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By John E. Rourke, O&apos

This paper describes some of the results of a project for the design and demonstration of subsidence monitoring systems for underground coal mines. The project was designed to test monitoring systems described in an earlier feasibility report (O'Rourke and others, 1979). General objectives of the project were to develop reliable cost- effective monitoring systems for use above caving- type mining operations, over supported mines, and in urban undermined areas. Topics selected for discussion in this paper include a description of the instrumentation systems, the site conditions, problems of installation, resulting recommendations and an over- view of subsidence performance data obtained. There were some particularly difficult problems of installation to overcome at this site. Some of these could be experienced at any surface or under- ground project, others are probably more directly related to Western coal fields. Almost any subsidence monitoring program may face the following difficulties:

Jan 1, 1982

By Roger M. Turpening

This study was performed to examine the feasibility of using seismic shear waves to detect the presence of abandoned coal mines. !he Antiquity Coal Mine near Antiquity, Ohio was used as a region of known voids. No attempt was made here to accurately locate the mine tunnels if detection was obtained. The results of this study were positive. Sharp changes in the amplitude of the received shear waves were clear indications of the presence of a fluid (gas or liquid) filled region between the source and receivers. When moving the source showed no change in the received signals it was concluded that the voids existed beneath the sensors. Prior to these tests drilling (SM-3) had determined that a void did exist in this area. This void was confirmed by this shear wave test and two additional voids were found.

Jan 1, 2012

By M. M. Tilman

In a Bureau of Mines investigation to develop lead alloys with improved tensile strength and creep resistance, lead-base alloys containing cadmium and antimony in nominal 1-to-1 atomic ratios were melted in air, cast, and rolled into sheet to 90 percent reduction at temperatures varying from room temperature to 175° C. Tensile testing at room temperature and stress-rupture testing at 900±3° F were conducted on the as-rolled alloys. The best tensile properties were observed in an alloy of Pb-4.2 wt pct Cd-4.5 wt pct Sb which exhibited an average tensile strength of 7,270 psi with 36 percent elongation in 2 inches. An alloy of Pb-5.5 wt pct Cd-6.0 wt pct Sb had 100-hour stress-rupture values of approximately 2,100 psi and 1,000-hour values of approximately 1,700 psi.

Jan 1, 1969

By F F. Pitard, K J. Ehrig

The Olympic Dam iron-oxide copper-gold (IOCG) uranium-silver deposit is second in size only to Norilsk, the gigantic metalliferous deposit. Olympic Dam is the largest publicly declared uranium, fifth largest copper and third largest gold resource. The deposit is typified by texturally destructive brecciation and intense iron metasomatism of the Roxby Downs Granite, bedded clastic facies rocks and mafic-ultramafic dykes. The deposit contains over 100 minerals. Copper mineralisation consists of chalcopyrite, bornite and chalcocite. Uraninite, coffinite and brannerite are the dominant uranium-bearing minerals. Gold mineralisation consists of electrum, tellurides and Au-Cu alloys. Hessite is the major silver-bearing mineral. The economic minerals are disseminated throughout the breccia matrix where the average grain sizes of the Cu-sulfide, uranium, gold and silver minerals are ~50, 20, <5, <5 microns, respectively.A significant number of sampling theory-based test programs have been completed since the mid-1990s to establish sampling nomographs, select appropriate sampling (ie split versus chip and interval lengths) and sample preparation protocols, quantify the errors associated with each subsampling stage, determine the practical uncertainty limits of Olympic Dam matrix-matched standards, and identify improvement opportunities related to the ongoing assaying quality assurance / quality control (QA/QC) program. Invaluable knowledge and unexpected insights gained from sampling studies at Olympic Dam have helped to improve our understanding of the distribution of economic and deleterious elements within the Olympic Dam deposit.CITATION:Ehrig, K J and Pitard, F F, 2017. Underground bulk sampling, uniform conditioning and conditional simulation – unrealistic expectations?, in Proceedings Eighth World Conference on Sampling and Blending , pp 21–28 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By Daniel Briones

