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By A. Bruynesteyn

Procedures are discussed to determine if a waste material can become acid producing when left exposed to the environment. When wastes proves to be acid producing, methods are described that can be used to determine the characteristics of the effluents produced from a commercial size waste dump, taking into consideration that large quantities of pollutants can accumulate inside a waste dump during dry periods. The length of such dry periods and the quantity of rainfall greatly affect effluent characteristics.

Jan 1, 1980

By S. S. Hsieh

Bench-scale beneficiation studies were made on Idaho dolomitic phosphate rock using the TVA carbonate flotation process. The process employed diphosphonic acid as a phosphate mineral depressant and fatty acid as a carbonate mineral collector. Silica was subsequently rejected as float using an amine collector, with phosphate product recovered as the sink fraction. Two samples of prepared flotation feed from commercial operation were used; one contained 21% P205 and 3.2% MgO, and the other contained 26% P205 and 1.8% MgO. The results indicate that concentrates containing 31-33% P205 and 1% or less MgO can be obtained, with P205 recovery of about 80%.

Jan 1, 1984

By S. G. Malghan, J. P. Van Dillen

Introduction Some uranium minerals are paramagnetic and hence are amenable to concentration by high gradient magnetic separation (HGMS). This paper describes effects of the HGMS parameters-pulp velocity, field strength, matrix loading, and magnetic field gradient-on the product recovery and grade. Unsatisfactory separation of uranium minerals by HGMS is related to ore-specific properties, such as lack of liberation, fine dissemination of uranium minerals, uniform distribution of magnetic minerals throughout the ore matrix, and interference of fine-sized slimes. Experimental techniques to identify and resolve some of these problems are outlined. HGMS of Uranium Ores The mechanism by which uranium minerals are attracted to a magnetic field is either due to its magnetic susceptibility or its association with other minerals that are magnetic. Data on magnetic susceptibility of uranium minerals are scarce. The only reported data are for uraninite at 2360 X 10-6 cm3/mole. Povarennykh (Andres, 1976) concluded that the magnetic properties of minerals depend on: • Structure of the outer electron shell in a mineral with electropositive atoms; • Valence of the atoms; • State of the chemical bonds; • Type of coordination; and • Proportion of magnetic atoms (Fe, Mn, Cr, and Ni) in the composition of the mineral. However, information on the magnetic susceptibilities of the constituent atoms of a mineral alone does not suffice for evaluating the mineral compound as a whole. Most often, uranium minerals can be beneficiated by HGMS if they are associated with other minerals that are magnetic. This appears to be a more predominant mechanism by which the uranium minerals are beneficiated. Experimental A Sala-HGMS (Malghan and Subramanian, 1981), model 10-15-20, separator was used in the experiments. The matrix material-ferromagnetic stainless steel in the form of expanded metal or steel wool-was packed into a 38-mm (1.5-in.) diameter by 360-mm (14-in.) long canister. The matrix material occupied only a 150-mm (6-in.) length. The experimental set-up and slurry flow direction are described elsewhere (lannicelli, 1976). The response of uranium ores in the HGMS was studied by feeding well-dispersed slurry at 10% solids and examining the influence of process variables on selectivity and overall uranium recovery. The chemical and mineralogical characteristics of the ores under study are presented in Table 1.

Jan 12, 1983

By Ioannis Nicolaou

This paper demonstrates the method of approach for the optimization of such filters. This does not only incorporate the proven and simple recently developed equations for the calculation of the solids throughput, the residual moisture and gas throughput, but also introduces equations for the calculation of the specific product costs for both vacuum and hyperbaric filtration under consideration of the influences exerted by the filter compressor and a possible thermal drying. An easy-to-use method is offered which incorporates a special graphic representation concerning the plotting of the target parameters in dependence of the pressure difference with which the optimal process pressure difference can be established, independent of the specific cake permeability or product fineness. Finally, the optimization method is exemplarily demonstrated for a concrete application.

