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This report summarizes the results of several field tests conducted by Collins for the Bureau of Mines under contract S0122076 and contract H0232056. The field projects represent a part of Collins continuing effort on a broad study of coal mine communications. These experiments analyze the propagation characteristics of radio signals in a working coal mine environment. The intent of the program is to provide basic propagation loss characteristics by which we may evaluate various approaches to an integrated mine communications system. The goal of such a system is to satisfy both operational and emergency communications needs in the mine.

Jan 1, 1974

By James Gibbs

In order to provide an initial approach to the deposits of oil shale, nahcolite, and dawsonite in the central area of the Piceance Creek Basin in northwestern Colorado, the U.S.B.M. and associated contractor personnel drilled and cased a 96-inch ID shaft to a depth of 2,371 feet. The shaft was constructed using "big hole" drilling techniques and succeeded in giving access to previously inaccessible deposits of the above minerals. This report documents the construction from its beginning in January 1977 to its completion in January 1978. Procedures used and problems encountered are discussed in derail.

Jan 1, 1978

By L. R. Moore

Arsenic is among the list of major contaminants in mining aqueous waste streams. Though the elemental form is toxic, the aqueous oxyanions are more so. The most common forms of arsenic released during mining processes are arsenate and arsenite. The common treatment technologies to date can be summed up in these major categories: oxidation, coagulation, absorption, and media filtration. These methods can often involve many expensive processing steps that may also be limited by variables, such as total dissolved solids, other cations and anions, and the oxidation state of the arsenic. An innovative technology, falling in the absorption category, was developed that can successfully reduce such aqueous forms to a level below the EPA recommendations. This new technology offers a unique and viable solution which is transparent to the above mentioned limitations.

Jan 1, 2012

By Geo. S. Krueger

This paper, describing mining methods and costs at the Judge mine Park City, Utah, is one of a series being prepared by the Bureau of Mines on mining practices in the United states. ACKNOWLEDGMENTS The writers acknowledge the assistance of E. D. Gardner, supervising engineer, Southwest Experiment Station, Bureau of Mines; Paul H. Hunt, mine manager, Park Utah Consolidated Mines Co.; Wm. Osika, chief mine accountant; and Eric Neilson, assistant master mechanic of the mine.

Jan 1, 1938

By N Cusworth, W R. Mackenzie

"In 2007, the authors presented a framework for the conduct of resource project feasibility studies and provided guidance on minimum standards and best practice (Mackenzie and Cusworth, 2007).This paper will present the authors’ observations in relation to feasibility studies undertaken to support investments made during the unprecedented period of resource project capital investment since 2007. It will also provide comments on general trends in the mining industry’s approach to project assessment and update recommendations on best practice.CITATION:Mackenzie, W R and Cusworth, N, 2016. The use and abuse of feasibility studies – has anything changed?, in Proceedings Project Evaluation 2016, pp 133–148 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By R. E. Allen

THERE was once a time when a practical oil man would appraise or buy a producing property on the basis of from $200 to $500 per barrel of average daily settled production. Curtailment-has, for the present at least, caused a virtual abandonment of the "barrel -of settled production" as a yardstick of, oil property value and in its place has come the "barrel of allowable production," which, although an artificial thing, is nevertheless now the principal factor governing the rate of ?pay out? or investment return. The potential production of a well, settled or otherwise, is of less importance in determining the present worth of a well than is the rate at which it may be produced. Speaking only of true potential for the moment, it is obvious that of two similar wells having the same potential, the one having the highest rate of allowable production would be worth proportionately more than the one of lesser allowable. The discount factor for deferred return and risk can easily vary the present values of the two wells by as much as 20 per cent when allowable rates are not greatly different.

