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Jan 1, 1965

By Mike Amick

As virgin coal reserves dwindle, more and more mines are being opened in areas with previous mining. As addressed in this conference before, there are solutions available for designing mines extracting coal from reserves with known underground workings above or below the target seam. Often times, however, mining begins with limited knowledge of the underground workings. Even with careful planning, the proposed design has limited success because the ?facts? as presented during planning turn out not to be as accurate as one would like. At National Coal?s Mine #14, mining the Walnut Mountain seam, after driving the main entries in some 34 crosscuts, it was found during routine mine examinations that the pillars had separated from the roof in a few areas of the mains. Immediate roof conditions proved to be sound but questions arose concerning the stability of the main roof and floor. Core tests were done to better determine the rock strengths and characteristics. The paper presents the ideology used to tackle the effects of mining over old works in an operating coal mine. This paper discusses the analysis of the symptoms observed and the steps taken to ensure that this pillar separation was caused by the underlying old workings and that the separation was expected and controllable.

Jan 1, 2009

By G. T. Austin

This is an overview of the gemstone industry with special attention on particular states within the united states. The U.S. Bureau of Mines, Department of the Interior compiled and analyzed the information contained in this report. The report should be viewed as a current "still photograph" of a dynamic system. The information presented on a specific gemstone or for a specific state can and will change with time. This overview presents historical and reference information on the principal gemstones and their production in certain states. The report is not a definitive work on gemstones within the select states or United states.

Jan 1, 1995

The applicability of borehole assaying techniques, both conventional and advanced, to orebody evaluation in the mining industry is reviewed and assessed, and the research, development, and demonstration programs necessary to apply the various logging techniques to mining are outlined. At present, the principal method of orebody evaluation in the mining industry is coring. However, coring is costly and time-consuming, and potentially great savings can be realized if all or part of d coring program is replaced by a borehole logging suite specialized to the needs of the particular mining industry. Using a set of 12 minerals, most of which are essential to the U. S. economy, an algorithm is presented for calculating the priority of developing suitable borehole assaying technology to replace all or part of the coring in each mineral industry, The priority is expressed in terms of dollars currently spent for that portion of present orebody evaluation techniques which may eventually be replaceable by in-situ assay techniques. The orebody assay requirements (grades, accuracies, etc.) of the 12 selected mineral industries, as determined from mining industry interviews and published literature, are compiled and represent performance criteria for borehole assaying instruments for the particular industry. Current logging techniques, applied chiefly in the petroleum industry, and advanced assay techniques which are or may be packageable for borehole use are evaluated to determine their performance characteristics. The performance characteristics of the various conventional and advanced techniques are then compared with the performance criteria in each of the 12 mineral industries in order to determine the potential benefit derivable from each technique. Finally, the benefit available from each technique, averaged over the 12 mineral industries, is compared with the cost of development of the technique, to determine the overall priority for investment in research to develop the technique for use in mining. The technology assessment and cost-benefit analysis shows neutron activation analysis in its various forms to have the highest priority for research and development as a borehole logging technique. Other techniques found to be promising include x-ray fluorescence, x-ray diffraction, photoluminescence (optical fluorescence), and infrared spectroscopy. Of the 12 industries considered in the study, those where the need for advanced borehole logging technology is greatest are uranium, copper, gold, and iron.

Jan 1, 1976

By Kenneth H. Johnston

This report describes in detail three waterflooding projects and a pres-sure-maintenance project in Butler and Cowley Counties, Kans., that will be visited on the 1963 annual spring tour of the Kansas-Oklahoma Waterflood Association. Among the unique features of the projects are the flooding of five oil-producing horizons separately with injection water furnished by two water treating plants. Discussion of the individual projects includes information on their early history, the source and treatment of the injection fluids, oil production decline curves, and the results of water injection on oil production.

Jan 1, 1963

By Michael Valencia, Alonso Marchena, Fredy Arcos, Miguel Chumbe

Cobrepampa es un depósito de cobre ubicado en Acarí (Caravelí-Arequipa). La mineralización se emplaza en pórfidos dioríticos pertenecientes al intrusivo Cobrepampa (Superunidad Linga) y está constituida por bornita, calcosina, covelina y calcopirita y en la zona de oxidación cuprita, crisocola, malaquita y hematita. El magmatismo es calcoalcalino con alto K. El intrusivo Cobrepampa evoluciona por fraccionamiento y contaminación en una corteza más delgada que la superunidad Linga. Petromineralógicamente se tiene epidotización con diseminaciones de calcopirita, pirita y bornita, gangas de cuarzo y calcita con hematita acicular. Las inclusiones fluidas muestran temperaturas de homogenización de 165.5 - 266.43 °C y salinidad 3.5 - 16.8 % eq. peso NaCl de un mesotermal o epitermal, pero que por sus características geomineralógicas sería un mesotermal. Por tanto, Cobrepampa presenta más de un evento de mineralización: una con magnetita y actinolita, y otro mesotermal de vetas de cuarzo con sulfuros.

