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By John Songstead

INTRODUCTION The Bunker Hill mine, located at Kellogg, ID, in the Coeur d'Alene mining district, has been a major pro¬ducer of lead-zinc-silver ore since 1887. Since its dis¬covery, it has produced over 25 401 171 t (28 million st) of ore from 20 to 25 veins and ore zones. The mine now covers an area of approximately 1.609 km (1 mile) in length and 0.8 km (1/2 mile) in width and extends from 1097 m (3600 ft) above sea level to 488 m (1600 ft) below sea level. Production is presently at a rate of 1542 t/d (1700 stpd). During 1965, a new stoping method, the Bunker Hill pillar system, was developed to enable the profitable mining of large, low-grade zinc ore bodies. The system was specifically designed to in¬corporate the Atlas Copco T26GH rubber-tired loaders. High productivities were achieved, and the method was adapted for mining the higher grade stopes where large timber square sets are utilized. This results in nearly 100% extraction. GEOLOGY The area encompassing the Bunker Hill mine lies immediately south of the Osburn fault, a major east-west striking, deep-seated strike slip fault which is the dominant structural feature in the Coeur d'Alene district. The Bunker Hill forms a series of veins and mineralized zones which occur as link structures, tension fractures, and breccia zones in folded, interbedded argillaceous quartzites of the Revett and St. Regis formations of the Precambrian belt series. The Rosco ore body is predominantly a zinc ore body above the Cate fault, which is presently known to occur from the 13 level. [elevation 488 m (1600 ft)] to the 1600 level [elevation 304 m (1000 ft) ]. These ore bodies are stringer zones with at least one dominant 1.8 to 4.5 m (6 to 15 ft) wide band of ore. They dip 0.09 to 0.26 rad (5° to 15°) steeper than the local 0.61 rad (35°) dip of the Cate fault, and also deviate 0.26 to 0.52 rad (15° to 30°) in strike from the Cate. Because of the flat dip and fractured weak hanging wall, normal cut-and-fill mining has not proven practical in this ore body. The mechanized timber methods described in the next section and the Bunker Hill pillar system are the mining methods successfully used. MINING METHODS While pillar stoping and mechanized cut-and-fill stop¬ing methods were obviously superior to the widely used timber stoping methods, as far as cost and productivity

Jan 1, 1982

By R. L. Virta

Four companies mined ball call in four states in 2009, H.C. Spinks Clay Co. Inc. (owned by Lhoist Group), Kentucky-Tennessee Clay Co. (owned by Imerys Group), Old Hickory Clay Co. and Unimin Corp. Production, on the basis of preliminary data, was 820 kt (904,000 st) with an estimated value of $39.4 million. That was a 15-percent decrease in tonnage from 967 Mt (1.1 mil-lion st) with a value of $44.3 million that was produced in 2008. Tennessee was the top producing state with 59 percent of domestic production, followed by Texas, Mississippi and Kentucky. About 71 percent of production was airfloat, 18 perc

Jun 1, 2010

By Y. V. Vasylchuk

This paper presents an algorithm for optimizing the classification of surface mine material subject to excavating constraints. High-resolution expected profit models are input and optimized to classification maps subject to site-specific rectangular excavating constraints. This optimization problem defies traditional closed-form analytical solutions; a practical heuristic algorithm has been developed to quickly determine the optimal final destination for the material subject to realistic constraints. The optimization is fast and generates results that achieve up to 98–99% of the total expected profit achieved with free selection. This algorithm provides a fast viable option for practical application in short-term grade control and in managing multiple realizations in long-term resource estimation.

By Y. V. Vasylchuk

This paper presents an algorithm for optimizing the classification of surface mine material subject to excavating constraints. High-resolution expected profit models are input and optimized to classification maps subject to site-specific rectangular excavating constraints. This optimization problem defies traditional closed-form analytical solutions; a practical heuristic algorithm has been developed to quickly determine the optimal final destination for the material subject to realistic constraints. The optimization is fast and generates results that achieve up to 98–99% of the total expected profit achieved with free selection. This algorithm provides a fast viable option for practical application in short-term grade control and in managing multiple realizations in long-term resource estimation.