Jan 1, 1934

By F. M. C. C. Vieira

Four mining alternatives for exploiting an ultra-deep orebody were assessed through a multidisciplinary evaluation process which involved: the generation of a 3D geological model; the design and scheduling of life-of-mine layouts; the analysis of anticipated ventilation and cooling conditions; the study of rock-related risks of mining in ultra-deep stress environments; the logistic implications of transporting men, rock and materials; and, lastly, the economic implications of each option. Once results from the integrated mine design assessment were available, mine planners were faced with an important problem to solve: how to identify the optimal mine design alternative when numerous assessment measures and multiple decision criteria needed to be considered simultaneously? To address this ‘multiple-attribute decision problem’ and arrive at the ‘optimal layout for ultra-depth’, a generic decision methodology that uses principles of ‘utility’ was applied. The methodology assumes that ‘single-value risk estimators’ do not account for the inherent variability of real conditions. Therefore, risk estimators were represented by statistical distributions of their incremental changes, where applicable. The stochastic variables, once defined, are used as inputs in the ‘utility’-based layout decision scheme. This ‘utility’-based decision methodology offers a framework for mine design decisions to be made objectively, when complex trade-offs between multiple risk domains need to be considered simultaneously. Upon applying it, one of the layouts emerged as the preferred alternative. Keywords: Utility; mine design; multiple-attribute decision; layout selection

Jan 1, 2003

By Phil Keele

Canadian Natural ??Business Approach Efficiency and Execution ?Drive to be the low cost producer ?Focus on exploitation ?Augment exploitation with strategic acquisitions ?Maintain Discipline and Strength while Delivering on the Defined Plan ?Maintain flexibility and control allocation of capital ?Strive for balance (asset portfolio) ?Maintain financial strength

May 1, 2010

By Klaus L. Cappel

In 1972, the Bureau of Mines of the U. S. Department of the Interior commissioned the development and design of a Simulator for research and testing of mine roof supports used in long-wall mining. The purpose of the Simulator is to reproduce forces and displacements of a section of a mine roof in contact with one or more supports. This report is an account of the design process that resulted in the final configuration of the Simulator presented here. It includes discussions of engineering considerations that led to major changes in important details of the Simulator. These changes, however, did not substantially alter the basic design originally proposed, except for the elimination of certain originally-specified features that were adjudged as insufficiently cost-effective by both the Bureau of Mines and the design agent at an intermediate stage of the design.

Jan 1, 1974

By R. P. Sloan, A. S. Whitford

In November 1999, CCI's Empire Iron Mining Partnership and MinnovEX Technologies Inc. developed an expert system for advanced control of their Empire IV Grinding Section. Empire IV is comprised of three autogenous Primary Mills and six autogenous Pebble Mills, with a single Pebble Crusher and high pressure Roll Press. The challenges of controlling and optimizing three distinct grinding lines that are inter-woven by a pebble crushing circuit were met with innovative and unique solutions. This paper will detail the approach employed at Empire and will focus on the aspects that make this application unique.

Jan 1, 2001

By C. A. Jeffrey

The Dirtlow Rake vein deposit, which is up to 12 m thick, contains a range of paragenetically linked replacement mineralisation styles typical of many Mississippi Valley-type deposit environments. The main ore zone lies within the solution collapse breccia domes, the more southerly of which has recently been well exposed, allowing its relationship to the associated mineral-hosting structures to be studied. The domes were largely formed during early silicification, propagated by dissolution collapse and infilled by subsequent fluorite-barite mineralisation. The location of pipes and pervasive replacement was also controlled by early silicification. Structurally controlled bow tie shears were formed as a result of fluid access at fracture-bedding plane intersections. The nature and distribution of the mineralisation styles indicate that the degree of fluid access, residence time of solutions in contact with the wallrock and susceptibility of the limestone to silicification each played a major role in dictating mineralisation

Jun 19, 1905

By Wesley T. Holmes

This report describes the first phase of an investigation aimed at obtaining a wider knowledge of the problems involved in smelting titaniferous magnetites. Liquidus temperature measurements were made on selected slag compositions in the titania-alumina-silica-calcia-magnesia system. Both the melting-holding-quenching method and the hot-stage microscope method were used in the tests. Liquidus temperatures of slags studied ranged from 1,217° to 1,667° C. The lowest liquidus temperature of the slags occurred when the difference between CaO plus MgO and Si02 was less than 12 weight-percent. Liquidus temperatures were also lowered when Si02 was substituted for Ti02 plus Al2O3 when CaO and MgO levels were held constant. Improved methods for the measurement of liquidus temperatures on very small samples are described.

