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By L. Alan Weakly

The Powder River Basin of northeastern Wyoming and southcentral Montana contains the largest strip minable reserve of compliance coal (0.27 kg or 0.6 or less Ibs of sulfur per million Btu) in the United States. In mining parlance, it is the mother lode. Wyoming's portion of the Basin is called the Southern Powder River Basin (SPRB). It has been the nation's top coal producer for the past nine years. And based on 1997 production statistics and estimated strippable compliance coal reserves, Wyoming should remain the nation's top producer for the next 51 plus years. In August 1994, ME featured 10 articles that covered all aspects of coal production in the SPRB. In this issue, five authors update the 1994 articles and provide a pre- diction of what the Basin will look like at the turn of the century. In addition to this article, the titles and authors of the other five articles include: ? "Geology of Wyoming's Powder River Basin coal field," by Gary B. Glass and Robert M. Lyman. ? "Coal quality challenges in the Powder River Basin," by Sharon Roness, Richard A. Turpin and Robert A. Young. ? "Markets for Southern Powder River Basin coal," by , Patti J. Best and Patrick W. Wright. ? "Evolution of mining equipment in the Powder River Basin," by Kenneth R. Miller and James L. Long. ? "Hauling coal into the 21st century," by Dave Willis and Will Cunningham.

Jan 1, 1998

By Howard N. Eavenson

DURING the past year, as in the preceding ones, prices continued to fall, production to decrease, and more mines were closed. Much attention is being given by the industry to suggested plans for betterment of its position, and if the scheme recently brought out for consolidation of sales agencies into district agencies is loyally carried out, it cannot but help to improve conditions. The progress in the anthracite industry is shown in the report of its chairman, E. H. Suender; changes in coal preparation are outlined in the report of J. B. Morrow, chairman of Committee on Coal Preparation, while increased mechanization of the western mines is described by Eugene McAuliffe, chairman of the Committee on Machine and Strip Mining. In spite of the depression, interest in the Coal Division has been increasing, its meetings have been well attended, and its committees are active and have been doing excellent work.

Jan 1, 1932

By Michael G. Zabetakis

The autoignition temperatures (A.I.T.'s) of natural and synthetic lubricants in air were generally found to decrease with increasing pressure. Of the two types of fluids, synthetic and natural, studied in some detail, the phosphate esters had higher A.I.T.'s at any pressure between 1 and 200 atmospheres than the mineral oils. Most of the A.I.T. data obtained in this study obeyed the relationship predicted by Semenov's theory of ignition.

Jan 1, 1962

By Cornelius F. Kelley

DURING the war, events moved with unprecedented rapidity. Situations, industrial, economic and financial, arose over night that stressed to the uttermost the ingenuity and ability of those who dealt with them. It was essentially a time demanding action rapid and concentrated, and not one for discussion, either academic or polemic. As a result, matters of importance were necessarily transacted without the desirable opportunity being afforded of enabling a general understanding to be gained as to the relative merit or demerit involved, and in some instances, legislation essential to enable the consummation of an important matter was passed without attracting the public attention then deeply engrossed in the larger aspects of the situation. The result was that so long as the public mind was occupied, little or no concern was given to questions that ordinarily would have invited immediate attention; and in some instances, only when as an aftermath of war a particular subject has become a matter of discussion, criticism not altogether fair is made without first obtaining accurate knowledge as to the conditions that prevailed, the purpose sought to be accomplished, or the results obtained by the action taken.

