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By R. L. Grayson

Following lip on a USBM-sponsored research project, the authors have utilized the knowledge-base structure and system concepts from the Sun Sparcstation-based worker scheduling system of the Mine Management Support System to develop a PC-based application. The new software adopts the nested-window concept to facilitate data collection and modification on personnel, their availability on a shift, and work priorities for a shift as well as to allocate manpower optimally on a work shift and delineate supervisory training responsibilities. The various components of the software are described in detail, along with enhancements made to the original system.

Jan 1, 1996

By L. F. Zeiler

In the past, health concerns in coal mines have primarily centered on those elements which have been essentially inherent to the mining environment. These would include respirable coal mine dust, respirable crystalline silica, excessive noise levels, and diesel exhaust particulates. Commercially-available chemical products are prevalent on mine property. These potentially toxic materials are chemical formulations that can degrease, clean, and lubricate metal parts, separate coal from rock in float/sink operations, and aid in roof consolidation, among other uses. As the general public has become more aware of the hazards of chemical exposures, miners have likewise become more concerned about working with an ever-expanding variety of chemical products on the job. Often, product or chemical specific hazard communication training is inadequate or ineffective, and miners do not know exactly what the ingredients are in the products they handle, or the health hazards involved with their use or misuse. Currently, the Mine Safety and Health Administration (MSHA), by law, enforces 1972 Threshold Limit Values (TLV). MSHA is making preparations to adopt new personal exposure limits for enforcement. The values given throughout the article are 1994 TLV's and are not enforcement standards, but are used for discussion purposes. They reflect the current scientific thinking regarding personal exposure to these chemical agents. An overview of these products is presented, and the potential health hazards associated with their use are discussed. Controls needed to prevent overexposures, such as proper handling procedures and personal protective equipment, are covered. Methods used to collect and identify contaminants are presented.

Jan 1, 1995

By Frank L. Bazzanella

Se presenta una breve introducción de la concentración gravimétrica, incluyendo alguna discusión sobre los minerales mas comunes recuperados normalmente. Se mencionan las consideraciones importantes para el diseño básico de una planta de concentración y se presentan cuatro esquemas de flujo sobre las operaciones más corrientes. Las plantas estudiadas en detalle incluyen: "Climax Molybdenum Co. By-Product Plant" y "Canada Tungsten Ltd. Plant". Las plantas brevernente reseñadas incluyen: "Palabora Mining Co. Uranium Recovery Facility" y "Bridge Hill Ridge Heavy Mineral Recovery Plant of Mineral Deposits Ltd."

Jan 1, 1982

By S. A. Jeric

In-pit crushing and conveying of waste has been utilized in the mining industry for over 30 years. In recent years, innovations in crushing, conveying, and particularly waste and leach stacking technology have sparked a renewed interest in continuous haulage systems for large-scale open pit applications. A review of the advantages/disadvantages and operating techniques of crushers, feeders, conveyors, and stacking systems currently available is made. The paper examines some operations that are currently using large scale continuous haulage systems. Finally, a case study is presented that evaluates the application of a continuous waste haulage system in a large open pit mine in the Western United States, The case study includes a economic comparison with the existing truck haulage system.

Jan 1, 1997

By J. Wagner, P. Eger, G. Melchert

In 1991, LTV Steel Mining decided to close an open-pit taconite mine in northeastern Minnesota using a passive-treatment approach consisting of limiting infiltration into the stockpiles and wetland treatment to remove metals. More than 50 Aft (55 million st) of sulfide-containing waste had been stockpiled adjacent to the mine during its 30 years of operation. Drainage from the stockpiles contained elevated levels of copper, nickel, cobalt and zinc. Nickel is the major trace metal in the drainages. Before the closure, the annual median concentrations ranged from 1.5 to 50 mg/L. Copper, cobalt and zinc are also present but they are generally less than 5% of the nickel values. Median pH levels range from 5 to 7.5, but most of the stockpile drainages have pH levels greater than 6.5. Based on the chemical composition of each stockpile, a cover material was selected. The higher the potential that a stockpile had to produce acid drainage, the lower the permeability of the capping material required Covers ranged from overburden soil removed at the mine to a flexible plastic liner. Predictions of the reduction in infiltration ranged from 40% for the native soil to more than 90% for the plastic liner. Five constructed wetlands have been installed since 1992. They have removed 60% to 90% of the nickel in the drainages. Total capital costs for all the infiltration reduction and wetlands exceeded $6.5 million, but maintenance costs are less than 1 % of those for an active treatment plant. Because mine-drainage problems can continue for more than 100 years, the lower annual operating costs should pay for the construction of the wetland-treatment systems within seven years.

