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By J. E. Lees

Advanced remote sensing can be a powerful new information tool to help private and public entities make better environmental and resource management decisions. However, some regulated entities are reluctant to develop or use this tool because of their concerns that it will lead to increased risks and costs of environmental legal liability. They fear that new ways of monitoring the environment will increase liability, undermine existing enforcement agreements, reopen compliance agreements, and generally provide a competitive disadvantage to early adopters by accelerating environmental cleanup costs. Others counter that the increased risks are marginal, and that several advantages outweigh these risks, including the opportunity to more effectively manage environmental operations, target and set priorities, measure and track management and compliance effectiveness, provide more defensible environmental assessments and baseline conditions, make and defend optimal siting decisions, and avoid or resolve environmental disputes. This paper offers strategic advice on ways regulated entities can enjoy the benefits of these powerful new information tools while mitigating down-side legal and compliance risks as much as possible.

Jan 1, 1999

By Andrzej M. Wala

The determination of the air quality needs to dilute diesel exhaust gases to a safe level must be individually evaluated for particular cases. One such case is when diesel-powered vehicles are working in long dead- end headings with forcing auxiliary ventilation. The vehicles perform specific operations in a cyclic order required by the technical process. The dynamics of this process in certain conditions has a vital influence on environmental conditions in the working area and in the rest of the heading. Recent studies on diesel gas behavior in long headings have shown a zone of increased concentration of pollutants (accumulation) between the face and the mouth of the heading. To be able to control these accumulations of pollutants, use of the concept of planned air discharge by using the Coanda-type ducts is proposed. The main objective of this paper is to demonstrate an application of computer simulation of that process. It is shown that, by planning the additional air discharge, the concentration of diesel gases can meet required limits along the heading.

Jan 1, 1987

By B. Howerton, M. M. Matlock, D. A. Atwood

In the Gold-Cyanide Process (GCP) the cyanide anions act to solubilize the gold and silver present in the ore, and mercury as well. The resulting mercury and cyanide rich effluent are serious health and environmental problems. Currently, there is no mercury treatment from the ore leach solution since there are no precipitating agents or other technologies which can be used effectively in the pH ~ 10solutions. Recently, however, we have developed a new chelate ligand that is impervious to this level of pH and it can be used to precipitate Hg from NaCN solutions. On an actual sample taken from an active gold mine the chelate selectively reduced the mercury level from 34.5 ppm to 0.008 ppm within 15 minutes. Importantly, the gold and silver levels remained unchanged throughout this process. Thus, the environmental impact of Hg released in the GCP can be drastically reduced. Moreover, with a mercury treatment technology now available it may be possible to change, or reinvent, the entire GCP process.

Jan 1, 2003

By D. Legg

This is the first in a series of studies commissioned by the European Environment Agency that aim to raise awareness of the use of economic instruments and assess their effectiveness. The emphasis is on sharing good practice and increasing knowledge and understanding across European countries in this emerging policy area. A methodology for evaluating the effectiveness of economic instruments has been developed and this will examine whether the inclusion of economic instruments in complex policy packages can improve the overall performance, particularly as a prevention tool in terms of resource use and waste generation The focus for this initial study is the use of aggregate taxes in four EU countries which include the Czech Republic, Italy, Sweden and the UK so that a range of experiences (e.g. geographical, political etc.) can be included. The findings will be used to inform and influence future policy development in other EEA countries. The methodological approach is divided into two main sections: - Technical analysis, which covers quantitative and qualitative analysis. - Process design, i.e. who should be involved when, where and how. Process design is essential if the full learning benefits are to be gained from the technical analysis, which is the ultimate objective of these evaluations.

Jan 1, 2007

By M. H. Foroughi

In this paper, the compressive strengths, failure modes and acoustic emission behaviors of cubic coal specimens containing bedding planes at various inclinations are considered. Test results showed that the compressive strengths and the modes of failure of coal specimens depend on the inclination of the bedding planes. From the acoustic emission (AE) measurements, the count rate detected through a low-pass window (AE (L)) was compared with that through a high-pass window (AE (H)) in each test. The results of accumulated AE history were compared with AE signatures of others. It is shown that the AE signature of coal depends on the inclination of the bedding planes, and the AE signatures can be classified into three groups. Each group corresponds to a particular mode of failure, namely, slip on the bedding planes, fracture across the bedding planes and fracture extension through the bedding planes. The parameter r, defined as the ratio of AE (L)/ [AE (L) + AE (H)], is plotted against the stress for each test. Test results showed that r also depends upon the inclination of the bedding planes.