Jan 1, 1921

By John A. Gann

THE Iron and Steel Division has shared in the general increased activity of the industry. The fall meeting at Chicago was not only well attended but particularly characterized by the virility and scope of the discussions at the various sessions. The program for the February meeting indicates a similar interest in technological developments. The Blast-Furnace Committee continues to have the hearty support of the industry with discussions of such a nature as to be of real help to the operator as well ass the technologist. The work of the Open-Hearth Committee continues to be outstanding, with ever increasing attendance and ever mounting interest in the meetings. Formation of a conference on the physical chemistry of steelmaking has given those interested in this phase of work an organization allowing the same

Jan 1, 1936

By K. Brady

Making progress on sustainable development will require greater attention to the management of materials produced from mine exploration through use to reuse, recovery and recycling. Material stewardship is a concept that embodies the range of activities required for optimal and appropriate use of minerals and metals in society. The following paper provides an overview of some recent initiatives that promote the stewardship of minerals and metals in society. The initiatives described are being conducted by organisations ? the International Zinc Association, the Canadian Copper & Brass Development Association and the International Council on Mining & Metals. These associations illustrate stewardship activities at three different levels: - an international association representing companies that produce a range of minerals and metals; - an international commodity association; and - a regional association. For each initiative, information is presented on its development, scope and outlook. This paper draws heavily from work of the associations but the viewpoints are the responsibility of the authors.

Jan 1, 2007

By Brian Parsons

In June of 2013, Odyssey Marine Exploration conducted sea trials of the newly installed SeaBat 7150 full-ocean multibeam sonar system on the M/V Dorado Discovery over the Fierberling Guyot in the northeast Pacific Ocean. Fieberling Guyot is located approximately 990 kilometers west of San Diego, California and it rises abruptly from the deep ocean floor (~4300 meters) to a minimum depth of approximately 438 meters. The SeaBat 7150 operates at two distinct frequencies, 24 kHz (shallow to 3000 meters) and 12 kHz (full-ocean depth greater than 2000 meters). Onboard operational data are managed by a suite of state-of-the-art software. A SQL Server 2012 database provides the highly specific management and visualization tools as ArcGIS 10, Micromine 2013, and Geobank 2013 database. The 7150 is mounted on a gondola one meter lower than on previous system and greatly reduces bubble interference. The 7150 generates 880 beams

Sep 14, 2011

By G. V. Fernandez

Sociedad Minera Cerro Verde S.A.A leaches secondary copper sulfides. In recent years, the mine has introduced innovations that have improved the management of mineral crushing, agglomeration, curing, and leaching. The crushing plant, for example, uses the concepts of degree of balance and percentage of time in an operationally balanced state which, displayed in real time, facilitate more intensive and uniform utilization of the crushers. High agglomerate quality is ensured with the correct dose of moisture, which is adjusted to the changing characteristics of the mineral through the use of electrical conductivity measurements. The amount of acid used for curing the agglomerate is also adjusted by using quality control information. Finally, the stockpile irrigation regime is managed using the criteria established by the "Lixiviant Request Rate", which optimizes the addition of leaching solution, creating such benefits as faster recovery, and reduced acid and energy consumption.

Jan 1, 2007

By T. W. Wlodek

In this paper the relative merits of shot peening, induction surface hardening, spiral-rolling, and the combination of these surface treatments, are evaluated on the basis of their capacity to increase the fatigue strength of drill steel. The S-N relations for plain car-bon steel (SAE 1080) and Ni-Cr-Mo drill steels in the as-rolled condition were determined previously, using the new Canadian method of testing drill steel introduced at the annual meeting of the Institute in Toronto in 1950 (19). S-N curves have now been determined by this method for these two drill steels in the following conditions: shot-peened and drawn, induction hardened, induction hardened and shot-peened, and spiral-rolled. ( S.R.) . The ratios of the fatigue strengths of these steels after surface treatment, to their fatigue strengths in the as-rolled condition, are compared and the most beneficial treatments are thereby pointed out. The expected range of stresses and their distribution during actual drilling operations are estimated from data available, and the mechanism of failure of drill steel in the as-rolled and surface-treated conditions is analyzed. The magnitude of the surface compression stresses and their effect on ?fatigue strength are discussed.

