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By K. Moxham, A. Smit, R. Pickering

Since the early 1970s research has been ongoing to develop a cost-effective way of continuously mining the narrow reef, hard rock, typical of South African gold and platinum mines. In the late1980s it was shown that impact ripping was a practical solution for the deep gold mines. In March2001 Lonmin and Sandvik agreed to co-operate in an endeavour to design and manufacture a prototype narrow reef mining machine with the ultimate aim of producing such a machine on a commercial basis that would enable Lonmin to create a safer and more productive environment within its mines and for Sandvik to enhance its leading position as a supplier of a new generation hard rock cutting machine. This paper describes the developed technology, the current progress of the delivery of the required objectives and the optimum mining layout for the roll-out of the mining method.

Jan 1, 2006

By H. C. Li

Mechanical models are established in accordance with the degree of mining on both sides of the coal pillar, and formulae were derived which calculated the superposition stress distribution and the width of the plastic region. The stability of the coal pillar was analysed and a reasonable size of coal pillar determined, in accordance with the elastic region rate. Further practical examples for the stability of the coal pillar are calculated and simulated.

Jan 1, 1992

An index covering the papers presented at the 19 Open Hearth Conferences from the first meeting at Pittsburgh, April 15 and 16, 1925, through the most recent meeting in Detroit, April 16 and 17, 1936, the reports of the meetings and the discussions that took place has been published, accompanied by a list of the papers presented, grouped by subject matter and a list of books of interest to open hearth men The list below gives the Open Hearth Conference meetings in chronological order and the symbols used to designate them in the index SYMBOL MEETINGS P25 Pittsburgh, April 15 and 16, 1925 C125 Cleveland, Oct 13 to 15, 1925 Ch26 Chicago, April 12 and 13, 1926 P26 Pittsburgh, October, 1926 B27 Buffalo, May 3 to 5, 1927 D27 Detroit, Nov 2 and 3, 1927 Y28 Youngstown, May 3 and 4, 1928 P28 Pittsburgh, Nov 15 and 16, 1928 C129 Cleveland, May 16 and 17, 1929 Ch29 Chicago, Nov 5 and 6, 1929 B30 Buffalo, May 20 and 21, 1930 C130 Cleveland, Nov 20 and 21, 1930 Ch31 Chicago, May 12 and 13, 1931- D31 Detroit, Nov 24 and 25, 1931 P32 Pittsburgh, May 24 and 25, 1932 Ch33 Chicago, June 29 and 30, 1933 P34 Pittsburgh, June 28 and 29, 1934 C135 Cincinnati, April 11 and 12, 1935 D36 Detroit, April 16 and 17, 1936 The list of papers mentioned in the first paragraph above is reprinted on pages 428 to 431 The Index of the Open Hearth Proceedings may be purchased at A I M E headquarters, 29 W 39th St, New York

Jan 1, 1936

By Robert Hopler

In accordance with the 57th section of the Explosives Act, 1875, the following report on the working of the Act during the year ending December 31, 1903, is submitted. There have been no modifications of the law during the year. No complaint is made of any falling off in the general condition of factories and magazines, and in one instance only during the year have legal proceedings been taken for any irregularity. The occupiers of factories and magazines have invariably shown perfect readiness to remedy any defects, and the managers have themselves in many instances introduced improvements tending towards greater safety. The number of deaths (5) from accidents by fire or explosion in the manufacture of explosives is below the average for the decade (6•4). Looking to the large number of persons employed in this trade, the number of deaths is not excessive and will compare favorably with the death-rate in other dangerous trades. Notwithstanding the large increase in the manufacture of explosives, the average number of deaths has greatly decreased since the passing of the Explosives Act, whereas the number of fatal accidents with explosives under conditions to which the Act does not apply appears to increase with the extension of trade.

Jan 1, 2006

The Mine Safety and Health Administration (MSHA) defines an independent contractor as any person, partnership, corporation, subsidiary of a corporation, firm, association or other organization that contracts to perform services or construction at a mine. Contractors that perform specific types of work are required to report the number of employees who work at coal mines and noncoal mines.