El presente trabajo señala las bases que fundamentan la aplicación de los Sistemas de Gestión Integrados y se ofrecen argumentos que sustentan los mecanismos usados para integrar los sistemas de Seguridad (NOSA), medio ambiente (ISO 14001) y calidad (ISO 9001); y la necesidad de su uso como herramienta de gestión por parte de la organización, llegando a todos los niveles hasta alcanzar la madurez del Sistema. Asímismo, se describen algunos ejemplos del impacto positivo, que ha significado la implementación de este Sistema en la unidad de producción Uchucchacua (cuarta productora mundial de Plata,), desde el inicio del Proyecto, hasta lograr la revalidación de la Certificación de las normas ISO 14001, y la cercana certificación en OHSAS 18001 e ISO 9001.

Sep 12, 2005

By J. Nakayama

For drilling large diameter holes for deep foundations, the common and distressing difficulty of long standing has been in coping with ground containing rocky formations and boulders. Where geological formation contains weathered rock or boulders, or deep rock socket is specified, drilling equipment occasionally is found to be unable to drill through and therefore will need supplementary equipment and procedures. Incentive of the MACH Drill Development has been to realize a capable drilling system for rocks of weathered to fresh rock without losing its applicability to usual overburden. Through seven decades' experience of manufacturing and operation of boring machines, the best features of all sorts of drillhead are known such as the drag bit, wing bit, auger bit, diamond bit, rock roller bit, down-the-hole hammer bit, etc.

Jan 1, 1988

By Mait Mets

In Estonia, the deformations monitoring of 1500 buildings are currently under investigation, buildings on pile foundations make up 10 per cent of these. In the following text we will be considering the behaviour of pile foundation buildings in various parts of Estonia, in differing geotechnical conditions.

Jan 1, 2002

Techniques have been developed for the dissolution of a wide range of rocks and minerals by a sodium peroxide sinter process. A olarge number of elements are determined by atomic absorption spectroscopy, and other elements such as arsenic and sulphur are determined by chemical analytical methods. The methods adopted to overcome inter-element and ionization effects on the atomic absorption results are discussed.

Jan 1, 1974

By G. S. S. Raman, M. S. Klima

Coal refuse slurries stored in tailings impoundments can potentially lead to environmental concerns such as effluent seepage, property devaluation, and in extreme cases, dam failures. Pressure filtration offers an opportunity to reduce the impoundment requirements by providing significantly drier solids. A full-factorial design was used to study the effects of temperature and pH on dewatering a refuse slurry obtained from a coal preparation facility in Pennsylvania, USA. The experimental results indicated a strong effect of temperature on cake moisture as the cake moisture after about 2800 s was 22% at 43 °C and only 36% at 10 °C for tests conducted at pH 3. ANOVA results confirmed the statistical significance of pH, temperature, and their interaction effect. Also, the results showed no significant differences between the tests conducted near neutral and alkaline pH values at low and ambient temperatures. On the other hand, Tukey's test indicated higher reductions in cake moisture at higher temperatures for lower pH values. This study affirms the need to monitor and control the pressure filtration process as throughput could significantly vary with changes in temperature and slurry conditions.

Jun 17, 2019

By G. S. S. Raman, M. S. Klima

Coal refuse slurries stored in tailings impoundments can potentially lead to environmental concerns such as effluent seepage, property devaluation, and in extreme cases, dam failures. Pressure filtration offers an opportunity to reduce the impoundment requirements by providing significantly drier solids. A full-factorial design was used to study the effects of temperature and pH on dewatering a refuse slurry obtained from a coal preparation facility in Pennsylvania, USA. The experimental results indicated a strong effect of temperature on cake moisture as the cake moisture after about 2800 s was 22% at 43 °C and only 36% at 10 °C for tests conducted at pH 3. ANOVA results confirmed the statistical significance of pH, temperature, and their interaction effect. Also, the results showed no significant differences between the tests conducted near neutral and alkaline pH values at low and ambient temperatures. On the other hand, Tukey’s test indicated higher reductions in cake moisture at higher temperatures for lower pH values. This study affirms the need to monitor and control the pressure filtration process as throughput could significantly vary with changes in temperature and slurry conditions.