Jan 1, 1958

By José Luiz Rodrigues Bravo

The production of electrolytic copper with assured quality corresponding to international standards, in a conventional electrorefkery of a custom smelter, is a hard and cautious task, if no advanced technologies for selective control of electrolyte impurities are available. The improper control of the amount of As , Sb and Bi in the anode that enter the tankhouse , attributable either to a bad schedule of concentrate input or to the unavailability of clean concentrates in the international market , as well as the lack of means to maintain the suitable level of these elements in the electrolyte together with other operational circumstances, can result in off-grade copper, as well as affect the starting sheet chemically and physically. This paper presents in a practical way the relationship between the operational conditions and the cathode and starting sheet quality produced at CMSA, covering the period of the last five years of operation, discusses the technologies available in the market for antimony and bismuth removal and compare the results of testwork, achieved in the laboratories of CMSA, using two resins not associated with patented technologies.

Jan 1, 1997

By Sang-Su Lee

This paper shows the application of the porous plug system in the Mitsubishi continuous copper smelting and converting process. This system has already been adopted and utilized in the steel industry to enhance productivity. Recently, some copper smelters have adopted this system but the results have not been satisfactory. The porous plug system was installed at the anode furnace in December 2001 to reduce the oxidation time and decrease the oil consumption. A good effect was that the nitrogen stirring of the melt through porous plugs improved the melt heat transfer. As the result of the enhancing heat transfer the oil consumption and the build-up inside the furnace were actually decreased. But until now the oxidation time has not been sufficiently reduced. In the future, further research and tests are needed in order to increase the productivity and save costs.

Jan 1, 2003

By Irving Wender

This report describes Bureau of Mines experiments and reviews the work of others on the exposure of coal and coal-derived products to gamma rays and some other types of radiation. Results are presented on tests of three bituminous coals and a lignite that had been pulverized to minus 200-mesh particles and exposed to 1,000 megaroentgens of gamma irradiation from spent-fuel elements of a nuclear reactor. Of about 20 chemical and physical tests in Bureau work, only mass spectrometry of gases evolved during vacuum pyrolysis of the coals to 450° C gave results indicating differences in the irradiated and unirradiated samples. Mass-spectral distribution curves for CO and CO2 evolution showed fewer irregularities (reversals of curvature) for irradiated coals; thus, mass spectrometry appears to be the most sensitive method for determining radio-induced changes in coal. It is concluded that coal is not significantly altered by gamma irradiation owing to the resistivity of its highly condensed ring structure. High-level gamma irradiation, therefore, is unlikely to prove advantageous in coal processing and utilization. Specially treated coals, because of resistivity of coal to radiation damage, may be useful as an absorbent in processing radioactive wastes.

Jan 1, 1968

The Telfer Underground sublevel cave (SLC) Operation is located approximately 850 m below surface. The cave was designed to propagate through an old decline which was initially used to monitor the cave. There was a requirement to install air blast plugs at two locations in the old decline in order to isolate any potential air-blasts from the active workings in the event of the rock mass collapsing into the cavity. There was a further requirement for an air-blast plug in another section of the mine where there was a risk of the cave intersecting an old workshop and providing an air-blast pathway through an abandoned incline. The design criteria for the plugs was that they should withstand the design air blast loading, be free draining, cost effective and easily constructed with the mining expertise available on site. A plug consisting of grouted mullock was considered robust and least challenging to construct. For the purpose of estimation of maximum air pressure on plugs, it is supposed as a worst case that the rock above a cave falls as an airtight piston onto the top of a muck pile, forcing air into it and also mine workings intersected by the cave. Airflow through the muck pile is governed by Ergun's equation for turbulent flow. In a time-stepping integration scheme, transient air pressures and velocities are calculated according to equations of thermodynamics, in the cave and at intervals along intersected drives by means of a finite difference spatial discretisation. The ability of plugs to withstand computed pressures is assessed by finite element elastoplastic analysis. This paper outlines the rationale for potential air blast loading, calculation of transient air pressures, plug design and analysis of plug behaviour. The plug construction method is also discussed.

Nov 25, 2010

By J. Hunter

The Highland Uranium Project in Wyoming is an in-situ leach (ISL) facility owned and operated by Power Resources Inc. It is the largest uranium producer in the U.S. and the largest uranium producer by ISL in the western world. With its limited capital investment and low operating costs, the ISL technique has been demonstrated to be an effective and environmentally sensitive method for recovering minerals from these low grade and otherwise uneconomic orebodies.

