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By Charles L. Kimbell

This study is intended to serve three roles. First, it is the second annual edition of this study in a separate volume that represents a global overview and summary to supplement and complement the five regional volumes that now constitute the U.S. Bureau of Mines international, geographically arranged studies. In this regard, it also extends previous works under this title that appeared in the inter-national volume of the Minerals Year-book from the inception of that volume (the 1963 edition) until it was subdivided into six separate volumes in 1989. Following the traditional format of past chapters under this title, the basic statistical presentations herein deal chiefly with 1990, and in a few instances with 1988 or 1989; these latter two only because more recent, comprehensive global statistics simply are not yet available owing to delays in data collection and processing in some countries and continued governmental suppression of data in others. The second role of this study is to provide an update to the coverage of events impacting on the world's mineral industry that have occurred between the end of 1990 and the preparation of this study. Inclusion of this update is almost essential because of the potential effect of some of these events on global mineral industry activities.

Jan 1, 1993

By Charles L. Kimbell

The concept of data availability must be addressed, because there are perceptible changes from year to year, and the availability of accurately reported, precisely defined statistics and nonstatistical information provides the only sound basis for analytical studies required for government policy planning or industry market analysis. As the countries of Eastern Europe and the former U.S.S.R. undergo the transition from centrally planned economies to market economies, there has been a perceptible increase in information availability for rather obvious reasons. Any industrial operation seeking economic assistance from Government and/or private sources outside the country in which the facility is sited must provide some appraisal of its operations at the time it seeks assistance, as well as some information on previous performance to serve as tools in evaluating its potential under the proposed development scheme for which it seeks financial assistance. Additionally, there was growing governmental recognition that concealment of much of the national mineral production, trade, and consumption data for purposes of national military and/or economic security probably never was very successful, never was really necessary for most commodities, and certainly proved unnecessary with the end of the so-called cold war. Indeed, the long-term unwillingness to publish uniform statistical series of reliable,

Jan 1, 1993

By R. Karl Zipf

MULSIM/NL (multiple seams, nonlinear) is a new U.S. Bureau of Mines boundary-element-method (BEM) program for calculating stresses and displacements (is., convergence) in coal mines or thin, tabular rnetalliferous veins. This manual gives detailed operating instructions for MULSIM/NL and illustrates its use with several practical examples. While this manual concentrates on the practical aspects of actually running and using MULSIM/NL, another companion report titled "MULSIM/NL- Theoretical and Programmer's Manual" provides mathematical and programming details to those engineers and programmers who need to fully understand the FORTRAN program or desire to alter and enhance it. MULSIMINL analyzes one to four parallel seams that have any orientation with respect to the Earth's surface. Three main features distinguish MULSIM/NL from its predecessors: (1) nonlinear material models, (2) multiple mining steps, and (3) comprehensive energy release and strain energy computations. MULSIM/NL has six material models for the in-seam material including (1) linear elastic for coal, (2) strain softening, (3) elastic plastic, (4) bilinear hardening, (5) strain hardening, and (6) linear elastic for gob. The multiple mining step capability enables the user to simulate a changing mine geometry. Finally, MULSIM/NL performs comprehensive energy release rate calculations.

Jan 1, 1992

By Alan G. Mayton

A prototype end-cab shuttle car (SC) design has been developed to improve protection and address ergonomic concerns of the SC operator in low coal mines. The new design features an end cab transversely mounted to the SC and equipped with a closed-circuit video system. The end cab was retrofitted to a low-coal SC and evaluated in surface trials at the U.S. Bureau of Mines. During surface trials, test operators evaluated the end-cab SC relative to visibility; cab features-space, seating, controls, and operator position; tramming-inby, outby, and turning corners; and dumping. Trials were conducted using 12 test subjects; 6 were experienced SC operators. Results of the trials were promising. Of the experienced operators, the only operator with low-coal experience gave the new design the highest rating. Four experienced operators rated the end-cab design "better" to "much better" than a standard center-driven, side-cab SC for visibility when tramming, protection from roof and rib hazards, and no change in seat position with direction of travel. This report discusses research to modify a used 21SC JOY SC, retrofit the SC with the Bureau-developed end-cab, and evaluate the retrofitted end-cab SC in surface trials.