By G. S. S. Raman, M. S. Klima

Coal refuse slurries stored in tailings impoundments can potentially lead to environmental concerns such as effluent seepage, property devaluation, and in extreme cases, dam failures. Pressure filtration offers an opportunity to reduce the impoundment requirements by providing significantly drier solids. A full-factorial design was used to study the effects of temperature and pH on dewatering a refuse slurry obtained from a coal preparation facility in Pennsylvania, USA. The experimental results indicated a strong effect of temperature on cake moisture as the cake moisture after about 2800 s was 22% at 43 °C and only 36% at 10 °C for tests conducted at pH 3. ANOVA results confirmed the statistical significance of pH, temperature, and their interaction effect. Also, the results showed no significant differences between the tests conducted near neutral and alkaline pH values at low and ambient temperatures. On the other hand, Tukey’s test indicated higher reductions in cake moisture at higher temperatures for lower pH values. This study affirms the need to monitor and control the pressure filtration process as throughput could significantly vary with changes in temperature and slurry conditions.

By S. P. Godby, S. P. Sharples

Wind-tunnel tests were carried out of the conditions under which nuisance dust particles (100-1 000 micrometres) become entrained by wind. A laser entrainment monitoring system (LEMS) was used, and was found to provide an accurate means of assessing nuisance dust emissions from a surface. Accurate determination of the threshold entrainment velocity of dusts using the LEMS gives a baseline against which the performance of dust control techniques can be evaluated. Minerals tested included coal, petroleum coke, limestone, sand and pulverised fuel ash. Pilot field trials of a portable wind tunnel equipped with the LEMS have been successfully completed, providing a means of validating laboratory results in the field

Jun 19, 1905

By S. A. Hovanessian

The method of characteristics which reduces the Buckley-Leverett mnlineur, partial differential equation to two first-order, linear differential equations is applied to the solution of a waterffood recovery problem for multiple lines of producing wells and one line of injection wells. The application of the method is described by a numerical example, and a brief theoretical background is given. From the results of this study, it is concluded that the cumulative water injected and oil produced are the same for single and multiple sets of producing wells. INTRODUCTION In this paper, the method of characteristics is applied to the solution of a waterflood recovery problem with multiple lines of producing wells and one line of injection wells. The application of the method to this type of recovery problem considerably simplifies the procedure of obtaining a numerical solution. It differs from the method described by Kern1 because it eliminates the need for integration in obtaining saturation fronts. In addition, the saturation history at any location within the field is obtained from a single diagram (time vs distance with saturation as a parameter)'. The paper includes a brief theory of the method of characteristics and its application to the solution of oil recovery problems. A numerical example is worked out, and the cumulative oil recovery-vs-time curve for a system with multiple sets of producing wells is obtained. This curve is then compared with the recovery curve of a system with only one set of producing wells. From this study, it is concluded that the cumulative water injected and oil produced are the same for single and multiple lines of producing wells. However, the recovery time is considerably longer for multiple sets of producing wells.

By Todd Clarke, Ralf Winterberg

For more than a decade the tunneling industry has explored the potential and benefits of macro synthetic fiber (MSF) reinforced concrete solutions for precast tunnel segments. Parallel to industry investigations, academic research is being undertaken to better understand this material when subjected to the typical loads expected during mechanized tunneling. This paper investigates the performance of MSF reinforced precast concrete tunnel segments by means of an experimental program comprising testing of full-scale tunnel segments. The presentation of the satisfactory results of the experimental testing regime will be complemented by a brief case history from a successfully executed project—an America’s First.

