Spelling suggestions: "subject:"strip mining"" "subject:"ntrip mining""
101 |
Physical, chemical and mineralogical properties of mine spoil derived from the Wise Formation, Buchanan County, VirginiaHoward, Jeffrey Lynn January 1979 (has links)
Physical disintegration of the rocks is promoted by the closely spaced blast-hole grid used in the mining operation. Wet-dryfreeze-thaw forces are effective in causing disarticulation of the weakened rocks in 6 months or less. The silty spoils cause excessive dust, are crusted and support ponds. Application of organic amendments promotes infiltration. Some of the spoils contain enough salts to seriously retard growth of non-tolerant plant species. Exchangeable bases are overestimated, but the salts are a nutrient source. K is low, but adsorption isotherms indicate that, unlike the naturally occurring soils of the locality, there is no serious problem of K-fixation in the spoils. NaHCO₃ gives the most accurate measure of spoil P. A response to fertilization is likely. Adsorption isotherms suggest a problem with P-fixation by the goethite rocks.
There was no measurable pedogenic activity in the spoils after two years of weathering other than physical disintegration of rock fragments and weakly developed structure in some spoil surface layers. There was no evidence of leaching of salts during this period.
When regrading the spoils on the benches, maintenance of adequate drainage is essential to prevent nutrient depletion, Fe-generated toxicity and acidity and toxic accumulations of salts. A mixture of 70% sandstone, 20% siltstone and 10% shale should yield a well-drained sandy loam spoil upon weathering. The ferruginous and silty rocks should be regraded well below the surface. / Master of Science
|
102 |
A mixed integer model for optimizing equipment scheduling and overburden transport in a surface coal mining operationGoodman, Gerrit V. R. January 1987 (has links)
Recently, competition has increased in the surface coal mining industry, which has necessitated the development of more efficient methods for coal removal. Despite this trend, very little emphasis has been placed on the development of optimization techniques applicable to the surface coal industry. The available methods are inadequate in that they recognize neither the complex equipment interactions present in a surface mining operation nor the interdependence of overburden removal and spoil placement.
The lack of available techniques prompted the development of a mixed integer model to optimize the scheduling of equipment and the distribution of overburden in a typical mountaintop removal operation. Using this format, a (0-1) integer model and transportation model were constructed to determine the optimal equipment schedule and optimal overburden distribution, respectively. To solve this mixed integer program, the model was partitioned into its binary and real-valued components. Each problem was successively solved and their values added to form estimates of the value of the mixed integer program. Optimal convergence was indicated when the difference between two successive estimates satisfied some pre-specified accuracy value.
The performance of the mixed integer model was tested against actual field data to determine its practical applications. To provide the necessary input information, production data was obtained from a single seam, mountaintop removal operation located in the Appalachian coalfield. As a means of analyzing the resultant equipment schedule, the total idle time was calculated for each machine type and each lift location. Also, the final overburden assignments were analyzed by determining the distribution of spoil material for various overburden removal productivities.
Subsequent validation of the mixed integer model was conducted in two distinct areas. The first dealt with changes in algorithmic data and their effects on the optimality of the model. The second area concerned variations in problem structure, specifically those dealing with changes in problem size and other user-inputted values, such as equipment productivities or required reclamation. For each of these optimal schedules and assignments obtained from the model, analyses were conducted in manner similar to that discussed above. / Ph. D.
