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By B. W. Haynes

This Bureau of Mines report describes the laboratory processing of manganese nodules and the results of tailings characterization obtained during the cooperative program with the Department of Commerce's National Oceanic and Atmospheric Administration (NOAA) and the Bureau. Five technically feasible first-generation nodule processing methods were operated at bench scale to generate sufficient tailings and slags for physical and chemical analyses. A description is given for the laboratory operation of the individual unit operations of each process. The laboratory-generated tailings and slags were tested for physical properties, mineral content, elemental and ion content, and leachability for all five processes. The results of leachate testing using the Environmental Protection Agency extraction procedure (EP) toxicity test, the American Society for Testing and Materials shake extraction test, and the EPA-U.S. Army Corps of Engineers seawater elutriant test showed very low to negligible leaching of metals from the tailings and slags. Results of the EP toxicity test demonstrated that the wastes are nonhazardous as defined in the Resource Conservation and Recovery Act (Public Law 94-580).

Jan 1, 1985

By C. Golumbic

Most early research on solvent extraction of coal has been concerned with the molecular structure of coal. Although rush work is continuing, practical aspects of the subject also are being emphasized. For example, development of the Pott-Broche extraction process resulted from the discovery of very efficient solvents for the pressure-extraction of coal. Recently, Orchin and Storch reported the use of even more efficient solvents under similar conditions. In addition to the discovery of more effective solvents, the possibility of efficient extraction at atmospheric pressure is obviously of practical interest. H. J. Rose observed that phenanthrene at its atmospheric boiling point readily dispersed 80 percent or more of Pittsburgh-bed bituminous coal. This fact served as the starting point of the present investigation, ill which determination of the chemical specificity of this solvent and the chemical nature of the resulting extracts was undertaken. This paper represents a progress report of the results obtained to date.

Jan 1, 1950

Beneficiation of Coal Fines from Tailing Ponds of Tuntbilek Washing Plant

Sep 13, 2010

Rock mass classification is widely used throughout the underground mining industry—in both coal and hard-rock mines. It is used in all stages of the mining process, from site characterization to production operations. The goal of the International Workshop on Rock Mass Classification in Underground Mining was to provide a forum for leading practitioners of rock mass classification to come together and share their methods and experiences with the technique. The workshop was held in Vancouver, British Columbia, Canada, on May 31, 2007. It was co-chaired by Christopher Mark, Ph.D., P.E., National Institute for Occupational Safety and Health, Pittsburgh, PA, and Rimas Pakalnis, P.Eng., University of British Columbia, Vancouver, Canada. The proceedings of the workshop contain 16 invited papers from 9 countries, reflecting the international depth and breadth of current practice. Applications in both hard-rock and coal mining are well represented. Some of the topics that were addressed at the workshop include: • Major rock mass classification systems used in mining and their variants • Collection of input data through observation, rock testing, and geophysics • Design of mine layouts and rock support systems using classification • Estimation of rock mass strength and other input parameters for numerical models from classification • Applications in weak rock, raise boring, cavability assessment, and other special topics • Risk assessment using rock mass classification

Jan 5, 2007

By Milner A, Brockway D, Hodges S

The combustion of brown coals in Latrobe Valley power stations produces approximately 500 000 tonnes of solid wastes each year. This material, which includes precipitator ash, char and furnace ash, is hydraulically sluiced to large ashing ponds and the supernatant solution is ultimately discharged to the sea. There are significant operational and capital costs associated with the current ashing system. The ash produced from the Latrobe Valley coals is unique and has a wide variety of potential applications including soil conditioning, concrete and cement extenders, fillers in non-metallic materials, components of building products. In addition, with the application of appropriate technology, it is possible to extract char, sodium sulphate, calcium carbonate and magnesium metal (as the chloride) in substantial quantities from the ash. Research has been carried out to explore the prospects of these various options for ash utilisation. The research has focused on detailed characterisation of the ash material and the potential extraction efficiency for various species under various conditions. From this work a conceptual process has been developed and subsequent studies have been directed towards understanding variables and optimising operating regimes for product extraction. Currently, the work is concentrating on the separation of char, the development of high-grade carbon products and the extraction of sodium sulphate.

