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By Samantha Smith

Nautilus is completing the world's first environmental impact assessment (EIA) of seafloor mineral extraction and Nautilus has gained extensive experience conducting environmental studies in subsea environments. Nautilus is currently working on the Solwara 1 Project in the Bismarck Sea, Papua New Guinea, where high grade seafloor massive sulfide deposits lie at ~1600 m water depth. Conducting an EIA in the deep sea presents some interesting and exciting challenges. Seafloor studies commenced in December 2005 using a remotely operated vehicle (ROV) fitted out with highly specialized scientific equipment to conduct water quality, sediment, biological and oceanographic studies. During 2007 and 2008, Nautilus launched two two 30-day ROV programs dedicated to environmental baseline studies and during this campaign, over 550 biological, sediment and water samples were collected and over 20,000 seafloor observations were logged. On board specialists included an international team of experts in the field of deep sea marine science. Collaboration between industry and scientific research institutions allows data to be collected for the EIA but also provides an extraordinary opportunity for researchers to access sites that might otherwise remain unobtainable to science. This presentation will review the studies conducted as part of this exciting project. Keywords: Seafloor Massive Sulfides, Environmental Impact Assessment

Jan 1, 2008

By Charles D. Litton

This report describes a smoke particle detector which utilizes a novel three electrode configuration and 5.0 [] source of Americium 241. The detector operates on the principle of diffusional charging by a region of unipolar molecular ions. The detector is sensitive to particle concentrations in the range of 10 to 5 20 ug/m3. The detector is intended for use primarily as an early warning fire detector but has the potential for other applications of particulate monitoring. In particular, this report adresses the potential use of the detector for monitoring diesel particulate matter (DPM). To assess the viability of this application, particle size data obtained from in-mine sampling of both DPM and dust were used to derive detector sensitivity functions for DPM and dust as a function of their mass concentrations only. These sensitivity functions are dependent upon the average diameters and size distributions of the DPM and dust. Using the derived sensitivity function for DPM, experiments were conducted in a ventilated tunnel where the true DPM mass concentrations, measured using a Tapered Element Oscillating Microbalance (TEOM) were compared to the mass concentrations calculated using the detector sensitivity function. The agreement between the two measurements was good, indicating that with additional experiments, coupled with in-mine evaluation of the detector, refinement of the device for use as a continuous monitor for DPM appears feasible.

Jan 1, 1989

By Donald G. Dahle

Project Payette is a conceptual nuclear experiment under the Vela Uniform program intended to further evaluate the mechanism of seismic decoupling. Vela Uniform is a Department of Defense program to improve this country's capability to detect, locate and identify underground nuclear detonations. This program evolved from recommendations of the Panel on Seismic Improve¬ment, (Berkner Panel), an officially appointed group of noted U. S. scientists. This Panel, taking note of difficulties in detecting the differences between some underground nuclear detonations and some earthquakes recommended a program of increased basic research in seismology. The theory of decoupling, Which involves possible reducing of seismic motion resulting from underground explosions by reducing the coupling or physical linkage between the explosion and the geologic environment, was investigated by Dr. Albert latter and his associates at RAND during the late 1950's. The concept has been further investigated theoretically by scientists of the Lawrence Radiation Laboratory and the Sandia Laboratory. The theory has been tested experimentally under Vela Uniform Projects Cowboy, Dribble and Sterling. The Salmon Event of Project Dribble was a tamped (with the explosive in firm contact with the geologic formation) nuclear detonation 2700 feet below ground in the Tatum Salt Dome. Project Payette, if found to be feasible and if authorized for actual execution, would become a decoupled experiment in the same environment.

Jan 1, 1968

By Ronald E. Heuer

A 1995 RETC paper of similar title presented a method for estimating rock tunnel water inflow based on semi-empirical correlations with borehole water pressure tests. Since that time the author has found the method to be very useful, and it has been used by others in the industry. This current paper is an update which is intended to: A. More clearly explain assumptions and limitations of the method. B. Describe some case history examples. C. Respond to questions which have been raised; and extend the method to other considerations including distribution of inflow along the tunnel, panning requirements, interpretation of tunnel probe hole water inflow, and estimation of potential effectiveness of pre-excavation grouting to reduce water inflow.

