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The principal activities of the Bureau of Mines Explosives Research Center during fiscal year 1969 (July 1: 1968, to June 30, 1969) are reviewed in part 1. Part 2 presents short abstracts of the publications issued during this period in the Bureau series and in the outside press. These publications are referenced in part 1 by underlined numbers in parentheses. Other publications, which are not abstracted, are cited in footnotes throughout the paper. ACKNOWLEDGEMENTS The Bureau acknowledges the support received through cooperative agreement in fiscal year 1969 from the Manufacturing Chemists Association. It also acknowledges the sponsorship by the following Government agencies of research conducted during that period: Department of the Air Force, Department of the Army, Department of Health, Education, and Welfare, Department of the Navy, Federal Aviation Administration, National Aeronautics and Space Administration, Space Nuclear Propulsion Office, and United States Coast Guard.

Jan 1, 1970

By W. Hustrulid

In the mid-to-late 1800’s the U.S. mining industry was on the threshold of nearly a century of golden times. Nearly every state had a prosperous and growing mining sector. The importance of the industry was reflected in the creation of the state school of mines. Today, with the depletion of readily available mineral reserves, much of the U.S. metals mining industry is considered to be in a sunset phase. The same is true with the mining schools that serve the industry. However, the United States is still a major consumer of the world’s minerals and requires a dependable supply of both minerals and minerals professionals. In his 2002 Jackling Lecture “You Can’t Make a Silk Purse Out of a Sow’s Ear” the author presented a list of concerns, propositions and recommendations. In this follow-up paper, the author further explores the subject through the presentation of a detailed case example focusing on the iron mining industry of Minnesota and minerals education at the University of Minnesota.

Jan 1, 2004

By Javier A. Llano

GPS, wireless communications and on-board and off-board computing capabilities provide today’s mining companies with unprecedented process improvement and cost reduction opportunities. All aspects of the operation from engineering, surveying, drilling, loading, hauling and support can benefit from products like CAES and Drill Monitor. These technologies, which have been working at world class mines around the world in some cases for over three years, are helping customers achieve new lows in cost per ton. Manually intensive and time-consuming processes like in field surveying are replaced by timely mine status information wirelessly transmitted from the machines to the office.

Jul 17, 2000

By R. K. Zipf

A method is presented for creating realistic numerical models for practical coal mine ground control. The method includes procedures to collect the necessary mechanical input parameters from a geologic core log, procedures to set up a model and procedures to interpret calculation results. The input parameters come from a detailed geologic core log and extensive point load tests of estimate rock layer strength. A suite of material property input parameters is proposed which allow the user to go from core log to numerical model inputs. Rock bolt anchorage properties are also linked to the material properties of each geologic layer in the model. Following this procedure leads to very realistic calculations of the rock failure process and rock support system behavior. These calculations in turn enable realistic comparison of the effectiveness of alternative rock support systems.

By Richard J. Mainiero, James H. Rowland III, Marcia L. Harris

This paper reviews the potential hazards posed by the toxic fumes produced by detonating explosives in surface mining and construction operations. Blasting operations produce both toxic and nontoxic gaseous products; the toxic being mainly carbon monoxide (CO) and the oxides of nitrogen (NOx). The quantity of toxic gases produced by an explosive is affected by formulation, confinement, age of the explosive, and contamination of the explosive with water or drill cuttings, among others. Techniques to protect workers and the public from the potential hazards of explosive-related toxic fumes are discussed. These include: • Minimizing the quantity of toxic fumes produced. • Determining where the fumes may go so workers and neighbors can be moved out of harm’s way. • Preventing the fumes from moving towards workers and neighbors. • Monitoring the air near workers and neighbors so they can be relocated if fumes appear. • Ventilating structures or confined spaces until CO falls below a hazardous concentration.