|
103 |
Monitoring the impact of surface coal mining on vegetation in southwestern Indiana using remote sensing and GISWang, Wei J. January 2008 (has links)
Surface coal mining leads to inevitable changes and notable impact on the physical environment of the earth and engenders immense damage to the landscape and the ecological environment. The dramatic high-speed rock digging and disturbance unavoidably causes ecosystem degradation and destruction. Detecting how surface coal mining affects the environment on the process of land use/cover change is one of the primary concerns to preserve nature and minimize the environmental impacts. Therefore, monitoring and understanding the environmental impact processes in mining areas is critical for sustainable management of the Earth's environment. In this thesis, remote sensing and Geographic Information System (GIS) are applied to assess the spatial environmental impact caused by surface coal mining in southwestern Indiana. The goal of this research is to develop a methodology to classify the coal mining field using satellite imagery and to quantify and assess land use /cover changes using remote sensing and GIS. The specific methods include classification of Landsat Thermal Mapper (TM) data and comparison of the spatial patterns of the classification results in the study region. The results are presented with a 3-D model to better understand and visualize the coal mining effects on the landscape. Results obtained in this study indicate the change area of land use/cover and the potential area for planting crops in southwestern Indiana. Based on the observation of the data results, vegetation in the study area was found to have changed significantly over the study period. In particular, the developed areas have been increasing quickly and the areas of agriculture and forests have been decreasing appreciably. / Department of Geography
|
104 |
Ecotypic Differentiation of Andropogon Virginicus L. In Relation to Strip Mine Spoil BanksHurt, Valina Kay 01 May 1979 (has links)
Reciprocal plantings of populations of broomsedge, taken from an abandoned strip mine and from an abandoned farm plot in south central Kentucky, on strip mine spoil and abandoned field soil resulted in patterns of populations differentiation. Clonal plantings of populations from strip mine habitats and old field development appeared equal in height and biomass when grown on old field soils in both field trials and growth chamber studies. Populations when planted in strip mine soils in field trials and controlled growth experiments. Later flowering in strip mine populations may be a key to survival strategy in the harsh microclimates of spoil banks. Andropogon virginicus L. may prove to be a significant and economically sound species in reclamation programs.
|
105 |
Estimation of the propensity of remnant underground coal pillars to spontaneously combust during opencast mining at a colliery in the Witbank coalfieldGemmell, Graham Barry January 2017 (has links)
A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Engineering, 2016 / Spontaneous combustion of coal may occur when coal is mined, stored or transported and is influenced by a combination of intrinsic and /or extrinsic factors. While it is unusual for intact seams to burn in the highwall, the most common occurrence is when surface mines extract seams previously partially mined by underground bord and pillar operations.
The aim of the study is to provide a predictive model (matrix) of the spontaneous combustion potential of remnant pillars at Colliery X. A number of different thermal, chemical and petrographic tests (coal factors) will be undertaken to determine their individual and collective impacts on the sponcom predictive model. The primary geology at the mine is conformable with that of the Witbank Coalfield. Battacharyya (1982) described 3 main factors in the spontaneous combustion of coal, mining factor,
coal factor and geological factor which have an aggregate effect.
Some of the main historical and present theories of sponcom are the pyrite theory, the bacterial theory, the oxidation theory and the humidity theory. It is important to note that no single factor is responsible for spontaneous combustion. The oxidation of coal occurs constantly. The temperature of the coal is a function of the rate of heat generation versus the rate of heat loss. Fires can start at
outcrops and move through interconnected workings with heat transfer by conduction (into the
overburden) or convection (between panels).The overburden can also insulate the burning coal seam.
Geological factors such as depth of overburden, the degree of fracturing, and the nature of the
overlying strata vary between coalfields.
A coal seam fire or mine fire is the underground smouldering of a coal deposit, often in a coal mine.
Such fires have economic, social and ecological impacts In order to extinguish a fire, one of three
elements, fuel, oxygen, or energy, must be removed. The components of the fire triangle can be
further subdivided into conventional mine control techniques and more or less unconventional or
unproven mine fire control techniques. The thermal techniques discussed include the crossing point
temperature, thermogravimetric analyses and oxygen absorption. Macerals, the microscopically
identifiable organic constituents of coal, are one of the three basic parameters that define coal. The
other two parameters are the coal rank and the mineral matter Vitrinite is the principal maceral group
of the No.5 seam and inertinite dominates the No.2 and No.4 seams.
The results obtained from the 22 drill-core samples and 2 ROM samples were matched to the existing
borehole dataset (2296 boreholes) based on similarity of heat value (figure 3.11). A total of 24 test
results (thermal, chemical and petrographic) from borehole A and borehole B were thus assigned to
the borehole database which has approximately 1500 samples for each seam. By linking the
laboratory datasets (borehole A and B) and the existing borehole database used for resource
modelling, the sponcom variables could be modelled in a similar way to the coal resources. The overall risk matrix was calculated on a full seam basis by combining 15 variable scores, each
variable having a score of 0, 1 or 2 (low-mod-high probability). The overall results from this research
produced clear and unambiguous contour plans of different factors effecting sponcom of coal using
single variable and combined variable datasets. In conclusion, it appears that the acceptability of a
method for determining spontaneous heating characteristics of coal mainly depends upon how closely
it predicts the spontaneous heating behaviour in the field conditions / CK2018
|
106 |
Settlement of open cast mine backfill : two large scale field testsVan Wyk, Wilhelm Jacobus January 1998 (has links)
A dissertation submitted to the Faculty of Engineering, University of
Witwatersrand, in fulfillment of the requirements for the degree of
Master Science in Engineering / The Electricity Supply Commission of South Africa (Eskom) have identified open cast coal
mine backfill areas as potential disposal sites for the large volumes of coal ash produced
by their power stations. As Eskom's power stations are mainly situated in agricultural and
coal rich areas of the provinces of Mpumalanga and the Free State, the sterilisation of
substantial areas of agricultural soil and coal deposits is thus reduced.
