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By David Bendersky

This report covers the activities of a feasibility study of fiber optics technology fur use in mines. The objective of the study was to evaluate, both technically and cost-wise, the possible use of fiber optic technology for underground mine communication and monitoring systems. The first phase of the study was devoted to the collection of information on the present underground mine communication systems and monitoring techniques, and the status of applicable fiber optic technology. In the second ph se of the study, a communication and monitoring system for a hypothetical underground coal mine was designed and the costs estimated. The significant findings and conclusions are presented.

Jan 1, 1982

By W. M. Dressel

A simple, reliable field test for beryllium in rocks has been developed by the Rolla Metallurgy Research Center of the Federal Bureau of Minas. A small portion of the pulverized rock is fused with a sodium carbonate-sodium hydroxide flux in a wire loop. The fused mass is dissolved in water, a few drops of quinizarin solution are added, and the solution is viewed under ultraviolet light. A pink-to-orange fluorescence reveals the presence of beryllium in a sample containing as little as 0.013 percent beryllium (0.26 percent beryl). INTRODUCTION New and potential uses for beryllium make necessary a more intensive search for this metal, which is so similar to aluminum in its chemical reactions that it is not separated from aluminum in ordinary chemical analyses. The principal ore mineral of beryllium is beryl, a beryllium-aluminum silicate, which contains only 5 percent beryllium. This mineral is so similar to quartz in appearance that it is not always possible to distinguish one from the other in the field. While the distinction may be made easily with a petrographic microscope, few prospectors have access to such an instrument, and fewer still know how to use it.

Jan 1, 1960

By G. Djambazov, D. Shevchenko, D. Burnard, V. Bojarevics, K. A. Pericleous, W. Griffiths

Contactless ultrasound treatment can be useful for high-temperature or reactive alloys in the liquid state, where contact with an immersed vibrating probe is undesirable. The alternating component of the Lorentz force can generate sound pressure levels leading to cavitation of gas bubbles in the melt, through acoustic resonance. Resonance is a function of the speed of sound in the liquid, the shape of the volume containing it and surrounding boundary conditions. Induction forces applied to a crucible lead to bulk stirring and in general deform the free surface, whose precise shape may influence the resonance conditions. This effect is investigated here b ymulti-physics computer modelling. Calculated results for aluminium melts are compared with experimental data and conclusions are drawn as to the sensitivity to process parameters and the reliability of this type of ultrasound metal processing.

Mar 1, 2017

By Wolfgang Kern

More and more coke oven plants worldwide face the task to improve their emission reduction at their coke oven batteries. In the 90’s PROven® was invented and developed by DMT to regulate the inner pressure of a single coke oven chamber. Generally, most of the coke oven chambers can only close and open their connection to the collecting main but without the possibility to regulate the pressure during the carbonization time. Through the installation of PROven® the load on the coke oven door sealing system and the charging lids will be decreased and so does the emissions of crude COG as well. The current PROven® system, installed in the collecting main, does not only regulate the chamber pressure, it replaces the valve between the goose neck and the collecting main, too. This variable pressure control allows decreasing the leakages at the emissions sources to a minimum and allows operating the collecting main under optimum pressure. Subsequently, this will lead to enhanced emission reduction. PROven® proved its value with more than 2,100 units installed by licensee worldwide. Nevertheless, DMT is always focused on its client’s needs and therefore enhance PROven® to provide the Best Available Technique (BAT). Among the main features of the now available system is the plain arrangement with a higher reliability and the possibility to install the system outside of the collecting main without modifying it. Hence, upgrading coke oven plants during operation is possible without any noticeable impact on the plant operation.