May 22, 2019

By C. Taschereau, G. A. Vickell, A. R. Laplante

Evidence in support of an iron-gold corrosion cell during the high-temperature/highpressure elution of loaded carbon is presented herein including, but not limited to, its discovery, mode of genesis, and confirmatory laboratory testwork. A discussion of metallurgical and economic impacts, remedial investigations, plant design considerations, and future work including mitigative possibilities is presented.

Jan 1, 2006

By Soule&apos, John H.

Although known since 1902, the Capitan iron deposits have not been tined, mainly because of the low grade of the ore. Only a small amount of exploratory work has been done since the discovery. C. H. Johnson, district engineer of the Bureau of Mines in New Mexico in 1942-4, visited the property; as a result, preliminary sampling of the property was done in 1943.2/ Owing to the results of this preliminary work, an extensive development program by wagon drilling was planned and executed early in 1944. Equipment available at that time was limited in the depths that could be reached; and as geologic studies indicated the possibility that other limestone beds below the surface might have been replaced by iron minerals, a supplementary development program by churn drilling to reach greater depths was prosecuted in late 1947 and early 1948, with the author as project engineer.

Jan 1, 1949

This paper describes a proposal to reopen the Sylvia gold mine for underground exploration and development for an initial production of 10 000 tpa. A combination of trackless mining equipment and railtrack would be utilised for development with ore extraction being carried out by undercut and fill methods. The use of the smallest LHD units for mucking, and rail track for the main haulage together with airleg drilling will form the basis for development and stoping. The proposal has been subjected to an environmental impact assessment report to evaluate the impacts of the proposal on the natural and social environment in the area.

Jan 1, 1987

By William R. Yernberg

The combined 75th Annual Minnesota Section of SME meeting and 63rd Annual University of Minnesota Mining Symposium was held April 9 and 10, 2002, in Duluth, MN. This year’s theme was “Keys to the Future: Imagination, Innovation and Technology.” The meeting consisted of plenary and technical sessions and a special General Manager’s Session. The technical paper presentations included concurrent mining and mineral processing sessions. In the General Manager’s Session, representatives from the region’s taconite operations presented the current status, concerns and future plans for each of their operations.

Jan 1, 2002

By F. Dieu, C. Laughton

CERN, the European Laboratory for Particle Physics, is, at present, constructing an underground tunnel and cavern network to house a Large Electron Positron (LEP) colliding beam machine. This paper describes the techniques adopted to permit the excavation and temporary support of the access shafts through a series of glacial moraines, at depths of up to 80 m, to reach the bed-rock. Owing to the presence of superficial and deep water-tables, the variable nature of the moraine deposits and, above all, the tight work schedule, a combination of diaphragm walling and ground freezing was employed.

Jan 1, 1987

By J. A. Theron

"This paper provides guidelines on performing mass and energy balance modelling involving coal and coal derivatives. Usually, the inputs to a pyrometallurgical process would be specified in terms of elements and compounds. Reliable thermochemical data is more widely available for species involving uniquely defined, relatively smaller molecules. However, in the case of coal, the molecules are extremely large and not uniquely defined. Consequently, modelling processes involving coal and its derivatives involve several potential pitfalls. These are outlined in the present paper.It was found that coal proximate analysis should not be regarded as absolute; it could vary with several parameters, including heating rate. For modelling, the use of ultimate analyses should be considered a preferable option to proximate analyses, where ‘fixed carbon’ and ‘volatiles’ are not defined in terms of chemical composition. Significant errors could be incurred if the larger molecules are neglected during calculation of the calorific value (CV) of coal gas (the gas liberated when coal is heated in the absence of oxygen).For elemental analysis determination, the oxygen content (which is calculated by balance) should be checked to ensure it is within the expected range. For representation of sulphur in coal, one should avoid doublecounting due to SO3 in the ash analysis.Potentially, oxygen in coal could be represented as O2, H2O, CO, or CO2.However, use of some of these species without considering the experimentally determined gross CV leads to significant errors in the energy balance. If coal enthalpy is calculated from elemental analyses without correction, representation of coal oxygen as H2O(l) gives reasonable accuracy. Coal volatiles could be represented by a complex mixture of compounds, even using different oxygen-containing species than these four, provided the enthalpy is corrected.It is recommended that an ‘enthalpy correction value’ be incorporated in energy balances involving combustion, devolatilization, or conversion of coal and coal derivatives, e.g. coke, char, or tar. That would imply that proximate analysis, elemental analysis, as well as the gross CV would be required for all solid or liquid coal-derived substances being modelled. No other correction due to carbon being present in a form other than graphite should be used, as that would imply double-counting some effects."