Jan 1, 1995

By Philomene Verlaan

The Code for Environmental Management of Marine Mining (the Code) was adopted in 2001 by the International Marine Minerals Society (IMMS) following extensive and wide-ranging consultation, and updated in 2002. The Code provides a framework and benchmarks for development and implementation of an environmental program for a marine exploration or extraction site by marine mining companies, and for stakeholders in governments, NGOs and communities in evaluating actual and proposed applications of environmental programs at marine mining sites. The Code provides for its review by IMMS after five years, with a focus toward possible modifications based on experience with its implementation and in light of developments in the field of marine mining and associated environmental practices, in consultation with the marine mining industry and with other stakeholders at marine mining operations. As the review of the Code is now due, to begin the process, this paper will present an analysis of the Code and initial suggestions for its modification. Keywords: marine mining, marine environment, sustainable development, marine environmental risk management

Jan 1, 2008

By E. William Rossi, Audrey F. Glowacki, Richard L. Unger

The U.S. Bureau of Mines has developed a graphics-based computer model to assess operator visibility for continuous miners, shuttle cars, and scoops. Using digitized drawings of the machine, the program can analyze visibility for both 5th percentile female and 95th percentile male operators. This model was used to predict 95th percentile male operator visibility for two shuttle car designs. These results were then compared to those obtained from a manual assessment of visibility using the actual shuttle cars. The methods showed good correlation except for several cases which were attributed to imprecise digitization of the machines.

Jan 1, 1992

By Pieter Hoekstra, Jim Hild, Mark Blohm

In the Basin and Range Province of Nevada, geophysics is used to assist exploration for bulk minable gold deposits, particularly over pediments. It is employed for mapping thickness of alluvium and Tertiary valley fill, for mapping covered structures, and for identifying alteration zones. In addition to potential field and seismic methods, three different electrical and electromagnetic methods are frequently used, resistivity-induced polarization, controlled source audiomagnetotellurics, and time domain EM. A review and comparison of the principles of these methods, illustrated by case histories, is the topic of this paper.

Jan 1, 1989

By C. J. Bise

Continuous mining accounts for about 69% of the nation's underground coal production. This level is not expected to change much in the near future. This is because continuous mining represents the primary means of under- ground coal production. It is also the primary means of driving development entries for underground coal mines, including longwall mines. The continuous miner worksite contains many characteristics that can lead to personnel accidents. It continues to be an area of concern for mine managers, safety engineers, and training coordinators. In an effort to assist mine management in attempts to reduce the number of accidents and injuries sustained in this area, this paper presents a loss-control-based, non-intrusive strategy for conducting safety evaluations at continuous miner worksites.

Jan 1, 1991

By Bart Hogeweg

The development of deep sea mineral deposits creates a new horizon for the mining industry. In a field where mining technology meets deep-water offshore engineering, new challenges are faced to come to the successful exploitation of these deposits. With the absence of proven technology for the mining of these minerals, a ?technological green field? is entered. IHC Merwede (IHC), a global market leader in the dredging and wet mining industry, is on the frontline of these developments. MTI Holland, IHC Merwede?s research and development company, has undertaken a number research efforts focused on the successful development of technology for the mining of deep sea minerals. This paper highlights a number of these efforts and illustrates IHC?s continued dedication for the research and development of technology to enable the commercial mining of deep sea minerals.

Jan 1, 2008

By Peter Erlynne

Rising costs have affected the cost of operating and install­ing crushing circuits, just as they have affected every other area and there is little possibility that the cost cycle is about to be reversed - power costs, wear materials costs and labour costs continue to increase but a basically stable gold price makes little allowance for these cost increases. Additionally, lower grades of ores being worked, and harder feed materials have a significant effect on the potential for higher processing costs. There are, of course, options for size reduction - some of them newer than others - some are suitable for certain types of ores and less suitable for others and it can sometimes be difficult to ascertain the accuracy of anticipated results before plant design and con­struction are completed - by which time the capital outlayed will preclude a change to another method ofreduction. Nordberg's patented WaterFlush Technology has the potential to change the way that Ball Mill Feed production is viewed: Some of the elements that must be considered are: • Capital Cost • Operating Cost • Efficiency • Flexibility • Availability • Control • Support Efficiency • Expertise • Spares availability • Environmental considerations