Aug 1, 2018

By Gordon T. Austin

The combined production value of natural abrasives, which consist of tripoli, special silica stone, garnet, staurolite, and emery, increased in 1987. The increase was, in certain cases, because the materials were used in nonabrasive applications, such as the increased use of tripoli as a filler and special silica stone material as a special-purpose crushed stone. The increased use of garnet as a blasting media accounts for most of its growth. Production and sales of garnet were at a record-high level in 1987. [ ]

Jan 1, 1989

By Bruce McDonald

This report contains the Phase I findings of a study to select and test devices for preventing lack of alertness in haulage truck drivers. The extent of the problem was determined by visiting surface metal and nonmetal mines, interviewing drivers and safety personnel and reviewing accident reports. A number of devices for detecting a lack of alertness were considered and three were recommended for testing in actual operation.

Jan 1, 1977

By B. G. Thomas

"Mathematical process models can be applied in several different ways to serve industry by inducing beneficial changes to process operation. This paper attempts to summarize the different uses, types, and attributes of these models, and to offer some ideas to consider when developing, using, and reporting on them. Process models range from empirical to mechanistic in nature and vary in complexity from simple analytical solutions to coupled, 3-D transient numerical simulations. They are classified here according to the way in which they are implemented in practice, viz. fully-online models, semi-online models, off-line models, and literature models. The purpose of the model should dictate how choices are made during its development. Ways to validate and compare the model with experiments are suggested. Examples are taken in the context of the author's experience in modeling the continuous casting of steel.IntroductionThe objective of this paper is to provide a partial introduction for this symposium by discussing some basic aspects of the application of mathematical process models in industry. Essentially, the aim is to explore how process models are used to benefit industry, and to offer some general comments and suggestions, based on the experience of the author, on how models can best meet this goal.This work is concerned with process models, which consist of systems of mathematical equations and constants that are solved on a computer to make quantitative predictions about some aspect(s) of the process. The specific variables required as input data and generated as output data are important features of the model. The equations often derive from a numerical solution to one or more differential equations and their boundary conditions. The model also includes the constants, which represent material properties, empirical relationships, and other knowledge about the process, and usually require considerable effort to obtain. Thus, general purpose commercial software packages, (ie. finite-element or finite-difference based codes), are not models in this context. They are useful tools, however, serving as frameworks for the development of process models."

Jan 1, 1994

By R. B. Tippin

To study continuous operation of the heavy liquid separation (HLS) of minerals, the Bureau of Mines concentrated spodumene from a typical ore. The studies included heavy liquid concentration, removal of the heavy liquid from the mineral products, and recovery of the heavy liquid for reuse. The research program examined the influence of feed moisture, steam consumption, stripping time, and condition of steam. Operation of multiple cyclones in series resulted in spodumene concentrates assaying 92 to 95 percent spodumene and indicated mineral recoveries of 86 to 89 percent. Continuous filtration and steam stripping produced mineral products containing less than I pound of heavy liquid tetrabromoethane (TBE) per ton of material. Problems unique to this process are discussed, including heavy liquid properties and viscosity, toxicity, material handling hazards, and safety precautions.

Jan 1, 1970

By S. W. Asihene, K. Osseo-Asare

The thermodynamic data necessary for the quantitative treatment of Metal-NH3- H2O systems at elevated temperatures are lacking in the literature. As a result discussions of the chemical basis of high temperature processes, such as leaching and hydrogen reduction, have tended to rely on low temperature thermodynamic data. In this paper a critical review is presented of the available high temperature data for metal ammine formation in aqueous systems, and methods are suggested to enable extrapolation of elevated temperature stability constants from low temperature thermodynamic data. Predictions of the Van't Hoff Lsobar, the simple cation Correspondence Principle (whereby metal ammine complexes are treated as simple cations) and Helgeson's Electrostatic-Nonelectrostatic Model are compared with the available high temperature stability constants for nickel ammines. Up to 80 °C all three estimation methods yield results which are in agreement with experimental data. However, serious deviations occur at higher temperatures; the various models overestimate the stability constants in the order Van't Hoff Isobar > electrostatic-nonelectrostatic model > simple cation Correspondence Principle. Using the experimental nickel data as a basis, a method is presented which permits reasonable estimates to be made of the stability constants of metal ammine complexes for temperatures above 80 °C.