Jan 1, 2005

By C. A. Pickles, S. J. Splinter

Silicon oxynitride, Si2N20, has many of the intrinsic properties of a potential high temperature engineering ceramic material. Some of these properties are similar to those of silicon nitride, which has been more intensively studied. However, although silicon nitride ceramics are approaching a state of microstructural refinement for various engineering applications, silicon oxynitride has received little attention. This has been mainly due to a lack of an economical and reproducible method of producing pure crystalline Si2N2O. Several reports exist on the preparation of crystalline Si2N2O from SiO2 and Si3N4, yet very little kinetic data exist. Even less is known about the carbothermic reduction of SiO2 in a nitrogen atmosphere to produce Si2N2O. In this paper, a review of the properties and methods of preparing silicon oxynitride will be presented. In addition, results obtained by reactively sintering SiO2 and Si3N4 will be discussed. The overall reaction is as follows:

Jan 1, 1990

By E. Topuz

Productivity is the most important determinant in the economics of underground coal mining operations. Lower labor productivity increases labor requirements per ton. This, in turn, increases the unit cost of production. Intensive labor requirements may also affect miner injuries and fatalities by increasing man-hours of exposure necessary to produce a given amount of coal.

Jan 1, 1988

By D. Kump

The Bullfrog Mine is an underground gold mine that uses the underhand-cut-and-fill mining method. The portal was established on June 18, 1991. Mining is expected to be completed by the summer of 1999. This paper starts by discussing what it took to get from nothing to 2000 tons-per-day backfill, and ends with a hindsight commentary on things that did and did not help.

Jan 1, 1999

By W. C. Carter

In mid 1978 Inland Cement Industries Ltd. brought on-line their new one million megagram (Mg) per year cement plant at Tilbury Island, Delta, British Columbia. The Plant--Its Philosophy of Design The design of this plant began in 1974, at the beginning of the rapid rise in petroleum costs later referred to as the "energy crisis". The trend in fuel costs was clear, so one of the basic criteria for the selection of process equipment was high thermal efficiency. Throughout the process of selection of materials handling and process equipment, energy consumption was a factor in decisions. A second factor which influenced the design of the plant was its location on navigable water. The plant is designed to make maximum use of this means of transport to minimize transportation costs. All raw materials (and some fuel) are received by water, and a major portion of the cement and clinker is sent out by barge. Extensive modern dock and material handling facilities were provided to accomplish the shipping and receiving functions. A plant meeting stringent environmental regulations was the third major factor which formed the basis for design. To meet this requirement, all storage facilities had to be covered, 53 bag type dust collectors were applied throughout the plant, and materials handling equipment was designed to minimize dust and spillage.

Jan 1, 1979

By C. P. Mangelsdorf, Richard A. Allwes

At the request of the U.S. Department of Labor, Mine Safety and Health Administration (MSHA), the U.S. Bureau of Mines evaluated the suitability of using tri-sets for protecting mine personnel in roof-fall prone areas. A steel-set arch provided by MSHA served as a basis for evaluating the performance of the tri- set. All tests and analyses were conducted according to the arch canopy test and design procedures developed by the Bureau. Theoretical resistance functions were established for the steel-set arch and tri-set and were representative of their experimental behavior. The resistance functions were used to determine the energy absorption capacity of the structures and to predict their dynamic response to impact loading. The dynamic tests demonstrated that the arch canopy design procedure is appropriate for tri -sets and yields conservative designs for both steel-set arches and tri-sets. As a result of this work, it is recommended that tri-sets may be considered for protection against roof falls, provided that the arch canopy design procedure is utilized for each application and that the principles underlying the design procedure are understood.

Jan 1, 1992

By S. J. Stokowski

An extensive drilling and laboratory testing program indicates that diagenetic dolomitization of the Oligocene Sombrerito Fm. limestone, southwestern Dominican Republic, is detrimental to the usefulness and quality of the potential construction aggregate resource. The first part of this program was the collection, photographing, and geologic logging of diamond drill cores to allow lithologic subdivision of the strata into potential quarry layers. The primary lithostratigraphic units are: I (youngest) approximately 10 m of white, dense marine limestone; II, approximately 5 m of white, interbedded dense and chalky marine limestone; III, 2+ m of tan, chalky calcitic dolomite. Unit I has been often altered by lateritic weathering and/or dolomitization; Unit II is often altered by dolomitization. The quarry layers were individually crushed, by core, into coarse aggregate sizes for chemical and physical (specific gravity absorption, MgSO4 soundness, sand equivalent, and LA degradation) analyses. The non-weathered units decrease in coarse-aggregate yield and quality with depth and dolomitization. Dolomitization typically causes about 5% lower yield of coarse aggregate, a sand equivalent of about 20 units below the original value, an increase in absorption of about 3%, an increase in the LA of up to 13%, and a decrease in the average 5-cycle MgSO4 soundness by about 17%.

