Ventilation requirements after dust criteria in fully mechanized longwall districts in Valea Jiului coal basin, Romania

The restructuring of mining activities in Valea Jiului coal basin, imposed by the transition to the market economy and the requirements of the recently adopted environmental law by the romanian government, calls for an increased coal output which is to be mainly obtained from fully mechanized longwall districts. Obviously, it becomes a major problem which has not been solved yet in Romania: assessment of ventilation requirements for maintaining the dust concentrations under the prescribed legal levels. The paper presents the results of experimental and field measurements carried out in a few collieries in the main coal basin from Romania, which were focused on this issue. Dust levels were measured for several different conditions and a statistical data processing allowed us to obtain the optimal field of air Velocities from dust concentration viewpoint. The results of these analyses and research will be used in selection of mining machines in correlation with their operating conditions and environment.