Jan 1, 2004

By A Chandra, P Guj

Only a few complex real options can be valued using closed-form equations, such as the Black and Scholes formula, because these algorithms are restrictive and prevent the construction of practical project evaluation models. Although a binomial lattice method paired with the ærisk-neutral probabilityÆ provides an easier and flexible modelling of exploration and mining projects, it has limitations when projects are complex, long-lived and influenced by the interplay of various market and private uncertainties. In order to overcome these limitations, modern decision tree software using dynamic programming capability can be used for real option valuations. This is a powerful computational tool in which the impact of various sources of uncertainties can be differentiated, so that the optimal decision path can be explicitly displayed visually. There has been significant academic controversy surrounding whether different real option (RO) valuation methods would lead to different real option values (ROV). This paper, using a realistic copper mining example, demonstrates that as long as the same degree of subjectivity and consistency are used in different real option valuation methods, they yield the same result. This conclusion is valid irrespective of whether the cash flow volatility generated by various sources of uncertainties is handled in an aggregated or in an explicit and differentiated manner. This paper compares two choices for an investor either to æbuy now and developÆ a project or to enter into a ætwo-year option to purchaseÆ after the proponents have developed it. It also shows how significantly different net after-tax operating cash flows may be generated by these different choices on the same underlying asset represented by the project. This is due to the difference in the amount and timing of the relevant capital investments affecting the depreciation and amortisation charges and as a consequence, the income tax paid. CITATION:Guj, P and Chandra, A, 2012. Real option valuation of mineral exploration/mining projects using decision trees - Differentiating market risk from private risk, in Proceedings Project Evaluation 2012 , pp 177-188 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 24, 2012

By Thomas P. Mucho

Retreat or pillar recovery mining redistributes the overburden weight onto the adjacent coal pillars in a room-and-pillar section. The additional stress and the resultant energy stored in the remaining pillars can become so great that pillars may bump or violently fail. An investigation at the Gary No.2 Mine was conducted to examine the effectiveness of the thin pillar mining method for mitigating bump occurrences. Field observations were made and instruments were installed to monitor pillar behavior during extraction. Stress monitoring instruments and roof-to-floor convergence stations were installed in pillars and entries and crosscuts, respectively. Results indicated that high pillar stress concentrations occurred in these bump-prone geologic conditions. The thin pillar mechanism, the creation and progressive outby movement of an expanded yield zone, was also monitored through the instruments. The expanded yield zone, a result of using thin pillars in a highly stressed pillar line area, mitigates bump risk.

Jan 1, 2010

By John W. Tieman

The increasing magnitude of our nation's pollution problems seems to stem from two main factors: urbanization and technical advance. In 1920, less than half the country's 106 million people lived in cities. Forty years later, the urban population accounted for 70 percent of the nation's 179 million. It is predicted that by the end of the century, 95 percent of the U. S. population, estimated at 280 million, will live in urban areas. As these people live increasingly in city concentrations, their residues also concentrate. With technological advances to support the increasing population, the variety and quantity of goods that we use also increases. New materials and processes result in increases in pollutants, some of them new. The harmfulness of these pollutants is sometimes known, but sometimes only suspected. One pollutant of concern at the present time is sulfur dioxide, the product of combustion of sulfur-containing fuels. Research on processes to remove sulfur oxides from flue gas has been in progress for many years. Pioneers in this field were the British who, in the early 1930's, installed a full-scale flue gas scrubbing unit on a 120 MW boiler using alkaline water from a Thames estuary plus chalk. Since that time, various methods have been studied by many investigators. Federal laws covering air pollution started with the 1955 Air Pollution Control Act. With the advent of the Air Quality Act of 1967, and subsequent publishing of criteria and available technology for control of sulfur oxides in January 1969, the clamor for information on commercially available control techniques to remove sulfur from fossil fuels has rapidly increased. Although many state-of-the-art papers have deluged the literature during the past several years, the research going on in the area of sulfur oxides control is of such importance that periodic reviews are justified. It is the purpose of this paper, therefore, to again review the state-of-the-art, but this time from the stand-point of what is immediately commercially available

Jan 1, 1972

By John C. Wilmot, Robert E. Brewer, Royce J. Smith

In March 2003, Phelps Dodge started up an innovative pressure leach facility for processing copper concentrates at the Bagdad mine in Arizona. This paper describes the development of the concentrate leaching plant at Bagdad and the operational results from start up to present. Optimization efforts and an approach to mineralogical modeling of the concentrate to calculate oxygen utilization are also presented.