Jan 1, 1999

By D. J. Shields

The goal of public policies is to connect desired ends with practical means toward their achievement. How the desired ends are determined, and whose goals and objectives they incorporate, depends upon the culture and political system of the country in question. With few exceptions, policies change over time to reflect changed perspectives and understanding of the world around us. This is true regardless of the policy area in question. Thus, how societies view and manage their mineral resources has evolved in response to public attitudes, societal needs, economic circumstance, cultural perspectives, political orientations, technological advancements, and geological knowledge. In this paper we examine how the scope of concern has changed for mineral policy. We then review the overarching issues that have in recent years been considered essential components of mineral policies. We point out how neoclassical microeconomics has influenced recent policy design. We then use a market flow diagram to illustrate how policies can be focused at specific market issues. We next discuss mineral resources in the context of sustainable development. We identify issues that become relevant when the frame of reference is enlarged beyond ensuring supply and capturing economic rent. We show that policy based solely on neoclassical economics may not be able to effectively incorporate these issues.

Jan 1, 2007

By Andrzej Wala, Waclaw Dziurzynski, Janusz Tracz

Recent advancements in computer hardware have led to the development of new ventilation planning software for PC's. These programs now can be run more quickly and can display their outputs with graphical techniques. Only a few of the existing programs have the capability to display the output data graphically on plotters. Graphical presentation of ventilation simulation data is essential for quick and sure comparisons of alternative analyses. Recently a noticeable growth has occurred in the application of graphics for display and interpretation of the data that have been developed by simulation procedures. The process of mine ventilation network analyses used for planning and design can benefit from this development. The authors describe and present graphics-assisted software that has been developed to work with a mine ventilation simulation program. This software has some of the following features: - graphic editor on screen, - graphical display of output data on screen (EGA, VGA), - graphical display on plotter or printer, - scaling capability (desired part of the entire schematic can be displayed), and - such values as flow, pressure loss, gas concentration for branches, and pressure and elevation at junctions can be presented as labels.

Jan 1, 1991

By C. Mermiris

Bauxite ores in Fokida belong to Parnassus-Giona zone and are found exclusively in limestone in two bauxite horizons, which are of great economic importance and with very unfavorable conditions for the reclamation process. The ore bodies are usually less than two million tones. They are in many cases encountered near the surface as a result of the erosion and are exploited either with open pit or underground methods. Mining activity, which dates back 70 years, causes many changes to the environment and most of all to vegetation and landscape. The first step to mining exploitation of bauxite ores is the selection of an underground or open pit method taking into consideration mostly economical and technical criteria. Open pit exploitation, which causes the most severe environmental consequences, is done with the method of vertical benches in hard rock with the use of explosives. The impacts on the landscape that result from the method of vertical benches are: ? The front of the excavation that is usually solid rock of the hanging wall (limestone). The height of the benches varies from 10 to 20 meters and the gradient of the final slope is designed to be around 65o, unless the rock is not so stable and the gradient is reduced accordingly.

Jan 1, 2002

By Charles F. Herbert

The waves of prospectors who struggled across the wide Alaskan wilderness between 1898 and 19 10 came close to but did not actually find the rich copper/zinc/silver deposits strung out along 161 km ( 100 miles) of felsic schist in the remote Brooks Range of northwestern Alaska. They had heard rumors of gold in the valley of the Kobuk River, so they skirted the Arctic ice pack in the Chukchi Sea and, in a force at least 800 men strong, ascended the Kobuk River in 1898. Twenty-eight placer mining camps were established but only a handful survived for more than a few years. One of the placers that died rapidly was Ruby Creek. A map showing the location of Alaskan mineral deposits is given in Fig. 1. The Ruby Creek miners, disappointed with the scarcity of gold in that creek, followed copper-bearing float to two places where the float was especially plentiful. Pits, a short adit, and a shallow shaft uncovered copper carbonates, bornite, and chalcopyrite in fractured limestone but the remoteness of the district blocked efforts to sell the claims or to raise capital for development. Shortly after 1906, the copper prospects were abandoned and, except for an account published in 1913 by the US Geological Survey, they were forgotten, as were the names of the prospectors.

Jan 1, 1991

By G. Brofas

Mt Giona situated in the floristic hot-spot of southern-central Greece has an especially rich flora that counts more than 1000 native vascular plant taxa (species and subspecies) and an important plant endemism that is estimated to be about 10% of the native flora. The danger of population reduction of rare and endemic plant species and the opportunity to use rare native species in rehabilitation projects are two different aspects of rehabilitation planning in Mt Giona. In this study, an inventory of rare and endemic species of the area, their classification into IUCN threatened categories and an estimation of their habitats vulnerability are provided. The results emphasize the necessity to develop a monitoring program to analyze population viability of certain threatened plant species. The creation of artificial micro-reserves on calcareous spoils derived from bauxite mining for the conservation of water-stress tolerant rare and endemic plants is also proposed. An inventory of the species that have colonized the mining spoils was also undertaken. Twelve of them are endemics. Seven native species, because of their biological and ecological features, were selected for rehabilitation purposes of disturbed areas by mining activities. Seed germination, aspects of their reproductive biology and seedling emergence after sowing in pots under field conditions were studied. The seed germination study in the laboratory led to the identification of the optimum germination conditions and the creation of germination protocol for each species. Seedling emergence depends on the sowing season and the mulching. The use of the above species is recommended for rehabilitation purposes. The creation of artificial micro-reserves on calcareous spoils derived from bauxite mining for the conservation of water-stress tolerant rare and endemic plants is also proposed.