Jun 13, 2021

By Charles H. Fulton

There are comparatively few accurate data on the melting-or the freezing-point temperature of metallurgical slags, or on related physical phenomena, such as fluidity near the melting-point, specific heat, latent heat, etc. With the exception of the work of H. 0. Hofman,' and some older work by R. Akerman, P. Gredt, and H. M. Howe, no information is available that is of direct interest to the metallurgist. Hofman's valuable work is the only one that refers to slags produced in the metallurgy of copper and lead. The classic work of J. H. L. Vogt,2 who views slags from the standpoint of physical mixtures (solutions in which the entities are minerals), has opened up a new field in the study of slags, and has placed the investigation of such properties as melting-temperatures, etc., on a rational basis. The recent work of A. L. Day, E. T. Allen, and W. I?. White, of the Carnegie Institution, at Washington, and of European investigators3 on certain systems of silicate minerals confirms the value of the investigation of silicate series from this standpoint, and it is my aim to apply this method to metallurgical slags, in order to gain exact data of value in metallurgy. The work recorded in the present paper is the result of an investigation of reverberatory-furnace slags made for a Western smelting company to determine exactly the influence of change in composition, within comparatively narrow limits, on the melting-point. For a general discussion concerning the mineralogical character of slags and the principles on which this investigation is based, reference should be made to other work: for the subject is too large to be stated in this paper, except very briefly in the following outline:

Jan 1, 1913

By P. D. White, J. T. Moss, J. S. McNiel

Results of experimental work on the in situ combustion process were first published in this country in 1953' when Kuhn and Koch described results of a three-well test in Jefferson County, Okla. Shortly there-after Grant and Szasz2 described field studies in Nowata County, Okla., in which several modifications of the basic combustion process were investigated by injection of various oxidizing gas mixtures other than air. In the past five years speculation concerning this method of oil recovery has continued, with a number of interesting papers on various aspects of in situ combustion appearing in the literature3,4,5,6,7. However, only one of these' provided actual engineering information on pattern-type field experiments. The primary objectives of the Oklahoma three-well test were to check operation of specially designed electrical ignition equipment and evaluate problems associated with initiation of combustion in a natural oil sand reservoir. Immediately following successful completion of this test in the Pontotoc sand, plans were activated for a second field experiment to be conducted in the same sand a short distance away. The objective of this second field test1 as to establish a relationship between field observations and information derived from laboratory experimentation and computations. Secondary objectives of the test were to develop operating tech- niques and define operating problems, and to obtain information that would assist in the economic and engineering appraisals of the process. Careful planning was required since this test was designed with the hope of providing basic information on the characteristics and operation of a combustion drive. It was necessary to include test facilities which would not only permit precise control and measurement of the process variables but would also provide sufficient flexibility of control to insure that variables in the combustion process could be studied during the course of the test under a wide range of conditions. In order to accomplish these objectives elaborate instrumentation and several control wells were included in the design of the test installation. This type installation was felt to be well suited for an experimental study, but was in no respect intended as a counterpart of a commercial-scale operation. PRELIMINARY LABORATORY WORK An important objective of the field experiment, as stated previously, has been to obtain reliable data on operating variables which might be compared with similar data obtained in laboratory combustion tests. The value of successful correlations between quantities that can be measured in the laboratory and those obtained in a full-scale commercial venture has been well established for other industrial processes. The difficulty of following a process underground should make such correlations even more essential here. Also. approaching the field test phase of development of in situ combustion, it was considered desirable to precede design of test equipment with laboratory combustion studies under a variety of conditions to establish likely ranges of variables. These included temperature, air injection rate, frontal advance rate and produced gas composition.