By F. T. Cawood

One of the consequences of globalizing mine finance is a necessity to apply uniform accountancy and valuation standards that are clearly understood and consistently applied by the global investment community. However, each country has unique circumstances, which sometimes make it difficult to align domestic practice with international requirements. South Africa is no exception and issues such as its political history, a taxation regime enforcing different rules on different mineral producers and a unique mineral rights ownership distribution, are barriers to internationalization. The economy is in a transitional phase as a result of the many and diverse policy documents following the change in political dispensation in 1994. Many of these documents have recently been implemented through new legislation and, in the case of mining, negotiations are continuing in order to ensure an acceptable outcome. This paper discusses the challenges that the South African minerals industry faces in the field of mineral property valuation. It draws on international experience and includes a discussion on the unique considerations that the South African mineral property market must take into account in establishing a code for this purpose, as such a code could later be aligned with international practice.

Jan 1, 2004

By E. D. Calvert

The room temperature tensile properties of commercially pure titanium and seven titanium alloys prepared by skull casting were determined in the as-cast and heat-treated conditions. Data were compared with property data from tensile tests on wrought alloys of the same compositions in the as-worked and heat-treated conditions. The alloys evaluated were Ti-5Al-2.5Sn, Ti-6Al-4V, Ti-6Al-4V-lSi, Ti-6A1-2Sn-4Zr-2Mo, Ti-6A1-6V-4Zr-4Mo, Ti-6A1-6V-2Sn, and Ti-11.5Mo-6Zr-4.5Sn. Test specimens were prepared from both static and centrifugal castings and from plate fabricated by forging and rolling vacuum-melted ingots. The data indicate that the alpha and alpha-beta alloys have strength properties in the as-cast condition that are reasonably close to the strength properties of their wrought counterparts in the as-worked condition. An exception to this was the Ti-6A1-6V-4Zr-4Mo alloy for which insufficient data were available to form any firm conclusions. Fine-grained cast structures of Beta III (Ti-11.5Mo-6Zr-4.5Sn) were shown to be generally stronger in the as-cast condition than the wrought alloy in the as-worked condition except for the yield strength of one structure that was unusually low. Heat treatment of this alloy produced properties that were unpredictable. Indications are, however, that optimization of heat treatment parameters for each cast structure could produce strength properties equal to that of wrought materials.

Jan 1, 1974

By David Forrester

Subsidence beneath the land surface has traditionally been monitored using the most accurate surveying methods of the day. Over the several hundred years of subsidence investigation, these techniques have improved, and thus the accuracy of subsidence measurements has improved. In circumstances where the subsiding surface is masked by water or rock, novel methods must be developed. This method describes the recent successes of subsidence monitoring using advanced bathymeric techniques in the Sydney Coalfield. In order to obtain subsidence profiles above submarine coal extractions, seafloor bathymetry surveys, run before and after mining, have shown that subsidence profiles can be detected, despite the primitive nature of some of the trials. Very recently, there have been considerable advances in this field, associated with the availablity of high-powered personal computers to control data collection and analyse the results. The recent surveys described in this paper have demonstrated the considerable potential for such methods. This paper describes bathymetric subsidence monitoring developed in the Sydney Coalfield, illustrated with some typical results, and summarizes the findings of the research leading to the development of subsidence design criteria specific to the Sydney Coalfield.

Jan 1, 1996

By G. A. Craig

The Moon, asteroids, and planets of the solar system represent the most distant caches of wealth that humanity has ever considered recovering. Yet, in addition to the potentially recoverable values represented there, harvesting off-Earth resources has a second, almost incalculable sustainable benefit in that they can be retrieved with absolutely no damage to Earth. Previous research mostly assessed the potential of asteroids and the Moon for mining purposes from a theoretical and scientific point of view. These studies investigated drawbacks that could be experienced in this type of operation, but no detailed economic evaluation that is meaningful for mining project management has been conducted and the parameters that are most likely to make an operation feasible are unknown. This paper provides a preliminary economic and sensitivity analysis of a possible off-Earth mining business extracting minerals from an existing asteroid.