Jan 1, 1968

By L. A. Morely

Volume II of the final report concerns the application of sensitive ground-fault interrupters (GFIs) to ac utilization circuits in U.S. mines The main concepts examined are shock prevention and methods for reducing nuisance tripping. The research involved a literature search, input from previous Bureau of Mines contracts, and contacts with electrical manufac-turers and mining personnel. Following this background work, several devices that showed promise were obtained and tested. Results of testing indicate the existence of GFIs that may be modified to perform adequately on U.S. mining systems. A recommended set of guidelines is included in the report, covering design, construction specifications, and performance tests.

Jan 1, 1982

By M Lynch, B White

The historic city of Charters Towers in North Queensland is underlain by an extensive labyrinth of old mine workings in a large number of flat lying, subparallel, main and cross-cutting cross reefs extending of the order of 5 km along strike and down to a depth of 700 m in parts. These old workings produced over 6.6 million ounces of gold at a grade of over one ounce to the tonne prior to closure in 1920.Citigold is progressing the development of a modern, high productivity, low cost new mine to extract extensions of these reefs as well as other as yet un-mined reefs. To do this it is changing the paradigm for operating in such circumstances. This paper first briefly reviews the setting for the development and then discusses the philosophies and concepts that Citigold is proposing to use, harnessing technology to create a mine that exemplifies more productive and safer mining based on operating in the digital age.The paper addresses how a modern approach is being applied to the planning of a mechanised, deep, narrow vein, hard rock gold mine under a city. It also describes briefly the successful æexperimentationÆ with longhole open stoping methods developed at the companyÆs small underground operation (the Imperial Mine) to the south of the city, which will also be expanded substantially as part of the Charters Towers Gold Project.The paper also addresses the development of new and/or modified technologies in the venture, with the objective of pursuing continuous and autonomous mining methods. The company is adopting a holistic systems approach, addressing people, process and technology in order to efficiently identify and locate the high-grade ore zones and then extract them effectively at a high grade by minimising waste development and haulage, dilution and energy consumption, and with minimal environmental impact.CITATION:Lynch, M and White, B, 2013. Brave new world autonomous mining systems, in Proceedings World Gold 2013 , pp 157-166 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By Landy Stinnett

"When performing a valuation of a mineral property, a developing mine or perhaps an ongoing operation, the appraiser is typically provided with a range of information prepared by the property owner. This information can include ownership records, geological interpretation, assay data, an estimate of the reserves or resources believed to be on site (tons and grade), mine plans, production forecasts, capital and operating cost projections, and so forth.The appraiser familiarizes himself with the data, analyzes the various reports and then prepares the appraisal. There is usually a site visit, and there may be some effort at comparison of the particular mineral deposit with others in the region or with those of similar depositional characteristics, but for the most part, the appraiser is relying on the corporate documents, tempered by his/her experience in the field. Time is usually of the essence, the cost for the assignment has been trimmed, and therefore independent verification of the various components comprising the underlying data base (legal review, redrilling portions of the deposit, collection of new samples, re-assaying, etc.) is unlikely in most situations.In the case of high-value commodities — gold, silver, diamonds, perhaps the platinum-group elements — there have been numerous examples of the property owners attempting to increase the value of their holdings by nefarious methods. Most of these involve salting the deposit in some fashion; i.e., introducing small amounts of the commodity into samples being sent to a laboratory for analysis so that the resultant assay shows a higher grade (Donaldson, 2002; Greeley, 2001; Lechler et al., 2008 and Meech, 2001). Other schemes to enhance the apparent worth of a property include the use of nonstandard assay procedures, incorrect handling or withholding of the underlying information, and false reporting."

Sep 1, 2016

By R. Dahlke, J. A. Finch

A campaign was undertaken during the greater part of 2001 at Noranda’s Brunswick mine concentrator to investigate the role of gas (air) superficial rate (Jg) distribution to the cells in the final Zn cleaning stage (bank of seven cells), i.e. the Jg profile. Three profiles were tested: “balanced” (each cell with same Jg), “increasing” (from cell 1 to 7 proportionally), and “decreasing,” along with an “as found” profile in a parallel control bank. The experimental design allowed for two confounding factors, changes in ore type and circulating load. The increasing profile consistently gave the best metallurgy (down-the-bank grade / recovery). The reason for improved performance was the response of the first cells in the bank where the increasing profile gave the highest selectivity of sphalerite against nonsulphide gangue (NSG). The other profiles gave lower selectivity and higher zinc recovery in the first cells, which combined to reduce overall bank performance. The higher selectivity with the Increasing profile is attributed to the low gas rate in the first cells reducing water recovery and hence limiting entrainment of NSG. The increasing profile was subsequently configured for all four stages in the zinc cleaner circuit.

