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[en] The implementation of the Surface Mining Reclamation and Control Act of 1977 has been criticized as sporadic, lackluster, and dependent upon the political proclivities of primacy states. This dissertation explores the effect of national-level and state-level variables on implementation patterns in Colorado, Wyoming, and Virginia. Surveys and personal interviews, combined with longitudinal analyses of implementation performances of the Office of Surface Mining and individual state agencies, provide the heart of the research data. The research findings suggest the importance of considering state variables when explaining implementation performance. Moreover, support for both national and state variables as important determinants of the implementation process are provided by the research results
[en] Over the past decades, quarrying activities have produced a vast array of physical and environmental impacts worldwide. In the past 20 years, there has been a growing need to address the issue of rehabilitation and requalification of quarry areas that, to be effective, should be strictly linked to local territorial resources and context, as shown by different types of rehabilitation schemes implemented in different parts of the world. This paper focuses on the rehabilitation of a recently dismissed quarry area in the Rio della Rocca valley (Emilia Apennines, northern Italy), near the ceramic tile district of Sassuolo, which is considered the largest in the world. During the past 50 years, quarrying activity has deeply modified the pristine landscape of this valley, which, however, still holds biotic and abiotic features of great natural interest and scientific value. The methodological approach and actions that led to an environmental rehabilitation scheme, based on the combined appraisal of geological, biological and industrial heritage within a Master Plan, are presented. Territorial resources, restrictions on development, geological hazards, as well as inputs from the local community at different stages were taken into account in defining the Master Plan.
[en] The working life of an uranium mine is long, usually a few tens years: exploration is the first stage, at the end of it, profitability and the environmental impact are assessed. The second stage is mining operations, there are 3 types of mines: open pit mines, underground mines and in-situ recovery mines. The in-situ recovery technology is used for low-grade deposits. A lixiviation solution (diluted sulfuric acid) is injected and made circulating through drills in the deposit. Uranium is dissolved by the sulfuric acid and sucked out with the lixiviation solution. The lixiviation solution is then processed on resin and the uranium is recovered. There are several advantages from the in-situ technology: less perturbation on the mine surface, far less mine wastes and less investment. At the end of their working lives, mining sites have to be dismantled and remedial actions have to be undertaken according to environmental legislations in force in the country. (A.C.)
[en] Surface mining for coal has dramatically altered millions of hectares throughout the Appalachian region of eastern North America. Flat benches and vertical high walls have replaced well-drained slopes, and wetlands have developed 'accidentally' on abandoned benches. Surface mining is continuing in this region, but new regulations do not include specifications for wetland construction in the reclamation process. Recent research has suggested that many ecosystem services appropriate for the Appalachian landscape could be performed by constructed wetlands. Inclusion of wetland construction in a reclamation plan could lead to a net increase in wetland acreage locally, as well as offset the loss of natural and/or accidental wetlands that are constructed to enhance nontreatment goals in reclamation. Study sites included 14 emergent wetlands in Wise County, Virginia. Sampling in June and August detected a total of 94 species in 36 vascular plant facilities. Obligate wetlands species, species that occur in wetlands over 99% of the time, were found in all 14 sites and included 26 species. The presence of so many wetland species without intentional management efforts suggests that wetland establishment could become a common component of mine reclamation. 18 refs., 2 tabs
[en] An open pit mining operation consists of mining processing and refining stages. The mining stage is responsible for provision of required amount of ore of pre-defined grade to the processing plant. The heterogeneity in the ore grade in various parts of the deposit leads to the definition of cutoff grade. The material below cutoff grade is sent to the stockpiles for utilization in later years when it becomes economical. The cutoff grade optimization theory maximizes the Net Present Value (NPV) of a mixing operation with a declining effect as the deposit leads toward exhaustion. This declining effect of NPV defines dynamic cutoff grades i.e. higher cutoff grades in the early years of mine life and lower cutoff grades in the later years. However, this precisely defines the amount and grade of material sent to the stockpile for processing in the later years. The management i.e. supply of material from the mine to stockpile and from the stockpile to the processing plant is an issue that is addressed in this paper by developing a cutoff grade optimization algorithm with option to stockpile. The benefits of methodology are elaborated in a case study. (author)
[en] Brown coal colliery ''Turow'' pays great attention to diminished harmful effects on the environment caused by external dumping, noise, dewatering, water pollution etc. The areas of external dumping as well as around the reservoir of drinking water are recultivated and forests are planted. Daily noise is within permitted levels due to concrete screen, special walls etc. Noise at night exceeds the standards and should be lowered. As a consequence of dewatering some damages in houses appeared. In the period 1991-1995 142 families were moved to new houses
[en] We studied an underground coal gasification technique using strip mining-face mining gasifier controlled retraction injection technology (SMFM). This green mining approach offers several advantages over conventional strip mining but the stress distribution and stability of SMFM operations remain largely untested. In particular, hyperbolic coking pillars are used in SMFM compared with rectangular pillars used in traditional strip mining, which can influence the ultimate bearing capacity and stability. We use numerical simulations to investigate the influence of different factors (arch height, pillar height and width, mechanical characteristics), under the coupling effect of high temperature, on the ultimate bearing capacity of hyperbolic pillars. Our results indicate that arch height has a strong influence on pillar stress, while changes in pillar width and height are less significant. A stability evaluation method is proposed and tested on a case study in Inner Mongolia. Our theoretical results have practical significance for the promotion and application of SMFM.
[en] In Niger, uranium is produced by two companies, Societe des Mines de l'Air (SOMAIR) and Compagnie Miniere d'Akouta (COMINAK), which have mined uraniferous sandstone deposits since 1970 and 1978, respectively. SOMAIR has a production capability of 1500 t U/a from open pit operations, while COMINAK's production capability of 2300 t U/a derives from underground mining. Current production is about 3000 t U/a. The Government owns 33% of the production, while other governments and a private foreign mining company own the remainder
[en] In Estonia, reforesting has been considered to be the most sustainable way of restoring the productivity of land damaged by oil shale mining. As distinct reforestation alternatives give different results, three alternative ways of reforesting oil shale opencasts are compared: natural succession, and planting seedlings of either Scots pine or black alder. The present research shows that the use of unassisted natural succession is the most sustainable way of reforesting oil shale opencasts