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By G. R. Burman

Gilsonite is a brittle, natural solid bituminous resin, classified as an asphaltite. It is found in near-vertical veins in the Uintah Basin of Eastern Utah. Discovered well over 100 years ago by Samuel Gilson, this unique material has, since its finding, enjoyed a variety of commercial and industrial applications. Early uses for the product included black automotive paint and beer vat linings. Among its many important uses today are additives for oil well drilling fluids and cements, additives for sand castings for the foundry industry, reinforcing agent for asphalt pavements, and dispersing agent for black inks. Gilsonite is mined and processed in Bonanza, Utah, by two companies, American Gilsonite Company (AGC), an operating division of Chevron Resources, and Ziegler Chemical, a privately held company headquartered in New York.

Jan 1, 1990

By R. R. Klimpel

This paper is a summary of the author's industrial experiences on the selection and optimization of flotation reagent schemes for the recovery of gold species. The trends given are a composite of data and experiences gained on 24 different gold ores from around the globe. The primary emphasis is on the benefits of matching the associated gold mineralogy to a reagent scheme most appropriate for that mineralogy. Two general categories are discussed: the flotation of free or native gold species and the flotation of gold associated with a variety of sulfide minerals. Important plant operating factors influencing each of these two categories are presented with supporting examples. Carefully matching reagent chemistry and appropriate operating conditions to any given gold-bearing ore will not only lower the total reagent cost but, more importantly, can lead to measurable increases in gold recovery.

Jan 1, 2000

By M. Menegaki

Restoration of abandoned mine sites is still one of the weak points of mining practice. The latter stands especially for the case of the surface coal and lignite exploitations, where the extended size of the disturbed land and the drastic changes to the geomorphologic features do not facilitate the implementation of a cost effective and environmentally sound reclamation plan. The paper examines the parameters involved towards the legal requirements for the reclamation of the first lignite exploitation in Greece, namely the ?Plakes? mine, located at Euboea, due to the particularities of the site. Then an integrated redesign procedure is presented, aiming at minimizing aesthetic degradation, confronting technical difficulties and preparing the site to accept new uses.

Jan 1, 2005

By E. Karampinos, P. Morissette

"INTRODUCTION Ground support is a critical element in maintaining the stability of mining drives in deep and high stress mines. In challenging ground conditions, it is necessary to continuously explore ground support strategies that can control the resulting large deformations. It is an objective of mining operations to optimize the ground support by selecting both appropriate systems and the time of installation of each reinforcement element. A successful ground support strategy will result in the use of a system that ensures both the structural and operational integrity of the excavations and mitigates the need for rehabilitation. Preliminary ground support design is often based on empirical observations and methods. Once a design is implemented, field trials, observations and in situ pull tests are used to fine tune or improve the design. Although not often employed during this process, numerical modelling can provide helpful insights on the impact of different ground support strategies. In this respect, it is possible to explore the use of multiple options before selecting the most promising ground support system for implementation in field trials. The challenges associated with the numerical modelling of rock support for mines have been described by Lorig and Varona (2013) and Potvin (2017). The employed numerical models should capture all potential failure modes of reinforcement over the mining sequence of the excavation. In particular, it is important to emulate the observed in situ ground support performance, as well as the influence of the installation sequence of the support. However, the time and expertise required for this type of modelling of ground support is not often available at mine sites. Even when the expertise is available it requires a major time and commitment of resources to set up, run and calibrate the sophisticated models capable of explicitly capturing the behavior of ground support. Rock reinforcement is an integral part of all ground support systems used in underground mines. Long flexible tendons can reinforce the rock mass deeper into the walls and create a thicker reinforced shell around the underground excavation. This paper focuses on the optimization of the cable bolting strategy in squeezing conditions at the LaRonde Mine by integrating the 3D distinct element method (DEM) in the design process. A calibrated numerical model is used to investigate a series of cable bolt configurations and provide recommendations for the ground support design."