By Gleason

"From June 16 to 19, more than 1,400 tunneling and underground construction professionals gathered in Chicago, IL for the bienial Rapid Excavation and Tunneling Conference (RETC). There, they were greeted by a full technical program and an exciting exhibit hall that provided a comprehensive look at the world’s bustling tunneling and underground construction industry.The successful conference was a reflection of the industry itself, which is to say, busy. As much of the world has begun to focus on creating a cleaner and greener environment, the global tunneling industry has seen an uptick in infrastructure projects move from design-build to construction phase. With a global shift away from the use of fossil fuels, major cities around the world are looking to increase public transportation options, which leads to the need for more transportation tunnels. And as urban populations continue to grow, the need for clean water calls for more tunnels, and as urban footprints continue to expand, the need to increase and update combined sewage overflow tunnel grows with them.During two and a half days, more than 20 sessions covering all of these topics were presented at the Hyatt Regency in Chicago, many to packed rooms in which every seat was taken and people were standing along the side and back walls.RETC is a biennial conference and one of the largest in the North America for the tunneling and underground construction industries. As such, it hosts a robust exhibit floor. This year 172 vendors occupied 205 booth spaces. The exhibit included everything from tunnel boring machine manufacturers, like Robbins and Herrenknecht, to the companies that supply all kinds of parts and services to the industry."

Sep 1, 2019

By Joel Lööw, Jan Johansson, Lena Abrahamsson

Industry 4.0 offers new possibilities to combine increased productivity with stimulating workplaces in a good work environment. Used correctly, digitalization can create attractive jobs in safe control room environments, which provide space for the employee’s full expertise and creativity. This is true also for the mining industry. But, to succeed, it is important to analyze the development from a worker’s perspective. What will happen to their work? What skills will be needed in the mine of tomorrow? We must also consider the risks, such as privacy issues, increased stress, and work-life boundaries. These questions must be understood if we are to create workplaces that can attract a young and diverse workforce to tomorrow’s mining industry. In this article, we try to illustrate what the new technology can mean for the individual miners. We formulate the notion of Mining 4.0 (Industry 4.0 in the mining industry), where we try to create an image of how the future might look from a miner’s perspective and how mining companies may navigate their way to a future that works for all miners. To illustrate the range of possible outcomes, we formulate two scenarios: one utopian and one dystopic. At the end of our article, we bring forward six recommendations that can be considered a beginning of a road map for the human side of Mining 4.0.

By Joel Lööw, Jan Johansson, Lena Abrahamsson

Industry 4.0 offers new possibilities to combine increased productivity with stimulating workplaces in a good work environment. Used correctly, digitalization can create attractive jobs in safe control room environments, which provide space for the employee’s full expertise and creativity. This is true also for the mining industry. But, to succeed, it is important to analyze the development from a worker’s perspective. What will happen to their work? What skills will be needed in the mine of tomorrow? We must also consider the risks, such as privacy issues, increased stress, and work-life boundaries. These questions must be understood if we are to create workplaces that can attract a young and diverse workforce to tomorrow’s mining industry. In this article, we try to illustrate what the new technology can mean for the individual miners. We formulate the notion of Mining 4.0 (Industry 4.0 in the mining industry), where we try to create an image of how the future might look from a miner’s perspective and how mining companies may navigate their way to a future that works for all miners. To illustrate the range of possible outcomes, we formulate two scenarios: one utopian and one dystopic. At the end of our article, we bring forward six recommendations that can be considered a beginning of a road map for the human side of Mining 4.0.

By R. L. Virta

Ball Clay -- Four companies - H.C. Spinks Clay Co. Inc. (owned by Lhoist Group), Imerys Group (formerly Kentucky-Tennessee Clay Co.), Old Hickory Clay Co. and Unimin Corp. - mined ball clay in four states during 2010. Production, based on preliminary data, was 910 kt (1.11 million st) with an estimated value of $42.9 million. That was a 10-percent increase in tonnage from 831 kt (916 million st) with a value of $37.7 million that was produced in 2009. Tennessee was the leading producer state with 61 percent of domestic production. It was followed by Texas, Mississippi and Kentucky. About 70 percent of production was airfloat, 20 percent was crude and 10 percent was water-slurried.

