Search Documents

By J. N. Van der Merwe

The paper provides an overview of subsidence research which was done by the Sasol Company in South Africa over a period of more than six years. The magnitudes of subsidence elements in South Africa are largely similar to those in the U.S.A. and Australia, as opposed to Europe. The research resulted in a subsidence prediction method with a new approach to the prediction of ground strain. The paper also describes the effects of subsidence on various commonly occurring surface structures such as roads, overland conveyor belts, pipe lines and power pylons. It is concluded that while most structures are not specifically designed to accommodate mining induced displacements, they can nontheless be undermined safely and economically with only minor precautions.

Jan 1, 1986

By Dale L. Pitt

Introduction In opening up a new country, one of the most vital problems is that of transportation Without roads, railways, or water routes, development is very slow because these are the arteries through which the life-blood of the country flows. British Columbia is unusually fortunate in having along its western coast, for some 600 miles, a stretch of inside water unequalled, for comfortable and safe navigation, by any other similar stretch of ocean in the world. This solves in a general way the major north and south transportation problem for the coast section, and offers comparatively cheap rates for the shipping of all commodities. The principal cities and centres of distribution will naturally grow up on the coast. These cities, however, must have methods of communication with the hinterland, and it is the necessity of supplying these, as feeders to the principal ports, which presents problems of considerable magnitude.

Jan 1, 1930

By J. R. Andrews, R. P. Young, J. M. Reyes-Montes

"Microseismic monitoring provides insight into the location and extent of rock-mass fracturing induced by cave mining, enabling interpretation of the cave profile and validation of predictive numerical models. Source location uncertainties can lead to misinterpretation of the inferred characteristics of the fracture network. One principal source of uncertainty is the velocity model used to invert the location algorithm. Large-scale 3D numerical models of modulus changes across a caved mass can represent such complexities in the location algorithms, allowing more accurate interpretation of the microseismic activity. A Northparkes mine case study applies this advanced approach to microseismic data interpretation.RÉSUMÉ Le suivi microsismique fournit des renseignements sur la localisation et l’étendue des fractures de la masse rocheuse induites par l’exploitation par blocs foudroyés; cela permet d’interpréter le profil de la chambre foudroyée et de valider les modèles prédictifs numériques. Les incertitudes quant à la localisation de la source peuvent conduire à des mésinterprétations des caractéristiques inférés du réseau de fractures. Une des principales sources d’incertitudes est le modèle de vitesse utilisé pour inverser l’algorithme de localisation. Des modèles numériques tridimensionnels à grande échelle des changements du module d’élasticité à travers une masse foudroyée peuvent représenter de telles complexités dans les algorithmes de localisation, permettant ainsi une interprétation plus juste de l’activité microsismique. Une étude de cas à la mine Northparkes applique cette approche avancée à l’interprétation des données de microsismicité."

Jan 1, 2016

By Jesús E. Gómez

This work is a continuation of a paper presented in the 32nd DFI Annual Conference, Colorado 2007, titled ?Hollow Core Bar Micropiles - Design parameters interpreted from 260 load tests.? The first paper presented the results of the verification and proof tests performed for the retrofit of two bridges with hollow core bars that used 260 micropiles. It included an interpretation of the unit bond values in the different soils where micropiles were installed. Recently two additional bridges within the same geological environment were also retrofitted using 144 hollow core micropiles. This paper includes the interpretation of the additional data from the proof tests performed and refines recommended values for design of hollow core bar micropiles in soils similar to those encountered in these two projects. The authors believe that the data collected will significantly add to the relatively small existing database on micropile tests and may also be useful during implementation of the LRFD design methodology.

Jan 1, 2008

By William D. Dodge

A typical quality program plan is presented for explosion-proof (XP) electrical enclosures. The plan is suggested for manufactures of XP enclosures which are to be certified by MSHA for mining use. The plan describes the quality system, organization and implementing mechanisms which are to be applied in the manufacture and delivery of certified XP enclosures. Example forms and example procedures are included.

