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By W. E. Falck, A. Usubiaga, J. Spangenberg, P. Schepelmann, S. Šolar, D. Wittmer, F. Blanchard

The extraction and processing of mineral resources may be accompanied by environmental impacts. In spite of technological advancements, the enormous increase in production volumes within the last decades has induced sizeable environmental impacts along the life-cycle of products. Beside environmental impacts, social issues associated with mining need to be considered to ensure the social acceptability of mining activities. The project EO-MINERS aims at deploying Earth Observation (EO) tools to inform best practices in mining and to thus assist the global mineral resources industries in their transition to sustainable development. In order to facilitate the handling of complex sets of information requirements from a wide variety of stakeholders, a set of indicators was developed that will inform the process of EO tool and services development. The project strives to enable stakeholders outside the industry to meaningfully participate in decision-finding processes on mining-related issues by developing and providing EO products and services that fit the information requirements. The project has identified a wide range of such information requirements by stakeholders that could be potentially provided by EO tools. The applicability of the EO tools on the local level is tested on three mining sites.

Jan 1, 2011

By S. S. Pathak, S. Mishra, M. H. Tyeb, A. K. Majumder

Roping in hydrocyclones is a well-known phenomenon in mining and mineral industries which put serious restrictions on their continuous and maintenance free operation. Roping is mostly observed in association with high underflow solid concentrations which can be attributed to higher fraction of solids reporting to the underflow or the feed solid concentration itself being higher. This paper proposes a newly designed spigot with a truncated conical geometry which can allow for a rope-free discharge at higher feed solid concentrations. The experimental observations revealed that in the operation of a 50.8-mm-diameter hydrocyclone, roping ensued at 10% to 12.5% (wt%) feed solid concentration depending on feed inlet pressure for the cylindrical spigot, whereas with the modified spigot, rope free discharge was attained even at 25% (wt%) feed solid concentration.

Jan 8, 2022

By Simón Díaz-Quezada, HUMBERTO ESTAY

The heap leaching process has been widely used for recovering different metals since its first application at the end of the 1960s. In Chile, copper production via heap leaching has accounted for between 30 and 40% of annual copper production over the past 10 years. This level of production has been achieved through and supported by the use of a mathematical relation, known as the leaching ratio (LR) or irrigation ratio (IR), which relates operational parameters with metal extraction in a heap leaching operation. This ratio has been used to develop leaching column tests, to scale up results from the laboratory to industrial operations, to design new heap leaching plants, and in metallurgical control and production estimation. In spite of the widespread industrial use of this relation, few scientific studies mention it. This is due to its simplicity and basic theoretical foundations. This disparity between industrial practice and scientific research could lead to operational decisions which lack substantial theoretical support, and to scientific studies which have limited industrial impact. Against this background, several questions arise about the use of the LR: What are the constraints on the use of the LR? Are there practical advantages with respect to reported kinetic models? What is the main reason that industry prefers the use of the LR over kinetic models, which enjoy greater theoretical support? In order to guide its future use, this paper describes the leaching ratio and its current uses and limitations, through a literature review and case studies.

May 2, 2020

By Bruce Geller

The 2005 Prospectors and Developers Association of Canada (PDAC) convention continued the upbeat mood found in 2004. The global mining industry is booming due to higher commodity prices in nearly every sector. Other factors include low commodity inventories, China’s strong resource demands, the weak U.S. dollar, the very strong Euro, global uncertainties, an almost overripe investment climate for natural resources and the highest mining exploration budgets in seven years. Even unglamorous commodities, like iron, uranium and zinc, received copious attention in talks, the investors’ exchange, the core shack and in certain hospitality suites. The following impressions were gathered at the convention and enhanced by conference handouts and some abstracts that are available on the PDAC’s Web site, www.pdac.ca. At least 119 papers were presented, almost twice last year’s number.

Jan 1, 2005

By H. R. Manouchehri

In flotation practices, as particles become finer, such as smaller than 20 μm, process efficiency declines markedly. Selective agglomeration of fine particles is a technique to enhance the recovery of fine valuable minerals in flotation circuits. Different agglomerating methods have been introduced and tested. One method that has recently received much attention is to make use of magnetic force to aggregate fine particles. A selective aggregation of fine paramagnetic particles, such as sulfide minerals, can be achieved in the high-intensity magnetic field prior to or during flotation. The method is simple, selective and effective for fine particles and has low operational cost, though a minimum magnetic susceptibility for fine grains is required to promote the process. In this paper, the implementation of the ProFlote magnetic conditioning device in Boliden’s Garpenberg old concentrator in Sweden, where a complex massive sulfide ore is treated, is presented and discussed based on Boliden’s Garpenberg plant. The results showed an increase in the flotation recovery of fine valuable minerals. Zinc (Zn) production was increased by between 1,100 and 1,500 t/a, while salable yearly silver (Ag) production was increased by 1,500 kg. The copper (Cu) grade in the final concentrate was increased by 1 percent, while reductions in its Zn and lead (Pb) grades were obtained. Moreover, considerable reduction in Zn deportment to the final tail was observed