Jan 1, 1993

By Audrey F. Glowacki, August J. Kwitowski, Richard L. Unger, Edward F. Fries

Well-prepared personnel and an effective emergency response plan are essential components of any emergency command center. Unfortunately, evaluating emergency preparedness is often difficult until a disaster actually occurs. For example, unexpected events may develop during an emergency that were not considered during the planning phase. Also, the command center may need to cooperate with organizations that it has not worked with previously. Preparation can be especially difficult for smaller or remotely located command centers, or those with limited resources to conduct mock drills. This paper explores the potential of using the Internet to teach and evaluate command center skills. The National Institute for Occupational Safety and Health (NIOSH) is developing an Internet-based, computer simulation training package for the mining industry. Trainees will play the role of command center leaders at a mine, while the actions of other individuals and organizations are simulated. Trainees will be able to test their emergency response plans and learn valuable lessons from past mine emergencies. Nationally recognized experts will be able to create new training scenarios and make them available to mines throughout the U.S. This product should better prepare command center personnel for large-scale disasters such as fires and explosions. Keywords: emergency preparedness, simulation, training, internet

Enable prospective in situ leach mine operators to evaluate the economic potential of an ore body by using a user-friendly, computerized in situ copper oxide leach mining cost model. Background As part of its research on in situ leach mining technology, the Bureau of Mines produced a 5-volume contract report that mining companies can use to design an in situ mining operation for copper oxide deposits. Written for the Bureau by the Science Applications International Corporation (SAIC) in 1988, the generic design manual also contains a computerized cost model for evaluating the economic feasibility of in situ leach mining for any specific copper oxide deposit. The cost model is to be used with Volume II of the contract report. But because of certain complexities associated with running it, the Bureau found that the model could be improved by making it more user friendly. Approach The approach taken by Bureau researchers to make the original model more user friendly was to incorporate a HELP function to define input parameters, and to enable the display of output on the monitor. An accompanying handbook, U.S. Bureau of Mines Information Circular (IC) 9284, contains further details on running, the 1990 model.

Jan 1, 1991

By John H. Scott

At the request of the Mine Safety and Health Administration, U.S. Department of Labor, the Bureau of Mines evaluated the model BT 300 C-D blasting machine tester, manufactured and distributed by Research Energy of Ohio, Inc. (REO), to determine whether the tester performed as stated by the manufacturer and responded satisfactorily to electrical faults introduced into the blasting machine circuit. Tester readings were recorded for 13 blasting machines and for 12 circuits constructed to simulate the electrical parameters of actual machines. The tester readings were acceptable for all of the blasting machines, although the switch position assigned to one machine produced an off-scale reading. The tester responded satisfactorily to the simulated circuits and detected serious voltage or capacitance faults when they were introduced. However, it did not respond accurately to certain resistance faults. Temperature tests were also made, and the tester performed equally well at temperatures of 20°, 42°, and 81° F. This tester was judged a useful accessory for field checking blasting machines for defective batteries and capacitors, despite its limitations. It is recommended that the tester manufacturer specify the lowest acceptable reading at which a blasting machine may be used and below which the blasting machine should be returned to the laboratory or manufacturer for maintenance.

