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By Joseph L. Jordan

Coal is essential to America?s future energy needs. To meet these needs mining methods must be safe, economical, and environmentally acceptable. Belt conveyor systems for coal haulage from surface mines offer great potential in this situation. The advantages over conventional truck haulage are particularly promising for area strip mines in western coal fields such as the Powder River Basin where relatively thick, flat-lying coal seams occur. The current demand for low-sulfur coal specifically emphasizes the need for better mining methods in these areas. Underspoil haulage is the term applied to transportation of coal from the pit to the surfate in area strip coal mines by belt conveyors in tunnels under the spoil. The advantages over trucks include lower manpower requirements, greater pit safety and efficiency, and improved reclamation procedure. This evaluation includes a comparison of total mining costs for truck haulage versus six variations of the underspoil haulage concept. The more efficient of these underspoil haulage systems have economic advantages over truck haulage which become more pronounced with deeper overburden, thicker coal, and higher annual production.

Jan 1, 1977

By R. E. Collom

The commercial development of petroleum and natural gas fields has reached its present status within 60 years and is still considered by some operators to be "100 per cent wildcatting." 1 A tendency to drill for gusher production, the production that yields big returns in spite of any mechanical defects in drilling methods, has frequently caused drillers to pass by oil-bearing strata of comparatively small yield and actually to overlook rich oil zones in proved fields; in addition, whole fields have been ruined by water because development methods were never carried beyond a hole-in-the-ground stage.2 Unfortunately, the petroleum industry has no mine dumps or tail. ing piles as at metal mines to yield fortunes through later and bette!' methods of treatment. The wasted oil and gas are gone, as are the time, money, and effort wasted in ill-advised or haphazard drilling. Probably as production costs increase less oil will be wasted, but the need to develop and produce from sands of low yield will become more urgent with the increase in consumption of oil and the decrease in supply. Hundreds of wells are producing steadily as the result of months and perhaps years of careful prospecting and of tests during drilling. The Bureau of Mines has studied the testing and drilling methods used at such wells, and presents in this paper a criticism of these methods and suggestions on future work. The term pr08- pecting here means correct identification and measurement of strata as they are exposed by the drill. The term testing means the determination of the kind and amount of fluid stored within the pores or crevices of any stratum exposed in the hole.

Jan 1, 1922

The objective of this handbook is to provide the inspector with guidance for recognizing hazards from inhalation contaminants in above ground work areas of underground and surface metal and nonmetal mining and processing facilities and evaluating these hazards by collecting samples or making field determinations and interpreting the analytical results. Portions of the handbook that should prove most useful to the inspectors include a survey check list, rules for determining if sampling is required, list of most frequently encountered contaminants, list of candidate contaminants and their sampling conditions, interpretation of results, and a procedure for a health and safety inspection.

Jan 1, 2011

According to reports in August, Botswana RST's copper- nickel-cobalt smelter at Selebi-Pikwe produced 7 percent above the rated capacity of about 3,500 metric tons of matte per month. This record production occurred after 2 years of plant production difficulties and was brought about by a new management team. A shutdown for furnace maintenance had been planned for this year, but was postponed because of the improvements in production and operations. However, the mining operation continued to face problems relating to higher costs and some outstanding claims. COPPER: Effective December 1, ASARCO, Inc. and Phelps Dodge Corp. reduced their domestic copper prices by 54 per pound. Within a period of 3 days, a11 other producers (Kennecott Copper Corp., Newmont Mining Corp., Cities Service Co. , Copper Range Co. , Duval Corp., and Inspiration Consolidated Copper Go. ) had either lowered or discounted their market postings by 5¢ to 65.625¢ per pound on electrolytic wirebar and 65$ on cathode plate. Between November 29 and December 3, New York merchants decreased wirebar quotations by 1.8¢-2¢ to within a range of 57.8¢-58¢ per pound. New York Commodity Exchange (COMEX) spot-contracted copper in the week was priced at 57. 1¢ on Monday, 56.7¢ on Wednesday and Thursday, and 57.4¢ on Friday, resulting in a 5-day average of 56.9¢, London Metal Exchange (LME) cash (prompt) wirebar averaged 56.3¢ last week, opening Monday at 56.6¢, falling from Tuesday?s high of 57.2¢ to Wednesday?s low of 55.6¢ and closing Friday at 56.1¢. Foreign producers, guided by LME market transactions, lowered wirebar quotes to 56¢ per pound. Copper stocks as of December 3 totaled 187,702 short tons at COMEX warehouses and 654,573 tons at LME depositories, compared to 97,413 and 537,481 tons, respectively, for the corresponding 1975 period.

