Coal, ash and environment protection

This paper presents non-selective excavation and cleaning low-grade quality coal from deposits where the waste substance occurs in the form of clay and fine sand. By cleaning such a low-grade quality lignite, three products are made: coarse clean coal for house heating, fine clean coal for thermal power plants and clay-sand tailings, which are used as a protection cover of ash dams from thermal power plants. Applying two-stage cyclone-technology for up-building dam embankments, height stability of ash disposal is achieved. Non-porous clayish waste is used to protect soils under ash-waste disposal. Coating the open sides of ash embankments with waste slurry, which contains humus materials, prevent flying of ash picked by wind. Final upper surface of disposal is also covered with these humus materials and on this way complete remediation of deposit is assured.