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By Robert D. Ewing

The computer program described in this user's guide provides for the static, three-dimensional, linear and nonlinear analysis of structural and geological systems by the finite element method. The guide describes the capabilities and general features of the program and shows how input is prepared. A number of recent advances in finite element theory and computer technology are incorporated in the program. Nonlinear material properties are provided for, including isotropic, anisotropic, and time-dependent material properties, gravity loading, simulation of a sequence of excavation or construction, and a slip or joint element. The finite elements include beam, rod, axisymmetric and plane quadrilateral, hexahedron, thick shell, and axisymmetric and plane joint. The program also has an automatic mesh generator to minimize user input preparation for continuum finite element meshes.

Jan 1, 1976

By Albert L. Toenges

[During the past few years there has beer trend away from locomotive haulage of coal from the loading point to the preparation plant of bituminous-coal strip, miner to motorized. haulage. The question has arisen whether this is always economical, and the purposes of this investigation is to determine, if possible the economic limit for motorized haulage. The operators of strip coal mines and of open-pit ore mines have shown great interest in this problem, and it is thought that the findings of this investigation will. Provo helpful to them.]

Jan 1, 1938

By P Mulvey

"Currently mine process studies and geochemical waste characterisation are considered as two interdependent studies, necessary for the development of the mine and inclusion in the environmental impact statement (EIS). Geochemical waste characterisation will utilise the simulated tailings produced by the mine process studies team to understand the behaviour of the tailings, but the two teams rarely integrate these to develop a coherent and agreed final design.Thorough mine waste geochemical assessments can develop processes to minimise environmental harm, resulting in substantial savings in the decommissioning, closure and rehabilitation phases, and may also be able to address changes in mineral processing methods that can result in substantial savings in process inputs, or even recovery of metal concentrates.Based on geochemical waste characterisation, the full cost of waste management can be calculated and incorporated into the costing of milling.  This allows for a more effective evaluation of the metallurgy.  A number of examples are presented in which substantial improvements have been made from the collaboration of both the metallurgical and geochemical teams during planning and the metallurgical team and environmental team during operations.*This paper is only available for individual download. It is not included in the conference proceedings*CITATION:Mulvey, P, 2013. Optimising metallurgy at the planning stage to minimise environmental impact - a feedback loop from geochemical waste characterisation, presented to MetPlant 2013 Conference (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 15, 2013

By David J. Baxter

Use of bored displacement piles has experienced significant growth in the UK piling market sector, largely due to their environmental advantages over other piling methods and through cost benefits. Bored displacement piles are a cast-in-situ construction which can be formed with minimal production of spoil and offer low noise and vibration compared to driven displacement piles. A large variety of bored displacement piles have been developed. This paper describes a standard system for their classification. The development of the different types is described along with the factors which have led to their increased use. Consideration is given to processes undergone by the soil during pile installation and design approaches for bored displacement piles are compared. Comparisons are made between the different classifications of bored displacement pile. Comments are also made on the installation of such piles. It is concluded that complex changes occur in the stress states of the surrounding soils. Such effect of the pile installation on the soil should be accounted for and there is a need, therefore, to further refine the design process for these piles.

Jan 1, 2006

The distribution of tin and iron between slag and metal phases at about 1150°C was studied in pot scale experiments. The distribution coefficient k = (Sn/Fe) In metal X (Fe/Sn) in slag was found to vary from about 300 for metal corresponding to nearly pure tin, to about 100 for metal of about miscibility gap composition (17' 4 per cent Fe). Results conformed reasonably well to a straight line relationship between log k and (l-2NFe), as expected on theoretical grounds, and are consistent with thermodynamic data for the Fe-Sn phase diagram and the reaction Fe + SnO = FeO + Sn.Calculations are presented indicating the feasibility of smelting low-grade tin concentrates in a two-stage counter-current reduction process.