Jan 1, 1981

By G. Nuñez, M. A. Pathak, A. A. Afshari, C. F. Stanley

"To help evaluate the vibration patterns of an excised lung, a method is developed to determine which parts of the surface of an excised lung are responding to acoustic excitation via the trachea. Holographic interferometry, a very' sensitive technique ·that can measure movements of a few microns, is used to detect the lung surface movements.The intact lung and heart are excised from Long· Evans male rats weighing 250 gm. A tube is inserted into the trachea and connected via a funnel to a 3 inch cone speaker. The assembly is positioned in the holographic unit and excited at frequencies up to 10,000 Hz. The holographic unit contains an acousto-optic shutter used with a 0.5 watt Argon laser.The resulting reconstructed holograms contain interference fringes that are indicated of lung surface vibration.INTRODUCTIONA 1986 report by the U.S. National Committee on Biomechanics [1] describes diseases of the lung as a major national health problem. One of the recommendations of the report is for continued study of the mechanical properties of lung tissue. As an example, the report cites at least three areas that would benefit from a better understanding of the vibratory patterns or the lung."

Jan 1, 1989

By E. P. Youngman

A new mining law for the Recublic of Polend was promulgated by presiden- tial decree dated November 29, 1930, published in the Journal of Lews (Dzienni stex) No. E, text 654, December E, 1530, and wes to become effective January 1, 1932, in all Polend except Silesie. Its adoption in Silesia wes dependent pon the action of the Silesian Diet. As the new law is considered an im- provement over the old Austrian Mining Lew, which is operative in the Silesian districts of Bielsk and Cieszyn, and the Prussian Kining Law, which is opera- tive in Upper Silesia, no delay in its adoption for Silesin was looked for. This new law codifies the various juridical regulations pertaining to ines existing in different parts of the Polish Republic but does not include legislation with respect to the extraction of minerel oil, especially crude oil. Petroleum legislation was postponed to a later date in order to facili- tate codification in other fields. Koreover, as the oil industry exists in Galicia elone, deley will not be detrimental.

May 1, 1932

By Victor J. Lynch

The Andover-Sulphur Hill mines are 12 miles northeast of Andover and 5 miles southeast of Newton, in Sussex County, N.J. The property is situated on the Lehigh Valley and Hudson River Railroad and half a mile east of U.S. Highway 206. It is connected with the main highway by a hard-surfaced county road. (See fig. 1.) Howard J. Hewitt of Lafayette, N.J., has under lease the Sulphur Hill tract, consisting of 28 acres, and has an option on the Tar Hill tract of 106 acres. The Tar Hill property adjoins the Sulphur Hill on the northeast. (See fig. 2.) The Andover-Sulphur Hill property is owned by the Lenape Corp. of Andover, N.J., while the Tar Hill tract is owned by the Crane Iron Co. of Phillipsburg, N.J. These mines produced iron ore during a period of about 100 years but have not been operated since 1880. Zinc and lead sulfides occur mixed with iron ores in the lower workings of the old mines. A diamond-drilling program was recommended to determine the extent of the sulfide mineralization in depth and also to explore further the iron-ore deposits on the property. The project was started October 6, 1942, and finished November 25, 1942.

Dec 1, 1947

Although early Spanish settlers used coal several centuries ago, significant commercial coal mining in New Mexico began in 1861, when the U.S. Army opened a mine to supply Fort Craig. Since then, coal from the state has been used to fuel railroads, lead and copper smelters, and other local industry. In recent years, lower-cost strip mining methods and an increased demand for coal by electric utilities in the Southwest have caused an increase in New Mexico coal production. The coal-bearing regions of New Mexico underlie about 25,000 square miles or20.6 percent of the total area of the state. However, the majority of coal-bearing regions lie under Indian lands that are regulated by the Office of Surface Mining (see Navajo and Hopi data on pages 72-75). Today, most of the coal produced in New Mexico comes from the San Juan Basin in the northwest part of the state and the Raton Area in the north central part. New Mexico's reserves are estimated to be 4.6 billion tons, about one percent of the national reserve. New Mexico's permanent regulatory program was conditionally approved December 3 1, 1980. Its Abandoned Mine Lands Program was approved July 17,198 1.