Jan 1, 2015

By J. Kortnik

Mining has always been, and still is, an activity which is vital for the development of mankind. This is because a predominant proportion of industrial products and energy is produced from raw materials that are excavated using mining methods. The need for environmental protection and the close proximity of urban settlements and mines in Slovenia have necessitated ever stricter requirements for the excavation of raw materials and introduction of more environmentally-friendly mining methods. This is achieved by implementing a closed eco-technological cycle of raw material excavation within the scope of mining methods. In surface mines, this means prompt reclamation of the degraded surfaces, and in underground mines the use of methods with minimized impact on the surface and on underground water. In underground mines, mining methods with backfilling installed according to the multi-barrier disposal system are the only ones that allow the possibility of implementing a closed eco-technological cycle of excavating raw materials. Various industrial waste materials are also included in the backfilling material in order to improve its strength properties. Backfilling consisting of several different waste materials is produced in the form of a composite. Before backfilling consisting of waste material composites can even begin to be used in mines, an environmental impact assessment of its suitability for mines needs to be made. In order to make such an assessment, a pressure leaching cell and an open diffusion cell were made, i.e. a pressure leachate test and a sorption test were developed. The two cells and the developed tests will enable the study of the influence of backfilling on the environment if installed in an underground mine. The pressure leachate test performed with the use of the pressure leaching cell simulates leaching from a consolidated backfill during the seeping of underground water into the backfilling material under pressure. The sorption test performed in an open diffusion cell simulates the flow of eluate leached from the backfilling material through the rock/geotechnical barrier. The two tests were developed in such a manner that they are performed either in succession immediately after one another, but they can also be performed separately at a certain time interval. The paper presents an assessment of the suitability of backfilling made of different waste material composites. Keywords: environmental impact assessment, multi-barrier disposal system, waste material composites, pressure leachate test, sorption test, pressure leaching cell, open diffusion cell, eco-technological cycle, mining methods with backfilling.

Jan 1, 2003

By J. E. Nesset, L. S. Urbanoski, J. R. Goode

"The benefits and advantages of pre-competitive, collaborative industry/university research are not always well appreciated. This paper presents the case study of a current collaborative project between CAMIRO-Metallurgical Processing Division and McGill University that is investigating the understanding and prevention of sphalerite activation in lead and copper-lead flotation circuits. The benefits of the research findings to the sponsors can be maximized by an approach which links the researchers themselves with the sponsors at frequent, interactive project review sessions. Some examples of the findings and their application to industry are also presented along with a general update on CAMIRO-MPD.INTRODUCTIONThe history of Canadian efforts in the area of collaborative pre-competitive research is not long when compared to Australia (AMIRA) and Britain (MIRO). AMIRA (Australian Mineral Industry Research Association) began over 40 years ago and has had a well recognized role in bringing together industrial sponsors and researchers to fund a large variety of very significant development projects in that country, The total AMIRA funding effort for mineral processing work currently exceeds some $Aus 40 million with new projects valued at about $Aus 12 million initiated each year. This high level of commitment by industry has contributed to establishing Australian researchers and their facilities as among the best in the world.Canadian companies have traditionally funded much of their R & D in-house with extensive facilities and large funding commitments. The past 2 decades have seen most of these facilities disappear. The current situation is one in which only the largest integrated metal and mining companies have retained their own R & D groups (e.g. INCO, Falconbridge, Noranda). Industry-funded research at universities was primarily through individual efforts by the mining companies and rarely included collaboration with other mining companies, equipment or chemical suppliers, or engineering firms."

Jan 1, 2001

By G. F. Livingston, F. K. Shelton, J. C. Stahl, R. E. Churchward

"INTRODUCTION An investigation of the metallurgy of cobalt from domestic ores has been in progress since February 1940 and has resulted in the formation of a hydrometallurgleal process for the production of electrolytic cobalt metal. Previous reports of these investigations have been given by F. K. Shelton; 7/ and Ruth E. Churchwrd, F. K. Shelton, and G. Knickerbocker. 8/ Briefly, the process, as applied to ores containing cobalt oxide, consists of leaching with H2SO3 or, preferably, with H2SO3 and H2SO4, to dissolve the cobalt. The cobalt solution passes through one or more purification stages to remove iron and elements of the copper group, and cobalt carbonate is precipitated under carefully controlled pH conditions. The cobalt carbonate is dissolved in on acid electrolyte containing sulfuric acid, boric acid, and sodium fluoride. The electrolyte then proceeds to electrolytic cells where cobalt is plated as a metal and sulfuric acid is regenerated.The present paper contains the results of several investigations signed to give a more complete chemical and engineering understanding of different unit processes involved in the electrowinning of colbat. Some work has been done to broaden the process to include arseniferrous cobalt ores as well as the oxide ores upon which the investigation was initiated. Most of the data presented herein have been obtained since the release of the previous reports; any changes suggested heroin that conflict with recommendations in earlier reports are based on more complete data and usually are preferable."