Jan 1, 2007

By T. L. Heidrick

Late Cretaceous-early Tertiary Cordilleran porphyry Cu-Mo districts and their consanguineous Zn-Pb-Ag-Au-W vein and replacement deposits of the Rocky Mountain region comprise one of the largest, best studied, diverse, complex, puzzling, and richest compound metallogenic provinces on earth. A concise space-time definition of intermineral plate, regional and local structure-tectonic frameworks is crucial to deciphering their diachronous metallogeny and enhancing the explorationist's odds of future discovery.

Jan 1, 2013

By M. G. Ayat, J. W. Leonard

Introduction Coal preparation plants are continuously losing clean coal in their refuse and contaminating their clean coal product with impurities. This is due to the lack of a system by which the immediate efficiency of the cleaning operation can be determined at any given time. Moreover, the advantage of developing tagging/ tracing techniques would be a reduction in the time and money spent in evaluating the performance of advanced cleaning techniques. Currently, conventional sampling and testing, on-line analyses, and computer information systems are the major tools with which engineers analyze and control the efficiency of processing plants. Conventional sampling and testing is an effective analysis technique but it is slow. On-line analysis provides information on quality parameters rapidly, but these parameters do not provide all of the necessary information. The use of tagged particles in coal preparation plants may provide the necessary link between diagnosis and the application of computers to process control. In this work, a novel technique that uses tagged particles to generate partition data is presented (Leonard et al., 1982). Individually prepared tagged particles are added to the feed and detected in the product or refuse port of specific gravity based processes. Providing that a computer can interpret the output of a detection device and trace particles with predetermined physical properties through the coal preparation plant and that the trace particles actually represent desired raw material, sufficient partition data can be provided for computer analyses and control of processing efficiency. Coal tagging technique The use of tagged particles in coal preparation operations are in the early stages of development. Though there is a brief history of particle tracing in the mineral processing industry (Gardner et al., 1986; Foreman and Amundson, 1976; Poston et al., 1962), the concept has not yet been applied to the analysis and control of processing plant operations. Several methods for tagging coal particles have been identified. These include magnetic, radioactive, and fluorescent techniques. As far as the magnetic tagging of coal particles is concerned, a method has been developed to manufacture synthetic magnetic particles of various sizes and specific gravities. Ideally the synthetic particles would have identical size and density as the coal particles being separated.

Jan 1, 1988

By James D. Reilly

The time-worn adage "an ounce of prevention is worth a pound of cure" was never more applicable than when used in reference to coal mine safety. Many individuals have dedicated many hours to developing effective accident prevention programs, and much has been accomplished. Each production escalation, however, creates new hazards and safety problems which need special study and research. It is a never ending cyle. To study the progress of coal-mine safety is to raise memories of many individuals who have been dedicated to removing the hazards that have developed with increased productivity and deeper penetration into the earth for coal. Some vivid examples of this dedication are the works of the men who pioneered the use of the safety lamp and the use of rock dust in mining.

Jan 1, 1968

By C. F. Bonney

Spherical or oil agglomeration has been recognised for many years as a possible process for the recovery of mineraVmetal values. BP has investigated the potential of spherical agglomeration for a number of minerals as have other workers. Testwork has also been carried out by both BP and others on the selective agglomeration of fine coal. The spherical agglomeration of both minerals and coal depends on the use of an immiscible liquid e.g. a hydrocarbon which is added to a suspension of the solids in water. On agitation the oil is distributed over oleophilic/hydrophobic surfaces and particle impact allows inter-particle liquid bridges to form causing agglomeration. It is also possible to enhance the oleophilicity of the material to be recovered by the use of collectors similar to those used in froth flotation.