Jan 1, 2018

By K. W. Deter

The gold ores in the Jerritt Canyon district have been recognized as refractory since they were first encountered by FMC geologists in 1976. Upon obtaining managing rights as joint venture partner, Freeport McMoRan Inc. developed an operating plan featuring carbon-in-leach gold recovery techniques for the oxide portion of the ores and a patented sulphide oxidation step followed by chlorination for treating the organic carbon constituents of the refractory ores prior to CIL gold recovery. The plant was successfully started up in 1981 with the first gold poured on July 4, 1981. Initial plant throughput was designed to be 2495 MTPD (2750 STPD) total through the dual processing trains.

Jan 1, 1991

By T. P. Meloy

Riffles on a shaking table have a major effect on particle separation. This effect is modeled in a spreadsheet.

Jan 1, 1993

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 Maria S. Adusumilli, A. Bhaskara Rao

ABSTRACT The presence of gold in lateritic crusts over mafic and ultramafic volcanogenic complexes in / and greenstohe belts, has called the attention in several parts of Brazil and also in Australia. Recent studies reveal the variety of structures and mineralogy of such crusts, and their importance in correlation with host(bed) rock types, as exploration guides, specially for greenstone belt metallogeny. The expected nature of growth of plates and/or nuggets in such crusts is under detailed study, and is considered as possibly due to dissolution and reprecipitation phenomenae of disseminated-fine-low grade ore in the host rock, in this investigation, laterite geochemistry, though incipiently discussed todate, is of fundamental importance and significance. Lateritic gold can be classified texturally as: dusty and diffused, fine, thin platy, taDular, and nuggets. Such gold is pure, and is often restricted to nodular (pisoliths, ooliths, concretions) forms or the matrix, that constitute the crusts or lateritised gravel beds which have an essentially goetnitic nature. Further this gold is recovered directly by mining the crusts or the adjoining placers with the metal derived from them. The thickness and extension of laterite crust zones is extremely variable depending oh the paleoclimatic conditions, and is conditioned to the favourable lithology and its structural expression. However, the "growth" of gold in these laterites will be conductive , without doubt, to several small scale mining activities, specially in the developing countries and regions limited to latitudes 309N and 309S.

Jan 1, 1987

By T. J. Malterer

Peat has unique physical, chemical, and biological properties. These include high porosity and water retention, high absorption and adsorption properties, high buffering capacity, and it is a rich medium for microorganism activity. Peat has traditionally been used for horticultural purposes. However, in recent years, peat is increasingly being used for waste treatment purposes. This paper reviews North American literature on the use of peat for waste treatment applications. The literature indicates promising use of peat in treating municipal and on-site effluent, removal of low concentrations of heavy metals from wastewaters, and adsorption of liquid and gaseous hydrocarbon pollutants.

Jan 1, 1995

By K. Hanna

Early identification of adverse geologic conditions and high stress concentrations during the high-speed extraction of coal using modern mechanized long wall systems is a major challenge facing the mining industry. Often, unexpected geologic anomalies that affect rock mass quality are encountered more rapidly, leaving the mine operator with insufficient time or information to deal with the changing ground conditions. The RockVision3DTM seismic tomographic system, developed by NSA Engineering, Inc., offers substantial benefits over conventional geologic/stress-detection methods and has been used successfully in coal mines worldwide. Tomographic images, produced economically and in near-real time, are easy to interpret, allowing mine operators to deal with potential hazards on a day-to-day basis. This paper focuses on the application of RockVision3DTM technology for delineating hazards caused by stress and geologic anomalies. Case studies for two bump-prone coal mines will be discussed. For example, (1) in a German deep (>1,130 m) mine, the drilling-yield method was used to verify the effectiveness of this technology in detecting stress anomalies ahead of longwalling; (2) in a Polish mine (-500 m deep), two longwall panels 4 km apart were monitored to assess structural and stress-related factors contributing to differences in mining conditions and magnitude of structural failures.