Jan 1, 1992

Coal-bearing beds underlie 23,000 square miles, about one third of Missouri's total area. Twelve out of more than twenty named coal seams have been or are being commercially mined. The remainder are too thin for commercial production. The coal is high volatile bituminous, with reserves estimated to be six billion tons, 1.24percent of U.S. coal reserves. Coal-bearing strata are generally thin seams which can be up to five feet thick. Typically, mined seams are about 28 inches thick. Coal deposits were first mined in Missouri in the 1840s, with the coal used primarily for domestic heating and blacksmithing. Production increased with the introduction of steamboats on the Mississippi. Coal production in 19 17 was six million tons. Production has steadily declined from a high of nearly seven million tons in 1984 to 2.3 million tons in 1991. Declining production is the result of several factors, including competition from other energy sources and the high sulfur content of Missouri coal. Today, coal-fired electric generating plants are the biggest consumers of Missouri coal. The Missouri regulatory program was conditionally approved November 21,1980, and fully approved January 17,1983. Its Abandoned Mine Land program was approved January 29, 1982.

Jan 1, 1992

By Sean Gallagher, Thomas G. Bobick, Diane M. Doyle-Coombs, Richard L. Unger

The U.S. Bureau of Mines has developed an in-house facility to evaluate selected effects of whole-body vibration (WBV) levels experienced by underground mobile equipment operators, Vertical vibration data were collected from a coal haulage vehicle via a uniaxial accelerometer attached to the machine frame under the operator&apos;s seat. Data were analyzed and processed so a computer-controlled platform could approximate the vibration signals. Eight men (35.5 yr 2 6.5 SD) participated in a pilot study to evaluate the effects of shock and kBV on heart rate (HR), blood pressure (BP), and subjective discomfort. Subjects were exposed to vibration for 30-min periods while seated in a typical seat (backrest angle at 90° or 130°) &apos;that was plain steel or modified with 2 in foam padding. Subjects repeated the same protocol on a separate day, without the vibration. Results indicated the vibration significantly increased the HR (Q< 0.01), systolic BP, mean BP, the number of times subjects reported discomfort, and overall subjective discomfort rating (pc 0.85). When seated in the steel seat, the overall discomfort rating (E< 0,081) ad the number of times discomfort was reported (p< 0.05) increased significantly. Seatback angle had no significant effect on any of the dependent measures.

By G. W. Birge

The Bureau of Mines investigated the effect of temperature on the mechanical strength of cokes of the type normally used in blast furnace operations. Eight samples of industrially produced cokes were subjected to ASTM tumbler tests at temperatures as high as 1,100° C (2,012° F); these temperatures had no significant effect on tumbler results for cokes with stability indexes of 40.6 to 59.9. Two foundry cokes which were tested at only one elevated temperature (900° C) decreased slightly in tumbler stability. Iron are pellets made from a variety of ores and by various industrial methods were not significantly affected by temperature when tested in an oxidizing atmosphere at 1,000° C (1,832° F) by the tentative standard ASTM method.

Jan 1, 1966

By Roger L. King

The Bureau of Mines has developed probes to be used in emergency mine rescue operations by being lowered through a borehole drilled into an underground mine. Various probes can provide two-way voice communication with trapped miners, continuous mine atmosphere monitoring, temperature indication, and television searching capability. At present, an infrared imaging probe is being developed for "seeing" through coal smoke.

