218,785 research outputs found
An assessment of the quantum for financial provision of mine closures: a Monte Carlo approach.
No full textIncludes abstract.Includes bibliographical references.Poor mine closure policy threatens both society and the environment. Some of the more prominent threats that have manifested are acid mine drainage, slimes dams and toxic dust from dumps. Current legislation requires that new mines set aside funds to cover their rehabilitation costs at closure
Incorporating judgment and decisionmaking into quarterly mine escape training based on a mine fire scenario
No full text"The major coal mine disasters of 2006 raised a number of issues about mine emergency preparedness and response. These included concerns about miners' judgment and decisionmaking skills under the stress of a mine escape and miners' familiarity with escape procedures. In response, researchers from the National Institute for Occupational Safety and Health (NIOSH) sought to learn how mines are incorporating judgment and decisionmaking skills into mine escape training. They took an in-depth look at previous research on judgment and decisionmaking in self-rescue and escape training. They also conducted interviews with safety and training personnel from six underground coal operations to understand how mine operators are conducting mandatory quarterly escape training. This report discusses findings from these interviews, presents an analysis of previous research on judgment and decisionmaking in self-rescue and escape, and offers guidance to trainers on how to build judgment and decisionmaking into quarterly training drills."- NIOSHTIC-2NIOSHTIC No. 20043381CDC-INFO Pub ID 221645221645Michael J. Brnich, Jr., Erica E. Hall."November 2013."Also available via the World Wide Web as an Acrobat .pdf file (5.97 MB, 24 p.).Includes bibliographical references (p. 15)
Application of Flowback Water and GOPS on the Prevention of Acid Mine Drainage in the Mather Mine
No full textAcid mine drainage (AMD) is an environmental pollutant that degrades water bodies and harms aquatic life. In the Appalachian Mountains of the eastern U.S., over 7,500 miles of streams are impacted by AMD. Current methods of active treating AMD such as neutralization with limestone are labor-intensive and costly. Passive treatments with lower maintenance and management costs are the more sustainable alternatives for AMD management. The research reported herein explores the possibility of applying flowback water from natural gas drilling operations and the chelating agent 3-glycidoxypropyltrimethoxysilane (GOPS) as additive to passively treat AMD. The hypothesis is that chemicals present in the flowback water will form insoluble salts with those in the mine residue and precipitate on the mine rock to passivate the surface.. Additionally, GOPS will improve upon the passivation process by complexing with metal ions in the precipitate to form a multilayer hydrophobic coating.
In order to develop a protocol for measuring the optimal dosage of flowback water and GOPS for AMD prevention, several preliminary batch tests were conducted. These tests evaluated the reaction time and volumes of flowback water and GOPS appropriate for further column testing, as measured by concentrations of Fe, Ba, and SO42-. From batch studies, it is observed that when 55 mL of flowback water was added to 500 mg of mine residue, the contaminants of major concern, Fe and SO42- reached their lowest levels. Meanwhile, a dosage of 0.0001 M GOPS is optimum to improve the microencapsulation. Results from the test column were compared to an identical control column, which was treated with deionized water. The results suggest that, for the experiment duration of one month, flowback water and GOPS have done an effective job in curbing the release of Fe and SO42- from mine residue. After 15 days of treatment, the concentration of Fe was 0.6 ppm, reduced by 96% relative to the control, and the concentration of SO42- was 90 ppm, reduced by 83%. However, trace metals including Mn were not reduced to within the requirements set by the Environment Protection Agency. As a result, more studies are needed to improve the performance of this technique
Offsetting of CO₂ emissions by air capture in mine tailings at the Mount Keith Nickel Mine, Western Australia: Rates, controls and prospects for carbon neutral mining
No full textThe hydrated Mg-carbonate mineral, hydromagnesite [Mg₅(CO₃)₄(OH)₂•4H₂O], precipitates within mine tailings at the Mount Keith Nickel Mine, Western Australia as a direct result of mining operations. We have used quantitative mineralogical data and δ¹³C, δ¹⁸O and F¹⁴C isotopic data to quantify the amount of CO₂fixation and identify carbon sources. Our radiocarbon results indicate that at least 80% of carbon stored in hydromagnesite has been captured from the modern atmosphere. Stable isotopic results indicate that dissolution of atmospheric CO₂ into mine tailings water is kinetically limited, which suggests that the current rate of carbon mineralization could be accelerated. Reactive transport modeling is used to describe the observed variation in tailings mineralogy and to estimate rates of CO₂ fixation. Based on our assessment, approximately 39,800 t/yr of atmospheric CO₂ are being trapped and stored in tailings at Mount Keith. This represents an offsetting of approximately 11% of the mine's annual greenhouse gas emissions. Thus, passive sequestration via enhanced weathering of mineral waste can capture and store a significant amount of CO₂. Recommendations are made for changes to tailings management and ore processing practices that have potential to accelerate carbonation of tailings and further reduce or completely offset the net greenhouse gas emissions at Mount Keith and many other mines
Synthetic faujasite based on coal by-products for the treatment of acid mine drainage (AMD).