Jan 1, 2014

By John L. Edwards, Anthony T. Iannacchione

There has been a persistent need to forecast roof falls so that miner’s exposure to hazardous underground environments can be minimized. Several monitoring techniques have been developed and are used today with varying levels of acceptance in the mining industry. This paper examines the potential for monitoring microseismic emissions activity as a means of forecasting roof falls. The use of this activity to forecast roof falls has drawn only limited attention, resulting in a lack of published field performance data. This deficiency is being partially addressed by analyzing data obtained during longwall mining at Moonee Colliery in 1998. The Moonee data base contains a wealth of information concerning roof fall forecast parameters and the seismic alarm criteria used to develop these forecasts. Four seismic alarm criteria were developed and used by Moonee with varying degrees of success. Roof falls were forecasted 73% of the time with average forecast times of 54 minutes. Ninety percent of the predicted roof falls had a warning time, i.e., the time between warning and roof fall event, of greater than 1 minute. The fraction of forecasted roof falls decayed logarithmically as a function of warning time, until only 20% of events were predicted more than 100 minutes prior to roof falls. False alarms occurred in 50% of the warnings. Many of the false alarms were quickly followed by a cessation in mining which could have temporarily halted the on-going failure process. If mining had continued immediately after the false alarms, a roof fall may have occurred soon after. The microseismic activity collected from Moonee Colliery demonstrates that techniques to forecast roof rock instabilities in underground mines are possible.

By H. P. Willard, R. W. Gates

Basic Inc., has been mining magnesite and brucite for 27 years at Gabbs, Nev. This is a medium sized open-pit mine. The magnesite deposits are in north-western Nye County about 30 miles east of Luning, Nev., on the west slope of the Paradise Range, at an elevation between 5000 and 6000 ft. The magnesite and associated brucite is used to make magnesia refractories employed principally in the steel industry and magnesium oxide for various chemical uses.

Jan 10, 1963

The 103rd Annual General Meeting of The South African Institute of Mining and Metallurgy was held in the Gold Room, Transvaal Automobile Club, 60 5th Street, Lower Houghton, Johannesburg on Wednesday, 16th August, 2000. Welcome The President extended a special welcome to the guests and representatives of our sister institutes and other associations. Also to recipients of awards, senior members of industry, Honorary Life Fellows, Past Presidents, our Members and other guests, among them the following: Reinie Meyer, President, The Geological Society of South Africa Dr Nielen van der Merwe, Chairman, The South African Institute of Rock Engineering Chris Fourie, President, Institute of Mine Surveyors of South Africa

Jan 1, 2000

By Y. Wang, S. Sridhar, B. Coletti, G. N. Shannon, S. Vantilt

The final removal of inclusions in the ladle, tundish, and mold in a continuous casting process involves the kinetic steps of liquid film drainage, interface rupture, and absorption of the inclusion into the overlaying molten slag. During this process, oxide inclusions can undergo chemical reactions with the slag. This paper presents recent results on imaging the slag/steel interface and elucidates the evolution of Al2O3and Al2O3-CaO inclusions during their separation from the steel and on their incorporation into the slag. Experimental results, obtained through a Confocal Scanning Laser Microscope, are compared with thermodynamic predictions.