Jan 1, 1999

By J. K. Brooke

Fluorine is a lively element in both its chemical and economic behavior. It was not isolated as an element until 1886 by Moissan. However, its principal source to this day, fluorspar, was known and its special merits recognized long before that time. Our own mining brother, Agricola, is credited with having named fluorite, the mineral name, in 1546 from the Latin, "fluere", to flow. It made things melt and was already being used as a flux. Because fluorspar has been found as a relatively common gangue mineral in metal ore veins, it has long attracted the attention of geological thinkers seeking to, explain the whys and wherefores of veins. Fluorine has been thought of as one of the principal mineralizers, holding metals in ascending vein solutions for deposition close enough to the eventual surface to be accessible for profitable mining.

Jan 1, 1964

By E. Woodburn, Harrison R. Cooper, R. Putman

The key to concentrator automation is practical means for obtaining continuous assay data from concentrator streams. The technique most successfully used is x-ray fluorescence analysis. The practical reality of on-stream x-ray analysis has been achieved through effort over the past twenty years, marked by an occasional breakthrough, but more typically a step-by-step development to which many individuals and organizations have contributed. The net result of this progress is the present capability to install on-stream x-ray analyzer systems on a turn-key basis. It is now possible to provide all components of an x-ray analysis system as a completely engineered unit which can be put into immediate use, minimizing needs for specialized application know- ledge to benefit from continuous assaying in process control. The economic factors which influence the choice of system and limitations of the x-ray fluorescence technique for slurry analysis are reviewed.

Jan 1, 1976

By Ralph W. Crosser

The emergence of residuals management as a planning and management tool in the mineral industry has been recently accelerated by the proliferation of environmental regulation and its associated costs. Residuals management practices allow for the early determination and integration of both production and environmental goals in the development of management strategies to arrive at the most cost effective, environ- mentally sound solution. The term residuals management was in actuality derived from the substitution of the word residual for the term ?pollutant? or ?waste?. A residual can be defined as a non-product output having no value in existing markets or a value less than the cost of marketing it. The values of the residual can be determined by time, technology, government policy, market conditions, etc. Residuals basically fit into two classes -- materials which are composed of liquid, gaseous or solids; and, energy, which mainly consists of heat and noise. These residuals are interrelated and can be modified by adding materials and/ or energy, which also may become a residual; thus, lending themselves to alternate disposal schemes to control the adverse effects.

Jan 1, 1979

By David Butts

Solar ponding to crystdlize sodium chloride has been used for thousands of years.1 The systems used were inefficient and usually small compared to the large 25,000 acre pond areas seen today. It has only been in the last 25 years that any real effort has been applied to develop solar ponding technology. Many large solar pond systems have been constructed without much thought to efficient and optimum production rates. The recent high costs of labor, of equipment and of energy have forced producers to take a closer look at their solar pond systems in an attempt to squeeze out the highest possible yields. Other companies such as the Arab Potash Company, the Dead Sea Works, Texas Gulf (Moab, Utah) and San Francisco Salt Companies have no more land area in which to expand and therefore efficient ponds are essential. This paper is written to show how the subdivision of solar ponds can result in production increases of up to 20% and beyond.

Jan 1, 1984

By S. M. Alvarez

The Moon Creek Reclamation Project provides a case study in the development of creative cleanup solutions for an abandoned lead and zinc mine and mill site located in northern Idaho. Innovative design features include construction of a 88,000 cubic yard combined waste containment facility on soft in-situ tailings, water-balance cap, limestone gravel drains, a geocell mattress for stability, and a below-grade scour protection berm. The stream, including a wetlands buffer, will be relocated within an existing road alignment and rehabilitated to provide trout habitat. These elements allow for the integration of reclamation and stabilization measures into an effective site design.