Jan 1, 2008

By D. R. Wilburn

The worldwide budget for non fuel mineral exploration was expected to increase by 27 percent in 2003 from the 2002 budget, according to the Metals Economics Group (MEG) of Halifax, Nova Scotia. The increase comes after five years of declining spending for mineral exploration. For the first time in several years, all regional exploration budget estimates for 2003 as defined by MEG would increase from similar 2002 estimates. However, MEG included 193 more companies in its 2003 survey than in 2002. As with previous MEG survey reports, estimates reflect anticipated expenditures rather than actual dollars spent. Caution, therefore, must be taken when comparing 2002 and2003 estimates or evaluating the magnitude of regional changes from year to year. Sample variations and currency exchange rates may influence year-to-year variations of MEG data. Even so, it is likely that the general climate of improved metal prices in 2003 encouraged companies that had previously left the mineral exploration sector or reduced their exploration activity to once again focus on minerals exploration or increase exploration activity and budgets.

Jan 1, 2004

By John C. Edwards, Gene F. Friel

A series of liquid fuel fire experiments evaluated the comparative responses of five types of commercially available smoke detectors and a diffusion-mode carbon monoxide (CO) detector under normal and reduced airflow conditions based upon the alarm times of the detectors. These experiments were conducted in the Safety Research Coal Mine at the U.S. Bureau of Mines Pittsburgh Research Center. Two of the smoke detectors had manufacturer set alarms. For the other three smoke detectors, an alarm point was defined in terms of their background analog signal and the detector's electrical output noise under ambient conditions. A correlation was developed of the travel time of 5 ppm CO between pairs of CO detectors with the travel time calculated from entry and crosscut volumes and measured airflow. Based upon the relative performance of smoke detectors in this limited study, smoke detectors can be as effective as CO detectors for mine fire detection once identifiable alarm values are defined. Implementation of smoke detectors as part of an atmospheric mine monitoring system will improve mine safety.

Jan 1, 1996

By M. Schlegel, J. A. Villa Mena, R. E. Vivas

ArcelorMittal, headquartered in Luxembourg, is one of the world’s largest steel and mining companies. It supplies steel to industries such as automotive, construction, and energy, with a strong emphasis on sustainability and innovation. The company employs about 125,000 people and, in 2024, produced 42.4 million tons of iron ore and 57.9 million tons of crude steel across 15 countries. Its mining operations span Canada, the United States, Mexico, Brazil, Ukraine, Bosnia and Herzegovina, Kazakhstan, and Liberia, focusing on iron ore and coal extraction to support steel production. This study examines Peña Colorada, one of Mexico’s largest iron ore mines (a joint venture by ArcelorMittal and Ternium). Facing declining ore grades, Peña Colorada adopted Hexagon solutions to uncover and capture project value. A comparison of two Life of Mine (LOM) plans from 2012 and 2016 (before and after implementing Hexagon solutions) shows that between 2019 and 2023, Peña Colorada reduced actual waste by 26% (compared to 2012 LOM) and 19% (compared to 2016 LOM). LOM Plans are generated yearly, and each time, opportunities for reducing mining waste were identified, evaluated and implemented. The key driver was schedule optimization using Hexagon MinePlan Schedule Optimizer (MPSO). This reduction means less waste transported to disposal sites, resulting in fewer hauling equipment operating hours, lower fuel consumption, and reduced carbon emissions.