No full textAcid mine drainage (AMD) has long been a significant environmental problem associated to mining operations at the Parys Mountain copper-lead-zinc deposit of Anglesey (North Wales), a volcanogenic massive sulphide district of major metallogenic importance. AMD is a natural occurrence resulting from the microbial oxidation of sulphide minerals, especially pyrite (FeS2), pyrite in presence of water and air, which produces polluted waters strongly acidic containing high concentrations of Fe, sulphate and toxic metals. The treatment of AMD has traditionally been conducted by neutralization with lime or similar materials. However, liming is often temporary and produces secondary wastes, such as metal hydroxide sludges and gypsum, which are highly regulated and have costly disposal requirements. Several methods for AMD treatment have been developed, although adsorption being the preferred method for heavy metal removal due to its effectiveness. AMD remediation can be very costly and difficult, due to the high costs of activated carbon production and regeneration for water treatment. Therefore, alternative low-cost liming materials are constantly sought. Such adsorbents should be readily available, economically viable and easily regenerated. The aim of this study is to investigate the efficiency of synthetic faujasite obtained from coal by-products as adsorbent in removing heavy metals from AMD generated at the Parys Mountain copper-lead-zinc deposit
Caribou mine reports
No full textMine report no. 700.Includes illustrations, maps.Typescript.Includes a compilation of reports and maps on the Caribou mine ranging in date from 1913 to 1920.Reports sent to Geo. E. Collins -- Report no. 1 on the Caribou mine, Caribou, Colorado by Stuart Croasdale -- Report no. 2 on the Caribou mine, Caribou, Colorado by Stuart Croasdale -- Report on the Caribou mine, Boulder County, Colorado by R.D. George and Fred A. Fair -- Letter to Henry P. Lowe from Edwin E. Chase -- Preliminary report on the Caribou mine, Boulder County, Colorado by Wm. G. Zulch -- Brief summary of the principal features of the Caribou property by W.C. Russell -- The Caribou mining property by Fred A. Fair -- Report on the metallurgy of the Caribou and Poorman ores by John Gross -- Map showing tungsten area of the Caribou mines and Mills Company, Nederland district, Boulder County, Colorado -- Set of maps and illustrations
Water Retention Capacity as a Measure to Evaluate the Effectiveness of a Green Liquor Dregs-Amended Till to Cover Sulfidic Mine Waste
No full textHydraulic conductivity is often used as a measure to evaluate the effectiveness of a sealing layer material on top of mine waste. However, the most important soil parameter minimizing the oxygen diffusion to the mine waste is the water retention capacity (WRC) of the sealing layer, as a high saturation corresponds to a low oxygen diffusion rate. This study shows that an amendment of Green Liquor Dregs (GLD), an industrial residue, to a till increases its WRC and has therefore potential to be a more accurate method to evaluate the effectiveness of a sealing layer than hydraulic conductivity.Funder: Boliden Mineral AB;</p
Water Retention Capacity as a Measure to Evaluate the Effectiveness of a Green Liquor Dregs-Amended Till to Cover Sulfidic Mine Waste
No full textHydraulic conductivity is often used as a measure to evaluate the effectiveness of a sealing layer material on top of mine waste. However, the most important soil parameter minimizing the oxygen diffusion to the mine waste is the water retention capacity (WRC) of the sealing layer, as a high saturation corresponds to a low oxygen diffusion rate. This study shows that an amendment of Green Liquor Dregs (GLD), an industrial residue, to a till increases its WRC and has therefore potential to be a more accurate method to evaluate the effectiveness of a sealing layer than hydraulic conductivity.Funder: Boliden Mineral AB;</p
Hydrological conceptual model characterisation of an abandoned mine site in semiarid climate : the Sierra de Cartagena-La Unión (SE Spain)
No full textA comprehensive study at Sierra de Cartagena-La Unión (SE Spain) abandoned mine site was carried out to characterise the regime and water quality of the groundwater system after the mine closure. The system consists of five geologic fractured blocks belonging to the Alpujarride and Nevado-Filabride complexes. The aquifer units are composed of limestone and dolostone materials. Recharge is mainly controlled by the N-130 fault system, man-made induced fractures, open-pits and underground workings. Discharge is indicated from open pit lakes by the proximal dome-shaped groundwater level contours. Aquifer natural recharge, assessed by fracture density maps and chloride mass balance, provided consistent results. The water hydrochemical facies show a marked sulphate concentration and acidic pH (average pH of 2.53-6.30). A maximum concentration of 4,100 mg/L of Zn and 40,000 mg/L of sulphate was observed in open-pit lakes. Springs present the lowest residence time and are low mineralised with an average pH of 7.6. Geochemical modelling based on the PHREEQCI code indicates water undersaturation with respect to almost all related mineral species and anoxic conditions prevail in the system. Although an adequate understanding of the regional system is provided, a further detailed hydrochemical study is necessary to assess the undergoing geochemical changes
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