By Steven I. Majtenyi

There is a growing interest among transportation planners to make more use of the subsurface to preserve the landscape and make transportation more efficient and economical. At the present time, utilization of the underground for transportation facilities is severely restrained by the adverse environmental impact and high construction costs. However, recent studies performed by the United States Department of Transportation indicate that, in spite of such problems, the volume of underground construction has significantly increased during recent years and projections point to continuation of these trends(1). It is estimated that the total volume of transportation tunnel construction will exceed $4 billion in this decade. This level of Investment justifies a significant research program. Due to the common interest in transportation tunnels and to the similarities of problems encountered during their construction, the tunneling research activities of the Federal Highway Administration (FHWA) are closely coordinated with the programs other agencies of the U. S. Department of Transportation DOT); specifically, the Federal Railroad Administration (PRA) and the Urban mass Transportation Administration (UMTA). The FHWA is responsive to the particular needs of these agencies but will benefit from the research results obtained also. In 1971, the Office of Secretary, DOT, initiated plans for an overall coordination of the DOT, FICA, UMTA, and FHWA tunneling research activities. The objectives of this effort have been to reduce tunneling costs by 30% and to increase the rate of excavation by 200% within 10 years. This coordinated program was developed and promoted during 1972 and 1973 by Dr. Eugene L. Foster, at that

Jan 1, 1974

By D. Parks, A. Miller, M. McNinch, R. Jacksha, H. Nickerson

Each year hundreds of mine workers are involved in machinery-related accidents. Many of these accidents involve inadequate or improper use of lockout/tagout (LOTO) procedures. To mitigate the occurrence of these accidents, new safety methods are needed to monitor access to hazardous areas around operating machinery, improve documentation/monitoring of maintenance that requires shutdown of the machinery, and prevent unexpected startup or movement during machine maintenance activities. The National Institute for Occupational Safety and Health (NIOSH) is currently researching the application of Internet of Things (IoT) technologies to provide intelligent machine monitoring as part of a comprehensive LOTO program. This paper introduces NIOSH’s implementation of an IoT-based intelligent machine monitoring system to improve safety during operation and maintenance at a concrete batch plant. INTRODUCTION Of the hundreds of machinery-related accidents occurring every year in the mining industry, incidents involving stationary machinery at surface mines continue to be amongst the most frequent [1]. A National Institute for Occupational Safety and Health (NIOSH) study showed that the majority of fatal accidents involving stationary machinery at surface mines occurred at sand and gravel (38%) and stone (26%) operations. Of these accidents, entanglement in conveyor components were the most common cause of fatal accidents (48%) [2]. The same study stated that one-third of these accidents involved improper lockout/tagout (LOTO) procedures as a contributing factor. The U.S. Mine Safety and Health Administration (MSHA) acknowledged this problem, stating in a recent request for information (RFI) [3]: “Since 2007, there have been 17 fatalities related to working near or around belt conveyors, of which 76 percent were related to miners becoming entangled in belt drives, belt rollers, and discharge points. Factors that contribute to entanglement hazards include inadequate or missing guards, inadequate or an insufficient number of crossovers in strategic locations, and/or inappropriate lock out/tag out procedures. Systems that can sense a miner's presence in hazardous locations; ensure that machine guards are properly secured in place; and/or ensure machines are properly locked out and tagged out during maintenance would reduce fatalities [3].” In response to this problem, NIOSH’s Spokane Mining Research Division (SMRD) is exploring the potential application of Internet of Things (IoT) technologies to provide cost-effective intelligent machine monitoring systems for improved worker safety [4, 5]. SMRD partnered with Central Pre-mix CRH Company (Central Pre-mix) to develop and install a proof-of-concept wireless IoT solution to monitor machinery and conveyors during operation and maintenance. The primary goals of the system were to provide real-time monitoring of access points and facilitate the planning and execution of LOTO procedures

Jan 1, 2019

By B. Caro Vargas

The Toulon South Tunnel in France is the second part of a project started 20 years ago. After the problems and delays suffered during the construction of the North Tunnel, due to a complex geologic context of highly fractured and soft rocks under a highly urbanized environment, a very dense automatic monitoring system was implemented to control the settlements of surface (more than 1000 points), the structures adjacent to the tunnel alignment and the underground galleries being constructed. The latest automatic instrumentation systems were installed, using for example AMTS capabilities in terms of ?automatic prismless settlement monitoring?. All the data (geotechnical, structural and geological) was gathered in a global automatic data acquisition system and continuously available on a web based interface. Three different threshold levels (notification, anomaly, alert) were set up, each one with a differential and an absolute value for settlements. Depending on the actual geological site conditions and the actual monitored settlements, different supporting systems and excavation techniques were used. Furthermore, the monitoring data was also used to predict and anticipate the future settlement, by comparing it continuously with the theoretical Peck settlement curves. This method allowed a better risk management by limiting the settlement on existing structures and helped to secure the Works progress schedule, for a project that lasts from July 2007 to March 2011. The implementation of this observational method application is presented in this paper.