Jan 1, 1984

By L. K. Witika, J. H. Masinja

"Investigations of flotation characteristics of Lumwana and Kansanshi ores using formulated frothers were carried out. Of the six frothers tested, two came from the alcohol family, two from the glycol family and last two were formulated products. The initial work involved determining the optimum mesh of grind and frother dosage for Lumwana and Kansanshi ores. Further work involved carrying out surface tension, bubble size and froth stability measurements. Finally, water recovery tests were conducted at Lumwana and Kansanshi mine sites. For froth stability tests, six frothers were tested on a two-phase (water–air) system using the Bikerman column flotation cell, while water recovery tests were conducted using a total of seven frothers, including the standards for each plant. The results of the testwork showed that (i) although a stable froth is essential for optimum recovery of valuable minerals, a higher molecular weight frother, like Dowfroth 250, caused poor selectivity when used on fine ores and (ii) a lower molecular weight frother was suited for Lumwana ore, while a mid to higher molecular weight formulated product was suitable for Kansanshi sulphide ore. INTRODUCTION Investigations of flotation characteristics of Lumwana and Kansanshi ores using formulated frothers were carried out. The initial work of this project involved determining the optimum mesh of grind and frother dosage for Lumwana and Kansanshi ores. Further work involved carrying out surface tension, bubble size and froth stability measurements. Finally, water recovery tests were conducted at Lumwana and Kansanshi mine sites. In order to investigate the gangue entrainment levels in the Lumwana and Kansanshi sulphide ores, two well-known methods (froth stability and water recovery) were used. Firstly, froth stability tests were conducted using six frothers, two from the glycol family (Dowfroth 200 and Dowfroth 250), two from alcohol family (MIBC and pine oil) and other two from the formulated family (Betafroth 20 and Betafroth 245), at the University of Cape Town’s Centre for Mineral Research (CMR) laboratories. Froth formation and stability measurements were conducted using the Bikerman column flotation cell."

Jan 1, 2015

By Gilberto Yanarico Apaza

"El presente texto señala las pautas necesarias para realizar una evaluación técnica integral de la influencia del collar de bolas para las operaciones de molienda, afectando al desgaste de los revestimientos de los molinos convencionales. Para la determinación del collar de bolas es necesario realizar los análisis granulométricos con la finalidad de obtener el F80 y el P80 de las muestras obtenidas en la alimentación y producto de los molinos, definir el índice de trabajo (Wi) y consumo de energía. Asimismo, se debe considerar el porcentaje de la velocidad crítica, las dimensiones de los molinos, la densidad de los medios de molienda (bolas), el porcentaje de la carga de bolas, las características geométricas de las bolas para molienda y el diámetro real de bolas, que influye de forma inversamente proporcional en la tasa específica del consumo observada."

Jul 1, 2015

The Bureau of Mines is responsible for a broad spectrum of programs for meeting the diverse and changing mineral resource needs of the Nation. These programs are managed by the Director and two Deputy Directors, who formulate general policy and program direction from the Washington, D.C., headquarters. A senior advisory staff, consisting of the Chief Staff Officer, Chief Scientist, and Chief Mining Engineer, provides advice and consultation to the Director on a wide range of scientific and technical matters and acts on behalf of the Director to maintain liaisons with other government agencies, mineral industries, and professional societies. Bureau program activities are classified into two major functions: (1) Developing new and improved technology that will make the production and processing of minerals more efficient, safer and more healthful for mineral workers and the public, and more compatible with a quality environment.

Jan 1, 1980

By C. M. Díaz, P. J. Mackey, P. Coursol

In a recent paper [1], the present authors discussed calculated energy consumption numbers in copper sulphide concentrate smelting for four different smelting technologies. For the present study, from among these technologies, they selected the Noranda/Teniente continuous bath smelting followed by Peirce Smith (PS) converting route to investigate the impact on total energy requirement of some key process variations, such as tuyere injection of dry concentrate vs. slingering of wet concentrate over the molten bath, continuous converting vs. conventional batch PS converting and commercially proven slag cleaning alternatives. In their calculations, the authors used the same thermochemical model and methodology used in their earlier paper. This approach to explore plant design options provides an interesting basis for evaluating flowsheet modifications that could lead to significant copper smelting energy savings. The METSIM software was used in the present paper to carry out heat and mass balance computations for 8 different flowsheet configurations. The results are presented and discussed in the paper with respect to copper recoveries, energy requirements and CO2 emissions.