Jan 1, 2000

By G. F. Friel, J. C. Edwards, C. C. Hwang

In the implementation of a mine fire alarm and location strategy, the Interpretation of the fire signature Is Important. Smoke and CO are the two dominant fire signatures, and many mine fire detection systems utilize sensors which respond to smoke or CO through a diffusion mode or a mechanical pump mode. The fire signature may be modified during its transport along airways and at crosscuts. The modification occurs through dilution of the contaminants. In this Investigation, computer codes were employed to compute the effects of contaminant dilution on the contaminant signature when a straight flow passage has one dead-end crosscut. The model predicted the airflow within always and the entrainment of contaminants into the crosscut from the airway. One application of the model is to determine the most suitable location for CO detectors for early mine fire detection.

Jan 1, 1995

By Martin L. Smith

Mine waste characterization and risk assessment currently focesses on water quality and largely ignores boththe charteristics of the wastes themselves and how wastes interact with the environment. Characterization of the parameters that control contamination of pore waters and their migration can quantitatively assess risk and remediation strategies in terms of cost effectiveness and risk reduction. Since mine waste characteristics are spatial, geostatistical methods should be used for characterization and assessment. A number of geostatistical methods are reviewed in terms of their application to mine waste sampling, modeling and risk assessment and management.

Jan 1, 1995

By K. Hanumantha Rao, P. K. Sharma

A pure strain of Paenibacillus polymyxa and mineral- adapted strains are used to bring about surface chemical changes on pyrite and chalcopyrite and, thus, theirflotation. Paenibacillus polymyxa was adapted by repeated subculturing in the presence of pyrite and chalcopyrite. The surface chemical changes of bacteria due to adaptation and of minerals after their interaction with bacterial cultures are evaluated by electrokinetic and infrared spectroscopy and are discussed with reference to their flotation responses. Interaction of bacterial cells, bacterial metabolites and whole bacterial cultures affected the Hallirnondflotation behavior of the sulfide minerals. The Xanthate flotation results show that pyrite, but not chalcopyrite, is depressed when the tests are carried out after interaction with chalcopyrite-adapted Paenibacillus polymyxa. This investigation demonstrated that the surface chemical properties of bacteria can be manipulated successfully to achieve the desired effects in the flotation process.

Jan 1, 2000

By J. Felipe Costa, Andrew H. White, Marcot T. M. B. Vilhena

Ordinary kriiing (OK) is an interpolation algorithm mostly used in earth sciences applications where it provides satisfactory results. Robust kriging (RK) is an alternative algorithm which at- tempts to minimise the problems caused by the existence of outlier values within a given data set. Robust kriging essentially consists of an editing step prior to running the traditional OK method. This study compares the interpolation results obtained by OK and RK. Two data sets were used. The first data set consists of 140 samples mimicking a drilling survey named cluster.dat. An additional feature of this sample data is that its parent population, the reference data set, is available, thus permitting direct quantitative assessment of the effectiveness of a given estimation technique. The second data set consists of a grid sampled at 1x1 m. The estimates obtained by OK and RK using cluster.dat were compared to the reference data set. RK provided better results in terms of quality of the estimates than OK

Jan 1, 1996

By John A. Herbst, Per-Olaf Samskog, Jan Bjorkman, Yi Chang Lo

The study described here is concerned with the development of a model for the simulation and optimization of a rod milllpebble mill circuit. A series of laboratory tests was conducted to investigate the effect of critical operating variables. The pebble mill model structure used was a population balance type which accounta for impact breakage and fines production from pebble wear. Model parameterization and verification were performed using data obtained in batch tests and in a plant test campaign. The model developed was found to provide accurate predictions of plant-scale grinding. The prediction errors are less than 21 for the product size and 31 for the mill power required to achieve that product with a mill volume scale-up of 14,000 to 1. These results indicate that accurate extrapolations from laboratory batch data to plant scale performance are poaaible using the population balance model and scale-up prediction procedures for pebble mill circuits as well as ball mills. Preliminary indications are that the new model developed here will provide vital input for pebble mill optimization and process control as well as pebble mill design.