Jan 1, 1987

By S. S. Churchill

Introduction Amidst the apparent chaos of the final push to complete a major construction project, a small group of specialists works with great intensity. Armed with yellow "in test" and green "turned over to operations" tags, these startup engineers follow detailed preoperational test procedures to confirm that a plant is ready to operate. They follow a test schedule designed to complete individual process system in the order they will be needed by operations. After extensive preliminary testing, the startup engineers begin the truly exciting part of their work - initial operations. The thrill of engaging the clutch for the first time on a 10,000 horsepower grinding mill makes all the long hours worthwhile. Preoperational testing and startup are of critical importance to the success of a project. No other aspect of a construction project allows such opportunities for success or failure, and no other aspect is so critically influenced by careful planning. At Bechtel, the tasks of preoperational testing and startup are among the responsibilities of the Mine and Plant Operations group. The Preoperational Testing Process Preoperational testing is the transition phase between constructon and startup on a new plant. It includes the preparation of detailed test schedules and procedures. The schedules are used to coordinate construction completion activities, so that systems are available for startup and operations in a rational sequence. The procedures form the basis for performing the testing and documenting its completion. Tests include instrument calibration, wire insulation tests, wire termination verification, mechanical alignments and inspections, and system cleaning and flushing. Where possible, the systems are then operated on water and their performance recorded. Normally, either the construction contractor or a team of specialists has the responsibility to perform preoperational testing. Witnesses to the testing may be owner operations and maintenance personnel, engineers from the design firm, or specialists assigned to the project who provide assistance and guidance to the contractor in addition to witnesing the work.

Jan 1, 1986

By E. Arioglu

Y. Luo and S.S. Peng are to be congratulated for their outstanding paper providing new results from surface subsidence monitoring over longwall panels under different conditions. This writer found the authors' paper very interesting. In reference to this paper, the following contributions are offered: • In the paper, the maximum possible subsidence (?Smax) induced by chain pillar convergence has been related to a parameter (h/I -p) by linear regression. (Notations are expressed in this discussion's Fig. I (b).) It is a well-known fact that in a goaf the roof lowers onto broken material that gradually compacts. Then the physical behavior of goaf may closely follow the compaction characteristics of broken materials. In light of this assumption, a mathematical means (Fig. 1(a)) of defining the expected compaction (i.e. surface subsidence) represents an exponential expression between ?Smax/m vs. h/1-p. This is based on Luo and Peng's field observations from the Appalachian, Illinois and Alabama coal fields. (The coefficient of regression "r" under consideration was computed to be 0.883). • According to Wardell's (1969) findings for board and pillar mining, the maximum possible subsidence can be expressed in terms of maximum pillar loading (depth, ratio of extraction) and the height-to-width ratio of the pillars left. Using Luo and Peng's 1991 results, this writer discovered a regression equation between the above-mentioned factors. As displayed in Fig. 1(b), the functional expression approximates as closely as possible the observed subsidence data.

Jan 1, 1992

By Steve Kral

The Fourth International Symposium on Hydrometallurgy was organized to give those in the minerals processing field an opportunity to discuss current topics of interest in the broad field of hydrometallurgy. Held in Salt Lake City, UT Aug. 1-5, 1993, this fourth symposium also paid tribute to Milton E. Wadsworth for his many contributions in this area over the past 40 years. The science of hydrometallurgy has made great strides since the last symposium was held 10 years ago. The use of electrochemical principles and techniques has produced encouraging results. For example, the application of in situ electrode spectroscopy has helped to understand the mechanisms operating in hydrometallurgical processes. Sophisticated computer models have been developed to handle the thermodynamic properties of concentrated electrolytes. However, it is up to the hydrometallurgist to continuing working on bridging the gap between theory and practice. The successful application of solvent extraction-electrowinning (SXEW) is one illustration of the successful transfer of technology. Its widespread use in the United States during the 1980s played a significant role in the revival of the domestic copper industry. Currently, electrowon copper accounts for about 30% of total US production. Impressive developments in precious metals recovery have also occurred. Since the last symposium, carbon-in-pulp (CIP) and heap leaching have become widely used in gold recovery. And recovery of refractory precious metals ores and concentrates by pres¬sure oxidation and bio-oxidation have made significant advances. In all these examples, hydrometallurgy has played a significant role in the recovery of minerals and metals from primary sources. In addition, considerable attention has been focused on the treatment and recovery of values from secondary sources.