Jan 1, 2004

By John H. Johnson

This report covers research which is directed toward the measurement and control of underground mine diesel emissions. The report consists of three separate reports presented as Sections 1, 2, and 3. Section 1 "Emissions Measurement Apparatus" (EMA 1) discusses the selection and evaluation of instruments and procedures to be used as part of a diesel tailpipe emissions dilution and measurement apparatus. The instruments selected for gaseous pollutants are the Energetics Science Inc.* E.S.I.) 2000 for CO, the E.S.I. 7000 for NO and N02, and the Fuji ZFP5 for C02. Particulate matter is presently measured with the Celesco 1013 Smoke Opacity Meter. The raw exhaust concentration of one of these constituents is used Lo calculate the dilution ratio. Either a modified high range E.S.I. 2000 CO instrument or a Daco Products Cobra C02 instrument can be used, but neither is totally satisfactory. The study also indicated that it may he possible to increase the sample collection time from 15 seconds to the total 30 seconds over which the engine can be loaded without increasing the probability of damaging the vehicle hydraulic systems. Section 2 "The Effect of Fuels, Catalysts and a Filter Trap on Drift Pollutant Concentrations" discusses research in the Mine Air Quality Laboratory. A Wagner ST5D LHD with a Deutz F8L714 engine was used to compare three exhaust aftertreatment devices and a muffler-only system. The effect of these four systems on CO, C02, NO and N02 and on total, soluble, sulfate, and solid particulate matter was measured in the drift and on the LHD. The filter trap successfully reduced particulate matter for both fuels without significantly increasing the concentrations of any of the other constituents. The PTX catalyst was effective in reducing CO, and soluble particulate, but significantly increased N02 and solid and sulfate particulate matter. The Oxy Cat catalyst tested didn't seem to he working on the gases, and it significantly increased sulfate, soluble arid solid particulate concentrations. Section 3 "Diesel/Coal Particulate Matter Characterization by Laser Raman Spectroscopy" covers basic research on a method for determining the percentage by weight of diesel particulate on a filter containing a diesel-coal mixture. Signal-averaged Raman spectra provide the necessary precision. The method developed is non-destructive and uses as-received filters requiring no sample manipulation. Particulate with diesel contents in the range of 10 to 50% by weight have been analyzed with accuracies better than 6%t of the mean value. A number of samples containing diesel-coal mixtures were characterized by the procedures developed and the results are analyzed in light of various spectral and other system variables including coal rank and form and diesel engine operating conditions.

Jan 1, 1982

By M. K. Larson

The U.S. Bureau of Mines conducted a study to evaluate support interaction between conventional bolts and the rib at two Western coal mines. The principal goal was to develop guidelines for designing rib support under various conditions. At mine A, seven rib bolts were installed with load cells and monitored over a 4-month period. Fifty-seven pull tests were conducted with two types of anchors at various depths. At mine B, 163 pull tests were conducted. Results showed that during the 4 months of monitoring bolt load, tension in the bolts decreased over time in some situations and that anchorage capacity was reduced in a yielded zone. Load-versus-deformation plots from pull tests in the rib showed fundamental differences in anchorage behavior at the two mines, particularly when comparing results of tests in old pillars at mine A and tests in new ribs at mine B. Numerical modeling experiments indicate that coal bonding strength was the most significant factor in determining postyield anchorage capacity. Correlation of anchor yield point with anchor depth were more pronounced at mine A than at mine B; measuring torque may be a reasonable method of monitoring deteriorating anchorage capacity in a rib undergoing fracturing and yield.

Jan 1, 1996

By Greg Smith

This paper documents the use of bench testing equipment developed to enhance the understanding of, and improve upon, common roof bolt support systems. Most roof bolt systems consist of components that are covered within the scope of ASTM (American Society for Testing and Materials) standards. However, ASTM does not specify testing methods or performance standards for complete roof bolt ?systems?. It only designates testing methods and minimum performance standards for roof bolt ?components?. Improved understanding and continuous improvement of these systems is essential given the enormous impact that they have on the safety and profitability of underground mining operations. Bench testing equipment has been developed that effectively measures and records multiple points of deformation in a rock bolt support system while load is being applied. With this testing capability, an improved understanding of component and system stress distribution can be obtained and devices and methods for visual load indication can be developed. This paper is formatted as case studies where testing was performed to demonstrate load versus deformation profiles and to develop system improvement products.