Jan 1, 1990

By Peter J. Lawson, John A. Rideout, Gregory W. Dicinoski

A considerable body of literature directed towards optimising the efficiency of gold and silver extraction from cyanide leach liquors has appeared in recent years. A few examples from dissolution to solvent extraction to adsorption in carbon-in-pulp (CIP) and resin-in-pulp (RIP) operations follow. Selective leaching of gold from copper-gold ores using ammonia-cyanide mixtures extends the % copper which may be tolerated in ores (Ruane, 1991, LaBrooy et al., 1991, Costello, 1991). The removal of copper and recycling of cyanide from high copper ores is another important development (Sceresini and Staunton, 1991). Solvent extraction of alkaline cyanide liquors (Riveros, 1990, Mooiman & Miller, 1991) and solvent aided elution in CIP (Muir, et al., 1985) look promising. Recent definitive papers on the mechanism of adsorption of aurocyanide by activated carbon should lead to more efficient use of CIP (Adams and Fleming, 1989, Klauber, 1991). Strong and mixed weak-strong base resins have been applied in RIP for aurocyanide extraction in Russian Plants since the 1970's (see for example Borovskii et al., 1985, and references cited in Fleming, 1988a). Fundamental studies on applications of commercial weak and strong base resins-in-pulp (Fleming & Cromberge, 1984a, b, Fleming 1988a, Hosking 1984, Riveros and Cooper 1987) have generated much interest in RIP. Detailed comparisons of CIP vs RIP efficiencies at Mintek in South Africa (Fleming et al., 1988b), and the inefficiency of CIP in contact with clay led to the commissioning of the strong base RIP Golden Jubilee plant in 1988. Its operation and improvements have been reported (Seymore and Fleming, 1989, Fleming & Seymore, 1990). The use of anion exchange membranes for aurocyanide extraction shows some promise (Mauthoor et al., 1991). However, the development of new gold specific resins at Mintek (Green et al., 1984, 1986, 1990, Johns and Green, 1991) and elsewhere (Asker et al., 1987, Wilson et al., 1987, Harris et al., 1992) should improve the viability of RIP processes. The polydiallylamine gold specific resins (Hodgkin & Eibl, 1988, Fawell et al., 1992a, b) have high capacities for auro cyanide recovery from high concentration liquors. The use of guanidine based liquid and solid ion exchange extractants for gold was recently reported by the Henkel Corporation (Kordosky., et. al., 1993). Such specific resins tailor made for gold and/or silver cyanide extraction should lower overall cost by improving metallurgical efficiency. In the case of strong base resins this selectivity largely eliminates the problems of poor base metal elution and/or poisoning. The work reported here outlines the approach taken at the University of Central Queensland to synthesize sterically hindered strong base anion exchange resins which are designed to have high selectivity for auro- and argentocyanide complexes. It summarises selectivity tests on low grade cyanide leach liquors from several mines. It also examines an RIP vs CIP comparison, and investigates the elution properties and cycling of one such promising resin.

Jan 1, 1993

By M. Henneman, M. Kosma, M. Eyll-Vetter

"For a long time, the recultivation of depleted opencast mines and operating systems was aimed at restoring the original state. The focus, as desired by policy-makers and the local population alike, was on restoring high-quality agricultural land and on creating reforested areas of value that suit their location. Until the turn of the millennium, recultivation measures were only rarely the subject matter of public planning processes beyond these general objectives. They were never regarded as nucleus and origin of sustainable structural developments. The rehabilitation of inactive lignite opencast mines in central and eastern Germany brought about a change in mind-set that understood recultivation to be a unique opportunity to completely redesign a landscape and gear it towards the future in the Rhenish mining area as well. The ""Inden residual lake"" and ""terra nova"" projects, planned in the last 10 years in cooperation with policy-makers and authorities, are two undertakings that provide sustainable structural impetus for the future today."

Jan 1, 2011

By C. P. Siess, S. L. Paul, E. H. Gaylord

Several types of tunnel supports are being investigated experimentally and analytically at the University of Illinois at Urbana-Champaign under the sponsorship of the Federal Railroad Administration, Department of Transportation. The results of work on two types will be discussed here. These are steel sets and continuous, monolithic steel-fiber-reinforced concrete liners. The latter is a model of a short length of liner that might result from a continuous slip-forming operation in a tunnel excavated with a boring machine. Tests have been performed on both types of support and analyses are being developed which will greatly broaden the scope of the test program. The objective of these studies is to improve the understanding of basic behavior of these supports, and to develop techniques for their analysis. The analyses will then be used to perform parameter studies that will lead to more rational procedures for structural design. The tests provide a check on the accuracy of the analysis and demonstrate the overall behavior and modes of failure. Another part of the project is concerned with the interaction of support and medium, and thus prediction of loads for the supports. These studies are presented in greater detail in a recent report (1). A brief outline of results obtained to date are presented in this paper. STUDIES OF STEEL SETS Description of Set Tests The sets tested were of the horseshoe type with a 5-ft radius arch section and 7-ft straight legs. They had bolted joints at the crown

