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By Eugene A. Dolecki

This final report describes the work accomplished under U.S. Bureau of Mines Contract #H0242011 - "Feasibility of Automated Rail Haulage Systems in Underground Coal Mines." The report outlines the base for the development and evaluation of automated rail haulage systems in terms of the service requirements for haulage systems in underground coal mines, and of the performance of existing haulage systems. A generalized automated rail haulage system concept is defined. A safety impact analysis of automating the mainline portion of the underground system indicates a 50% reduction in injuries and fatalities. A cost effectiveness (over the total life cycle) study for the system indicates a cost benefit can be obtained from implementing an automated rail system. The design specifications for the total automated rail haulage system - including subsystems and components -are developed, and the equipment types and general design approaches evaluated, with selections outlined. A detailed conceptual design for a prototype automated system is described. Conclusions and recommendations are presented, and a program plan devised for implementing a proto-type automated rail haulage system demonstration in an operating underground coal mine by 1980.

Jan 1, 1976

By Tiago Rafael Ferreira de Brito

O presente trabalho comparou o desempenho do fosfato de zinco e do microfosfato de zinco, ambos com tecnologia dry-in-place para verificação do comportamento destes revestimentos frente à conformação mecânica, por meio do ensaio de embutimento Erichsen, método Nakazima e curvas limite de conformação (CLC). Foram estudadas chapas de aço-carbono grau EM e grau EEP G4 eletrozincadas e fosfatizadas. As chapas foram fosfatizadas empregando-se dois banhos: fosfato de zinco e microfosfato de zinco, ambos com tecnologia dry-in-place. A caracterização da morfologia dos fosfatos estudados por microscopia eletrônica de varredura mostrou que as camadas de fosfato de zinco não apresentaram formação de cristais, quando aplicadas por roll coater e as análises por EDS comprovaram a presença do elemento fósforo. O ensaio de embutimento Erichsen somado aos resultados obtidos nas curvas CLC demonstraram que o microfosfato exibiu desempenho melhor em comparação ao fosfato. A diferença entre os dois tipos de fosfato foi mensurável e evidenciou que a tecnologia dry-in-place colaborou com a produção de camadas fosfatizadas adequadas para a lubrificação durante o processo de conformação mecânica.

Aug 16, 2017

By G. W. Jones

Fires in anthracite refuse banks are troublesome and may become exceedingly costly to combat. Instances are known in which refuse-bank fires have grown to such magnitude that entire mining properties have been endangered. In one instance4/ a refuse-bank fire cost the mine management several hundred thousand dollars to extinguish. The exact number of fires formerly existing or now active in the anthracite region of Pennsylvania is not known, There are hundreds of anthracite refuse banks in this region, some very high and large in area, that have never caught fire, although a few are over 50 years old. This would indicate that spontaneous ignition of the material in these banks is improbable, a conclusion confirmed by recent laboratory research.

Jan 1, 1939

By M. Nduna

Surface properties of metal sulphides have a great significance in various areas of engineering and science, such as acid mine drainage, contaminant sorption, and metal separation. In various attempts at producing metal sulphide particles from synthetic solutions, prodigious quantities of nuclei that grow only to colloidal dimensions have been frequently reported. This copious nucleation is promoted by the high levels of supersaturation that characterize most precipitation reactions. Colloidal particle formation in precipi¬tation-based separation processes results in sub-optimal solid-liquid separation, which is alleviated by the production of more highly crystalline particles or agglomerates. The current work approaches this challenge from an electrochemistry perspective, by measuring surface charge potential of precipitant particles during metal sulphide precipitation with respect to the concentration of metal sulphide lattice ions in solution. Electrophoresis was used to measure the metal sulphide particle zeta potential and the settling properties were obtained by performing settleability measurements using an Imhoff settling cone. A suspension of copper sulphide particles was precipitated from synthetic solutions of copper and sulphide ions at equimolar concentrations. Immediately after precipitation the copper sulphide particles had a zeta potential of -50 mV and a settleability of about 7 ml.l-1. With the addition of copper ions the settleability increased by a factor of nearly three times and the zeta potential also increased to a maximum of -40 mV. A decrease in zeta potential to a minimum of -60 mV was observed after the addition of sulphide ions and this was associated with a settleability of 0 ml.l-1.