Nov 1, 1945

By Pat Wilmoth, Joseph P. Gildner, Dan Nowak, Shane Yanagisawa, Don Z. Painter, Gordon F. Revey

Frontier/Traylor is presently completing construction of twin tunnels for the Tri-County Metropolitan Transit District of Oregon’s (Tri-Met) westside lightrail system. The tunnels are each 4,550 m (14,935 ft) in length and 6.48 m (21.29 ft) in diameter. The 1/3 of each tunnel was driven from the west portal using drill and blast methods and the remaining 2/3 was driven from the east portal using a TBM. The paper describes: The difficulties encountered by the TBM mining the weathered Columbia River Basalts. The execution of drill and blast work despite challenging ground conditions, stringent noise and vibrations specifications, and public relations problems. The excavation and lining of the Washington Park Station 79 m (260 ft) below the park zoo.

Jan 1, 1997

By Magued G. Iskander

The deterioration of concrete, steel, and timber is a serious hindrance to construction in marine and corrosive environments. Composite materials such as fiber-reinforced polymers (FRP) can offer performance advantages for construction in these environments. In the last decade, piling made of FRP composites has been used experimentally throughout North America. However, composites face obstacles because they do not have a long track-record of use in civil engineering structures. A comprehensive review of the current experience in research, testing, design, and practice of composite piling is presented in this paper.

Jan 1, 2002

By J L. Mauk

Golden Cross is a volcanic-hosted, low-sulfidation, epithermal Au-Ag deposit in the Hauraki Goldfield. Irrespective of the rock type (andesite versus dacite), hydrothermally altered wallrocks are enriched in K, Rb, As and Sb around Au-Ag mineralised veins of the Empire vein system and stockwork. Sodium and Sr are strongly depleted around these veins, whereas Mg and Fe are locally depleted. Calcium and Si display mixed behaviour, varying from unchanged to depleted to enriched. Other elements including Al, Ti, Mn, Zr, Y, and Nb show little change or are immobile during hydrothermal alteration. Element enrichment and depletion trends are directly related to the degree of alteration and the alteration mineralogy. Addition of K and Rb and converse loss of Na and Sr in intensely altered wallrock surrounding veins corresponds to the replacement of igneous plagioclase by hydrothermal adularia. Sodium and Sr occur in moderately altered rocks on the margins or in æhard barsÆ that contain plagioclase. Locally, elevated Si concentrations and depletion of Mg adjacent to the Empire vein system reflects intense silicification of the wallrocks and the replacement of mafic minerals by quartz rather than by chlorite. The geochemical zonation patterns at Golden Cross are very similar to those at the McLaughlin deposit California, and shallow levels of the active Broadlands Ohaaki geothermal system. Therefore, determination of K, Na, Rb, Sr, and Ca enrichment and depletion patterns provides insight into alteration intensity and mineralogy that is complimentary to traditional trace element analysis of As, Sb, Hg, Au, Ag, Zn, and Pb used in the exploration of shallow level (< 500 m) epithermal Au-Ag deposits.

Jan 1, 2000

By Daniel Briones

El presente trabajo señala las bases que fundamentan la aplicación de los Sistemas de Gestión Integrados y se ofrecen argumentos que sustentan los mecanismos usados para integrar los sistemas de Seguridad (NOSA), medio ambiente (ISO 14001) y calidad (ISO 9001); y la necesidad de su uso como herramienta de gestión por parte de la organización, llegando a todos los niveles hasta alcanzar la madurez del Sistema. Asímismo, se describen algunos ejemplos del impacto positivo, que ha significado la implementación de este Sistema en la unidad de producción Uchucchacua (cuarta productora mundial de Plata,), desde el inicio del Proyecto, hasta lograr la revalidación de la Certificación de las normas ISO 14001, y la cercana certificación en OHSAS 18001 e ISO 9001.

Sep 12, 2005

The prediction and control of ground deformations due to underground mining are important considerations in the permitting, planning, and monitoring of coal mining operations. The prediction of mining-induced ground movements using the influence function method is a mature technology and is widely used in many coal basins around the world. Such movements mainly include subsidence, horizontal displacement, and horizontal and/or ground strain. Predictions can be accomplished using regional subsidence parameters and site-specific data.

Jan 7, 2020