Jan 1, 1976

By G. S. Rice, H. P. Greenwald, H. C. Howarth

"Stoppings in coal mines serve, important and. vital functions, such as coursing the ventilating current, sealing off abandoned or dangerous workings, sealing fire areas, and separating mines at boundaries. Stoppings may hold back water, but normally that is not their function; their design is, or should be very different from that of a hydraulic dap which is designed to a definite load, often a very heavy one, from one direction over an indefinitely long period. Hence, a dam usually requires an arched structure to resist hydraulic pressure, and it must be massive to meet vertical stresses due to heavy ground pressure.Stoppings are designed primarily to resist a pressure applied laterally through air or gases. Their strength cannot be stated without specifying the direction of applied load. A stopping may be placed in stress by proof pressure subsequent to erection, through extraction of pillars in the vicinity which may act direct, or by squeezing the ribs or heaving the floor. These forces act more or less parallel to the faces of the stopping and may be very great but measures must be taken suitable to each case, and it is impossible to allow for these in general specifications other than to call for normally good construction. A stopping is principally designed to resist the action of forces at right angles to its face, such as the shocks of blasting, the pressure of gas from instantaneous violent out bursts such as have occurred in certain British Columbia coal mines, sudden compression of the air by great falls of roof in closed spaces, and at time pressures that accompany an explosion of either fire damp or coal dust or both. This paper deals with the tests of pressures of explosions only."

Sep 1, 1930

By W. C. Holliman

This report describes apparatus and procedure used for determining the vapor pressure of aviation gasoline in surveys of commercial aviation-gasoline characteristics made by the Bureau of Mines in cooperation with the Coordinating Fuel and Equipment Committee of the Coordinating Research Council, Inc. (CFR-CRC). The method is a modification of the Reid method, in which a mercury manor is substituted for the Bourdon-type gage of the Reid method. The method was used in earlier surveys made by the National Bureau of Standards in cooperation with the CFR-CRC, and was used in the Bureau of Mines surveys at the request of the cooperating organizations. It is designed for special research problems? particularly in vapor-lock studies, which require a precision greater than obtainable by the Reid vapor pressure method. A repeatability of + 0.01 p.s.i. average deviation from the mean may be obtained by method.

Jan 1, 1950

By Dean H. Ambrose

Computer programs are presented that provide mine electrical systems based on computer modeling for design and safety analysis suitable for large or small computer systems and handheld calculators. Bureau of Mines research has resulted in load-flow, fault, grounding, reliability, short-circuit, transient, and cable ampacity computer models that enable mine power system engineers to analyze their system or to design a system. This report describes the capabilities of the program.

Jan 1, 1984

By C. L. Brown

Among the more recent developments for breaking coal in mines is the Airdox system, in which high-pressure compressed air is conducted to the points of application by means of heavy-duty steel and copper tubing. Stray electric currents can be detected on y of the compressed-air lines, and evidence of such currents is rev led, by arcs and sparks when contact is made between the tubing and mine track or other equipment forming a current path with the track. Explosive gas is liberated in many coal mines; therefore, from the standpoint of safety, it is desirable to eliminate all possible sources of gas ignition, including stray electric currents. The purpose of this report is to reveal the source, magnitude, and possible methods of controlling stray currents in compressed-air lines that are used in connection with Airdox systems. Stray electric currents have been studied in most coal-mining localities in the United. States where Airdox equipment is used. The information given in this report is based on the find of these studies.

Jan 1, 1949

By A. B. Hooker, L. C. IlsLey

"Field inspections and data relative to the use of rubber-sheathed trailing cables in mines show that much cable is ruined or its probable life shortened by being overheated in service.The length of cable required to make connection from a source of supply to a machine at the face workings may be 100 to 500 feet. As a rule, the cable is carried on a reel and unreeled as required; and thus in most cases soma of the cable is not removed from the reel. The overheating generally occurs in that part of the cable which is left on the reel.Factors that determine the heating of trailing cables are:1. The size of the conductors in the cable.2. The maximum energy to be supplied through the cable, based upon the horsepower of the motor and the degree to which the motor is loaded.3. The voltage of the supply and the variation of the voltage at the receiving end.4. The time length of current flow and whether continuous or intermittent.5. The kind of current (direct or alternating).6. The amount of ca· le left or the reel.7. The type of cable used.8. The kind of reel used.In connecti0n with an investigation of the general performance of rubber-sheathed trailing callas, the Bureau of Mines has made a limited study of some of these factors, including the following points:"

Jul 1, 1931