Beginning Of Exploitation Research Articles

Possibilities of Capturing Methane from Hard Coal Deposits Lying at Great Depths

Methane present in coal seams is a natural hazard present during the exploitation of underground mining plants. It is an explosive and flammable gas that is released into mining excavations, and it is necessary to reduce its concentration. Capturing methane while preparing extraction is virtually impossible due to the low permeability of coal resulting from its deposition depth. After the beginning of exploitation and disrupting the seam’s structure, methane is released into mine air. The most common method of minimizing gas released into ventilation air is draining the rock mass. This method allows achieving the desired ventilation parameters but requires appropriate mining techniques in hazardous areas. The article presents the example of methane capture during the operation in the longwall B-15 with an overlying drainage gallery. The authors have highlighted an example of the longwall B-15 that when using this particular drainage method, allowed capturing twice the amount of methane forecasted, thus increasing the efficiency of methane drainage. At the preliminary stage of longwall development, the amount of methane charged by the drainage system had relatively low values, reaching 15 m3/min. In the next few months, these parameters increased and varied between 35 to 55 m3/min. A significant difference in methane capture appeared in the second stage of exploitation, where the highest value of captured methane reached 82 m3/min. This particular longwall example shows that it is crucial to properly design the drainage system for seams with high forecasted methane release. It is worth remembering that using a drainage gallery provides an increase in the methane capture from the desorption zone areas, thus increasing total methane capture in comparison to forecasts.

Determination of the Fermentation Parameters of an Artisanal Beer Based on Wax and Honey in the North of Côte d'Ivoire

The aim of this study is to evaluate some microbiological and physicochemical parameters during the production of artisanal beer based on honey and beeswax. Samples were collected at various critical points during the production process. The load of mesophilic aerobic germs and yeasts remains high during production. A total absence of lactic acid bacteria is observed in both types of beer during production. Moreover, Gram staining made it possible to isolate for wax beer, 26% of the Gram negative bacteria of which only one (1) is rod-shaped (5%) and (4) strains are hulls (21%) and 74% of the Gram positive bacteria of which three (3) strains are rods (16%) and eleven (11) strains are hulls (58%). For honey beer, 45% of the Gram-negative bacteria were isolated, of which seven (7) strains are hulls (32%) and three (3) strains are rods (13%), and 55% Gram-positive bacteria, of which seven (7) strains are hulls (32%) and five (5) strains are rods (23%). Wax and honey beers contain a high level of reducing sugars at the beginning of exploitation. During the heat treatment, the reducing sugars reduce the microorganisms disappear after 9 min and 11 min heat treatment respectively for wax and honey beer.

Effect of settlement of foundations on the failure risk of the bottom of cylindrical steel vertical tanks for liquids

Abstract Different types of foundations are used in steel, above-ground cylindrical storage tanks for liquids. If a sand-gravel foundation is used under the entire bottom of the tank or only in the central part of the tank, settlement can be expected, and it increases after many years of operation. The paper presents the typical kinds and types of soil settlements under the bottoms of the tanks, in which different types of foundations were used. Numerical analyses of the effect of the soil settlement on the state of deformations and stresses in steel sheets of the bottom under one of the real tanks, in which different types of foundations and different cases of settlement were assumed. The results of numerical analyses indicated the possibility of evaluating the state of the soil settlement and bottom sheet deformations on the basis of simple measurements of deformations of the lower part of the tank cylinder. These measurements can be very useful in assessing the possible risk of failure of the tank bottom during each period of its operation, as measurements of settlement of the bottom of a filled tank are not feasible in practice. It has been proposed that in each steel tank, the deformation of the cylinder’s sheets should be measured even before the beginning of exploitation, and that in subsequent periodical measurements, the influence of the soil settlement under the tank on the state of the cylinder deformation and bottom’s strain should be assessed more accurately.

STABILITY ANALYSIS OF SECURITY PILLARS WITH DI-MENSION 10 X 10 M FROMED BY ORE OF MINERAL BODY DURING THE EXPLOITATION OF THE "TREPÇA" MINE IN STANTËRG

Abstract: The Trepça mine in Stanterg consists from several mineral bodies, which if compared to the mineral bodies in the North and South part of mine can be found in different size. Their size in the hori-zontal plane ranges from 300-7000 m2 and as a matter of fact in the primary exploitation phase, only about two of thirds part of ore is used, while the remaining ore is used like pillars in the secondary stage with special methods. Since the beginning of exploitation at Trepça mine landfill, the security pillars are left in dimensions 10x10m, on the schedule of chess fields, at distances from 16 to 20m and all pillars at those distances are stable and over-dimensioned. In this paper we investigate the stability of the securing pillars with dimensions 10x10m, with surface S = a*b = 10*10 = 100m2 with a distance between them of 10 to 22m. Pillar stability analysis aims to increase the safety factor along with the increase of exploitation depth.