Jan 1, 1966

By J. Nesset, F. Rosenblum, P. Spira

"Sulphide concentrates may exhibit self-heating to various degrees during storage or shipping, the worst cases presenting a serious hazard from fire and SO2 emission. Based on measurements of heating rates on a wide variety of concentrate samples in a special apparatus, combined with field experience, a methodology has been developed which allows concentrates to be rated for their heating potential. This has proven to be very useful in practice, for example, in deciding on the need to take preventive measures. Oxidation under ambient conditions in the presence of moisture initiates heating locally within a stockpile. In the case of highly active materials, such as those that contain abundant pyrrhotite, heating may progress through three stages to temperatures well above 5000C. However, most concentrates show little or no propensity to selfheat. Heating rates were used to estimate values of the heat output, or self-heating capacity (in joules per gram), which sustains the process at each stage. Thermal data from differential scanning calorimetry are also reported. Variables which affect self-heating are discussed and an actual case of heating control on a stockpile by covering is described. A simple apparatus which can be used to simulate stockpiling conditions has been tested successfully and is proposed as a convenient test system.INTRODUCTIONPrevious publications from this laboratory on the evaluation of self-heating in sulphides dealt with tailings backfill (Rosenblum et al. 1982) and waste rock (Rosenblum and Spira 1995). Sulphide concentrates may likewise exhibit self-heating in storage or during shipping. In a comprehensive but dated review, Kirshenbaum (1 968) pointed out the conflicting nature of information on means of controlling the problem, particularly with regard to the application of water and ventilation. Modelling by Simpson (1 97 1) of autogenous heating in stockpiled zinclead concentrate and associated field measurements by Wright et al. (1972) showed that the supply of oxygen by wind and the shape of the piles were the major factors in the development of hot spots. Simpson did not attempt to explain the complex mechanism of self-heating, simply ascribing its onset to oxidation. Pearse (1 980) investigated a potential method of testing for selfheating which consisted of (i) reaction with hydrogen peroxide and (ii) differential thermal anal sis, to characterize the response of concentrates at both ambient and temperatures above 100 C. He found the method sensitive enough to identify the need for careful handling but not to predict ignition. He recommended compacting concentrates and covering stockpiles with plastic sheeting to prevent ingress of air. All these workers recognized the key role played by oxygen and moisture in triggering self-heating."

Jan 1, 2001

By Timothy P. Smirnoff, Tracy K. Lundin

INTRODUCTION The City of Phoenix, Arizona is located in the Phoenix Basin watershed which is prone to flash flooding several times each year. The runoff from these storms moves from the mountains in the north to the Salt River in the south. An extension of Interstate Highway 10 (1-10) will pass through the city east to west to form an Inner Loop through the downtown business district. PROJECT DESCRIPTION The I-10 Inner Loop extension will be a depressed roadway which would intercept the surface drainage of the Phoenix Basin and separate the watershed into two regions. To prevent flooding of the depressed roadway, runoff storm water collected from the northern half of the drainage area will be conveyed beneath the roadway to its natural outlet at the Salt River. A conveyance system composed of pressure tunnels beneath the city, shown in Figure 1, was proposed to achieve this goal . Table A presents the prominent features of each of the tunnels. This paper will describe geologic and engineering parameters specific to Phoenix which were used in the design of a series of tunnels to convey storm water from the I-10 Inner Loop to the Salt River. The design of tunnel initial and final support is described along with support and construction methods used by the Contractor.

Jan 1, 1985

By Héctor Quispe

El presente trabajo señala la aplicacíón de las estrategias en Sistema de Gestión de la producción en la mina Raura, de forma que mejore su administración de flujo de recursos y actividades para lograr óptimos resultados con mayor productividad. Entre sus principales objetivos están: la determinación de los stándares de producción en tonelaje, leyes, costos y plazos, que hagan rentables los procesos de operación minera, la definición de sistemas standarizados que generen valor económico en cada uno de sus procesos. Asmismo, se realizó un diagnóstico previó que abarcó los procesos de geología, planeamiento, exploración, explotación, beneficio de minerales en planta concentradora, mantenimiento y proceso de comunicación gerencial. Los resultados y datos de este diagnóstico tiene como base la referencia para la evaluación y avance del proyecto.

Sep 13, 2001

By David A. Hall

We present an analysis of the propagation in a uniform tunnel of semi -circular cross section that contains two axial conductors. In particular, we show that, even if one of these conductors has high ohmic loss, one of the two propagating modes has relatively low attenuation. This corresponds to the situation where an unloaded dedicated wire is used to improve radio frequency communication in a mine tunnel that contains a heavily loaded trolley wire.

Jan 1, 1978

By A. George Stern

The literature dealing with the drilling of oil wells has become extensive during the last few years, and oil men can find much information relating to drilling muds in the technical literature of the petroleum industry. Although large tonnages of clay are used in preparing drilling mud (also known as drilling fluid), almost no information has been published to apprise the clay industry of the types of minerals used, with their requirements and limitations. It is from this point of view that the present report has been prepared.