Jan 1, 2011

By W. D. Monaghan

Flame cutting and welding is one of the major causes of fires and explosions in underground U.S. coal mines. On May 20, 2006, a flame cutting operation at the Darby Mine No. 1 led to an explosion that resulted in five fatalities. On January 22, 2003, another explosion caused by flame cutting at the McElroy Mine resulted in three fatalities and three serious injuries. On June 22, 1999, a flame cutting and welding operation at the Loveridge Mine caused a fire that resulted in sealing of the mine for an extended period. Finally, on March 19, 1992, an explosion at the Blacksville No. 1 Mine that was caused by welding resulted in four fatalities. The National Institute for Occupational Safety and Health (NIOSH) conducted a study on fires and explosions in underground U.S. coal mines that were caused by flame cutting and welding operations to determine the root causes of these types of fires and explosions. The methodology included interviewing mining personnel who perform flame cutting or welding operations in underground U.S. coal mines and visiting mines to observe these operations, and MSHA reports of investigations and accidents statistics were analyzed. The results were used to identify and compare differences between flame cutting and welding practices and techniques in small and large mines, Eastern and Western mines, low seam and high seam mines, room and pillar and longwall mines, and between experienced miners and new miners. As a result of this study, best practices and interventions were developed to reduce the number of fires and explosions caused by flame cutting and welding. This paper provides a summary of this work. Disclaimer: The finding and conclusion in this report are those of the authors and do not necessarily represent the views of the National Institute for Occupation Safety and Health.

Jan 1, 2009

By Brendan Demich, Joseph McGuire, Emily J. Haas

Near misses recorded and reported by workers can provide awarenessto the potential causes of injury and prompt safety management initiatives. Although most companies require near-miss reporting, it is unclear what the value of these reports are, if any, and how they influence subsequent actions or controls to reduce on-the-job risks. Researchers at the National Institute for Occupational Safety and Health (NIOSH) conducted a case study with an aggregates company in which near-miss reports were analyzed at each of their locations over an entire quarter during the summer of 2018. Within that quarter, workers recorded 249 near misses. Of those, 167 were valid near misses that occurred at work. Researchers coded the reports using a qualitative 5 × 5 risk matrix. Of the 167 near misses, 19% were deemed low risk, 25% moderate risk, 30% high risk, and 26% critical risk. Several patterns in the near-miss incidents were documented, including classification of incidents and common corrective actions referenced (i.e., elimination/substitution, engineering control or redesign, work process/procedures, and personal protective equipment). The analysis provides insight into ways that risk communication and management programs can be improved to reengage workers and their situational awareness on the job.

By Shosei Ph. D Serata

The Stress Control Method of mine design provides enhanced engineering control over the behavior of underground structures in comparison to conventional mine design methods. The same Method can be applied to achieve design control of surface subsidence. The basic mechanism relating undergroued deformation and surface subsidence is disclosed by mine simulations, using the REM (Rheological Element Method) computer code, whose predictions have been validated by field measurements. The key components of the underlying mechanism of surface subsidence have been shown to be the stress envelopes formed in the process of underground excavation. It has also been demonstrated that significant control of surface subsidence can be achieved by designing the geometry and timing of underground excavation to regulate the formation of stress envelopes. A field example is given in this paper to illustrate this application of the Stress Control Method.

Jan 1, 1986

The 31st annual American Hall of Fame Awards Banquet and Fundraiser sponsored by the Mining Foundation of the Southwest (MFSW) will be held at the JW Marriott Tucson Starr Pass Resort on Saturday, Dec. 7, 2013. Each year, one living inductee, two Medal of Merit recipients, honorees from mining?s past, an industry partnership award, as well as a special citation, are recognized by the MFSW for their respective contributions to the mining industry. James D. Toole, past president and chief executive officer of Southwest Energy LLC, will be the Hall of Fame inductee, guest of honor, and featured speaker at the awards banquet. Toole founded Southwest Energy LLC in 1973 and is credited with introducing innovative explosive technology, providing even greater value to its mining customers. Medals of Merit will be awarded to Joseph M. Keane, principal metallurgical engineer for SGS Metcon Research/KD Engineering, and Sean D. Dessureault, associate professor at the University of Arizona. Keane is recognized for his metallurgical expertise, especially in design development and pollution abatement. Dessureault is recognized for his advanced mining research, with more than 25 journal publications, and his entrepreneurship as the founder and chief executive officer of two mineral-related companies. To honor mining?s past, the hall of fame will induct Bartolomé de Medina for his invention of the patio process for recovering silver; Ben Williams for his management of the Copper Queen Mine in Bisbee, AZ; Charles E. Mills for his contributions at Morenci and Inspiration Copper and founding Apache Powder Co. and The Valley National Bank; John S. Finlay and Edwin B. Royle for their invention of the mucking machine; and Louis Caryl Graton for his ore deposits research and teaching economic geology at Harvard University.