Геологічні подорожі Валеріана Домгера у басейнах річок Омельник, Самоткань та До-моткань

This article covers only a small but significant part of the territory of the former Katerynoslav and Kherson governorates, where Valerian Domger made his significant geological explorations between 1881 and 1884 on the commission of the Geological Committee. Here, 70 years after Domger made his exploration, a unique mineral deposit, one of the world`s richest deposits of titanium-zirkonium ore, was discovered. This article presents the results of analysis of the research made by the prominent geologist Valerian Domger, acknowledges the scientific and historical value of his proceedings; covers the main biographical facts of this researcher of the geology of the Middle PreDniproviya region; emphasizes the details which are less familiar and seldom mentioned in the literature; covers the analysis of Domger`s route across gullies, ravines and rivers, where he travelled to compose a 10 verst map for the project of constructing the Katerynynska railway. These journeys became the basis for all further studies in the region. This paper proves the fact that V. Domger was the discoverer of the world`s largest deposits of manganese ore; evaluates the results of Domger`s studies of the valleys of the rivers Omelnyk, Samotkan and Domotkan – these works were first to provide data on the structure of pre-Cambrian crystalline basement of the Ukrainian shield, its petrography and the mineralogy of its rocks. The study revealed important patterns in the structure of the sedimentary Paleogene-Quaternary cover; defined Domger`s role in determining the stratigraphic position of the Mandrykivski layers, which he discovered in 1882 during the construction of the railway bridge across the Dnieper. He was first to assign an Upper-Eocene Epoch for the Mandrykivska fossil fauna, which later would for a long period of time be considered Oligocene fauna. Using the works by prominent paleontologists Deshayes, Nyst, Wood and Michelin, Domger did immensely significant work on the Mollusca fauna. The paper analyses Domger`s view on the role of continental glaciations in the formation of Quaternary loess cover in the Middle PreDniprovya region. The researcher also wrote on the Kryvorizke iron ore deposits. His works on analysis of geology of the basins of the Saksahan and Ingulets rivers contributed to the beginning of exploitation of these deposits. Using particular examples, the paper analyses the current condition of the stratigraphic divisions of the different age associations which are mentioned in the works of V Domger; evaluates the significance of Domger`s research and the possibility of using it during geological surveys and monitoring of the most significant objects of geological heritage.

Study of sustainable production in two-phase liquid dominated with steam cap underlying brine reservoir by numerical simulation

The main issue in the management of the two-phase liquid-dominated geothermal field is rapid decline pressure in the reservoir so that the supply of steam to the power plant cannot be fulfilled. To understanding that, modelling and numerical simulation used reservoir simulators. The model is developed on liquid-dominated geothermal fields are assessed in various scenarios of production strategies (focusing only steam cap, brine reservoir and a combination) and injection strategies (deep and shallow injection, centered and dispersed injection), with the calculation using separated steam cycle method. The simulation results of the model for sustainable production are production 25% from steam cap + 75% from brine reservoir, dispersed and deep reinjection with make-up wells from steam cap results 9 make-up well number. The implementation of production-injection strategy needs to be planned right from the beginning of exploitation so that the strategy can adapt to changes in reservoir characteristics.

Depletion-Based Stock Reduction Analysis: A catch-based method for determining sustainable yields for data-poor fish stocks

We describe a method for determining reasonable yield and management reference points for data-poor fisheries in cases where approximate catches are known from the beginning of exploitation. The method, called Depletion-Based Stock Reduction Analysis (DB-SRA), merges stochastic Stock-Reduction Analysis with Depletion-Corrected Average Catch. Data requirements include estimates of historical annual catches, approximate natural mortality rate and age at maturity. A production function is specified based on general fishery knowledge of the relative location of maximum productivity and the relationship of MSY fishing rate to the natural mortality rate. This leaves unfished biomass as the only unknown parameter, which can be estimated given a designated relative depletion level near the end of the time series. The method produces probability distributions of management reference points concerning yield and biomass. Uncertainties in natural mortality, stock dynamics, optimal harvest rates, and recent stock status are incorporated using Monte Carlo exploration. Comparison of model outputs to data-rich stock assessments suggests that the method is effective for estimating sustainable yields for data-poor stocks.

Mobility of aqueous contaminants at abandoned mining sites: insights from case studies in Sardinia with implications for remediation

Public awareness of environmental health issues has increased significantly in recent years, creating the need for detailed scientific studies that can identify potential environmental problems. This paper reports the results of hydrogeochemical surveys carried out in Sardinia, an Italian region with a long mining history. When mining operations in Sardinia ceased, actions for limiting the potential adverse effects of mine closure on the water system were not undertaken. Drainages from flooded mines and seeps from mining residues left on the ground are the main mining-related sources of contamination in Sardinia. Due to the proximity of mining sites to water resources and land that is within reach of animals and humans, the major risks to human health are associated with the direct discharge of contaminated waters into the streams and soils located down-gradient of the abandoned mines. Results of hydrogeochemical surveys carried out under different seasonal conditions showed that the dispersion of toxic and harmful elements (As, Cd, Ni, Pb, Sb and Zn) increases during the rainy season, especially under high runoff conditions. These results should help regional and national authorities to address present environmental regulations, particularly those regarding the quality of water resources. Furthermore, the results might be useful elsewhere for planning remediation actions at abandoned mining sites. Lessons learned by past mining in Sardinia indicate that correct disposal and management of mining residues should be mandatory from the beginning of exploitation and processing at each active mine. This would allow reduction of the environmental risks as well as the cost of remediation.