Jan 1, 1941

By C. A. Pickles

Microwave processing is a relatively new technology that has been successfully applied in a number of industries. However, in the field of metal extraction, there is a paucity of success, despite considerable hype in the early years. Increased reaction rates, lowered reaction temperatures and higher energy efficiencies were some of the advantages claimed. Even with over almost two decades of research and some pilot plant studies, microwave metal extraction remains essentially a laboratory technique. In this paper, the research performed over the last few decades will be reviewed and some reasons for the lack of success in developing microwave metal extraction processes will be discussed. Based on the knowledge gained from these experiences, a more informed view of microwave heating can lead to the realization that there is still some untapped potential for this heating technique in metal extraction processes.

By K. Sawamukai, S. Ogasawara, D. Umenai, T. Tsuruta

"Removal of cobalt, strontium or cesium ion from the aqueous solution containing each metal ion only using microorganism was examined. Arthrobacter nicotianae which had a high ability to remove cationic metal ion was used for the removal of each metal. The removal of cobalt, strontium or cesium using A. nicotianae cells was affected by the solution pH, concentration of metal ion, and cell amount. The effects of above mentioned factors on the removal of each metal and time course of strontium from the solution containing each metal only using A. nicotianae cells were reported in this paper. INTRODUCTIONRadioactive elements, such as cesium, iodine, strontium, plutonium, barium, cobalt, lanthanum, yttrium, and tellurium, were detected around Fukushima Daiichi nuclear power plant, which was damaged by the magnitude 9.0 earthquake and the tsunami followed.The removal of radioactive elements from contaminated sources is a worthwhile subject to investigatein terms of environmental control. Research efforts have been especially concentrated on studying microorganisms that remove uranium including bacteria (Andres et al, 1993, Hu et al, 1996, Marques et al, 1991, Strandberg et al, 1981), actinomycetes (Byerley et al, 1987, Friiss and Myers-Keith, 1986, Golab et al, 1991), fungi (Byerley et al, 1987, Galun et al, 1983a, Galun et al, 1983b,Tsezos and Volesky, 1981, White and Gadds, 1990) and yeasts (Strandberg et al, 1981, Schmate II et al, 1978).We have investigated removal and recovery of uranium from aqueous systems using microorganisms isolated from uranium mines. We identified some strains of bacteria with extremely high uranium removing abilities (Sakaguchi et al, 1996), and thus, the microbial biomass may be considered as an adsorbing agent for the removal and recovery of uranium and heavy metals present in aqueous systems around Fukushima Daiichi nuclear power plant.In the present study, we screened various species and strains of bacteria, actinomycetes, fungi, and yeasts for their ability to adsorb uranium (Tsuruta, 2002). Basic features affecting uranium adsorption?co-existing cations and anions, cell amounts, pH, and the adsorption time course?by Arthrobacter nicotianae cells, which adsorbed the largest amount of uranium, were also investigated. In addition, we examined the removal of an other actinoid element, thorium ion, which may be present with uranium in refining effluents.In this paper, the removal of cobalt, strontium, or cesium from the solution containing each metal ion using A. nicotianae cells is discussed."

Jan 1, 2012

By A. P. I. Popoola, D. O. Okanigbe, A. A. Adeleke

In view of the steady depletion of primary sources of copper and the increased global demand for refined copper, it becomes necessary to explore some secondary sources for possible extraction of copper. The waste copper smelter dust (CSD) is a rich secondary resource for copper as shown by the chemical composition of the South African Palabora coppers smelter plant CSD that assayed 18.02, 13.36, and 3.4 wt% copper, iron and sulphur, respectively. Studies on CSD have focused majorly on either dust characterization or treatment, while hydrometallurgical extraction without pretreatment and with pretreatment using techniques such as oxidative roasting are also considered quite attractive. The challenge of iron dissolution during the leaching stage in these processes necessitates adequate purification of the leach liquor before the extraction of the metal as nano-particles. Hence, this review examined the theories relating to the characterization and treatment of CSD for copper recovery as nanoparticles; with factors having a bearing on the treatment process such as kinetics considered with the aim of providing scientific basis for the research.