Jan 1, 1976

By H. P. Cole

Methods for increasing compliance to medical and health regimens were reviewed along with similar research in industrial and mine safety. Principles abstracted from both areas suggest that compliance with health and safety practices is improved when: (1) Workers are cooperatively involved with management in setting safety goals and planning for their achievement, (2) the program has the support of workers, supervisors, and management, (3) specific tasks responsible for injuries are targeted, (4) company organizational policy, educational, and behavioral programs work together toward the same goals, (5) workers and supervisors are frequently informed about their degree of correct task performance, and (6) programs are monitored by the frequency of correct performance of targeted tasks, (the means to lowered accident rates) rather than by lowered accident and injury rates themselves (the goals for safety programs.) Safety programs that incorporate these principles increase persons' adherence to specified health and safety practices and subsequently decrease injury rates. It is recommended that: (1) a group of experts be convened to study the application of these principles to coal mine safety programs, and (2) a short course for safety trainers be developed to demonstrate how these principles can be used to strengthen existing mine safety programs.

Jan 1, 1985

By B Hayter, M Carr, K Williams, C Wheeler, W Chen

Current trends into mining iron ore have seen an increase in the exploitation of problematic orebodies that would typically be disregarded. These bulk materials cause problems within all facets of the material handling stream, from remains left in train wagons to transfer chute blockages, which can cause costly downtime to mining operations (Roberts, 1998). These problematic bulk materials are referred to as wet and sticky material (WSM) due to the adhesive and cohesive nature they possess. Their characteristics can be computationally expensive to model. With the development of discrete element modelling (DEM), in conjunction with advancement in computational power over the past decade, it is now more feasible to model WSMs into the DEM technique.This research will couple two different contact models that can represent the characteristics of a WSM. These models include the Simplified Johnson-Kendall-Roberts (SJKR) and the Easo liquid bridging contact models. The SJKR contact model is an expanded form of the classic Hertz model. This model includes the tensile forces that are in the contact zone between two bodies when they are separated, which the Hertz model failed to capture (Johnson, Kendall and Roberts, 1971). The Easo liquid bridging contact model accounts for the capillary effects and surface tension that will form between two bodies, such as that of a WSM (Soulié et al, 2006). Both of these models were coupled to give the best representation of a WSM, which was simulated using MoleculeX™ (Chen and Williams, 2017) as the software platform.Additionally, this research also investigated the adhesion of problematic iron ore samples onto impact plates under dynamic conditions. An experimental set-up consisting of an apron feeder and inclined impact plate was utilised, to gain an understanding of the way the material builds-up and the possible modes of failure that could be experienced. This was undertaken for different wall liner materials, wall liner angles and moisture contents of the iron ore samples. From this, a series of DEM calibration simulations were conducted on the experimental set-up and particle size distributions (PSD) of the iron ore samples. This enabled forming of a database of parameters, which can be scaled for on-site applications in relation to geometry of the plant and PSDs that would represent run-of-mine ores.CITATION:Carr, M, Williams, K, Chen, W, Hayter, B, Roberts, A and Wheeler, C, 2017. The dynamic adhesion of wet and sticky iron ores onto impact plates, in Proceedings Iron Ore 2017, pp 511–518 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Adrian Coombs

The York Durham Sewage System (YDSS) Interceptor Tunnel Project is located in the Town of Richmond Hill, Ontario, Canada, just north of Toronto. Construction commenced in September 2006 and completion is planned for early summer, 2008. The project involved public and agency buy-in of construction technologies and methods that minimized dewatering, design and construction of sealed shafts with jet grout break-in and out blocks in order that Earth Pressure Balance (EPB) mode could be maintained by the Tunnel Boring Machine (TBM) during shaft entry and exit. This paper will discuss the advances that were made possible through the opportunity to apply and test these technologies in order to accommodate the aquifer and artesian conditions present on this project.