Jan 1, 1996

By F. W. Lee

The paramount importance of water to life of all forms on the earth is too well known to require elaboration in this brief paper. It has repeatedly been termed the most valuable of all our mineral resources. Its importance is justifiably recognized in the extensive areas covering the earth which receive sufficient rainfall to sustain a relatively luxuriant vegetation; but in those areas where rainfall is insufficient to support anything but a relatively meager plant growth, the location of a water supply and its development become of even more vital interest to those attempting to obtain a living from the soil. Geological investigations concerning the water supply of the United States have been most extensive, important work having been accomplished by Federal, State, and local governments and by private enterprise. A casual examination of the titles of the 739 Water-Supply Papers published by the United States Geological Survey3/ alone testifies 'to the vital nature of our water resources and the extensive work that has been done on them.

Jan 1, 1936

By Hewitt Wilson

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Jan 1, 1927

By H. McIntire, R. Preston, D. Roberts

"Repeated 3D terrestrial digital photogrammetric surveys were conducted on hard rock mine pillars to characterize damage during secondary mining. Damage was quantified by measuring Depth of Failure, DOF, from spalling material and crack intensity, D21. These damage values were then correlated to visually assessed Pillar Damage Ratings and numerically estimated pillar loads. Measured damage, particularly Depth of Failure, correlated well with Pillar Damage Ratings. Numerical predicted pillar stress vs. damage exhibited the expected trend with shorter pillars being stronger. High resolution photographs and 3D models were also used to characterize damage mechanisms, which were found to be structurally constrained. INTRODUCTIONThe Doe Run companies Southeast Missouri Operations consists of six room and pillar lead mines (Brushy Creek, No. 29, Casteel, Buick, Fletcher and, Sweetwater) (The Doe Run Company, 2014). The mines are hosted in the Carbonates and Shales of the Viburnum trend with mining depths varying from 180 to 300 m. Pillars are commonly cut square with widths varying from 7 to 9 m and heights generally between 5 and 18 m, resulting in extraction ratios between 80 and 85% (Roberts et al., 1999). Figure 1 presents an idealized stratigraphic section through the Viburnum trend and Figure 2 shows a plan view of the five areas spanning the three mines included in this study."

Jan 1, 2015

By David J. Hatem, K. Bhattarai

The increasing popularity of alternative methods in delivery of underground infrastructure projects has given rise to innovative and collaborative contracting strategies to allocate and manage the unique risks associated with the work. This paper presents approaches and recent examples of how risk has been dealt with using various alternative delivery methods, including Progressive Design Build (PDB) and Construction Manager/General Contractor (CM/GC). Based on the experience gained from these examples, recommendations for an innovative and collaborative risk baselining approach using contingency sharing are presented that should advance the overall goals of equitable risk sharing and compensation.

Jun 13, 2023

By Robert S. Warfield

Eight samples of high-volatile bituminous coal, each large enough for a study of its coking properties by the Bureau of Mines, were obtained from a location along the Kukpowruk River, Arctic Northwestern Alaska. Bench scale and pilot plant carbonization studies with several patterns of coal blending were conducted. The data from these tests were compared to data from similar tests on a coking blend used by the Kaiser Steel Corporation at Fontana, Calif. The majority of the samples representing the 20-foot seam was found to have significant coking properties, and produced coke approaching metallurgical quality when blended with selected coking coals. Although oxidation effects were evident in the samples representing upper portions of the seam, it appears that the whole seam could be used.

Jan 1, 1966

By Dean. R. S.

The work of the copper metallurgy section during the year was devoted to laboratory studies of sulphur recovery from smelter smoke and combination smelting of copper and manganese. Both of these subjects were new this year. Combination Smelting of Copper and Manganese According to published work, the affinity of manganese for sulphur is greater than that of iron for sulphur, so that if a suitable mixture of com-pounds of iron, copper, and manganese be smelted to form a matte and slag, manganese should concentrate in the matte, together with copper.

Jan 1, 1937