Jan 1, 2013

By D Craw, P Whigham, C Rufaut

Geographic Information Systems (GIS) are computerised management systems for spatial data, offering improved data management, extensive data manipulation techniques and greater understanding of data. At the Wangaloa Coal Mine, South-East Otago, ArcGIS is being used to manage, integrate, analyse and visualise the diverse range of datasets being generated from an interdisciplinary research team. GIS will assist with identifying spatial and temporal patterns associated with the current site rehabilitation strategy. This paper will present an overview of how GIS can be a useful tool for understanding ecological recovery during mine site rehabilitation.   The Wangaloa opencast coal mine, owned by Solid Energy NZ Ltd, was closed in 1989 after more than 40 years of operation. Rehabilitation efforts involving more than 60 000 native plants began in October 2001. At Wangaloa sample points were randomly selected at 100 m intervals and recorded using a differential GPS. Plant, soil and invertebrate data have been collected at each sample point. Plots of 8 - 9 plants have been established within approximately 5 m of each sample point. Since September 2003 seasonal monitoring of plant growth and survival has been carried out. Chemical and physical datasets have been generated from soil collected in June and December 2003 for each sample point. A more restricted dataset is being generated for soil collected on a seasonal basis from March 2004. Plant and soil characteristics from these datasets have been attached to each sample point and GIS layers have been created. Relationships between data layers can be explored based on their spatial patterns. Examples presented from Wangaloa include distribution of planting success and temporal variation; temporal change in pH; interpolated pH map; digital elevation model; relationships between planting success and growth with pH and organic matter. GIS is proving to be a valuable tool on the integrated project at Wangaloa.

Jan 1, 2004

By J. J. Demeter

Experiments were conducted in 2- and 4-inch-diameter standpipes to evaluate the effectiveness of standpipes as pressure seals. During the experiments, these standpipes conveyed Alan-Wood magnetite (60 to 230 U.S. standard sieve mesh) by gravity flow from one vessel to another of relatively higher pressure. The information obtained has been helpful in a Federal Bureau of Mines investigation of how to make either synthesis gas or hydrogen by a modified steam-iron process employing a continuous recycling stream of granular iron-iron oxide at temperatures of 600° to 900° C. In this process the mixture of granular material flows by gravity from a reduction vessel at low pressures to an oxidation vessel at higher pressures. Data from the 2- and 4-inch-diameter standpipes indicate that it would be practical to use a standpipe as a pressure seal between the reductor and oxidizer. Investigators found that, by gravity flow, the standpipe could convey the Alan-Wood magnetite against pressure gradients up to 1.07 pounds per square inch per foot of column height.

Jan 1, 1961

By Bradley V. Johnson, Robert J. Timko, Edward D. Thimons

Water-jet-assisted cutting involves the use of a mechanical cutting bit in combination with a high-pressure water jet directed just in front of the bit tip. Such a jet can offer benefits in terms of improved cutting, reduced dust and fines, and improved bit wear. The Bureau of Mines, through a contract with the British National Coal Board, has researched the use of water-jet-assisted cutting on roadheaders. After several engineering design problems were overcome, this program led to the successful underground testing of these roadheaders. Today, more than 60 water-jet-assisted roadheaders are in operation around the world and numerous others are on order. This paper details the evolution of these machines and the benefits to be gained by their use.

Jan 1, 1987

By W. H. Oppelt

To provide a relatively structurally stable form of dried lump lignite, two North Dakota lignites from Mercer County were dried by the Fleissner process in an atmosphere of saturated steam at 200, 300, and 370 p.s.i.a. pressure, corresponding to steam temperatures of 382°, 417°, and 437° F., respectively. Two series of experiments were made at each test pressure with the individual lignites. In one series, the autoclave was preheated to the processing temperature before charging the lignite; in the other the lignite was charged into the autoclave at room temperature. In each case, heat losses were determined by blank tests of steam consumption over a similar operating cycle with the empty autoclave. The degree of moisture removal and net steam consumption were calculated from material balances. The amount of water removed as a liquid from the two North Dakota lignites during the heating and steaming periods was compared with results calculated from previously published data on drying Austrian lignite and Australian brown coal. These lignites, covering a wide geographical area, had original moisture contents ranging from 35 to 49 percent. The Austrian lignite and Australian brown coal are considered to be of Miocene Age, and the Dakota lignites belong to the Paleocene.