Jan 1, 2008

By John D. Rockaway

Failure of the mine floor supporting coal pillars frequently occurs when the subcoal strata include "underclays" or other low strength strata. The failure process has been studied to define the response of these materials to applied coal pillar loads and to determine the applicability of bearing capacity analysis to evaluate unsafe conditions. The study has been accomplished through an investigation of both the intact and insitu geotechnical properties of the subcoal strata and through the installation of floor movement monitoring instrumentation. The results of these studies have indicated that both the shear strength of the underclay and the stratigraphy of the subcoal strata must be considered in the analysis. The shear strength was the major controlling factor determining the ultimate load carrying ability of the materials, but the thickness and stratigraphic position of the weak layers influenced the mechanism of the failure process. The methods of bearing capacity analysis were used to define pillar stability that included provisions for taking into consideration a two-layer system. Conditions assumed for a coal mine where a weak underclay overlies firmer strata. The results of the analysis compared very well with observed mine conditions, indicating marginal conditions in areas of the mine which later experienced pillar support failure. In addition, a "heave factor" was derived to predict potentially unstable floor conditions in the mines studied in detail.

Jan 1, 1979

By D. Robert Weir, M. J. H. Ruscoe, R. M. Berezowsky, M. A. Clegg

The metallurgical processing involved in the produc-tion of the new Canadian one dollar coin is reviewed starting with the hydrometallurgical production of pure nickel powder, followed by the powder metallurgy process for the production of nickel strip and coinage blanks, and concluding with the Aureate bronze electroplating and heat treatment procedure. Coinage requirements are then reviewed with regard to economic, public acceptance, and service requirements. Finally the properties of Aureate nickel coinage are presented in the light of the many and varied coinage requirements, and it is concluded that the new Canadian dollar coin exceeds the requirements admirably.

Jan 1, 1990

By Tom Treleaven

The success of any blast is dependent on the accuracy of the blast design and the field controls used on the shot. This point cannot be over emphasized because when the geometry is not measured and/or field controls are not properly implemented, it can often have devastating effects on the final blast results. Thus drilling accuracy, tiont row burden control, explosive confinement, energy distribution, explosive selection, timing and structural geology become critical parameters in the design of successful blasts. Understanding the actual dynamics of the blast and why certain results were achieved is the fast step in optimizing a blast design. As stated by R. Frank Chiappetta, “Of all the blast monitoring systems available today, high speed videography still remains as the best stand alone instrumentation system for blast diagnostics.” Over the past years I have analyzed hundreds of blasts using either high-speed lowcams (500 frames per second) cameras or standard digital (30 frames per second). These analyses confirm, without a doubt, that shot geometry, in combination with structural geology, is the most important factor in overall blast results. Drilling accuracy is the single most important component in efficient blasting. Having equal mass associated with an equivalent energy is the basis in which blasts are designed. When drilling inaccuracy or borehole deviation occurs, not only is the energy unevenly distributed, but the basis of all design calculations becomes invalid. Over the past several years, quarry and mining operations have employed the use of boretracking measuring devices to measure borehole deviation and hole toe locations. In cases of operations using top hammer drills, it was discovered that the amount of deviation was significant and far greater than they believed they had. Set up error, improper drilling techniques and bit wear were some of the contributing factors. Through video anaysis of boretracked blasts, blast results were directly linked to drilling ..accuracy. The comparisons here took into account blast design, energy factors and hole sequencing.

Jan 1, 2000

Workers at the Consolidated Aluminum Corp. primary aluminum smelter at Lake Charles, LA walked out at midnight March 31 when their contract expired. Management personnel operated the smelter and prebaked carbon anode facilities until an agreement for a new 3-year contract was reached April 18. The Aluminum Company of America (Alcoa) began operations at its can recycling facility at Taylor, MS. The facility can process 3 million pounds per month of aluminum and steel cans. Alcoa announced plans to increase the capacity of its aluminum paste and flake production plant at Logan's Ferry, PA by 50 percent. Completion was scheduled for mid-1980.

Jan 1, 1979

By D. Harrington

This paper is a revision of Information Circular 7380, by D. Harrington and J. H. East, Jr., published in 1946, entitled ?Safe Storage, Handling, and Use of Commercial Explosives in Metal Mines, Nonmetallic Mines, and Quarries.? Issued soon after the close of World War II, this earlier circular described the unprecedented increase in the production and use of commercial explosives during the war as a result of expanded industry and the tremendous demand f or metals and minerals. In the years following World War II, the production and use of commercial explosives in the United States have continued to rise. Hence, the Bureau of Mines presents these revised figures through 1952. In rewriting this Wormation circular, most of the text prepared by Harrington and East has been retained, with newer statistical information compiled by Seth T. Reese, Accident Analysis Branch, and V. E. Wrenn, of the same branch.

