Coal mining can result in a number of adverse effects on the environment. Open cast coal mines leaves areas of land that are no longer usable and leaves a scarred landscape with no scenic value. Rehabilitation can mitigate some of these concerns. Mine tailing dumps produce acid mine drainage which can seep into waterways and aquifers with consequences on ecological and human health. Subsidence of land surfaces due to collapse of mine tunnels can also occur. During the mining operation methane, a potent greenhouse gas and a constituent of fire damp, can be released. Wherever it occurs in the world, surface mining of coal completely eliminates existing vegetation, destroys the genetic soil profile, displaces or destroys wildlife and habitat, degrades air quality, alters current land uses, and to some extent permanently changes the general topography of the area mined.
Variants of technological schemes of aggregates production by open-cast mine with mobile crushing and grading units is described. The measures to improve safety in open-cast mining are offered, and also ways to increase productivity of open-cast mines by changing the technological schemes and reducing the number of movements of mobile crushing and screening units.
The mining-transport equipment in technological schemes with application of the mobile crushing equipment represents difficult mining system with consecutive and parallel connection of separate technological elements. Reliability of system is defined on the basis of reliability of its components.
At definition of benches height many features and factors are taken into consideration: conditions of burial and property of taken out rocks; necessary intensity of mining work; the planned schedule of strippings; demanded quality given out, from mineral opencast; parametres of drilling-and-blastings; working conditions of excavators and a condition of transportation of ore. The basic condition of correctly chosen bench height is its stability in the course of operation the opencast mine providing safety of conducting of mining operations.
