity of the atmosphere by height. These factors can act together and separately.In the presence of wind and developed convective flows, air exchange is the most complete and active. The presence of only convective air flows in the absence of wind somewhat worsens air exchange, but provides active transfer of harmful impurities from the lower part of the quarry to the upper zone and beyond the quarry space. Sometimes wind energy is considered sufficient for air exchange in quarries. However, the decisive role in the implementation of air exchange in quarries play convective flows, formed due to a certain temperature stratification of the atmosphere.

The wide introduction of mechanisms with internal combustion engines in the mining industry has led to the need to create protective devices from harmful and poisonous impurities contained in the exhaust gases (carbon monoxide, nitrogen oxides, aldehydes, lead oxides, etc.). Depending on the type of engine and its design, as well as the fuel used, the composition of exhaust gases may vary.

The main harmful component of exhaust gases is acrolein (СН2 = СН - СН - СНО) - a colorless liquid with a characteristic sharp smell of burnt fats. Being in exhaust gases in the form of vapors, acrolein strongly irritates the mucous membranes of the nose, mouth and eyes. Its permissible concentration is 0.002 mg/l (0.00008% by volume). The content of acrolein in exhaust gases depends on the working conditions of the engine and its mechanical condition and, according to our measurements, ranges from 0.00330 to 0.0312%.