Jan 1, 1992

Recycling and Recovering Fine Particles from Auto Shredding Residue (ASR/SR) to Conserve Raw Materials and Protect Environment

Sep 13, 2010

By R. V. Ramani

One area of study in the Coal Mine Injury Analysis project was to illustrate and enhance the ability of mine safety management personnel to apply analytical techniques to injury experience data and to justify requests for funds for safety enhancement actions on a cost/benefit and other quantitative basis. Four volumes of this final project report detail (1) the objective and scope of the mine safety management research, (2) the results of literature review, and case studies, and (3) models developed for mine safety management. The four volumes are titled as Volume III: Mine Safety Management, Volume IV: Analytical Techniques for Mine Safety Management; Volume V: Mine Safety Management Case Studies and Volume IX: Training Cost Model. In this volume, the following material is presented: (i) review of related literature, (ii) mathematical models to perform quantitative analyses of accident/ injury experience data using the tools and techniques of risk analysis, time series analysis, and the Markov process, and (iii) descriptions of the HDBSEL and ACIM programs which are used to perform accident/injury experience analyses and cost analyses, respectively.

Jan 1, 1993

By L. G. Marshall

This report is one of a series published by the Federal Bureau of Mines, describing mining methods and performance at individual mining operations throughout the United States. The objective of these papers is to promote development and conservation of our mineral resources by disseminating reliable technological information on mining methods, practices, and performance. Limestone deposits in Iowa are extensive and reserves are large. Most of the past production came from the eastern third of the state, although over half of the counties in the state have produced, or are now producing limestone. The stone is used as aggregate, road metal, agricultural lime, riprap, fluxing stone, railroad ballast, and in the manufacture of cement and lime.

Jan 1, 1962

Experiments in the bolting of a mine roof were commenced at Elrington Colliery on the South Maitland Coal Field early in 1949, following the appearance of an article in the American publication, "Coal Mine Modernisation Year Book" 1948. Prior to this, although bolting had not been used in the maintenance of satisfactory roof conditions, the principle of roof bolt anchorage had been illustrated in instances such as the hanging of a trolley locomotive power wire using an expanding shell type of bolt anchorage, or the insertion of an eye bolt with a split and wedge, as used to suspend a rope block over a winze being sunk in a metalliferous mine.The experiments at Elrington Colliery were the first efforts in this country to supplement the work of timber supports under a mine roof with systematic placement of roof bolts.Following the series of experiments at Elrington, full scale bolting was commenced at that Colliery in a trackless mobile section in April, 1950.The obvious success of the system at Elrington indicated that it might also be a success in the support of weak roof strata immediately overlying the workable section of the Victoria Tunnel Seam at John Darling Colliery.The system was commenced at John Darling Colliery in April, 1951, in one mechanical section on the Victoria Tunnel Seam, and the scope was gradually widened until by December, 1952, ail'six mechanical units then operating on this seam were working under bolted roofs.

Jan 1, 1954

By J. Wennerstrand

Slender steel piles have found an increased use in Sweden in resent years. These piles are often driven throw soft normally consolidated clay to refusal in till or at the rock surface. In contrast to most other piles the bearing capacity with regard to failure of the shaft is in many cases smaller than the bearing capacity with regard to failure of the soil or rock at the lower end of the pile. Imperfections such as deviations from a straight line of the pile centerline and residual stresses in rolled and welded profiles are important for the capacity of the pile shaft. Even thow the second order moment caused by initial deviations in piles is only half of that in a column with the same slenderness, imperfections can and should be accounted for in much the same way as for columns.