Jan 1, 1999

By Lawrence Adler

[An innovative framework is proposed which most efficiently and systematically handles the large quantity of information needed for equipment failure and other non-performance analyses. It is based on the accepted engineering dimensions of mass (material), length (geometry), and time (MLT). To these are added human and machine factor. Several failure "Modes" are identified for each dimension, which are then subdivided into specific "Types". Material Failure Modes such as Separation and Slip are easily recognized, but others had to be established. Geometric Failure Modes are usually straight-forward, Obvious ones include Geometrics Design and Stability with more synthesized. Time Failure Modes are again largely self-evident such as Life and Chemical Effects, others are needed. Human and Machine Factors as failure modes are loosely assembled. The results contain strengths, but also organizational weaknesses which are noted. Lacking a better alternative its use is recommended.]

Jan 1, 1989

By F. Mauviel, J. Bernard, G. Herrouin, J. P. Lenoble, C. Charles, B. Taine

Manganese nodule projects were quite fashionable during the 1970s. At the beginning of the 1980s, low metal prices led to an almost complete reduction of such activities; however, the Law of the Sea incited the countries that signed it to build a strategy for this ocean resource. Gemonod was created in France in 1984 with a four-year mission. This paper presents the results of its program devoted to the technical and economic studies of nodule exploitation. A commercial mining system is presented. The nodules would be collected by a self-propelled miner and lifted hydraulically through a rigid pipestring. A complete optimized scenario has been built taking into account offshore mining, ore transfer at sea, transportation and processing to analyze the profitability of the project. Considering an average conservative basis for metal prices, after a deep analysis of the market, the return rate of investment of the project appears fairly interesting. These results are new and are explained in comparison with previous foreign studies. These results must not hide the innovative nature of the project nor the associated risks. This is why a mining pilot is required and has been specified by Gemonod.

Jan 1, 1991

By K. Nielsen

The Norwegian tunnelling industry has made remarkable improvements both with regard to productivity and cost efficiency over the last 30-40 years. This development has been made possible by continuous improvement driven by innovation. Based on a generic description of the innovation process and the innovation system, the paper has used the development of modern tunnel drilling in the Norwegian tunnelling industry to discuss the characteristics of its innovation system with a focus on human capital issues and knowledge management.

Jan 1, 2006

Load transfer capacity and failure mechanism of a fully grouted bolt installed across joints in shear is evaluated both experimentally and numerically in five types of bolts (low strength steel, rebar bolt and high strength steel). The strength of the concrete, bolt profile configuration, bolt mechanical properties and bolt pretension load play significant influence on the shear resistance, shear displacement and failure mechanism of the reinforced medium. Failure location moves towards the bolt joint intersection due to the increasing shear load, shear displacement and axial load developed along the bolt. Finally bolt failure occurs as a result of the induced axial and shear stresses acting between hinge points on either sides of the shear joint plane.

Jan 1, 2006

By Paul E. Scheerer

Synthetically produced magnesium hydroxide serves as the precursor for much of the magnesium oxide produced in the world today. Magnesium oxide, in a variety of physical and chemically reactive forms, is a very important commodity. It is used as the main component in refractories employed in steelmaking furnaces and in many base metal refining furnaces. In the chemical industry, it serves as a raw material in the production of epsom salts, rayon acetate, oxychloride and oxysulfate cements and magnesium sulfonates. It is a minor component in fertilizers and animal feeds. It serves as the starting material for producing fused magnesia, used as an electrical insulator in electric heating elements. It is employed in the magnesium sulfite process for pulp digestion in the paper industry. Additional uses are in SO2 scrubbers, as a neutralizing agent in the tanning industry and as a component in rubber compounding. Magnesium oxide is produced not only from synthetically produced magnesium hydroxide. It is produced from natural magnesites, natural brucites, and natural and synthetic hydro-magnesites. Synthetic magnesium hydroxide, as a starting material provides more control of the chemical purity and chemical reactivity of resulting magnesium oxide products because of the uniform nature, chemical and physical, of the hydroxide that can be produced. Synthetic magnesium hydroxide is produced by precipitation of Mg (OH)2 from magnesium chloride bearing seawater or natural brines through the use of a base such as Ca(OH)2 or NaOH.

Jan 1, 1978