Jan 1, 1994

By L. Michael Kass

Editor’s note. The following letter was sent to The Washington Post following the coal mining accidents in January that claimed the lives of 16 coal miners. The Sago Mine disaster in West Virginia and tragic deaths of 19 coal miners nationwide have reminded us that mining coal is still a hazardous occupation. The public outcry has already led to the passage of stronger mining regulations in West Virginia. Improved federal regulations will likely follow.

Jan 1, 2006

By G. Gregory Bryan

G. GREGORY BRYAN 33.1-DEFINITIONS 1. Engineering-Engineering may be defined simply as the science and art of making materials and energy serve the purposes of mankind. There are many fields of engineering, each with specialized branches. The basic fields are: civil, mechanical, electrical and chemical. Others may be specialized phases of one of these or a combination of two or more of them. Mining engineering, for example, requires a working knowledge of construction, mechanics, electricity, metallurgy, geology, accounting and economics, in addition to mining techniques or methods. Mining geology and geological engineering involve rocks and their structure and the forces that act upon them, and chemistry, physics and mechanics also are important to practitioners in these fields. Metallurgical engineering requires chemistry and physics but also a working knowledge of mechanics and electricity. The fields of engineering with which this section are concerned are those primarily involved in the finding, mining, processing and utilization of the natural mineral resources of the earth. They include geology, mining engineering and metallurgy, each with several specialized subdivisions. 2. The Engineer-The engineer is an individual who has had specialized training to qualify him to practice the profession of engineering. The term engineer is used here in its broadest sense to include such professions as certain applied branches of geology, physics and chemistry, whose practitioners may not have acquired engineering degrees but who, nevertheless, by training and experience in some area of the minerals industry, qualify under the above definition. To become a successful engineer, a person should have certain pronounced aptitudes and preferences, even before embarking upon the requisite course of training. Among the chief qualifications that the engineer-to-he must possess are: (a) a natural inclination toward mathematics and the physical sciences, and (b) intellectual and moral honesty. Among the qualities the student engineer must develop are: (a) independence of thought, open-mindedness, sound judgment and the ability to observe, deduce, plan and apply solutions, (b) the ability to articulate and convince, and (c) the ability to organize and direct the activity of others. These qualities are normally developed through sound education, followed by pro¬gressive experience. 3. The Consulting Engineer-The consulting engineer is an engineer primarily in the business of furnishing specialized advice and engineering services on an intermit¬tent, part-time or occasional basis to clients who do not have continuous or full-time need for those services. He must be able to make and take full responsibility for decisions and recom¬mendations where original thought is required. He should not be confused with the engineer, surveyor or technician who also may furnish services on an intermittent basis, such as regular periodic surveys, the overseeing of drilling programs and other such routine work as may require little original thought and planning. 33.2-THE PROFESSION OF CONSULTING ENGINEERING 33.2.1- QUALITIES REQUIRED A successful consulting engineer must first have, as a minimum, the qualities and preparation of an engineer. In addition, he must have sufficient knowledge,

Jan 1, 1973

By Y. Ye

Induction times for a variety of minerals have been measured at a particle bed. Electrostatic repulsive forces between bubble and particle generally are of secondary importance in determining the hydrophobic state; nevertheless, the shortest induction times are measured at the isoelectric point of the solid. More importantly, the study shows that the film-rupture mechanism at a polished surface might be different from that at a particle bed. The induction time measured at a particle bed, besides being dependent on the surface chemistry of the system, shows a definite relationship to particle size and density. Theoretical analysis suggests that such a measured induction time at a particle bed should properly be defined as an attachment time which consists of the induction time and the film-displacement time. Thus one portion of the measured attachment time is the induction time, the time required to thin the water film between the particle surface and the gas bubble to a critical thickness so that rupture of the film takes place ('1)' The other portion of the measured attachment time is the time required for the film to be displaced to such an extent that the attachment is stabilized with respect to the upward motion of the bubble and the downward gravitational force acting on the particle ('2)' Further, the present study illustrates that '2 is related to the hydrophobic character of the surface, the rate of film displacement after rupture, the upward velocity of the captive bubble, and, most importantly, the particle size and density.