Jan 1, 1995

By J. A. Cervantes

A statistical model for assessing the risk of ground subsidence in abandoned mine areas is presented. The model is based on the relationship that exists between .the frequency and the location-of subsidence events in a given area and the physical conditions of the ground. These conditions can be described by a series of geological, mining, and physical variables. The model suggests the existence of regions in the multidimensional space of variables which are associated .with increases or decreases in the frequency of subsidence events. Regions associated with an increase in the frequency of subsidence events correspond to regions of higher risks, and vice versa. Risk assessment is based on the ability to express the limits of these high and low risk regions in the, space of variables, and on the ability to express the degree of membership of blocks of land within any of these regions. The theoretical framework for the model is extracted, from discriminant analysis. Risk is quantified by the probabilities of membership of blocks of land into any of these regions. Risk maps are produced by displaying membership probabilities in. appropriate contouring levels. The model has been applied in two urban areas where subsidence of the ground has been active in the past. The two areas are Penn Hills, near Pittsburgh, and Scranton/Wilkes-Barre in northeastern Pennsylvania. In this paper, only the results for the Scranton/Wilkes-Barre area are presented. Those for the Penn Hills area have been presented elsewhere (Cervantes, et al, 1990). In the- Scranton/Wilkes-Barre area, geostatistical estimates of variables likely to affect the stability of the ground were made using samples from 53 drillholes. The estimates were made for 2000x2000 ft squared blocks of land covering the study area. Discriminant functions were computed from the estimated variables and used to establish regions for classifying blocks of land into one of these two populations: 1) blocks not likely to have a subsidence event, and ii) blocks likely to have one or more subsidence events. The same, discriminant functions were used to compute membership probabilities for blocks of land to tall within any of these two populations. These probabilities were contoured to produce a risk map. The risk map produced compares well with the location of the subsidence events which have occurred to date in the area.

Jan 1, 1992

By G. T. Adel, J. D. Miller, C. L. Lin

In view of the success of recent laboratory studies using X-ray computed tomography (CT) to determine coal washability and with the availability of high-speed CT systems, it now seems possible to design an on-stream washability system for the control of coarse coal-cleaning circuits. Design features for such a system are examined and possible control strategies are discussed for different applications.

Jan 1, 1995

By T. J. Kim, S. Suh

The purpose of this paper is to evaluate overall prospects of the export market in the Pacific Rim for Illinois steam coal in terms of recent changes in global socioeconomic factors. To pursue this objective, three factors affecting the prospects of Illinois coal in the Asian market were selected for detailed analysis: quality requirements of imported coal, particularly those of the Japanese market; import controls and regulatory factors; and transportation factors affecting the export of Illinois coal. Based on these analyses, alternative long-term strategies are suggested for promoting Illinois coal export in the Asian market.

Jan 1, 1988

By David Akers, Clifford Raleigh, Glenn Shirey

Under a Cooperative Agreement with the U.S. Department of Energy’s National Energy Technology Laboratory (NETL) and the Mining Industry of the Future Program, CQ Inc. is demonstrating the GranuFlow™ process for improving the recovery of fine-sized coal in commercial coal preparation facilities. The State of Pennsylvania’s Energy Harvest Grant Program is also providing funding for this project. The GranuFlow technology involves the addition of an asphalt emulsion to a slurry of fine-sized coal (<100 mesh or 0.15 mm, typically froth flotation concentrate) before mechanical dewatering in screen-bowl centrifuges. The emulsion selectively agglomerates the carbon-rich particles, resulting in increased particle size and improved recovery of the coal fines during the dewatering process. This paper summarizes the test conditions and current results for both bench-scale investigations and full-scale commercial plant demonstrations.