Feb 22, 2026

By A. D. Pelton, Y. -B. Kang, S. A. Decterov

Computerized thermodynamic databases for solid and liquid metal, slag and solid oxide phases in the Al2O3-CaO-CoO-CrO-Cr2O3-FeO-Fe2O3-MgO-MnO-NiO-SiO2-S system have been developed by critical evaluation/optimization of all available phase equilibrium and thermodynamic data. The databases contain parameters of models specifically developed for molten slags, liquid steel and solid oxide solutions such as spinels, pyroxenes, olivine, monoxide (wustite, periclase, lime), corundum, etc. By means of the optimization process, model parameters are found which reproduce all thermodynamic and phase equilibrium data within experimental error limits. Furthermore, the models permit extrapolation into regions of temperature and composition where data are not available. The databases are automatically accessed by user-friendly software that calculates complex equilibria involving simultaneously slag, metal, refractories and gases, for systems with many components, over wide ranges of temperature, oxygen potential and pressure. A short review of the available databases is presented. The critical evaluation/optimization procedure is outlined using the Al2O3-CaO-FeO-Fe2O3-SiO2and Al2O3-CaO-MnO-SiO2systemsas examples. Several applications of the databases to deoxidation of iron and to inclusion control in steel are discussed. Keywords: thermodynamics, phase equilibrium, phase diagrams, databases, ferrous metallurgy, steelmaking, inclusion control, slags, oxide systems.

Jan 1, 2004

By J. A. Marts

Reservoir properties including porosity and permeability distributions in longwall coal mine gobs have direct application to modeling the flow patterns and gas distributions in the gobs. Proper assessment of these distributions is required to assess gob gas hazards such as spontaneous combustion and explosive methane mixtures and to optimize gob gas venthole operation and nitrogen inertization. Determining the reservoir properties is difficult given that the gob is inaccessible and direct measurements cannot be easily taken. Several techniques have been used by previous researchers and will be discussed. This paper will present the methodology used to model the gob compaction by simulating the sequential extraction of coal. Two Western US coal mines were used for case studies. By determining volumetric strain, the porosity and permeability distributions in the gob can be calculated. The geo-mechanical model predicts an axisymmetric volumetric strain distribution with a steeper slope near the start-up room and a shallower slope near the active face.

Feb 23, 2014

By Alice Turcot

Knowledge of risks from exposure to hand-arm vibrations is usually presented by clinicians and researchers from a medical and engineering point of view. There is a strong need to develop innovative health promotion programs for exposed workers. Risk perceptions by vibration exposed workers and HAVS (hand-arm vibration syndrome) affected workers are less well known. In 1983, Brubaker demonstrated that 75% of studied fellers thought that whitening of the fingers was part of the job and/or an unrelated nuisance, while only 25% believed it was a disease. 1Grounds also showed that even though there were a very high number of forestry workers with white fingers, none considered quitting because of their condition. 2 It seems that many workers hesitate to declare the illness or believe they are less affected than they really are, perhaps from fear of losing their jobs and livelihood. 3 Risk awareness, on the part of exposed workers and their employers, as well as knowledge and acceptance of available preventive solutions are necessary steps before installing adequate preventive measures, whether organizational, behavioral or environmental. Workers need to understand fully the hazards and risks in order to be able to make informed decisions under uncertain conditions.4 Prerequisites include the following: workers knowledge about the risk, their attitude towards it, which in turn, can be influenced by values, needs and interests. Also, knowledge and attitudes towards safety behaviour, organizational or environmental barriers must be taken into account. Our research focuses on these key elements, which help bridge the gap between health promotion research and practice. Methods A descriptive exploratory study is in progress with workers exposed to hand-arm vibrations. It uses qualitative methods that include focus group discussions with workers exposed to hand-arm vibrations, as well as individual interviews with other key informants (employers, health care professionals). An open-ended questionnaire was developed to collect qualitative data on perceived risks and solutions to prevent or reduce HAVS. Based on an integrated theoretical framework related to known determinants of behavior change, the analysis will focus on the following5: 1) knowledge of health effects, safety, well-being and/or quality of life 2) related beliefs about individual susceptibility and severity of consequences 3) attitude and values related to hand-arm vibration exposure 4) knowledge and attitudes towards exposure reduction, as well as perceptions of barriers and facilitating factors for these measures, in the workplace environment or otherwise.