Jan 1, 1974

By John Duff Erickson

Determination of the final pit limits of an open pit copper mine is a problem that has far reaching effects on the life, profitability and operation of a mine. The solution to this problem requires that all of the significant variables affecting the final pit limits be considered together with corporate objectives as the guiding principle. This paper discusses the use of these variables and how they should be applied to plan the future of a mine. The objectives of a final pit plan; are determination of the extent and location of ore reserves, the allowable stripping to be accomplished to uncover the ore, the final pit surface intercept, final pit topography and the contained metal values in both ore and waste. The objectives of the plan must be consistent with corporate objectives as they pertain to profit, future investment in the mine, return on investment, alternative investments, conservation and perpetuation of the corporate entity. The subject will be treated in three parts: economic considerations, effect of leaching and pit design technique. At the outset, it is assumed; that the extent of and metal values in the mineralized area to be considered have been reasonably defined by development drilling and sampling.

Jan 1, 1968

By T. W. Healy, M. S. Moignard

The use of electrokinetic or zeta-potential phenomena in studies of the properties of mineral sulphides has increased greatly over recent years. This review aims to examine and discuss the body of literature on the subject of electrokinetic properties of sulphides in a comprehensive and critical manner. Although the review covers the period from 1925 to 1975, it is only in the past ten years that researchers have been fully aware of the implications and problems of chemical reactions, notably oxidation and precipitation reactions, on the surface properties of sulphide minerals. These papers are discussed in more detail than the earlier publications. A table containing a list of determinations of iso-electric- points and points-of-zero-charge of mineral sulphides, and the methods employed in obtaining these results, is presented.

Jan 1, 1976

By R. Jerez

This paper describes practical applications of lineal" programming techniques to help in the planning of production, transportation and shipments at different coal mines. The models are being used by Cyprus Coal Company in eastern and western operations to plan coal production, economic dispatching and blending over variable time horizons. In addition, where a preparation plant exists, the models establish the amount of washing required to meet specific coal sales qualities. The emphasis on this paper is on model development and implementation together with a system to track coal flow and qualities, either raw from the mines to the loading facilities 01" processed through a preparation plant.

Jan 1, 1991

By J. G. Pippenger

The Coteau Properties Company's Freedom Mine is a surface lignite mining operation utilizing large draglines, trucks and shovels, tractor-scrapers, and bulldozers to uncover a single coal seam. In 1989, a work order system was instituted to record data by equipment type, cost, productivity, and distance, and to provide historical information for planning the most efficient and economic use of each equipment type in the mining operation. This report explains how the work order system was initiated, what data is tracked, and how the data is utilized for equipment and project scheduling.

Jan 1, 1994

By Y. C. Kim

To generate a most profitable, ultimate pit limit is generally the first step in mine design. This paper presents a new graph theory oriented, optimum ultimate pit limit design algorithm which will maximize the total undiscounted net profit. This algorithm performs much better than the well known Lerchs-Grossmann algorithm, in terms of the reduction in computation time and computer memory requirements. This algorithm operates on many directed trees in a graph, where each vertex in a tree represents a block in the mine model. The formation of each directed tree is based more on the ore-waste support concept than the geometry constraints alone. The general procedures of the algorithm, programming considerations and two case study results are discussed in the paper.

Jan 1, 1992

By G. Zandt, H. R. Pratt, W. A. Hustrulid, M. Bouchon, D. E. Stephenson

PREFACE The National Waste Terminal Storage Program was initiated to conduct the research to select a site for the disposal of high level radioactive waste in deep geologic formations. As part of this program, the Savannah River Laboratory at Aiken, South Carolina, is conducting geologic research of generic applicability on the potential subsurface damage to a repository from an earthquake. Part of this study involved the collection of data on subsurface damage due to an earthquake, and another part involved the calculation of displacement fields as a result of an earthquake. Both of these studies were conducted at Terra Tek of Salt Lake City. This report is an abridged and combined version of both studies which was presented at the Rapid Excavation and Tunneling Conference in Atlanta, GA, on June 19, 1979.

Jan 1, 1979

By C. J. Bise

Virtual Reality (VR) is a concept in which the human experience of perceiving and interacting with a computer-modeled environment is achieved through the use of sensors and effectors. It is an advanced fonn of computer graphics where the images are generated based upon where the user looks and how the user moves. As personal-computer-based (PC-based) instruction gains acceptance as an innovative approach to providing safety training, VR offers the capability of providing a multisensory, rather than merely a multimedia, mode of presentation. VR has been effectively used by the military for training tank commanders and by hospitals for training surgeons. However, these applications have been limited to small numbers of highly skilled participants. The purpose of this paper is to examine VR's potential for enhancing the hazard awareness of larger numbers of individuals in a broad-based approach to mine safety training, such as new-miner, annual-refresher, and independent-contractor training.

Jan 1, 1996