Nov 1, 2013

By Tom Dettweiler, Robina Sharpe, Wright. Michael

The International Seabed Authority and a number of countries have or are in the process of developing environmental impact assessment guidelines and legislation for seafloor mineral development. The formal decision to grant a project an environmental permit is based on an environmental and social impact assessment (ESIA), culminating in an environmental impact statement (EIS). The EIS needs to be supported by sufficient data upon which an assessment of impacts can be made and mitigation measures developed. Given the remote locations of many seafloor prospects, collection of sufficient environmental data to inform an EIS is often a difficult, expensive and lengthy process.

Sep 1, 2014

By L. G. Stolarczyk, Y. Luo, S. S. Peng

Detection and assessment of severe geological anomalies ahead of a longwall face greatly benefits the mining operation. Electromagnetic-based Radio Imaging Method (RIM) is one of the most promising geophysical methods for this task. Based on two decades of development, the latest RIM instrumentation (RIM-IV) has expanded its operational range up to 1,800ft.A site demonstration of the RIM-IV technology was recently conducted within a longwall panel. An extensive ground truth study was performed to evaluate the accuracy of the RIM survey results. This study compared the generated RIM tomograms of attenuation rate with the mapped geological anomalies. Three different approaches have been employed to examine the accuracy of the RIM results and to correlate the measured signal attenuation rates with physical properties of the coal seam. The study shows that the RIM-IV technology is able to identify and delineate those geological features that would severely affect the longwall mining operation.

Jan 1, 2004

By J. C. Stankus

To protect mine personnel and moving equipment at underground roof fall areas, mine operators typically install steel sets, which are covered with wooden blocks and backfilled with an expanding type cement material. In large roof falls, the cost of void backfilling becomes prohibitively high causing some mines to leave the voids open. However, the durability of wood over time and the capability of the steel set and wood lagging to resist falling rock are unknown. This has caused concerns for the Mine Safety and Health Administration (MSHA) and ground control engineers. During past two years, Keystone Mining Services, LLC designed and developed various impact-resistant steel set designs that were approved by MSHA and installed in various underground fall rehabilitations. This paper presents the patent pending impact-resistant steel set design methodology, including (1) steel set design per AISC national standard, (2) design, development, and laboratory testing of a water proof composite impact resistant lagging panel, and (3) impact resistant steel set design based on Law of Conservation of Energy. Two underground cases will be included detailing the application of the system.

Jan 1, 2011

By Mustapha A. Raji, Alafara A. Baba, Christianah O. Adeyemi, Aishat Y. Abdulkareem, Rafiu B. Bale, Malay K. Ghosh

The increasing demand for pure aluminum and aluminum compounds of industrial quality from kaolinite ore cannot be overemphasized. Nigeria is one of the African countries endowed with abundant solid mineral resources that have not been sufficiently exploited to assist its indigenous industries. A wide array of applications of pure aluminum and its compounds are available, such as paper filling, refractories, adsorbent, catalysis, and paint additives. In this study, the upgrading of a Nigerian biotite-rich kaolinite ore by a hydrometallurgical route was investigated in oxalic acid media. During leaching studies, the effects of parameters including reaction temperature, lixiviant concentration and particle size on the extent of ore dissolution were examined. At optimal conditions (1.0 mol/L C2H2O4, 75 °C), 92.0% of the initial 10 g/L ore was reacted within 120 min. The dissolution curves from the shrinking core model were analyzed and found to conform to the assumption of surface diffusion reaction, and the calculated activation energy of 33.2 kJ/mol supported the proposed model. The unreacted product (~8.0%) analyzed by XRD was found to contain siliceous impurities and could serve as a valuable by-product for certain industries.

By Mustapha A. Raji, Alafara A. Baba, Christianah O. Adeyemi, Aishat Y. Abdulkareem, Rafiu B. Bale, Malay K. Ghosh

The increasing demand for pure aluminum and aluminum compounds of industrial quality from kaolinite ore cannot be overemphasized. Nigeria is one of the African countries endowed with abundant solid mineral resources that have not been sufficiently exploited to assist its indigenous industries. A wide array of applications of pure aluminum and its compounds are available, such as paper filling, refractories, adsorbent, catalysis, and paint additives. In this study, the upgrading of a Nigerian biotite-rich kaolinite ore by a hydrometallurgical route was investigated in oxalic acid media. During leaching studies, the effects of parameters including reaction temperature, lixiviant concentration and particle size on the extent of ore dissolution were examined. At optimal conditions (1.0 mol/L C2H2O4, 75 °C), 92.0% of the initial 10 g/L ore was reacted within 120 min. The dissolution curves from the shrinking core model were analyzed and found to conform to the assumption of surface diffusion reaction, and the calculated activation energy of 33.2 kJ/mol supported the proposed model. The unreacted product (~8.0%) analyzed by XRD was found to contain siliceous impurities and could serve as a valuable by-product for certain industries.