Jan 6, 2006

By Paul O. Knorr

The Bureau of Ocean Energy Management (BOEM), a bureau within the U.S. Department of the Interior, has responsibility over both energy and non-energy mineral development on the United States Outer Continental Shelf (OCS) under the OCS Lands Act (“OCSLA”). BOEM’s Marine Minerals Program (MMP) manages federal offshore mineral deposits through non-competitive, negotiated agreements for sand and gravel (“sand”) used in coastal restoration efforts and the competitive leasing of critical and hard economic minerals (“critical minerals”). As the steward of OCS critical minerals, BOEM MMP is responsible for understanding where critical minerals are located, identifying and understanding their environments, managing activities that affect these resources, and implementing pertinent federal policies. Fulfilling these responsibilities involves the collection and analysis of environmental, geological, and geophysical data; supporting the science needed to understand the impacts of resourcerelated authorized activities on the biological, physical, and sociocultural environments; encouraging emerging technologies that can reduce the environmental impact of activities; and communicating with stakeholders to foster an understanding of existing federal regulations and potential needs to revise the legal framework. Four U.S. federal rules in the Code of Federal Regulations (CFR) currently inform MMP’s procedures: 30 CFR 580 (prospecting for minerals), 30 CFR 581 (leasing of minerals), 30 CFR 582 (operations in the OCS related to minerals), and 30 CFR 583 (negotiated noncompetitive agreements for sand). Other federal laws and regulations are also pertinent, particularly those supporting the National Environmental Policy Act, Endangered Species Act, National Historic Preservation Act, Marine Mammal Protection Act, Coastal Zone Management Act, Clean Air Act, Federal Water Pollution Control Act, and Magnuson Stevens Fishery Conservation and Management Act.

Feb 22, 2026

By Marcello Crispi, Valdir Silva, Juarez Moraes

Companhia Vale do Rio Dote - CVRD is the largest mining company in Brazil and the largest iron ore producer in the world. Serra Geral Mine (SGM) is located at Iron Quadrangle of the State of Minas Gerais, approximately 80 kilometers from Belo Horizonte. Hematite and Itabirite are the two main minerals. A blasting with a spherical charge has been introduced at Serra Geral Mine, an iron ore producer in Brazil, belongs to the CVRD (51%) Kawasaki Steel Corporation (24.5%) others (24.5%), in order to improve fragmentation, as well, load, transportation and crushing productivity. This paper will present the results of a successful blast design with a spherical charge carried out by Serra Geral Mine, the Department of Mining Engineering at Escola de Minas - Federal University of Ouro Preto-UFOP associated to a Blasting Engineering Consultant. The results obtained in the field tests and how it was possible to increase the blast pattern in 53%, which allowed one reduction around 31% in the cost of blasting operation in the Serra Geral Mine, will be discussed in details.

Jan 1, 2002

By William F. Anderson

A series of pile load tests (maintained load tests, constant rate of penetration tests at different rates, and statnamic tests) was carried out on an instrumented model pile installed in clay beds prepared by consolidation of a slurry in a calibration chamber. The total load, shaft resistance and end bearing during the pile load tests were investigated. Following this, alternative methods of deriving the static load-settlement curve from a Statnamic test in clay taking into account damping effects have been proposed. These methods have then been used to interpret a statnamic test on a full size instrumented pile installed in a stiff glacial till.

Jan 1, 2006

By S. Nikolic, O. O. Kehinde-Philllps, O. T. Djamgouz, D. H. Rousell

"A bulk mining method is employed at the Lockerby mine resulting in the formation of large muck-piles. If these muckpiles remain in the stopes for some time they may agglomerate to the extent that the muck cannot be removed by a scooptram. A laboratory investigation was undertaken with sulphide material from the mine in order to detemine the time that oxidation begins and the flowability of the material as a f unction of several factors. The laboratory results are applied to the conditions in the muck-piles.The time of the beginning of oxidation of the material decreases as the sulphide composition, water content and availability of air increases. Oxidation is retarded by the addition of a copper sulphate solution instead of water. The unconfined yield force (strength} of the material increases with an increase in the sulphide composition, water content and time. The material ceases to be free-flowing before there is visible evidence of oxidation and this suggests that oxidation actually begins earlier and that agglomeration is also due to the capillary action of water.Broken ore should be removed from the stope prior to the time a muck-pile ceases to be free -flowing-perhaps as early as two days f or high-grade ore and 5 days f or low-grade ore. In order to control dust, 1.4 weight per cent of a 5 per cent solution of copper sulphate should be added 10 the muck-pile rather than water. This inhibits oxidation and increases the time that a muck-pile remains free-flowing."