Jan 1, 2005

By Gary S. Brierley, Ronald E. Romley, Alan L. Howard

The Price Road Drain Tunnel in Tempe, Arizona is part of the drainage system constructed in conjunction with the Outer Loop Highway in metropolitan Phoenix. The Outer Loop Project is a part of a much larger expressway system that includes other large drainage tunnels such as the Papago Freeway Drain Tunnels. Large diameter downhole inspection borings were utilized to obtain subsurface data for the design of these tunnels. Subsurface data obtained from the large diameter borings resulted in the development of empirical parameters that were successfully incorporated into the Geotechnical Design Summary Report and which satisfactorily predicted ground behavior, formed the basis for improved geotechnical design criteria, and facilitated the cost effective assessment of third party risk. The purpose of this paper is to describe the subsurface exploration program performed for this project and to explain the methods used to evaluate underground construction procedures.

Jan 1, 1991

By Steve Kral

Competition in the gold mining industry throughout the world has become fierce in recent years. The challenge facing operations personnel is to produce more gold for less money. Likewise, the explorationist&apos;s charge is to find more gold in a more cost-efficient manner. That means using new technology to find new gold deposits and expand present ones. More accurate mapping instruments are available to geologists in the search for new deposits. Advanced geophysical and geochemical methods enable explo¬ration teams to review previously mined districts in their search for minable reserves. Four technical sessions on the geology, exploration, and development of gold deposits were part of the program at `world Gold &apos;89,&apos; a Gold Forum on Technology and Practices," held by SME and The Australasian Institute of Mining and Metallurgy in Reno, NV, Nov. 5-8, 1989.

Jan 1, 1990

By A. Yazadni-Chamzini

Considering the nature of open pit mines, harvest volume, it usually is required to remove a lot of waste to access to mineral planned grade. So, one of the most important part of open pit mines design, is waste dump site selection. Many factors are effective in waste dump site selection. These factors are sometimes in conflict with each other. So selecting the desired location for waste dump is a process complex and multi-criteria decision making. There are a variety of methods for decision making under complicated condition, such as fuzzy, Delphi, multi-criteria decision making and Expert system methods can be hinted. VIKOR method, which is one of the decision making multi criteria methods, is useful tool for decision-making. On the other hand with regard to uncertainty in decision-making, fuzzy approach is a useful tool for this purpose. This article has tried to select the best waste dump site in Sari Gunay Gold Mine by Fuzzy VIKOR. The results show that C position has a higher priority than other positions.

Jan 1, 2012

By A. R. Przybylek

A fluid bed dryer has been designed for a nonconventional application to upgrade the value of fine anthracite culm and silt recovered from culm banks and anthracite tailings pond beds. This material can be seen as large spoil piles scattered throughout the anthracite coal regions of Eastern Pennsylvania. Engineering of the system commenced in December of 1986 and at this writing start-up is scheduled for late October or early November of 1987. This paper will focus on generalities concerned With system design and operation, and qualify the differences from conventional fluid bed coal drying systems.

Jan 1, 1988

By Wayne E. Kilker, Michael J. McBride, William P. Levy, Thomas J. Lamb

Between 1989 and 2004 the Massachusetts Water Resources Authority (MWRA)constructed several major wastewater and water tunnels associated with three major projects in the Boston area of eastern Massachusetts. There were many similarities and differences in the bedrock conditions encountered and among the contractual approaches for these independent projects. Through a clarification of the approach similarities and analysis of the contract differences, this paper addresses and presents what are considered to be valuable lessons learned. In doing so, the paper follows the evolution of such disparate issues as contract conditions, baseline reports and dispute review boards. The authors believe that the lessons learned even represent what, in certain cases, could be referred to as “universal truths” that are intended to have application to the next generation of tunneling contracts.

Jan 1, 2005

By Jorma Miettunen, Reijo Kalapudas, Pertti Koivistoinen

A new method for measuring the mill filling was developed by Outokumpu’s Pyhäsalmi concentrator during 1989-90. The method utilizes the power draw oscillation which is caused by the mill lifters. Each lifter bar causes a peak in the power draw and thus a continuous oscillation results. In a fixed time scale, the oscillation peaks will shift as the lifter bare hit the mill charge sooner or later depending on the volumetric filling of the mill. Thus the measuring method is based on the phase shift of the power oscillation. So far the measurement is utilized for maximizing throughput of the primary mills at Pyhäsalmi and Enonkoski concentrators and at Harjavalta slag concentrator. The paper describes the new method and the results achieved.

Jan 1, 1992