Jan 1, 1989

By Roy A. Imbsen

Following the 1989 Loma Prieta earthquake, California Department of Transportation (Caltrans) expedited an effort to evaluate and retrofit important state-owned toll bridges to en­hance performance of the state's transportation systems during and after major (credible) earthquake events. Imbsen and Associates, Inc. (IAI) along with their sub-consultants, were awarded a contract to conduct seismic evaluation and to develop retrofit design for Benicia-Martinez Toll structure, to meet a "Serviceable" performance requirement after the event of a "Safety Evaluation Earthquake." This paper describes the design and construction specifications for the deep foundations supporting the main spans of the Benicia-Martinez Bridge. Benicia-Martinez Toll Structure (George Miller Bridge), a high-level deck-type welded truss bridge with welded girder approach spans, carries Interstate Route I-680 over the easterly end of Carquinez Strait near San Francisco, CA. The nearly 5000 ft long main truss structure consists of ten spans, ranging from 330' to 528' in length, supported on cellular reinforced con­crete pier structures. Foundation systems across the waterway, consist of cellular reinforced concrete footings, supported by groups of 6' diameter, concrete filled, steel caissons, resting on 5' deep rock sockets, at depths of 50' to 150' below the water level. Seismic evaluation of the existing foundation systems accounted for spatially varying ground motion along the length of the structure, variability of foundation material strength (i.e. at bed-rock), variation and effects of scour depth on the performance of the foundations, and dy­namic soil-structure interaction. Performance of caissons beyond their elastic strength, as well as their effects on the behavior of the foundations and substructures were evaluated and considered in establishing foundation vulnerabilities. Several retrofit strategies were considered leading to a final retrofit strategy to strengthen end connections of existing caissons, as well addition of new caissons to provide adequate lateral force resistance for the foundations. Final design package includes specifications as well as construction methods and requirements for existing and new caissons, under traffic, and pile load testing procedures for design loads of up to 12500 kips per caisson.

Jan 1, 1998

By R. W. Raymond

WISH to call the attention of the Institute to a curious subject, brought to my notice last summer by Mr. Begger, the accomplished metallurgist of the smelting-works of the Boston and Colorado Company at Black Hawk, near Central City, Colorado. At these works, the richest auriferous sulphhrets of Colorado (particularly copper pyrites) are smelted in reverberatories, together with roasted tailings (iron pyrites), and the gold and silver are concentrated into a new, artificial sulphide, or copper matte, containing $1500 and upwards of the precious metals per ton, and this is shipped to Swansea. I will say in passing, that this shipment of an unrefined product, like the similar shipments from Utah and Nevada to San Francisco, Chi¬cago, St. Louis, Newark, New York, and Europe, of crude argentiferous lead or "base bullion," is not a sign of incomplete metallurgy here, but has a sound business reason. The separation of the precious metals in the West would be more expensive, to begin with ; and then it would necessitate the movement of these metals by express, at high rates and risk, to commercial centres or coining mints, while the base metals having no home market, must be shipped and sold at little or no profit. At present, the gold and silver, safely packed, as it were, in the base metals, are transported with safety as ordinary freight; and the base metals probably more than pay cost of shipment and separation. To return to the Black Hawk reverberatories. On a recent occa-

Jan 1, 1873

By Mark S. Sanders

This report presents a summary of the work reported by Sanders and Kelley (1981). A task analytic approach was used to define information requirements and visual features which served as sources of information. Information requirements were prioritized and the location of visual features determined. From this analysis, visual attention locations, containing one or more important visual features, were indentified. The visual attention locations are contained in this report. A procedure was developed for assessing whether operators in existing machines could be expected to see the visual attention locations. The procedure makes use of a Human Eye Reference Measurement Instrument (HERMI) designed for this project and an outside-in photographic procedure for documenting compliance with the recommendations. A sample of continuous miners, shuttle cars & scoops were used to test the procedure. Illustrative results are presented in the report.

