نتایج جستجو برای: mine investment
تعداد نتایج: 93940 فیلتر نتایج به سال:
An optimization process is described that can be systematically applied by mine planners to produce life-of-mine schedules aligned with their strategic targets, while maximizing the net present value of the mining operation. The software tool employed uses heuristics and an evolutionary algorithm to generate life-of-mine schedules of production and development activities. Generating such schedu...
According to the shortcoming of traditional artificial management mine-maps, the solutions of dynamic management digital mine-maps were proposed. Analyzing of the main tasks and characteristics in lifecycle stages of mining engineering maps, based on the idea and meaning of lifecycle, first we divided mine-maps lifecycle into seven stages, such as design drawing task assignation, design drawing...
Surface mining in Appalachia disrupts large areas of forested land. Federal and state laws require disturbed lands be reclaimed by re-constructing the landscape and replacing soil materials to provide a rooting medium. If insufficient quantities of native topsoil are available, substitute materials derived from the overburden may be used as soil media. This study examined soil and foliar nutrie...
Federal regulations require that refuge alternatives (RAs) be located within 305 m (1,000 ft) of the working face and spaced at one-hour travel distances in the outby area in underground coal mines, in the event that miners cannot escape during a disaster. The Mine Safety and Health Administration mandates that RAs provide safe shelter and livable conditions for a minimum of 96 hours while main...
Copper-mine tailings are the residual products after the extraction of precious copper metal from copper ores, and their storage can create numerous environmental problems. Many researchers have used copper-mine tailings for the preparation of geopolymers. This paper studies the enhancement of the cementitious activity of copper-mine tailings in geopolymer systems. First, copper-mine tailings a...
in the present study, an investigation was carried out on parvadeh coal mine in tabas, iran, to survey the effect of fractures on unusual methane gas emission in coal mines. this coal mine was chosen for investigating because of its high methane gas content in the coal body and available data from sensors in desired locations. gas concentration monitoring programs were carried out at the mine s...
Abstract– A mine ventilation system is an important component of an underground mining system. It provides a sufficient quantity of air to maintain a suitable working environment. Therefore, the mine ventilation system should be kept at a highly reliable level and also be maintained at a very reliable level during the whole service time of the coal mine. However, in reality, failures of a mine ...
The United States is trending away from traditional mine rescue contest training toward hands-on skills training that focuses on being better prepared for an actual mine emergency response. New technologies and engaging training exercises are providing more realistic experiences to mine rescue teams. The National Institute for Occupational Safety and Health (NIOSH), in partnership with LightsOn...
Heavy metal pollution is a worldwide problem. This study was conducted in a turquoise mine in Nyshabour (Iran) to find accumulator plant(s). Concentrations of metals were determined both in the soil and the plants growing in the mine. Concentrations of total K, Ca, Na, Mg, Mn, Zn, Fe and Cu in the mine area were higher than the control soil. The results showed that four dominant vegetations nam...
The complex pattern of mines made by leafminers is postulated to hinder the host-searching behaviour of parasitoids, and if this is true, parasitoids should have evolved strategies of searching mines in a way that will achieve the highest efficiency. We investigated the possible deterrent effect of mine pattern complexity on a parasitoid searching for a host within a patch, and the searching be...
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