Jan 1, 1954

By James G. Lyons

All machines vibrate and make noise. An increase signals impending trouble. Vibration and noise analysis allows the condition of the machine to be determined without costly interruption in service for disassembly and physical inspection.

Jan 1, 1977

U.S. Bureau of Mines contract H0122053, "Improved Sensors and Fire Control Systems for Mining Equipment", was an investigative effort involving: ? Study of the fire problem on large mobile mining equipment ? Identification of equipment most prone to fire, to serve as a design case example ? Design of an improved fire protection system ? Demonstration of the developed system This effort was performed during the period June 1972 through May 1973, and was conducted in two phases. Phase I, June through November 1972, was devoted to identifying the fire problem and developing and evaluating design criteria. Phase II involved translating the design into hardware and demonstrating its effectiveness during actual fire tests, first on a wooden mockup of a truck, then on an operating truck at a working mine site.

Jan 1, 1973

By Kenneth L. Cook

From March 1944 to July 1945 the Division of Geophysical Exploration of the Federal Bureau of Mines made magnetometer surveys of some of the principal iron ore deposits of the Iron Springs district, Iron County, Utah. The district comprises a belt about 23 miles long and 3 miles wide. Most of the large ore bodies are found as pods of replacement ore within a favorable limestone bed lying at the margins of three separate igneous intrusions in the district The magnetic surveys were confined chiefly to this geologically favorable zone at the margins. The iron ore is a mixture of magnetite and hematite. The magnetite content of the ore ranges from 14 to 58 percent. Magnetic anomalies of 1,250 gammas or more were usually found over the near-surface ore bodies. About 62,000 magnetometer stations were taken over a total traverse distance of about 300 miles. Outcropping ore bodies were surveyed to determine, insofar as was possible from the magnetic data, their probable length, width, depth, extent, strike, dip, and tonnage. Geologically favorable areas where no ore is exposed were explored in an endeavor to find new ore bodies. Favorable locations were determined for exploratory diamond drilling, both in areas of exposed ore bodies and in areas of newly discovered magnetic anomalies. Forty-five separate magnetic anomalies that indicate the possible existence of ore bodies were observed. Of these, 13 anomalies are caused by outcropping ore bodies of proved commercial size. Five are caused by non-outcropping ore bodies of proved commercial size which were discovered, in whole or in part, as a result of the geophysical surveys. Of the remaining anomalies, which lie in virtually un-tested areas where few or no ore bodies are exposed, six probably are caused by large, unexposed replacement ore bodies, nine are possibly caused by large, unexposed replacement ore bodies, and six are probably caused by unexposed magnetite veins of some small commercial importance,

Jan 1, 1949

By J. H. Jacobs

This report records a chapter in the history of the development of an electrolytic manganese industry in the United States. Nearly all the manganese requirements of the United States have been imported. Although there are large quantities of manganese ore in the United States, most of it is low-grade and cannot be used for the production of ferromanganese. Since the electrolytic production of manganese carried out by a process developed in the laboratories of the Bureau of Mines offers a method whereby the extensive low-grade deposits may be utilized and since commercial development had proceeded slowly, the Bureau constructed a new and larger pilot plant at Boulder City, Nev., where abundant electric power was available. An authorization in November 1940 covered a plant of only several hundred pounds daily capacity. Additions to some sections author¬ized by subsequent appropriations have enabled the plant to produce over 2,000 pounds a day for extended periods.

Jan 1, 1946

The criterion for assessing the accuracy of coal reserve estimates proposed by Philip and Watson (1982) is criticized.Following Royle (1977), it is suggested that the global estimation variance found by geostatistical methods is more appropriate.This method is applied to coal data from the Bowen Basin. This shows that two factors (the inherent variability of the variable under study and the total number of drill holes) have more influence over the accuracy of the reserve estimate than the form of the drilling pattern. Comparisons between the relative errors for different sized regions demonstrate that the spacing between drill holes is of secondary importance. The dominant factor is the total number of holes.Comparisons between the relative errors show that some variables such as sulphur need a much denser sampling than the others to obtain the same level of precision.