Jan 1, 2011

Minerals are vital to any industrialized civilization. Annually, the United States uses more than 4 billion tons of new mineral materials, or about 40,000 pounds per person-about half being mineral fuels and the other half metals and nonmetallics. Stable and economic domestic mining, mineral, metal, and mineral reclamation industries are essential to the economy. The value of United States energy and processed materials of mineral origin exceeds $200 billion annually. Although a number of minerals are imported, especially some designated as "strategic and critical," most U.S. mineral supplies are derived from the domestic mines and processing facilities that you will be seeing, reading about, and visiting as you use this visitor guide. We hope you enjoy your experiences. This pamphlet, a guide to mining and mineral operations that may be observed or visited and some other points of interest relating to minerals, is intended to aid tourists and students who are interested in mining. Some may wish to study our Nation's romantic past; others may plan to enter the minerals industry as a career; still others may have a primary interest in conservation practices. The pamphlet is also intended to aid State and local officials, Chambers of Commerce, and mining firms in answering some of the many questions of tourists and students.

Jan 1, 1977

By T. A. Klinefelter

ONE OF THE many services rendered by the Federal Bureau of Mines is the identification and general examination of ore and mineral samples. Many of these, coming from almost every State in the Union, are clay and shale samples. Other Government agencies, State geologists, universities, and other laboratories are often requested to make similar examinations. This publication describes methods of testing these samples. An earlier paper, published in 1943, described Bureau of Mines methods of testing such clays.3 This paper was to be followed later with another (part II) that would describe much more thorough testing than did the rather general outline of part I. Part I has been out of print for some time and needs revision, and part II was never written; hence, the present publication is designed to include part I and also those additions intended as part II. The tests presented in part I were simple, requiring only the ordinary equipment to be found in any good chemical laboratory. The second publication was to include a greater number of test procedures and information on increasing the accuracy and precision of those previously given.

Jan 1, 1957

By E. P. Ferrero

Analyses of 38 crude oil samples from 25 fields in Algeria, Libya, and Nigeria are presented in this report. The 38 crude oils are listed alphabetically by country and field. Also shown are the geographic and geologic sources of the samples analyzed, the companies that supplied the samples, the general characteristics and analytical and computed data, and the production for the fields from which the samples were obtained.

Jan 1, 1966

By E. P. Ferrero

Analyses of 38 crude oil samples from 25 fields in Algeria, Libya, and Nigeria are presented in this report. The 38 crude oils are listed alphabetically by country and field. Also shown are the geographic and geologic sources of the samples analyzed, the companies that supplied the samples, the general characteristics and analytical and computed data, and the production for the fields from which the samples were obtained.