Jan 1, 1955

By M. Nehdi

Deficient surface disposal systems of sulfidic mine waste often cause severe contamination of surface streams and groundwater reservoirs due to the oxidation of sulfide phases. The subsequent generation of leachates characterized by high acidity and elevated concentrations of toxic elements (commonly known as acid mine drainage) jeopardize the health of contiguous ecosystem. Stabilization/solidification (S/S) is recognized as a promising solution for treating such wastes. S/S processes generally mobilize alkaline and/or cementing materials/additives that act as neutralizing and/or binding agents. In the present research, industrial byproducts, namely, cement kiln dust (CKD) and Class C fly ash (FAC) have been used as candidate materials along with the partial addition of sulfate-resistant cement (SRC) in the S/S of polymetallic sulfidic mine tailings (MT). The effectiveness of S/S was assessed by comparing laboratory experimental values obtained from unconfined compressive strength, hydraulic conductivity and leaching propensity tests of S/S samples with regulatory standards for safe surface disposal of such wastes. Despite general regulatory compliance of compressive strength and hydraulic conductivity, some solidified/stabilized-cured matrices were found unable to provide the required immobilization of pollutants. Solidified/stabilized and 90-day cured mine tailings specimens made with composite binders containing (10% CKD + 10% FAC), (5% SRC + 15% FAC) and (5% SRC + 5% CKD + 10% FAC) significantly impaired the solubility of all contaminants investigated and proved successful in fixing metals within the matrix, in addition to achieving adequate unconfined compressive strength and hydraulic conductivity values, thus satisfying U.S. EPA regulations. Laboratory investigations revealed that, for polymetallic mining waste, leachate concentrations are the most critical factor in assessing the effectiveness of S/S technology.

Jan 1, 2008

By Richard J. Mainiero

The Bureau of Mines conducted research to evaluate the optimum design for a rock-breaking explosive charge that could be fired unconfined in a gassy or dusty coal mine without the danger of igniting the flammable atmosphere. Charges of various shapes, with and without cavities, were tested in a gallery using 3-by 3-by l-ft concrete blocks as simulated boulders. For these tests the optimum charge, in terms of cost, weight, and convenience in handling, consisted of a flat l-1/2-lb charge of permissible explosive seven-eighths of an inch thick and 7 in in diameter encased in a l/2-in thick layer of fine salt (NaCI). This work demonstrated that it should be possible to produce an inexpensive explosive rock-breaker charge that would be safe to use in underground coal mines.

Jan 1, 1982

By Juan J. Campo

The Freeport-McMoRan Main Pass Mine development in the Gulf of Mexico is a complex designed to extract up to 67 million long tons of sulphur over a 40 year period. The initial development includes 15 platforms and 13 bridges located in water depths ranging from 208 to 214 feet, approximately 15 miles east of the Mississippi River Delta. Three additional platforms were designed and installed for the oil and gas development in the complex. Over 110, 000 short tons of steel were required to fabricate the structures. As the sulphur is extracted significant subsidence is predicted over a major portion of complex in the shape of a very large bowl. Vertical elevations are predicted to change as much as 65 feet. Horizontal movements and mudline slope changes cause adjacent platform decks to move as much as 30 feet relative to each other. Differential soil movement is predicted between piling of individual platforms causing the piling to spread, resulting in significant lateral loading on the piling. Relative vertical soil movements are predicted along the lengths of the piles which causes "up drag" or "down drag" forces on individual piles. This paper addresses the design of the piling for the structures in the complex. Design criteria will be discussed explaining how the more traditional offshore environmental and gravity loadings were combined with the unique loading caused by subsidence. Design and analysis procedures will be explained and analysis results presented. These results include the incorporation of 100 ksi steel in thicknesses up to 5 inches in some of the tubular piles. Comparisons will be made between conventional offshore structures and these structures designed to accommodate the subsidence.

Jan 1, 1992

By H. J. McQueen

Before 1950, hot working was simply deforming above the recrystallization point and gave a soft product compared to cold working. From 1960 onwards, improved testing in compression and torsion (stress, strain rate, temperature, quenching) provided valid specimens for microstructural analysis by polarized optical and transmission electron microscopy (TEM). Indeed, TEM was essential to uncovering the hot working mechanisms because it could distinguish between cold and hot substructures (dynamic recovery) in either initial or new grains (dynamic recrystallization). Over the years, teams at Concordia, McGill and UBC obtained NSERC support for students and equipment. CANMET built up a hot forming group having capabilities from high-rate cam-plastometer compression to rolling of experimental alloy billets; this was combined with latest metallographic instruments for fundamental research. Al alloys of every class (2000, 3000, 5000, 7000, 8000) were studied to understand the effects of solutes, precipitates, dispersoids and composites. The complex flow patterns in extrusion were clarified and modeled by finite element methods. Physical simulations of rolling schedules (up to 20 passes and reductions of 98%) by torsion provided evidence of microstructure development during both the passes and the softening intervals, thus clarifying development of texture in different alloys. The results frequently appeared in proceedings of Light Metals symposia and Canadian Metallurgical Quarterly