Effects of iron mine exploitation on the population of brown eared pheasant

Brown eared pheasant, Crossoptilon mantchuricum, is a globally threatened species of pheasant that is native to China. Following research in 1997, effects of iron mine exploitation on this species were studied again in Wulushan Nature Reserve of Shanxi Province in the spring of 2000, aiming at further un- derstanding the current status of habitats and population dynamics. Before exploitation, brown eared pheasants were observed in all three buffer zones, i. e. 50 m, 50 - 100 m, 100 m. Early after ex- ploitation began, the species was not found in the 50 m buffers, and there was a small decrease on number in the 50 - 100 m buffers, and an increase in the 100 m buffers. The results indicate that iron mine exploitation caused brown eared pheasants in the 50 m and 50 - 100 m buffers to move to the 100 m buffers. After 3 years, brown eared pheasants did not occur in either the 50 m or the 50 - 100 m buffers. Compared with early after exploitation began, there was also a decrease in 100 m buffers. At the beginning of exploitation, because there were few iron mines, the effects on activities of brown eared pheasants were not great and population density did not change markedly. However, with increase in the number of iron mines and long-term exploitation many feeding sites were damaged, and this, com- bined with the effect of noise and explosives from mining, restricted normal feeding activities directly. Consequently population density and ranging pattern changed greatly. The results indicate that iron mines are an important factor determining habitat use by brown eared pheasants. The species has not accommo- dated to habitat change caused by iron mine exploitation.

Rapid worldwide depletion of predatory fish communities.

Serious concerns have been raised about the ecological effects of industrialized fishing, spurring a United Nations resolution on restoring fisheries and marine ecosystems to healthy levels. However, a prerequisite for restoration is a general understanding of the composition and abundance of unexploited fish communities, relative to contemporary ones. We constructed trajectories of community biomass and composition of large predatory fishes in four continental shelf and nine oceanic systems, using all available data from the beginning of exploitation. Industrialized fisheries typically reduced community biomass by 80% within 15 years of exploitation. Compensatory increases in fast-growing species were observed, but often reversed within a decade. Using a meta-analytic approach, we estimate that large predatory fish biomass today is only about 10% of pre-industrial levels. We conclude that declines of large predators in coastal regions have extended throughout the global ocean, with potentially serious consequences for ecosystems. Our analysis suggests that management based on recent data alone may be misleading, and provides minimum estimates for unexploited communities, which could serve as the 'missing baseline' needed for future restoration efforts.

Modeling the hydraulical behavior of a fissured-karstic aquifer in exploitation conditions

A 5-year daily measurement of the dynamic level in a borehole was plotted versus cumulative yield since the beginning of exploitation. Eighty percent of the experimental curve is explained by a linear function (h=aQc+h0) by intervals. Only floods, which follow heavy storms and non-pumping cannot be taken into account. The slopes of the straight lines are spread around two constant values of the slope: ar=+0.35×10−3mm−3, which characterizes the part which is controlled by recharge, and ap=−0.14× 10−3mm−3, which characterizes the draining part of the aquifer fractures. This linear fitting demonstrates that the borehole–aquifer system can be considered as an equivalent continuous medium, where the linear relationship between dynamic head and pumped yield are defined by the values of ar and ap. Thus the hydraulic behavior of the aquifer differs according to the pumping rate: equivalent continuous medium for a low rate, dual permeability for a high one. This work demonstrates that the long-term behavior of an exploited fissured aquifer can be described by a simple model, if the duration of the aquifer test is long enough (1–3 months). It also shows that the production phase must include repetitive head measurements in order to refine the exploitation yield and the management conditions.

Méthodes, objectifs et flexibilité d'un système de production Levallois dans le Nord de l'Italie

Methods, Objectives and Flexibility of a Levallois Reduction Strategy in Northern Italy. Flexibility of the Levallois method is directly expressed by all combinatorial variants that can occur as regards gesture, single intervention or sequence of interventions, and flaking modality, highlighting a behavioural variability at all the stages of the reduction strategy: raw material selection and beginning of exploitation; production and management; end-product use and shaping; discard. However, due to the still scarce knowledge of technical aims, we deal only partially with the nature of such variants and the controlling factors of the whole production system. In order to provide a new contribution in this sphere, the study of lithic industry of an open-air site is here proposed and discussed.