Jan 1, 1966

By G. G. Goble

Dynamic pile testing is now over 20 years old as a routinely applied tool for evaluating driven pile installation. The first test on a cast-in-place pile was performed more that 15 years ago. The research that produced the method began almost 30 years ago. But, questions still arise regarding the appropriate use of this technique so some review is useful. Today a number of methods including dynamic testing all depending in some way on the application of dynamics are in routine use. First, Wave Equation analysis can be used to predict pile driveability before going to the field. The same approach can be used during driving to estimate the bearing capacity based on the blow count observed in the field. Dynamic measurements, on the other hand, can only be used after pile driving has begun. They offer predictions of pile capacity as well as measurements of hammer, driving system, and pile driving performance characteristics. The first part of this paper will be devoted to discussing how the foundation engineer can use these tools. First, a brief review of what dynamic methods actually do. In Wave Equation analysis a numerical model of the hammer, driving system, pile, and the soil is created by the engineer. The hammer is dropped on the pile and using a discrete, dynamic analysis the motion of the individual pile elements is calculated as a function of time. Of course, input information must be supplied by the program user to describe the hammer, driving system, pile, and soil. In the current state of development, the primary problem in input data is with the hammer performance (efficiency) and the soil description. Research may be able to do a better job with the soil data, but hammer performance will always vary from hammer to hammer and is dependent on the affectiveness of the inspection process. Prior to beginning pile driving the Wave Equation analysis supplies the best available estimate of what will happen when driving begins. It gives an estimate of blow count during driving, driving stresses, both tension and compression in the pile, and for diesel hammers, stroke. The selection of the driving system can be checked with the results of Wave Equation analysis and modifications can be made if required. For example, if the blow count at the required capacity was deemed excessive by the contractor a larger hammer could be tried or if driving stresses were too high changes could be made in the cushion or the hammer selection could be modified. All of these modifications are possible with only the cost of a computer run. The primary questions regarding the accuracy and reliability of Wave Equation analysis at this time is with regard to the assumptions made to represent the soil characteristics and the difficulty in predicting hammer performance.

Jan 1, 1993

By A. C. Fieldner

The Sectional Committee on Classification of Coals, functioning under the sponsorship of the American Society for Testing Materials and the rules of the American Standards Association, in its 1934 report recommended to the American Society for Testing-Materials5 that Specifications for Classification of Coals by Rank be adopted as tentative. These specifications, slightly modified as recommended by the Sectional Committee, in its 1935 report,6 wore approved as tentative standards by the society in 1935. The specifications rover the classification of coals according to their degree of metamorphism, or progressive alteration, in the natural eerie s from lignite to anthracite. The basic scheme of classification is according to fired carbon and calorific value (expressed in B.t.u.) calculated to the mineral-matter-free basis. The higher-rank coals are classified according to fixed carbon on the dry basis, and the lower-ran]: coals according; to B.t.u. on the moist basis, that is, containing its natural bed moisture but free of visible surface moisture. Agglutinating and weathering indices arc used to differentiate between certain adjacent groups.

Jan 1, 1935

By K. Swedburg, M. Samuels

"The New Afton concentrator was commissioned in June 2012, reaching the design milling rate in September 2012. By late 2013, through a campaign of optimization and de-bottlenecking, it was recognized that the installed plant was capable of greatly exceeding the design throughput of 11,700 tpd. Because the value of the metal contained (by increasing the plant feed rate) exceeded the offsetting losses of copper and gold recovery (as the operation moved to a coarser grind), the concentrator feed rate was strategically increased with support of New Gold, while the operations team was given a mandate to evaluate, and then implement, flow sheet options that could re-establish the original design criterion grind target and achieve the corresponding improved recovery. Broadly, the two options implemented were the addition of a tertiary grinding stage consisting of Metso Vertimill® prior to rougher flotation (in order to address the grinding required at increasing throughput by increasing the power), and the addition of three Woodgrove Staged Flotation Reactors (SFR) added to the cleaner circuit after regrind of the rougher concentrate (to address the increased mineral loading to the cleaner circuit). Through test work, it was anticipated that the SFRs would be capable of achieving final concentrate grade in a single pass without the integration of recirculating loads, a strategy sometimes referred to pre-cleaning. This paper describes the expectations generated for the Woodgrove SFR unit operation through pilot plant testing on site, and compares those results with the performance of the expanded circuit that exceeded the original design criterion of P80 160 µm, which was commissioned in the second quarter of 2015.INTRODUCTIONThe New Afton concentrator, located near Kamloops, BC Canada, commenced operation in June 2012. The mill achieved the design throughput of 11,000 tonnes per day average during the month of September 2012 and, following various operational optimization efforts (O’Hara et al, 2015), achieved the design p80 grind size of 160 µm at the design milling rate in July 2013.During August 2013, trials were carried out to determine the throughput rate limits of the mill circuits and to evaluate mill metallurgical performance at higher rates. Milling rates up to 15,500 dmt per 24 hours were achieved during this trial, demonstrating potential capability for sustained milling rates exceeding the nominal design capacity. As was expected, the higher milling rates resulted in a coarsening of the grinding circuit product size, and resulted in marginally lower recoveries in the rougher flotation circuit. Despite the lower recoveries, the higher milling rates resulted in higher metal production and the financial analysis favored running at rates of at least 13,000 tonnes per operating day, with the higher cash flow in the near term offsetting the value of metal production loss at the end of the mine life (due to the short term increase in the rate of reserve depletion). Milling rates were sustained above 13,000 tonnes per day through the second half of 2013, and increased above 14,000 tonnes per day by mid-2014 (Figure 1)."