Jan 1, 2012

By G. Gaidajis, K. Angelakoglou

The development of a tool for assessing the environmental sustainability of mining facilities is described in this study. The tool is based on the analysis of basic components of the examined system, i.e., the quantities of the incoming materials and outgoing wastes, their hazardousness and scarcity, the utilization of water and energy resources, and the biodiversity. The developed tool provides both qualitative and quantitative assessment of the environmental performance of a mining facility in a broad time scales (past-present-future) and is easily applicable from non environmental experts. Moreover, relative software is developed to further support the application of the methodology. The implementation of the tool is expected to lead to an improved understanding of the environmental performance of a mining facility and more importantly identify the areas of significant environmental concern. However, based on feedback from industries, a number of shortcomings of the approach have been identified so far and are presented, indicating further actions for the advancement of the proposed tool.

Jan 1, 2011

By Sanford J. Douglas

This publication describes a study by the Federal Bureau of Mines of devices and methods used for testing and splicing 4,160-volt and 440-volt cables and for providing ground-fault protection for 440-volt circuits, as developed and used by the electrical staff of the Tecumseh coal mine, an open-pit operation at Boonville, Ind. The testing and ground-fault devices described should find ready application in other open-pit mines, and, with suitable modifications for voltages involved, in underground mining. The devices and testing methods are based on sound engineering principles and are time-tested and economically feasible, Four devices are used: A high-voltage tester, and a low-voltage high- current tester, both for testing 4,160-volt cables; a tester for 440-volt cables; and, electronic ground-fault protective device for 440-volt cable circuits. All the cable testers and the grounding device were designed and built at the mine from standard parts. They are inexpensive, dependable, and job tested, An attempt has been made here to describe them in enough detail so that interested persons can assemble duplicate units.

Jan 1, 1960

By Piyush K. Dutta

This report describes the design, development, manufacture and incorporation of noise control features on a jumbo drill and the results of successful tests of this drill in surface and underground mines. The noise-reducing features developed under this program are applicable to future designs of jumbo mounted drills that can be cost effectively manufactured and have the potential to reduce noise levels at the operator's position from 115-120 dBA to 95 dBA or less without a reduction of currently attainable drilling rates.

Jan 1, 1985

By D. Laguitton, D. Hodouin, V. K. Gupta, R. Spring

"The CANMET SPOC project aims at inducing progress in process evaluation and optimization by developing user oriented software based on state-of-the-art theory. The present work is the result of a joint effort by CANMET, Noranda Mines and Université Laval to develop two computer packages: one (RTD) to calculate the residence time distribution that best describes the material transport through the mill, the other (FINDBS) to estimate the rate of breakage and distribution function of the population balance model in a ball mill. The RTD package can handle data from various experimental methods (impulse or complex tracer feed, with or without recycling, etc...). The FINDBS package provides options for the functional description oj both model parameters Band S. The full detail of the methods and programs appears in a users guide. The program capabilities and several sample runs are presented.IntroductionSimulation of mineral dressing operations by computer has been largely contained within academic and research circles and has not yet gained a status of routine practice in the ore and coal industries. It is however a matter of time before process simulators are available on every process engineer's desk to assist process optimization tasks, flowsheet design and professional training. The CANMET SPOC project (Simulated Processing of Ore and Coal) was initiated in 1980 to assist the Canadian industry in integrating computer-based methodology for process evaluation and optimization(1). Software development, documentation and transfer is one of the main priorities of the project which will mature in 1985 by releasing a complete package of manuals and programs covering sampling, material balance computation, unit modelling, flowsheet simulation and optimization . This paper is a condensed description of a typical project element in its 1982-1983 state of development. The required methodology for ball-mill modelling and simulation was consolidated an d merged to other project elements during a joint study under contract financed by CANMET and Noranda Mines Ltd . The first part of the study dealt with documenting experimental methods and software for ball-mill computer simulation. Université Laval GRAAIM (Goupe de Recherche en Automatistion Appliquée à l'Industrie Minérale) acted as sub-contractor for this part of the study(16,17). A second part dealt with applying the model calibration techniques to a large industrial data base and is reported elsewhere(2,18,19)."

Jan 1, 1984