Jan 1, 1988

By R. D. Grove

The control of Florida phosphate flotation plants is largely based on the visual observations of experienced operators, both in recognizing good and bad froth conditions and in making judgments about the composition of feed, concentrate and tailing streams. Chemical analyses lag the process by at least two hours and, therefore, only assist in recalibrating the operators' vision when major deviations occur. An image analysis system was developed by IMC Fertilizer to improve the accuracy and precision of the composition estimation process. It still relies on the operator taking a representative sample, but provides a measurement in about 15 minutes after that sample is obtained. Background The search for a quick and inexpensive technique for estimating phosphate flotation stream composition continues. There have been attempts at using "wet chemistry," nuclearmagnetic resonance, neutron activation, X-ray diffraction and other techniques reported on in the past several years. None of these have yet found its permanent place in the flotation plants of the Florida phosphate industry. IMC attempted to use wet chemistry to provide 7.5-minute estimates of final concentrate insol and tailings BPL. This was aborted after 36 months of plant operation due to the high operating costs for chemicals and an operator. There was also no significant economic improvement in the plant's operation. Another factor was the necessity to limit these crude analyses to only a few process streams, which were insufficient to achieve improved plant operation.

Jan 1, 1993

By E. P. Chen

This investigation involves the development of a two-dimensional continuum model for the description of jointed media. Specific application of the model developed here is for the potential geological disposal of radioactive waste in the layered sequence of fractured volcanic tuffs under Yucca Mountain, Nevada. This is currently being considered by the Nevada Nuclear Waste Storage Investigations Project, administered by the Nevada Operations Office of the U. S. Department of Energy. The work is a direct extension of the previous constitutive model by Thomas (1982) based on the work of Morland (1974). The main feature of Thomas's model includes two parts: a continuum approximation based on average discontinuous displacements across jointing planes within a representative elementary volume, and a material constitutive description based on linear elastic matrix material behavior and nonlinear normal and shear joint behavior between jointing planes. The mathematical descriptions by Morland based on strain partitioning among matrix material and joint sets allow multiple joint sets to be included in the model. However, the initial effort by Thomas to implement Morland's mathematical model included only a single set of joints. To make the material model reflect more realistically the field characteristics, the current work extended Thomas's model to include orthogonal sets of joints. The nonlinear elastic normal joint behavior is retained in the present model. Joint shear response was treated as linear elastic in the shear stress versus shear displacement relationship prior to attaining the stress level governed by the Coulomb friction criterion. Beyond this critical stress value, a horizontal line is assumed in the work of Thomas for the shear stress versus slip displacement relationship such that the shear stress remains constant while the slip displacement increases. Motivated by experimental observation, the current work generalized the shear response to allow a line with finite slope to govern the slip behavior beyond the critical stress level. The inclusion of an orthogonal joint set led to a fourth order algebraic equation for the calculation of stress increments as compared with a second order equation obtained by Thomas. The nonlinear elastic normal joint behavior provides criteria which allow the selection of the root that yields result consistent with the loading condition of the problem. The addition of one more set of joints provides the potential to more completely study the interaction of various parameters representing the characteristics of jointed media behavior. Material responses to various loading conditions based on the present constitutive model have been obtained. These results and their comparisons to single joint set results are presented. Formulation of the Continuum Model The inclusion of an orthogonal joint set led to a fourth order algebraic equation for the calculation of stress increments as compared with a second order equation obtained by Thomas. The nonlinear elastic normal joint behavior provides criteria which allow the selection of the root that yields result consistent with the loading condition of the problem. The addition of one more set of joints provides the potential to more completely study the interaction of various parameters representing the characteristics of jointed media behavior. Material responses to various loading conditions based on the present constitutive model have been obtained. These results and their comparisons to single joint set results are presented. Let us focus our attention on the set with normal n first. Let the jump dilation displacement and jump slip dasplacement associated with the [ ]

Jan 1, 1986

By Leo J. Laughlin

In recent years, heavy mining applications have put an increasing demand on conveyor pulleys. This has resulted in the increased usage of turbine pulleys. The designs of these pulleys are often based upon the failures seen in the conventional welded designs, overlooking the interaction of pulley-shaft system components as the profile of the disc is modified. This paper will focus on the development of balanced design philosophy using case studies of turbine pulleys in heavy mining applications, evaluated with FEA.

Jan 1, 2002

The first of this three part series examines he history and some of the properties and characteristics of explosives. Use of explosives is discussed for underground and surface coal operations—the largest consumers in the mining industry. Part two of the series will deal with explosives use in surface and underground hardrock operations. Part three will discuss explosives transportation, storage, handling, and destruction.

Jan 7, 1981