Jan 1, 1981

By S. E. Phillipson

The Mine Safety and Health Administration?s (MSHA) Roof Control Division (RCD) collects a variety of geological and engineering information pertaining to mining conditions in surface and underground mines throughout the United States. Recently, lineament analyses, trends of geologic structures, and inferred stress directions based on mapping at mines with problematic ground conditions, have been integrated into a GIS. The incorporation of different kinds of information into the same geographic coordinates and map projection, placed on digital geologic maps, allows site specific data to be evaluated in a regional geospatial context, identifying trends in the orientation of horizontal stress or patterns of structural geologic features. As more information is collected, the GIS will evolve as a tool for district- and basin-wide evaluations of controls on ground instability, and may evolve into a predictive tool for some kinds of geologic hazards. In addition to the geologic and geotechnical evaluations, the GIS also serves as a searchable database of previous mine investigations. The database can be searched for a variety of criteria, and the results displayed in real geographic coordinates to find the locations of previously visited mines or to evaluate mine fatality and injury data. This not only allows old reports to be found, but also places the information in a geospatial context with respect to neighboring mines or geographic areas. The GIS also has the capability to serve as a digital mine map repository, where maps can be stored in digital, georeferenced format for display in relation to each other and various themes of interest. This allows evaluation of multiple seam mining interactions and proximity to other mines, and on a national level could serve as an abandoned mine map database.

Jan 1, 2008

The New Zealand microcontinent is relatively well endowed with gold deposits; its past gold production per unit area of 3.2 kg/km2 ranks high on a world scale. Total recorded production (1857 - 1986) is about 854 000 kg and most of this gold was mined between 1861 and 1920. There has been a strong revival in gold exploration and mining since 1979, with exploration expenditure of around $15 million per annum and a declared gold production in 1986 of 1265 kg (886 kg in 1985). In addition to numerous alluvial gold recovery plants working small to medium sized deposits (mainly in Westland and Otago), there are five medium to large projects that have started production (Martha Hill), or have reached advanced stages of construction (Grey River dredge), permitting (Golden Cross and Macraes) or exploration (Globe-Progress). This summary paper is taken from reviews by Brathwaite et al (1986) and Brathwaite (1988).

Jan 1, 1988

By D. M. Wyslouzil

"Micron or sub-micron size gold inclusions in sulphide minerals cannot be extracted by conventional cyanidation. The gold surfaces must first be exposed by decomposition of the sulphides. As an alternative to roasting, pressure oxidation was found to be a most satisfactory method to decompose the sulphides and expose the gold particles. For cyanidation the pressure oxidation pulp has to be neutralized and stabilized with lime. It was found that thiourea can extract the gold directly from the pressure oxidation pulp without pH adjustment and oxidant addition. The main obstacles against the common use of thiourea are circumvented by a recently described control method of the emf during leaching.INTRODUCTION Amalgamation and cyanidation are the most conventional processes for gold extraction. The prerequisite for gold extraction is the possibility of gold surface to be contacted by mercury or by the cyanide solution. Encapsulated gold has little chance of contact and this leads to poor extractions.The reasons why a gold ore may be refractory are: micron or sub-micron size gold particles included in the sulphide minerals, such as pyrite and arsenopyrite; presence of and association with antimony, arsenic, tellurium and carbonaceous minerals. Some alternative processes, such as double oxidation(1,2), pretreatment with lime , H202, chlorine and Caro's acid, roasting and thiourea leach, have solved some of the problems of ""refractory"", but the sub-micron gold in sulphide minerals still shows little response. Roasting and the cyanidation of the calcine was one of the most successful approaches for this type of gold ore.There are two disadvantages to the roasting process: (1) the generation of sulphur, arsenic, antimony and mercury containing gases is undesirable and the control is extremely expensive; (2) gold particles might be fused in the roasted product and the oxidized base metals in the calcine might reduce the cyanidation efficiency. In recent years the pressure oxidation process has been considered as one of the more effective and satisfactory methods to decompose the sulphide minerals and expose the gold surface to the cyanide leach solution. The pollution problem could be better controlled and the gold extraction is more amenable."