The construction of a tailings dam or dump on uncompacted open cast mine backfill
creates various problems related to the settlement of the backfill. The scale of the
operation, the large particle size and heterogeneous nature of the backfill and its method
of placement complicates the prediction for settlement of the backfill.
Areas in excess of 74 000 ha could be subjected to opencast mining in Mpumalanga and
for future development of these areas more information regarding the magnitude and
mechanics of mine backfill settlement is required.
This dissertation describes two large scale field tests in which the settlement of mine
backfiil was studied during the construction of a test section of an ash tailings dam and
the construction of a dry ash dump. / Andrew Chakane 2019
|
107 |
A study of the effects of the maintenance system at an open cast iron ore mineSetzkorn, Kevin Anthony January 2017 (has links)
A research report submitted to the Faculty of Engineering and the Built Environment,
University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for
the degree of Master of Science in Engineering
Johannesburg 2017 / The study assesses the drilling, loading and trucking stages of the mining cycle of an
iron ore mine situated in the Northern Cape province of South Africa for the period of
1 January to 30 June 2011. The purpose of this study is to investigate the effect of
increasing reliability and maintainability of mining equipment in an effort to increase
throughput of iron ore. The data processing indicated that both availability and
utilisation are contributing to the sub-optimal performance of the mine. Data
regarding reliability (MTBF), maintainability (MTTR), planned and unplanned
maintenance was analysed, and this provided input for the simulation model. The
intention of the simulation model is to simulate scenarios of proposed improvement
in MTBF and MTTR through increasing planned maintenance activities. A simulation
model provides insight regarding where to invest in interventions. It is determined
that the drilling equipment is the problem area. / MT2018
|
108 |
AN APPLICATION OF THE FINITE ELEMENT METHOD FOR ROCK SLOPE STABILITY ANALYSISHammel, David John, 1938- January 1971 (has links)
No description available.
|
109 |
This is our land, we have the right to be heard: Community-based Environmental Activism in the Late Twentieth CenturyJanuary 2012 (has links)
abstract: This dissertation examines the development of grassroots environmental organizations between 1970 and 2000 and the role they played in the larger American environmental movement and civil society during that period. Much has been written about growth in environmental values in the United States during the twentieth century and about the role of national environmental organizations in helping to pass landmark federal-level environmental laws during the 1960s and 1970s. This study illuminates a different story of how citizen activists worked to protect and improve the air, water, healthfulness and quality of life of where they lived. At the local level, activists looked much different than they did in Washington, D.C.--they tended to be volunteers without any formal training in environmental science or policy. They were also more likely to be women than at the national level. They tended to frame environmental issues and solutions in familiar ways that made sense to them. Rather than focusing on the science or economics of an environmental issue, they framed it in terms of fairness and justice and giving citizens a say in the decisions that affected their health and quality of life. And, as the regulatory, political, and social landscape changed around them, they adapted their strategies in their efforts to continue to affect environmental decision making. Over time, they often connected their local interests and issues with more sophisticated, globalized understandings of the economic and political systems that under laid environmental issues. This study examines three case studies in the rural Great Plains, urban Southwest, and small-town Appalachia between 1970 and 2000 in an attempt to understand community-based environmental activism in the late twentieth century, how it related to the national environmental movement, the strategies local-level groups employed and when and why, the role of liberal democratic arguments in their work and in group identity formation, the limits of those arguments, and how the groups, their strategies, and the activists themselves changed overtime. These three groups were the Northern Plains Resource Council in Montana, Southwest Environmental Service in Southern Arizona, and Save Our Cumberland Mountains in Eastern Tennessee. / Dissertation/Thesis / Ph.D. History 2012
|
110 |
Geomorphic Differences between Unmined and Surface Mined Lands in Southeastern OhioPollock, Matthew John 19 May 2015 (has links)
No description available.
|
Page generated in 0.0997 seconds