Mar 1, 2017

By A. D. S. Gillies

The use of refuge chambers for use in handling underground emergencies is an issue of topical relevance within the US mining industry. Chamber design is of importance to meet some new safety requirements of US federal and some state government mine regulations. A review has been undertaken of a steel mine refuge chamber design to predict what will be internal temperature within the chamber over an extended period with miners present? The design has been examined for the situation when the chamber is sited in still mine air. Spreadsheets have been developed to allow various design assumptions to be tested. The evaluation has been undertaken using thermodynamic heat transfer models with some assumptions specified to produce a model of appropriate simplicity but with adequate degree of accuracy. Under normal still air conditions it can be seen that internal chamber conditions rise quickly to often arduous conditions. There will always be quite a few assumptions necessary in complex heat transfer process evaluations. Some important refuge chamber design parameters are: ? External surface area of the chamber, its wall thickness and construction. ? Metabolic heat generated and number of persons making use of the chamber. ? The temperature of the external mine atmosphere to the chamber over the year and the influence of geothermal gradient on temperature at depth. ? The maximum internal chamber Apparent Temperature considered safe. ? The distance inside the underground mine and adjacent ventilation conditions.

Jan 1, 2012

By Roshan B. Bhappu

Integrating a research and development department into an engineering company's corporate structure can be rewarding to the engineering division, the R&D group, and, most of all, the company's clients. Actually, the R&D department is a logical extension of the conventional processing group within an engineering organization-but the R&D group provides services as needed to the engineering department while it is carrying out regular testing, pilot plant, and preliminary feasibility studies. Backup Services Provided With an R&D group, the engineering division does not need a process engineering group as such. The R&D group provides project backup services for feasibility studies, preliminary and detailed engineering, construction, and startup. The R&D group, in turn, benefits from its close association with project engineers, draftsmen, estimators, and computer capabilities in the engineering division. The client also benefits from the arrangement because R&D and engineering skills are available to both departments on an as-needed basis without standby eost. To handle the integrated responsibility of R&D projects, as well as conceptual design and preliminary feasibility studies, the R&D staff must be carefully selected. These research engineers should: • have a good background in plant practice as a mill superintendent or chief metallurgist; • be capable of organizing and supervising a testing program or a pilot plant campaign; •be innovative and willing to accept new ideas and concepts; • be able to translate lab test results into a workable flowsheet through sound conceptual design and feasibility studies; and •be able to communicate with clients. In short, the R&D engineer must be a jack of all process-engineering trades to successfully take a project from concept to operating reality. Engineers in a metallurgical R&D organization should have experience in mining and processing all types of

Jan 10, 1980

By W. L. Garrison

Improvements continue to be made in rapid excavation and tunneling technology. There are several ways to examine the impacts of such improvements. The most common procedure is to monitor current developments and to evaluate prospects for expansion of present types of uses. Other approaches are called for, however, if the technology might be used in ways not now imagined, if the search is for information for managers of technology development, and if the issue is that of the wise use of the technology by society. The first section of the paper will pose these matters as questions. These questions will be examined from the point of view of the processes of technology development and utilization, and then further examined against the backdrop of processes at work within the urban area. Such an examination will provide insight into the way technology developments should proceed. The final section will present some comments that may be useful to those guiding the development of the technology and to those who might provide leadership for its wise utilization. THE QUESTIONS Three questions are posed: 1. Are there uses for the technology beyond further penetrations of its present markets? 2. Can information be supplied to managers of technology development so that they may improve the assignment of priorities among development choices? 3. How can society make wiser use of the technology?

Jan 1, 1974

By Gordon T. Austin

The combined production value of natural abrasives, which consist of tripoli, special silica stone, garnet, and emery, decreased in 1986. Shipments of processed tripoli increased slightly in quantity and 20% in value. Production of garnet, a common iron- aluminum-silicate mineral, decreased 12% in quantity and value. There was a 4% increase in the quantity and an 11% increase in the value of refined garnet shipped when compared with 1985 shipments, a new record high. Production of crude special silica stone decreased 7% in quantity and slightly in value, and shipments of finished special silica stone products decreased slightly in quantity and increased 229% in value. Production of emery, an impure aluminum oxide, increased 77% in quantity and increased 269% in value of product mined and shipped. [ ]

Jan 1, 1988

By Carl G. Bock

INTRODUCTION The Washington Metropolitan Area Transit Authority (WMATA) has let a contract for the excavation of three rock stations, spaced about 3550' (1082m) apart, beneath Connecticut Avenue in Washington, D.C. Two previous rock stations have been completed, one of which had a crown pilot tunnel excavated to explore geologic conditions that would be encountered during the station excavation. This pilot tunnel was primarily for inspection by bidders and design was based on core hole information. The other rock station had no pilot tunnel and was also designed on the basis of core hole information. The three rock station areas, which are the subject of this paper, have been explored by crown pilot tunnels and an as-built report, with geologic maps and sections, has been prepared, for use by the design engineer as the basis of design for support of the structures. The geotechnical report describes the geologic structure in detail and relates it to excavation and support of the three crown pilot tunnels and the running tunnels which will be enlarged to create the 58'W x 44'H x 700'(+)L (17.6m x 13.3m x 212m +) stations. The information was complete enough to permit the design engineer to visualize the geologic structure and compute loads for the various types of rock conditions. It was therefore possible to determine the size and spacing of the steel sets for the several different conditions of rock structure encountered in the pilot tunnels.