Jan 1, 2004

By J. E. Chilton

Interim performance specifications are presented for carbon monoxide, methane, and air velocity transducers used in the Bureau of Mines intrinsically safe mine monitoring system. These specifications give quantitative values or qualitative descriptions of the transducers, including environmental parameters and monitoring system measurement and maintenance requirements as recommended by the Bureau of Mines. Commercially available transducer modules and prototype modules are listed together with selected characteristics.

Jan 1, 1983

By Martin McKinnon, Guy Reed, Russell Frith

"It is arguable that the development of reinforcing roof bolting systems has largely stagnated in recent times, primarily due to the prevailing industry view that few, if any, further improvements can be made to what currently exists. However, this paper contends that reinforcing roof bolting systems can be further refined by considering both the specific manner by which horizontally bedded roof strata loses its natural self-supporting ability and the specific means by which reinforcing roof bolts act to promote or retain this natural self-supporting ability. The Australian coal industry insists on minimising bolt-hole diameter to maximise load transfer and on targeting full-encapsulation by any means necessary. This has led to a significant, albeit unintended, consequence in terms of overall roof bolting effectiveness, namely increased resin pressures during bolt installation and the associated potential for opening bedding planes that may have, otherwise, remained closed during the bolt installation process. Given that the natural self-supporting ability of roof strata is strongly linked to whether bedding planes are open or closed, logically, minimising resin pressures should be a significant benefit. This paper focuses primarily on three key issues that relate directly to the function of the roof bolting system itself: (i) the importance of proper resin mixing in the context of maximising load transfer strength and stiffness, (ii) the importance of minimising resin pressures developed during bolt installation, and (iii) the importance of maximising the effectiveness of the available bolt pre-tension. All mine operators should be invested in improving the individual effectiveness of each installed roof bolt, even by relatively small incremental amounts, so this is an important topic for discussion within the mining community."

Jan 1, 2017

By D Ford

BHP BillitonÆs new rotary iron ore car dumper installation at Finucane Island (Port Hedland) was constructed to increase the total capacity of the port facility from 110 Mtpa to 120 Mtpa and to allow for incremental capacity increases in future. The arrangement of the dumper is similar to other car dumper installations existing on site. To construct the facility, approximately 120 000 m3 of material was excavated in six months, to a total depth of 22 m. The saline water table was nominally 6 m below ground level and the materials excavated varied depending on depth, ranging from sand to mangrove muds. There was a need to retain the sides of the excavation and limit the amount of water from entering the excavated area. This was required to allow excavation to progress and had to be maintained during construction of the permanent concrete and steel facility. The excavation was backfilled progressively as construction progressed. Various retaining wall methods were investigated with the preferred option being sheet piles secured by walers and ground anchors. Detailed electronic models were developed and assessed to complete the final design arrangement. Dewatering bores around the perimeter of the excavation removed the groundwater to intercepted sumps within the site. A strict and methodical program was developed to monitor the integrity of the temporary works and the quality of the groundwater. The works were completed on time despite the following challenges being encountered: availability of resources and equipment, movement of mobile plant on æboggyÆ materials, difficulty driving sheet piles into material at depth, drilling of ground anchors to 32 m, grouting of ground anchors, greater than expected groundwater flows, and the risk of hydrocarbons within the groundwater. The lessons learned from the use of the retention system and, in particular, the associated construction challenges overcome, provide a sound basis for similar work in this buoyant resource market. The conference paper describes the temporary works options investigated, design considerations and processes, construction methodology and challenges encountered, and the monitoring systems developed. Lessons learned are also discussed.