Jan 1, 2011

By R. H. Winn

A method for the selection of the most suitable corrosion inhibitor for a particular system is given. The method involves the evaluation of surface passivity by means of copper ion displacement after the metal surface has been subjected to the corrosive atmosphere. The application of the method to the selection of suitable inhibitors for use in producing wells is described. Correlation with recognized laboratory tests has beet1 found to be good within the limitations of the test. The use of the test to evaluate inhibitor persistencc is described. INTRODUCTION Corrosion as it is associated with the industry shows wide variations in its qualitative as well as its quantitative aspects. This complicates the work of the corrosion engineer. In the past few years the efforts of the corrosion engineer have been further taxed by the large numbers of products being marketed as corrosion inhibitors by various manufacturers. These products are submitted to him together with a limited amount of data to support their use as inhibitors. The data are usually authentic and reliable yet all too often when these products are applied to an actual corrosive system the results are disappointing due to the ineffectiveness of the inhibitor and the corrosive system. The corrosion engineer must select a comparatively limited number of inhibitors for field trial from the large number available. The selection is usually made on the basis of a standardized laboratory test such as that adopted by the National Association of Corrosion Engineers or by field experience in an area; however, testing of this type is discouraging on large numbers of compounds, particularly in view of the specificity of environment. It has been an object of this work to devise a method which will allow the corrosion engineer to select the best inhibitor for a specific environment under field conditions. The test would of necessity be rapid and inexpensive. It would preferably eliminate the need for expensive and delicate instruments. STATEMENT OF THEORY The test as developed makes use of the fact that metal ions will be displaced from solution by metals having a more positive electrode potential. Thus, if an active iron surface is exposed to a solution of a copper salt, free copper will plate spontaneously on the iron surface as it is displaced from the salt solution by iron ions. If the iron surface is passified, as by coating with an insulating-type organic corrosion inhibitor, it is no longer capable of displacing the copper ions due to its own limited ionization. The result will be a change in the amount of copper plated upon exposure to a neutral copper salt solution. In practice it has been found possible to measure the magnitude of the alteration of the cell potential by determining the copper deposited on a standard iron surface under controlled conditions. This means that, as the film builds up, the resulting shift in the electrode potential tends to cause the iron surface to act more like a noble metal, resulting in a reduction in the cell potential to a point that copper will no longer plate spontaneously. Obviously, the salts of other metals such as silver, gold or platinum might be used for this operation; however, copper was selected because of the color difference of the plate, the comparatively low cost of copper salts and the ease of evaluation of the plated copper. Furthermore, its high cell potential provides a substantial driving energy. The determination of the copper is readily done colorimetrically by dissolving it in 5 per cent ammonium hydroxide solution containing 2 per cent potassium per-sulfate. The blue color of the copper ammonic complex ion so developed may be compared with standards prepared by dissolving known quantities of copper powder in the same reagent. In routine screening it is seldom desirable to determine the amount of copper plated. It is usually more important to determine the concentration of inhibitor required to prevent the plating of copper.

By J. Gholamnejad

The aim of short-term production scheduling is to decide which blocks of ore and waste to mine in which time period (shift, days, weeks or months) so that several operational and geometrical constraints can be satisfied simultaneously. Since 1960s several mathematical programming approaches were developed for solving production scheduling problems that are based on a combination of various operational research approaches such as linear programming (LP), integer programming (IP), dynamic programming (DP), etc. A number of models have been developed in the past three decades but some models have limited application especially to geometrical mining constraints. One of the geometrical constraints is block accessibility. All blocks must be accessible to mining equipments on the same bench. In this paper a binary integer programming model is developed in order to incorporate block accessibility constraints in an efficient manner. This mathematical model insures that each block has been open and can be loaded and transported easily by shovels and trucks.

Jan 1, 2008

By Jean Igor Margem

Nestes dias materiais ecológicos como compósitos com fibras naturais em matriz polimérica estão chamando a atenção de pesquisadores científicos, devido ao seu bom desempenho na substituição de materiais como madeira, polímeros à base de petróleo e outros. Neste trabalho foram avaliadas as propriedades de tração de compósitos de matriz poliéster reforçados com diferentes espécimes de fibras lignocelulósicas. Compósitos reforçados com até 30% em volume de fibras longas, contínuas e alinhadas de malva, sisal e bambu foram testados em uma máquina Instron a temperatura ambiente. A fratura foi analisada por SEM. Os resultados mostraram alterações significativas nas propriedades mecânicas com a quantidade dessas fibras. Estas propriedades mecânicas foram comparados com outros resultados em compósitos testados em ensaio de tração. Como esperado, a análise da fratura revelou uma fraca interação da interface fibra / matriz, o que corrobora o comportamento típico das fibras naturais quando incorporadas em matriz polimérica.