Jan 1, 1976

By M. Moseki

Paper written on project work carried out in partial fulfilment of B.Sc. (Eng.) (Metallurgy of Materials) degree This paper presents the research into melting of scrap for job creation purposes in rural areas. The research was done on behalf of Mine Recycling Services (MRS), the company that will implement the project. The project involves the research into available cost effective and easy to operate technology. The paper covers the experimental and theoretical work that was conducted. The results were used to determine the best equipment and method for melting and casting brass scrap.

Jan 1, 2002

Sluiceboxes can provide a much higher concentration ratio than most other gravity concentrators (up to 50 000:1) at very high overall placer gold recoveries (greater than 99 per cent). They are also very reliable, inexpensive and simple to operate. This combination is very difficult to beat and explains why the sluicebox is still the most important placer gold concentrator in northwestern Canada, Alaska and the rest of the world. A sluicebox is a rectangular fl ume containing riffles on matting, through which a dilute (<12 per cent) slurry of water and alluvial gravel flows. Sluiceboxes are actually centrifugal concentrators with settling velocity playing a minor role in gold recovery. Due to their higher density, gold particles tend to segregate to the bottom of the slurry flow where they form a streamline that is diverted by a low pressure zone into a riffle. Under ideal conditions, this ribbon of slurry will be overturned as it flows down the rear of the following riffle and will continue fl owing in a circular path to form a vortex. At the bottom of this vortex, centrifugal and gravitational forces combine to drive gold particles into or beside the matting. To remove the gold concentrates, sluiceboxes are shut down and the riffles and matting are taken apart and cleaned. The slurry velocity provides the energy that powers the vortex. If the velocity of the slurry is reduced through overloading with solids, insufficient water flows or shallow gradients it may not sustain a full size vortex. If the riffles are too close, too far apart, too tall, or if there is not enough energy available to the vortex, the vortex will not be formed properly and gold recovery will be reduced. If the slurry velocity is too high, extreme turbulence and the resulting scouring will also cause gold losses. Testing sluiceboxes with conventional sampling and evaluation techniques is very costly, time consuming and problematic. Most placer gold ores contain a very small number of gold particles in a large volume of pay gravels. Sluiceboxes can lose coarse gold particles. The presence or absence of one of these particles in a tailings sample can lead to high unpredictable errors (nugget effect) even when large sample volumes are processed with care. Every time conventional samples are upgraded, additional errors are introduced due to the inefficiency of recovery equipment. Nuclear tracer tests are more accurate, faster, cheaper and safer than conventional sampling. In 1989 through 2002, the recovery efficiency of dozens of sluicing systems was determined by mixing radioactive gold particles (tracers) into the feed streams of dozens of placer mines in the Yukon Territory, British Columbia, Alaska and Guyana. Four distinct sizes of nuclear tracers were used and their recovery was related to the design and operational characteristics of the individual sluiceboxes and their pay gravels. At clean up, scintillometers were used to detect the very low level X-ray and gamma ray radiation emitted by these tracers and locate them in the sluice runs. The effectiveness of any given section of riffles was easily diagnosed by the presence or absence of tracers. At every mine the gravel feed rates, water flows, equipment dimensions and riffle performance were measured. After the gold tracers were removed from the fi nal concentrate and counted, the concentrate was sieved and weighed. These gold recovery, weight and sieve data were used to calculate the quantities and size distributions of the gold particles in the original pay gravels and those lost in the tailings. The expired tracers were stored in a lead lined container until their radioactivity was near background levels (about two months). The standard errors from these radiotracer tests were estimated from binomial probability theory with the equation: SE = {(n + p + q) ^ 0.5}/n. Where n was the total number of radiotracers added, p is the proportion recovered and q was the proportion lost. Each overall recovery estimate would be within one standard error of the true recovery value (14 times out of 20) and almost always within two standard errors of the true recovery (19 times out of 20). The maximum standard error with 100 tracers was five per cent and occurred when the recovery approached 50 per cent. With higher recoveries, standard errors usually ranged from one to two per cent.

Aug 1, 2010