Jan 1, 1983

The mineral Industry, following the economy as a whole, experienced little growth in 1992. However, with modernized plants, efficient workforces, and lower operating costs, the industry is well positioned to take advantage of possible improvement in the national economy during 1993. In addition to the significant 1992 events highlighted below, important events, trends, and issues within individual mineral industries are addressed in the commodity sections that follow. The value of processed materials of mineral origin is estimated to have been about $310 billion in 1992. The value of U.S. raw nonfuel minerals production in 1992 is estimated at approximately $32 billion, a 3% increase over 1991. The value of domestic minerals production has increased in all but 4 of the last 32 years.

Jan 1, 1993

By Leroy E. Schulze

A review of development and a reevaluation of uses of the hydraulic air compressor are suggested by the constant changes in technology, which frequently make an old art valuable in solving current problems. Contacts with research workers in various branches of engineering indicate that this older method of producing compressed air may not be familiar to some or that its salient features might be useful in solving problems involving uses of compressed air. Briefly, a hydraulic air compressor may be described as an inverted siphon, consisting of an intake head where water and air are mingled, followed by a gravity-fall tube in which air is intimately mixed with the water and is compressed as the water pressure increases during the fall down the tube, then a separating, or stilling, chamber in which air bubbles rise to the surface of the water and collect in the upper portion of the chamber at a pressure equal to the weterhead maintained by the height of water in the discharge leg of the circuit. The water, which now contains only the fraction of air that has gone into solution, passes out of the separating chamber and rises up the discharge leg to the surface, which is, of course, at some suitable distance below the level of the intake. Present-day applications include (1) utilizing low hydraulic heads, which otherwise have little commercial values; (2) utilizing low hydraulic heads in reclamation work to supply compressed air, or in some instances to produce a small suction, for air-lift pumping (or for operation of air motors), with minimum attendance and without need for electric power; (3) utilizing medium heads, as at dam and lock installations, to produce compressed air for pneumatic operation of airlifts, gates, valves, and rubber gate seals; (4) utilizing underground waters, as in mines, to produce compressed air for general mine use; (5) using this method of isothermal compression of air in combination with standard compressors wherever hydraulic head is available, thereby securing the advantages of low-temperature intake to the mechanical compressors and reduction of moisture content below that of atmospheric air; (6) development of large air supply at pressures up to 150 p.s.i.g., which, after performing work in reciprocating or centrifugal expansion cylinders, is available at temperatures approximating -50° F. Possibilities in freezing and reheating should be mentioned which may prove economical for obtaining uniformly dry air for process work, wind-tunnel tests, or large air-conditioning installations, such as ventilation of underwater traffic tunnels, and may be economic for supply of supercharged air to gas-turbine plants.

Jan 1, 1954

By A. D. McMahon

This survey is one of a series of Bureau of Mines publications designed to serve the needs of Government and industry for comprehensive information on mineral commodities and activities. Copper, a versatile metal, has been vital to all civilizations from prehistoric times to the present. Its essential value in antiquity and until the nineteenth century arose from its malleability and ease of working, its corrosion resistance and durability', its attractive colors in alloyed and unalloyed forms, and, of course, its availability. The principal uses were for tools, utensils, vessels, weapons, pipe, statuary and other objects of art, and for building and architectural pur£~ses where formability, permanence, and beaut)" were necessary qualities. Utilization of copper based on these physical and mechanical properties has grown tremendously for commercial, structural, mechanical, architectural, and art items; and its capacity for forming numerous alloys has led to a myriad of applications from miniature copper and brass eyelets to huge bronze battleship propellers. The early nineteenth century marks the epoch of the greatest use of copper, transmitting electrical energy. This particular property of copper is fundamental to the spectacular growth of the electrical industry and all associated industries relying on electricity for power, light, and heat. More than half of all copper produced is used for transmission of electricity. The copper industry has been able to expand along with the mounting demand because of the ever increasing discovery of resources in the world and advances in mining, metallurgical, and fabricating technologies. World production and consumption rose progressively from about 18,000 tons in 1800 to more than 4.5 million tons in 1960. The estimated world reserve of primary- copper has more than doubled since 1935, being 212 million tons in 1960. Ninety percent of this reserve is credited to eight countries-the United States, Canada, Chile, Peru, the Soviet Union, Poland, Northern Rhodesia, and the Republic of the Congo. The United States share is 32.5 million tons of copper in ore, averaging approximately 0.9 percent. Another reserve being accumulated in the industrial countries of the world is copper products now in use that will eventually be discarded as scrap and become available for recovering secondary copper. In the United States this resource of more than 30 million tons, provides about one-fourth of the annual supply.

Jan 1, 1965