Jan 1, 2016

By A. E. M. Warner, P. J. Mackey

"In 1988, two of the present authors Warner and Vahed [1] were amongst several co-authors on a seminal paper reviewing nickel pyrometallurgical operations of the era. Given that significant changes in the nickel industry have occurred since that time, including the overall political landscape, technology, the overall world energy picture, the countries sourcing nickel and finally the nickel market itself, the present authors considered it timely to provide a 2015 update. In 1988, total world nickel production from sulphide and laterite sources, including production in the former "Centrally Planned Economies"- was about 0.86 million tonnes/a, while in 2014 total world nickel production reached an all-time high of almost 2 million tonnes/a - some 230% higher. On the other hand, while in 1988, about 94% of world nickel was produced pyrometallurgically and of the order of 33% via laterites, today, about 88% of nickel is by pyrometallurgy, with some 41% from laterites, thus showing that more nickel is now sourced from laterites, a trend which is expected to continue.During the period under review, new processing technologies were developed and introduced, along with substantial improvements in both the technologies employed and the scale of operations. Significant productivity gains have been achieved in sulphide pyrometallurgy in part through more efficient mineral processing, particularly in pyrrhotite rejection, and the use of ever larger-scale process equipment. This made it possible to treat lower grade and more complex ores. The significant game-changer from a production perspective was the introduction in the early 2000s of nickel pig iron (NPI) in China via modified iron blast furnace smelting, an old technology long ago cast aside by other nickel producing countries. With the exception of the emergence of this new NPI capacity in China, in the laterite industry modernization and expansion of existing operations has been employed to gain productivity, to cut costs and/or offset the effect of declining ore grades. The NPI technology development has become a game changer in the traditional global supply and demand relationship, opening up a new frontier to supply nickel to low grade utility steel producers. One other key nickel development was the Indonesian ban on nickel ore exports effective in January 2014, thus effectively curtailing NPI production at existing Chinese plants, but on the other hand, potentially prompting new smelting facilities in Indonesia. This paper reviews and updates major pyrometallurgical sulphide and laterite operations worldwide, including changes in nickel extractive metallurgy. It also provides a brief review of new developments in pyrometallurgical operations, with special focus on the NPI process and presents an outlook of the potential future direction of the industry."

Jan 1, 2015

By J. F. Neill, O&apos

[The Cartersville mining district is in Bartow County, Ga., about 40 miles northwest of Atlanta. Barite, limonite, ocher, amber, hematite, and, manganese oxide ores have been produced from the strict since about 1840. In the search for a possible source of manganese ore, Bureau of Mines engineers made a preliminary study of the district from September 1950 to January 1951. During this study 139 deposits were examined, and many mineral exposures were sampled. Manganese mineralization occurs as fine oxide and concretionary pellets in residual clays, as fine oxides in umberous clay, in brown-iron deposits, and in a limited quantity in mud ponds and Jig-tailing piles. The future supply of ferrograde manganese ore from the district, using current mining and benefication methods, appears limited to the recovery of the hard manganese ores deposits. Rough estimates indicate a reserve of manganese-bearing clays of about 8,000,000 long tons. This type of deposit has been extensively exploited and the larger deposits mined out to depths of from 50 to 200 feet. The remainder of these deposits are low grade, are covered with deep layers of colluvium, or lie below the ground-water table. Any future production from this source will require systematic prospecting, improved concentration, and an increase in the price of concentrate.]