Jan 1, 1984

By V. Kecojevic

Environmental and economic costs related to equipment fuel consumption and carbon dioxide (CO2) emission present a substantial challenge to the mining industry. Haul trucks are an integral part of the overall surface mining system and they consume a substantial quantity of fuel. Consequently, they produce a significant amount of CO2. The objective of this research is to (i) establish a mathematical relationship among a truck?s fuel consumption, power and engine load factors and (ii) determine the amount of a truck?s CO2 emission and the associated cost that may arise from potential CO2 legislation. In order to achieve these objectives we have considered original equipment manufacturer (OEM) haul trucks, commonly used in surface mining operations. The research presented here may be used by mining professionals to help determine the cost and environmental burden of the trucks? application, and efficiently manage energy consumption.

Jan 1, 2011

By Roger J. Morrell

Bureau of Mines laboratory experiments with reduced scale cutter and cutter forces were performed to (1) define the fundamental relationships governing disk cutter performance and (2) to develop a method of predicting disk cutter performance in soft, medium, and hard rocks. The rock cutting experiments were performed in four igneous and metamorphic rocks that ranged in compressive strength from 38,000 to 67,000 psi. A special testing machine called a linear cutter apparatus (LCA) was used to load and traverse a free rolling disk cutter across a smooth rock surface. Each pass of the disk produced a single crater, and runs were spaced to avoid breakage between craters. During each run the normal and tangential cutter forces were measured and recorded. The soft and medium rock data were obtained from previous Bureau experiments with disk cutters. Crater depth, tangential cutter force, crater volume, specific energy versus normal cutter force, and crater width versus depth are defined within this study. With the use of standard physical properties, performance prediction equations were developed using stepwise linear regression analysis techniques. A method of using these prediction equations to calculate the boring rate, the cutter spacing, and the torque and energy requirements of a full-scale boring machine was also developed.

Jan 1, 1974

By P. T. Slatter

The efficient and accurate design of pipe and pumping plant for non-Newtonian mineral slurries remains a problem. The objective of this paper is to present the development of the Balanced Beam Tube Viscometer (BBTV), an instrument which could facilitate more accurate design for these slurries. The background of rotational and tube viscometry is reviewed and the fundamental principles and inherent advantages of the BBTV are given. The design, data acquisition and processing techniques are introduced and results showing the reliability of the new instrument are presented and discussed. It is concluded that the BBTV is a reliable and versatile instrument for both routine analyses and research work, and has the potential to provide data for the refinement of the design procedure for mineral slurry pipe and plant design.

Jan 1, 1998

By T. C. Vogt

The past history of uranium production has been dominated by strip and shaft mining methods, but recently in-situ leaching has emerged as a viable alternative for uranium recovery. (1-8) Mobil was the first company to start in-situ uranium leaching in New Mexico. Mobil's Crownpoint project areas are in Mdinley County and are part of the Grants Mineral Belt. The major uranium deposits in this area occur in the Westwater Canyon Member of the Jurassic Morrison Formation. (9-11) The ore depth at the Crownpoint project is about 2000 ft. In an earlier paper we discussed the uranium mineralogy of an areally broad sampling of Crown- point ore. (12) The organic carbonaceous material often associated with the coffinite ore was characterized in some detail. The organic material appeared to be a very mature, coaly-type kerogen derived from plant components. This result was consistent with other studies on such carbonaceous material. (13-15)

Jan 1, 1981

By Loring A. Wyllie

Preparation, understanding and use of soils reports must be a team effort to be fully effective. The soils engineer must know what is to be built and exactly where. The structural engineer and owner must be fully informed on the foundation problems of the site. There must be frequent team review of information obtained from subsurface investigation and of design as details develop. The soils engineer should be available on a continuing team basis as design proceeds and should be directly involved with inspection and interpretation of site conditions as construction continues.

Jan 1, 1986