Jan 1, 1998

By Duluth Engineers' Club, Engineers' Club of Northern Minnesota

"The Vermilion range extends from the vicinity of Tower to and beyond the ""international boundary, crossing into Canada at the eastern end of Hunter's Island. Merchantable bodies of ore have been discovered at but two localities along this extent, at Tower and at Ely, twenty-one miles east.The iron bearing formation of this range occupies the lowest position geologically of any of the Lake Superior iron formations, being placed by Van Rise and Clements in the Archean, as shown from the following succession:Lower Huronian Intrusive granites, granite porphyries, dolerites, and lamprophyresKnife Lake slatesAgawa formation (iron-bearing) Ogishke conglomerate(Unconformity.)ArcheanIntrusive granites, granite porphyries, and some greenstonesSoudan formation (the iron-bearing formation). (Minor unconformity.)Ely greenstone, an ellipsoidally parted basic igneous and largely volcanic rock The ores of the Vermilion series occur in the Soudan formation (the Agawa iron bearing rocks are not of commercial importance).At the Minnesota mine at Soudan the ore is a dense, hard hematite, occurring in irregular connected and disconnected lense shaped bodies in the jasper, which is intricately infolded in the ellipsoidal greenstone or green schists, so called on account of a characteristic ellipsoidal parting. The strike is about east and west and the dip approximately vertical, with a westerly pitch. The underground workings at this mine are some 4,500 feet in extent east and west, and over 1,500 feet in depth. The structure here is probably the most complex in the Lake Superior iron districts. Above the iron bearing formation, geologically, comes the basal conglomerate of the Lower Huronian, carrying large boulders and Masses of the iron bearing rocks."

Jan 1, 1920

By J. Nelsen

Social License to Operate continues to emerge as a paradigm fundamental to sustainable mineral resources development. It relates to a set of concepts, values, tools, and best practices that represent the view of reality held by each participant (industry and stakeholders). It enables a forum for negotiation through which all parties involved are heard, understood and respected. The exploration phase of the mine life cycle is generally the initial contact with local communities and forms the cornerstone for effective communication and trust building. This paper presents the development of a mineral exploration template, based on field studies, aimed at assisting exploration personnel to establish effective communications and engagement with local communities within a process to build a Social License. The template aims to provide practical assistance in conducting situational analysis - a process of examining and mapping a situation, its elements and their relations - in order to acquire knowledge and understanding of a project, locale and region. Situational analysis is the ?full situation of inquiry?, going beyond just ?knowing the subject? to being fully situated. It forms the initial foundation for a planning process presented in the paper that prepares for a strategy of initial engagement and consultation.

Jan 1, 2007

By N/A

finally, but not least, the staff of Vaal Reefs Chemical Laboratory for their assistance and patience with the introduction of a new technology,

Jan 1, 1991

By Blagoj Golomeov, Boris Krstev

Nowadays, in the papers of authors in the area of flotation concentration, we can find several equations that describe the kinetics of flotation process as follows: Agar's equation, Klimpel's equation, Beloglazov's equation and Group of authors' equation (equation with two kinetic constants). This paper makes an attempt to determine the most appropriate equation for mathematical interpretation of kinetics of the SASA mine rougher Pb - Zn flotation.

Jan 1, 2002

By M. Galetakis

This paper proposes a new approach for calibration of dual gamma-energy transmission (DU-ET) ash analyser for improved online analysis of run-of-mine lignite. An adaptive neuro-fuzzy inference system (ANFIS) was developed to model the relationship between the intensities measured by the scintillation counter of the analyzer and the measured ash. Samples collected from Megalopolis lignite mines were measured for their ash content by using standard laboratory methods as well as by DUET. Obtained data was divided into training, testing and validation sets. A first order Sugeno type ANFIS was used in conjunction with early stop training. The calibration performance obtained by this approach was significantly better compared with that obtained by standard calibration methods based on multiple linear regression analysis.

Jan 1, 2006

By Sara Swiokla Korsikas, Toren Olson, Amado Guzman, Yuri O. Zepeda

Ore agglomeration has been used as part of the heap leaching process for the last 40 years. However, industrial experience shows that the lack of a universal agglomeration standard has limited the benefits of this otherwise valuable unit process. The more complex the ore in terms of the nature and relative abundance of fines (particle size smaller than 74 μm), the more important that the agglomeration product satisfies some minimal requirements. This paper presents an agglomeration scale that identifies the quality standards for agglomerates and documents the resulting mechanical, physical and hydraulic (hydrodynamic) behavior associated with each level on the agglomeration scale. The hydrodynamic properties of an agglomeration product are critical for the proper design of a leaching operation and, as shown in this paper, can be used to select the optimal pretreatment method for a given ore sample. Agglomeration as a unit process not only allows better conditioning of the hydrodynamic behavior of the ore but also creates an opportunity for optimized delivery of reagents to kickstart the leaching process, which may ultimately improve the economic performance of leaching. Industrial case data are used to demonstrate the shortfalls associated with low-quality agglomeration and the benefits of improved agglomeration, which range from enhanced porous structure (better percolation and drainage characteristics) to better metallurgical response (faster kinetics and higher metal recovery). Proper agglomeration has been used to render otherwise untreatable ores into valuable leaching resources.

Sep 1, 2024