By C. C. Harris Discussion by B. K. Loveday

B. K. Loveday (National Institute for Metallurgy, Johannesburg, Republic of South Africa) - The paper and subsequent technical note' describing a method of determining the parameters of the three-parameter size-distribution equation developed in the paper were read with much interest. This equation was also used at National Institute for Metallurgy (NIM) to describe size distributions in grinding tests, because it was necessary to have a single equation to describe the size distribution at any time during a test. A graphical method also was used to determine the three parameters, and the use of this method as an alternative to Professor Harris's latest method is discussed here. The three-parameter model can be expressed as follows: Eq. 1 can be rearranged and transformed to Yield a linear reiationship between Y and X (transformed) log

Jan 1, 1970

By C. L. Karr

The efficient management of the distribution of goods and services is important throughout the minerals industry. From the scheduling of processing plant operations, to the routing of work crews in mines, to the planning of product development, vast amounts of time, energy, and money are wasted due to poor planning and scheduling. Thus, the U.S. Bureau of Mines is investigating computational algorithms that can be used to minimize the economic losses related to scheduling and allocating resources. Although there is commercial software available for tackling many scheduling problems, there has been little relief provided for solving the difficult traveling salesman with time windows problem (TSTW). The TSTW problem is a "derivative" of the classic traveling salesman problem, and can be used to minimize the distance traveled by vehicles or personnel to visit all points on a tour, with the additional constraint that each point on the tour must be visited within a specified time window. This paper is a survey of published work in which genetic algorithms have been used to efficiently solve the traveling salesman problem and its more difficult derivative, the TSTW problem. A genetic algorithm is a search algorithm based on the mechanics of natural genetics, and has been used to solve a broad spectrum of engineering optimization problems. Results indicate that the versatility, searching power, and simplicity of genetic algorithms can be used to provide substantial improvement in the area of scheduling and resource allocation.

Jan 1, 1994

By John R. Bartels

This U.S. Bureau of Mines report describes the development, system by system evaluation, and preliminary surface testing of a flywheel-powered shuttle car (FPSC). The use of a self-contained flywheel-power source has the potential to eliminate the numerous safety and routing problems associated with tethered mobile equipment. An alternative to conventional power cable systems was developed consisting of the world's fIrst seven-rotor stacked flywheel system capable of storing 6 kW·h of energy at 16,700 rpm. Numerous interdependent systems were necessary for successful interfacing with a conventional shuttle car. Each of these systems was evaluated and tested individually. Finally, the entire shuttle car was surface tested. The tests indicated that the flywheel energy system can function and operate a shuttle car. The economics of the system and the design of required support systems were not addressed in the project.

Jan 1, 1991

By W. R. ARGYLE, R. A. SHERMAN, Henry Kreisinger, John Blizard, B. J. CROSS, A. R. Mumford

On entering the World War the United States was confronted with the necessity of building in a short time a large number of ships of tonnage adequate to transport troops and war materials to Europe and to carry food supplies to the allied countries, whose merchant fleets had suffered greatly by submarine warfare. The necessity of building ships quickly led to the formation of the United States Shipping Board, which was charged with the duty of developing an efficient organization for the purpose. Such an organization was developed under the name of the Emergency Fleet Corporation; it was under the control of the Government, but could conduct its business in the most direct way, like a private corporation. In order to build the largest- number of ships possible without drawing too heavily on the steel industry, which was already taxed heavily by the production of munitions, it was decided to build wooden as well as steel ships. These ships were built from a few standard designs to enable a large number of duplicate parts to be fabricated in inland shops and transported by railroad to the shipyards on the seacoast, where they were assembled into ships. In other words, the plan was to manufacture the ships rather than to build them. The shops on the seacoast were reserved to make those parts of the ships' equipment that could not readily be transported. The inland shops made the parts that could be transported to the seacoast by railroad. Among the more important parts of the ships' equipment to be standardized were the boilers. As the Scotch marine boiler in large units is bulky and can not be transported by railroad, and as, for the same capacity,much more steelis needed in its construction than for water-tube boilers, a few simple designs of water-tube boilers were developed that inland shops having ordinary equipment could make in large quantities.

Jan 1, 1924