Jan 1, 2007

By J. M. Whiting

"North America has entered a period when greatly increased attention must be given to energy .supply and demand by government, industry and individuals. Such increasing concern about energy will be a long-term phenomenon, accompanied by continuing examination of future resource development and utilization. Those engaged in or associated with mining, a major energy consumer, are likely to experience a variety of problems which are associated with the end of an era of low-cost, virtually unlimited energy supply. Their efforts, furthermore, may be subjected to escalating public and government scrutiny, involvement and control. However, ever-growing recognition of the real and urgent necessity to systematically develop new energy supplies within Canada and the United States will provide unusual challenges and opportunities for those companies and individuals with mining expertise. The vast deposits of coal, tar sands and oil shale provide a relative certainty of supply which only stands to gain in attractive ness with time. In order to benefit from this aspect of certain supply, nevertheless, synthetic fuels will have to be produced at a tolerable cost. This will always require excellent process design and engineering. As synfuels development expands to any significant production level, however, and Jess than ideal reserves are scheduled, the usual geologic-productivity complexities encountered in making ore out of low-value rock will tend to become of prime concern. It is for this reason that the services of experienced mining personnel will be in growing demand in energy production."

Jan 1, 1973

By R. L. Stein

For the past several years, the Bureau of Mines has been actively engaged in developing two new oxygen self-rescuers through research contracts with private industry. These new oxygen self-rescuers are designed to be carried by a miner while he is at work and are used during emergency escape, supplying high-purity oxygen to the user and, at the same time, absorbing carbon dioxide (C02), The first of the two new self-rescue breathing devices is a 10-minute, self-contained apparatus developed by the Mine Safety Appliance Co, Size and weight of the unit are comparable to the currently used self-rescue devices. The second device, designed and developed by Lockheed Missiles and Space Corp., is 8. 4.5-lb package which supplies 1 hour of oxygen to the miner. Both devices have a canister which contains the oxygen-producing and CO2-absorbing potassium superoxide chemical, a breathing bag, a bite-type mouthpiece, noseclip, goggles, and hoses connecting the canister and mouthpiece. When needed in an emergency, the miner removes the outer protective cover and dons the unit. For both devices oxygen is immediately available once the mouthpiece is placed in the mouth. These two new units have received prototype approval from the National Institute for Occupation and Safety Health (NIOSH) and the Mining Enforcement and Safety Administration (MESA).

Jan 1, 1976

By S. S. Sephton

Sintering as applied to agglomeration of ferrous fines has shown little growth in the United States in recent years. The general concensus was that most of the existing facilities would remain in production at a reduced tonnage to dispose of and recover solid waste from steel plants. Further growth for ferrous sintering technology was not in sight in the United States and in the early sixties expansion came to a virtual standstill, however, we witnessed a rapid emergence of a tremendous pelletizing industry. On other continents, due to different raw materials supply and capital structure, sintering technology continued to grow, with a more cautious development of pelletizing installations. In the U.S. the diminishing supply of good quality, high grade coarse ore resulted in eventual disappearance of high grade ore fines for sintering. The finely divided concentrates produced from lower grade ores were not amenable to this type of agglomeration, but were more suitable for pelletizing. Furthermore, pellets seemed to possess all the features of an ideal blast furnace feed; namely pellets are free flowing, uniform in size, strong, with extremely uniform chemical composition and good reducibility. Importance and demand for such well stabilized furnace feed further increased as size of newly installed blast furnaces continued to grow. The in- creasing demand for a uniform, stabilized burden coincided with the effort to produce a fully beneficiated burden for smelting, thus reverting the blast furnace to its primary function of smelting.

Jan 1, 1973

By J. S. WARWICK, E. J. Browning

Ignitions continue to occur underground, sometimes leading to major explosions. There has been considerable effort in the UK, and more widely in the European Community, to formulate the best ventilation practices and other means of minimising these incidents. Practices and procedures to prevent ignitions are discussed in the light of the risks from current mining methods.

Jan 1, 1993