Jan 1, 1954

By R. J. Schafer-Frentz, T. G. Joseph, M. Curley

"Greenhouse gas emissions—specifically of carbon dioxide—are a concern in Canada, where industrial sectors such as mining are stringently regulated for carbon release. Cumulative emissions are positively related to fuel consumption, which is controlled by several factors. This study investigates one of these factors: the product of vehicle speed and running surface total resistance (TR; sum of rolling resistance and grade resistance). Results show that TR directly affects fuel consumption and emissions—a relationship that is mathematically predictable. Fuel consumption and emissions, which are principally associated with the durability or deterioration of wearing course materials, were analyzed to aid selection of road construction capping material of low rolling resistance. In the oil sands region in the province of Alberta, ground conditions change seasonally. Therefore, the annual fuel consumption for the same wearing course material was also compared. Results demonstrated that haul truck size was a contributing factor, but vehicle speed and TR more strongly influenced fuel consumption and emissions. ¦ KEYWORDS Carbon dioxide, Emissions, Fuel consumption, Grade resistance (GR), Greenhouse gas (GHG), Haul truck, Rolling resistance (RR), Total resistance (TR) RÉSUMÉ Les émissions de gaz à effet de serre (GES), et particulièrement celles de dioxyde de carbone, sont un problème au Canada, où les secteurs industriels tels que l’exploitation minière sont rigoureusement réglementés pour leurs émissions de carbone. Les émissions cumulées sont indéniablement en lien avec la consommation de carburant, qui est contrôlée par plusieurs facteurs. Cette étude examine l’un de ces facteurs, à savoir le produit de la vitesse du véhicule et de la résistance totale de la surface de roulement (la résistance totale, ou RT, est la somme de la résistance au roulement et de la résistance due aux rampes). Les résultats montrent que la RT affecte directement la consommation de carburant et les émissions, un lien qui est mathématiquement prévisible. La consommation de carburant et les émissions, qui sont principalement associées à la durabilité ou la détérioration des matériaux composant la couche d’usure, ont été analysées afin de contribuer à la sélection de matériau de recouvrement pour la construction de routes ayant une faible résistance au roulement. Dans la région des sables bitumineux de l’Alberta, les conditions au niveau du sol changent à chaque saison. Ainsi, la consommation annuelle de carburant pour le même matériau composant la couche d’usure a aussi été comparée. Les résultats ont montré que, si la taille des camions de transport est un facteur déterminant, la vitesse des véhicules et la RT influencent davantage la consommation de carburant et les émissions. ¦ MOTS CLÉS camion de transport, consommation de carburant, dioxyde de carbone, émissions, gaz à effet de serre (GES), résistance au roulement, résistance due aux rampes, résistante totale (RT)INTRODUCTION In Canada and around the world, global climate change has become a topic of great concern and discussion. Pres-sure on world leaders to quickly reduce their carbon footprint is prevalent, prompting new standards and regulations in various industries, including mining and oil and gas. In 2017, the Government of Alberta implemented a carbon tax. The majority of mining activities in this province are truck-shovel operations, where a large fleet of ultra-class trucks is loaded by shovels. Ultra-class haul trucks, classified as those with a capacity of 218–363 tonnes (t), emit high levels of carbon as they travel to processing entry points and waste dumps as designated by the mine plan and mine dispatcher. Mined ore and waste is typically moved over two 12-hour shifts per day throughout the year."

Jan 1, 2019

By A. C. Munro

This paper, which describes the milling practice at the Britannia concentrator, Britannia Beach, B. C., is one of a series being prepared by the Bureau of Mines. The concentrator treats copper ore at the present rate of 6,000 to 7,000 tons of dry ore daily and produces copper concentrate and pyrite concentrate by selective flotation methods. The copper concentrate is smelted and the pyrite product is utilized for acid manufacture.

Jan 1, 1932