The National Mining Hall of Fame and Museum (NMHF&M) will celebrate its 25th anniversary on Sept. 22, 2012 when the 2012 class is inducted during a special ceremony in Las Vegas, NV in conjunction with MINExpo 2012. The NMHF&M will induct four men representing the equipment manufacturing, minerals exploration, copper and coal sectors of the mining industry. The diverse cross-section of mining industry giants joining the hall of fame include Glen A. Barton, J. David Lowell, Samuel Newhouse and John Cleveland Osgood. They will join 214 other mining industry pioneers when they are formally inducted into the National Mining Hall of Fame at the 25th Silver Anniversary Induction Banquet & Ceremony. These men were selected for being visionaries, leaders and ambassadors within their own sectors and across the industry at large.

Jan 1, 2013

The Iron Ore Company of Canada (IOC) is the largest manufacturer of iron ore pellets in Canada and its customer base covers North American, European and Asian steel producers. The company operates a mine, concentrator and a pelletizing plant in Labrador City, Newfoundland and Labrador, as well as port facilities located in Sept-Iles, Quebec. It also operates a 418-km (260-mile) railroad that links the mine to the port. IOC has approximately 1,900 employees. Its shareholders are Mitsubishi Corp. (26.18 percent), Labrador Iron Ore Royalty Income Fund (15.1 percent) and the international mining group Rio Tinto, which is its major shareholder (58.72 percent) and operator, with activities in more than 40 countries throughout the world. The IOC was incorporated in 1949 and by 1954 it had completed the Quebec North Shore and Labrador (QNS&L) rail line. IOC began mining in Schefferville, Quebec by 1954 and closed those operations down in 1982. In 1962, IOC commissioned the present day Carol Project consisting of mining, concentration and pelletizing facilities in Labrador City, Newfoundland. In 2004, IOC shipped its one-billionth tonne of ore on the QNS&L Railway. In 2005, IOC celebrated 50 years of mining history. The company expressed an interest in reducing the amount of oversize material (>1 m x 1 m x 1 m or 3.2 ft x 3.2 ft x 3.2 ft) being produced and its subsequent downstream effects, including in-pit sorting and reduction, damage to mobile equipment and significant delays in the loading pockets and the primary crushers. To achieve this goal, an oversize reduction project was undertaken by the mine that, to date, has significantly improved upon baseline measures. One key approach used to reduce the amount of oversize was the implementation of thicker emulsion. The introduction of a thicker emulsion provided more resistance to the forces created by dynamic water and reduced the infiltration of the emulsion into the cracks and fissures of the rockmass, resulting in reduced amounts of oversize and more consistent fragmentation throughout the muckpiles. Additionally, a significant reduction in nitrates leached into the mine water discharge has been realized. To determine the effectiveness of the oversize reduction project, IOC used a first-of-kind technology to assess fragmentation presented to the shovel at the digging face. A digital vision system (DVS) was installed on one of the shovels to capture images that were stamped with GPS locations. A large population of digital images were analyzed to produce a robust fragmentation distribution baseline that was used as one of the mine key performance indicators (KPI). Changes to blasting practice were subsequently measured against the baseline KPI to assess effectiveness.

Jan 1, 2011

By G. Tiess, S. Mujiyanto

Indonesia is a fast growing democratic developing country comprising more than 17,000 islands, founding member of ASEAN and a member of the G-20 major economies. It is one of the most highly mineralised countries in the world, the mining sector playing a pivotal role in the country's economy. In 2001, the Decentralization Law No. 22/1999 came into force and caused a transfer of authority and responsibility from central to regional and local administrative governments. The new Mining Law of 2009 substituted its 40 year old predecessor, but lacked detailed regulations for its implementation. These were only issued in 2010, which lead to a period of great uncertainty for investors in the mining industry. The new legislation intends to foster domestic economic development, which may be interpreted as protectionist policy. For the development of a sustainable mineral resources policy, further endeavours will have to be made.

Jan 1, 2011