露天开采(Surface-Mining).pptVIP

Studies are currently underway to determine what can be done to improve the technology of in-pit belt conveying. Consideration is being given to the loop belt concept. This method works on the principle that depends on the radial forces generated by putting S curves in the profile of a sandwicked conveyor. By continually varying the curvature, a lift is achieved within “geometrical constraints” conforming to specified mine slopes. ( see Fig.2 and 3) Many high angle conveying concepts have been studied and the sandwick belt conveyor seems the most promising. Return 2.6 Waste disposal — planning and environmental protection aspects 2.6.1 Dump design A waste dump is an area in which a surface mining operation can dispose of low grade and/or barren material that has to be removed from the pit to expose higher grade material. The first step in designing a dump is the selection of a site or sites that will be suitable to handle the volume of waste rock to be removed during the mine’s life. Site selection will depend on a number of factors, the most important of which are: ? 1)????? Pit location and size through time. 2)????? Topography. 3)????? Waste rock volumes by time and source. 4)????? Property boundaries. 5)????? Existing drainage routes. 6)????? Reclamation requirements. 7)????? Foundation conditions. 8)????? Material handling equipment. Fig. 1 shows a waste dump. 2.6.2 Stability of mine waste dumps The overall stability of mine waste sumps is depend on a number of factors such as: 1) Topography of the dump site. 2) Method of construction. 3)?Geo-technical parameters of mine waste. 4) Geo-technical parameters of the foundation materials. 5)?External forces acting on the dump. 6)?Rate of advance (坡度)of the dump face. All of these factors combine in various ways during the life of a mine waste dump to aid in the stability of the dump or to contribute to its instability 2.6.3 Mine reclamation The purpose of