Jan 1, 2004

By Loren R. Anderson

A probabilistic slope stability computer model was developed at Utah State University and independently evaluated by CH2M Hill Consulting Engineers as a design and analysis tool. Volume I of this report describes the model and Volumes III and IV are users manuals for the computer programs. This volume (Volume II) constitutes the report by the CH2M Hill. It includes a description of a field investigation and stability analysis of an existing tailings dam. Based on the results of the analysis, the tailings dam was evaluated for redesign using probabilistic considerations. Conclusions are made regarding the usefulness of the model as a design tool.

Jan 1, 1982

By James A. Wasson

This report summarizes the results and conclusions reached by various investigators who have attempted to determine the extent to which hydraulic fracturing will affect the secondary recovery of crude oil by waterflooding. It also discusses the most advantageous use of this well-stimulation method in waterflood projects. A thorough search of the literature was made, and pertinent information was abstracted from appropriate reports. A carefully designed and controlled program of formation fracturing is an effective aid in waterflooding because it increases water-injection and oil- production rates. Generally, fracturing has resulted in little or no reduction in ultimate oil recovery, but under certain circumstances recovery has been substantially increased.

Jan 1, 1963

By A. Noble

"A supply of sustainably sourced rare earth elements (REEs) is critical for several high-tech industries, renewable energy technologies, and defense applications. Recent studies have shown that REEs exist in coal and coal combustion byproducts at elevated concentrations and in quantities that could meet domestic demand. Despite these promising findings, declines in rare earth prices, volatile commodity markets, and challenging geo-metallurgical conditions have jeopardized this potentially valuable REE resource. While the dilute REE concentrations inherently necessitate low-cost separation technologies, the ultimately operating cost threshold for economic extraction must be based on commodity price projections and market demand. In this paper, the micro-pricing principle is used to develop a rigorous economic model assessing the inherent value of REEs in coal materials. This model is based upon basket pricing of individual elemental oxides, and elemental distributions of coal samples from various basins. These results may be used to assess the economic viability of potential REE concentration and refining technologies INTRODUCTION Recent efforts by US Department of Energy (DOE) and the National Energy Technology Laboratory (NETL) have suggested that rare earth elements (REEs) may exist in coal and coal byproducts at concentrations suitable for economic extraction and processing. While the knowledge of REE occurrence in coal material dates back over 50 years, recent supply restrictions and material criticality considerations have prompted a national interest to establish a sustainable domestic supply of REEs. REEs are not “rare” in the sense of crustal abundance; however, few natural processes lead to concentrated ore deposits. As a result, the elevated concentrations found in coal material may provide a potentially promising resource for these materials. While the term “rare earths” is often used to describe a singular concept, the 15 rare earth elements actually have varying and sometimes contrasting scarcity and cost profiles. Various authors have proposed classification systems to provide information on REE criticality (e.g. Seredin and Dai, 2012, Zhang et al., 2015). The most straightforward classification is provided on the basis of geochemistry with designations for “light”, “medium” and “heavy” rare earths. Light rare earths (those to the left of the periodic table: Ce, Pr, Nd, and Sm) tend to be more common and less valuable when compared to their medium (Eu, Gd, Tb, Dy, and Y) and heavy (Ho, Er, Tm, Yb, and Lu) counterparts. While light rare earths are often found in traditional ore deposits at economic concentrations, the heavier rare earths are almost exclusively found as ion-absorbed clays (Seredin and Dai, 2012)."

Jan 1, 2016

By Fred Leighton

The Bureau of Mines has developed rock noise source location techniques that may be used to obtain precise and practical source locations from micro-seismic field data. These techniques enable one to monitor all or any part of a rock structure and map progressive stress buildup or rock movement. Thus, the microseismic method of determining instability in rock structures is becoming an invaluable engineering tool for the mining or civil engineer engaged in rock excavation and construction.

Jan 1, 1970