Development of Measures on the Improvement of Dust Environment in the Coal Mines Working Faces
Growth of loads on the coal mine working and development faces, which was noted in recent years in the coal industry, is accompanied by an increase in specific dust formation and specific dust yield. The efficiency of the applied means of complex dedusting in the conditions of increasing intensity of the dust formation and dust intake is significantly reduced. As a result, the dust conditions at the workplaces in the mine workings are deteriorating. The risk of developing occupational pulmonary disease becomes quite high. To improve dust environment, it is required to revise the approaches used for assessment of dust load and reduction of dust content. The analysis is given related to measures, methods and equipment used to combat respirable coal dust in the coal mines of the advanced coal-mining countries. In addition to the traditionally used hydraulic irrigation means, the cases are noted concerning the use of the splitter arms, deflector fins and scrubbers on the shearers, as well as advanced Venturi systems, the optimal location of which is determined based on the results of computer simulation of dust-dynamic processes in the mine workings. In Russia, in the coal mines, according to the existing regulatory framework, the use of wetting solutions is regulated to increase the efficiency of wet dedusting. However, with a change in the material and dispersed composition of the dust aerosol, an adjustment of the irrigation regime is required. It provides for an increase in the concentration of the wetting agent used and the application of other surfactants, which will be more efficient under the new conditions. Laboratory studies results are presented concerning the physicochemical properties and wetting ability of the currently used Elfor mine wetting agent, individual surfactants and the formulations developed. For a more accurate assessment of the risks associated with the exposure of workers to aerosols of predominantly fibrogenic action, the dust load assessment technique is proposed that takes into account the content of the respirable fraction.