Oct 30, 2017

By Lewis Dr. Wade

It is really an honor and pleasure to be here at the 231d International Conference on Ground Control in Mining. My name is Lew Wade. Until recently I served as the Associate Director of Mining for NIOSH. That's a position that I recently moved out of and that position is now filled by Dr. Jeffery Kohler. I now serve as the Sr. Science Advisor to the NIOSH Director. The topic of my talk today will be coal mine ground control, a look back at the last 30 years, and then a brief look forward. I will start by talking about coal mine ground control statistics and with just a brief look, those statistics clearly show that you people are making a difference and there have been tremendous improvements. I'll then look at reasons for those improvements and those will include people working together (this conference being a prefect example of that), as well as technology development. In the area of technology development, I will give you my top-ten list of technology developments in the area of coal mine ground control. Then I'll end with a look towards the future and point to some possible future developments. Then, I will be so bold as to issue some challenges to the participants of this conference. Again, if you take the broad look back at underground coal mine roof falls and ground fatalities, you see this tremendous improvement that we have all come to appreciate. We have all been a part of improving the safety conditions for our underground miners and the number of fatalities is orders of magnitude less than what it was at the turn of the previous century. We have every reason to be pleased and proud of what we have been able to accomplish. Now, the question is why. What are the reasons for those improvements? Just look around this room. You see evidence of what I think are one of the principle reasons: miners, mine operators, government workers and researchers, equipment suppliers, people in research and academia working together. Coming together and sharing at a Conference like this over the last 23 years.

Jan 1, 2005

By Thomas J. DeMull

Development of the Batu Hijau copper project was completed in the fourth quarter of 1999 with the formal handover and start-up of ore processing facilities. The project began in August 1996 when the owner, PT Newmont Nusa Tenggara (PTNNT), awarded an engineering, procurement and construction (EPC)contract to Fluor Daniel (FD) for the development of the project. This included a copper concentrator, port, power plant, town site and infrastructure. PTNNT managed the development of the mine and the procurement of the mine equipment. In 1996, Batu Hijau was the largest mining project ever undertaken. Developing the Batu Hijau Mine was complex. It involved the work of thousands of people in all parts of the world to plan, engineer, procure, fabricate and manufacture equipment, supply and deliver materials and equipment, and build the plant.

Jan 1, 2002

"The application of telerobotics to mining is currently being introduced into production systems around the world. Mining companies in Canada, Sweden, South Africa, and Australia have tended to lead the international charge to this form of technology for mining. While this introduction is taking place, a few basic questions have yet to be answered. How many machines can a single operator run? How many types of machines can a single operator run?A Canadian Research Chair in Robotics and Mine Automation has been established at Laurentian University to investigate these questions and many more through a series of experiments in a telerobotics laboratory that connects Laurentian teleoperation workstations to model mining machines at Cambrian College’s eDome. The laboratory supports many experiments allowing researchers to physically run multiple robot scenarios differing the numbers and types of machines at one quarter scale. Further experiments are being designed to investigate the potential for managing time delays in telerobotics. This paper describes the laboratory, experiments, and some preliminary results."

Jan 1, 2005

By A P. Brown

Comparison of legal permits required for mining (as opposed to prospecting or exploration) inNew Zealand, under the Mining Act 1971 and the Resource Management Act/Crown Minerals Act 1991. Mining generally receives the same treatment as any other industrial or commercial activity.

Jan 1, 1995

By George K. Burke

Jet grouting was first introduced into North America in the late 1970's, soon after the conception of the system in Japan. However, it was not until the mid-1980's that the technique began to gain acceptance through the renewed interest and efforts of specialist U.S. geotechnical contractors. Since this time, innovations by both American users and other users worldwide have further advanced the technology, with a corresponding increase in the range of practical applications. This paper discusses the evolution of jet grouting in North America, from simple single-fluid methods to more complex triple-fluid methods, to the energy-intensive double-fluid and SuperJet methods. Case histories, illustrating a variety of jet grouting methods and applications, are cited to support the newest United States applications.

Jan 1, 2002