Jan 1, 1985

By Larkin F, Farrer E, McGhie R. R

The Electrolytic Zinc Company of Australasia Limited commenced productive operations during February, 1936, at the- Rosebery and Hercules mines, which are situated near Rosebery, Tasmania. At this time it was decided that before re-organizing the steel sharpening shop a test should be made of the relative merits of conventional drill-steel and detachable bits. For this purpose Ingersoll-Rand type"I" thread centre hole.jackbits were selected and seventy-two of these were tested against conventional steel. Results indicated that, under the conditions pertaining at these mines, j ackbits should prove more economical than conventional drill-steel bits, and that a large-scale test, under working conditions, should be made. This was done by gradually replacing conventional drill-steel with jackbits at the Rosebery mine. Results were satisfactory and by the end of 1936 both mines were using only the jackbits.

Jan 1, 1939

By Bernard Hertlein

¦ Drilled shafts resist scour seismic loads better than groups of driven piles ¦ Drilled shaft construction creates less noise and vibration than driving piles ¦ Drilled shafts permit direct observation of bearing stratum, and confirmation of location ¦ Drilled shafts are cost effective

Jan 1, 2001

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

Jan 1, 1977

By J. M. Uys, T. B. King

WalSH, Chipman, King, and rant' have measured the water content (as hydrogen) of actual steel-making slags. An average water content of 290 ppm was found for basic open-hearth tapping slags and 114 ppm for acid open-hearth slags. Upon equilibration of these slags at 1550°C with a 25 pct H20-75 pct Nz atmosphere, the water content increased to about 410 and 300 ppm for the basic and acid slags, respectively. Walsh et al. concluded that an acid slag was thus relatively far removed from equilibrium, and that basic slags showed a closer approach to equilibrium, with the water vapor in the furnace atmosphere. Herasymenko2 contended that these conclusions were unjustified, as the oxygen pressure used in the equilibration experiments, ;bout 5 x X atm, was quite different from that found in the furnace. Consequently, during the experiments the slag composition would have changed due to oxidation of ferrous iron. As an extension of Walsh's work and to attempt to clarify this matter, the solubility of water in a basic open-hearth slag was measured as a function of oxygen pressure. Similar measurements were also made on synthetic silicates in the "Fe0"-Fe203-SiO, system. The experimental technique has been described previously by Walsh et a1.l and Uys and King.3 Samples of the basic open-hearth finishing slag, contained in 10-cc platinum crucibles, were equilibrated at 1550°C with atmospheres of different oxygen pressure but constant water-vapor pressure, Ph~o = 0.192 atm. Calculations, as well as measurements, indicate that this figure approximates the water pressure of the combustion gases in a steam-atomized, oil-fired open hearth. Oxygen pressures in the open hearth can vary from 10"2 atm in the combustion gases to between l0-' and 10" atm in the steel bath. The former figure depends on the combustion practice and the latter on the carbon content and temperature of the bath. The oxygen pressure of the slag should lie somewhere between these extremes and is expected to be closer to that of the steel bath than that of the combustion gases. Oxygen pressures were therefore varied between 10" and 6 x l0 atm. At the lowest pressure the slag "puffed up" when quenched (indicating possible loss of water) so experiments were not conducted at lower oxygen pressures. The results are shown in Fig. 1, which includes the water content of the slag "as sampled". The results show that the water content of the slag increased appreciably on equilibration with water vapor at 0.192 atm pressure and that the water solubility apparently decreases with increased oxygen pressure. The solubilities found are comparable to those of the Li20-Ca0-Si02 system.3 Work with synthetic slags in the "Fe0"-Fe203-SiOz system was performed at 1500" C, with Ph20 = 0.192 atrn and for oxygen pressures varying between 10"2 and 10-lo atm. Samples for chemical analysis were prepared as described by Larson.4 The results are shown in Fig. 2. Some low-silica melts tested at low oxygen pressures "puffed up" when quenched and analyzed less than 100 ppm water; these results are not included in Fig. 2. The melts containing 40 mol pct silica also showed a tendency to "puff up" during the quench, when they were tested at the lowest oxygen pressure. These results indicate that, at constant silica content, the solubility of water decreases somewhat with increased oxygen pressure. The effect is, however, small considering the wide range of oxygen pressures studied. Also, at constant oxygen pressure (above about lom5 atm) the solubility increases

Jan 1, 1963