Jan 1, 2012

By Dan Witkowsky

For the 36th consecutive summer, the Colorado Mining Association Education Foundation and the Colorado School of Mines have sponsored “A Total Concept of the Mining Industry” for kindergarten through grade 12 teachers. Teachers from 34 states, plus the District of Columbia and two foreign countries, have graduated from the four-week course. They received six hours of recertification credit. This summer 31 teachers from Colorado, Kentucky, Virginia and Alaska completed the program. The course is unique from other shorter courses in that it solicits teachers of all disciplines from all K-12classes. In addition to the expected earth science and mathematics teachers, the Class of 2004 consisted of educators who teach music, chemistry, biology, social studies, history, basic English and world history. Others in the program included those who teach American history, physical and life science, remedial reading, consumer/family studies, “world of work,” language arts, engineering technology, environmental science, world geography, human anatomy and physiology, and business.

Jan 1, 2004

By Hojong Kim, Isehaq Al-Nafai, Kwadwo Osseo-Asare

The standard Gibbs free energy of formation (ΔGo f, 298) of bastnasite, (Ce, La, Nd, Pr)FCO3, was estimated using four different methods. The obtained average values were − 1589.5 kJ/mol for CeFCO3, − 1599.5 kJ/mol for LaFCO3, − 1589.1 kJ/mol for NdFCO3, and − 1595.4 kJ/mol for PrFCO3. The value for cerium bastnasite, CeFCO3, was used to construct a potential vs. pH (Eh-pH) diagram to investigate the stability relations of cerium bastnasite. The diagram shows that CeFCO3 is stable in neutral to basic conditions (pH ~ 6.5–11).

By R. M. Barker

The historic Getchell property is currently being mined from the Getchell Main Underground workings, a foot wall extension of the Getchell open pit deposits along the Getchell fault. Drift-and-fill techniques are used to extract the ore through a ramp access. The adjacent Turquoise Ridge deposit is currently under development via two vertical shafts. Together, the two mines will continue to provide feed to the Getchell's 3,200 tpd mill/autoclave circuit, taking Getchell Gold from its current production rate of 200,000 ounces (Au) per annum, to over 400,000 ounces (Au) per annum by 1999.

Jan 1, 1997

By John J. Murray, Michael T. McRae, Michael A. Krulc, Kathy L. Schuler

The San Vicente Pipeline Tunnel Project involves the construction of an 8.5-foot-diameter water pipeline in an 11 mile tunnel in San Diego, California. The tunnel is located in extremely variable geologic conditions of strong granitic and volcanic rocks, weak sedimentary rocks, abrasive conglomerates, and mixed face conditions. One reach of the tunnel is a 5,200-foot mixed face reach that includes Friars Formation Conglomerate overlying granitic rock. Due to the variable ground conditions in this reach, the use of a TBM was deemed too risky and the contract documents required drill-and-blast and hand mining methods. Although it was not required, the contractor elected to construct this reach using NATM methods. This paper describes the geology of the 5,200-foot mixed-face reach, the design evaluation, and the construction challenges faced on this project.

Jan 1, 2007

By K. KAKLIS, O. SAUBI, Z. Agioutantis, R. JAMISOLA

Three-point bending (TPB) tests were conducted on prismatic Nestos marble (Greece) specimens. The specimens were instrumented with piezoelectric sensors, and comprehensive recordings of acoustic emission (AE) signals were obtained. Machine learning in the form of artificial neural networks (ANNs) was then applied in an effort to investigate whether specimen load evolution can be predicted as a function of AE signals. A number of ANN models were developed, and the optimum model was selected based on the highest coefficient of determination (CoD) value as well as the lowest root mean square error (RMSE) value that was calculated for each model. The best performing ANN model exhibits accuracy above 99% with an RMSE value below 4%. It can be concluded that ANNs can potentially be applied to predict rock behavior under load especially when such loads lead to failure.

Sep 7, 2022

By Jake Gibson

"As one of the most pressing and important political debates of this century, climate change has captured global attention and is forcing governments to take action toward decreasing greenhouse gas (GHG) and carbon emission levels below what was previously thought to be necessary. With the ever-increasing price of diesel fuel, accompanied by the popular topic of carbon taxes and greenhouse gas emissions, the mining industry is looking to industry specialists for assistance. The benefits of a no-idle policy reach far beyond carbon reduction and fuel savings, ranging from decreased maintenance to increased engine life. With products like battery-powered ac systems and diesel-fired heaters, going noidle is easier today than ever before. With both systems being manufactured to withstand the harsh environments of the mining industry, the end user will see a seamless change from conventional, inefficient belt-driven systems to future, standalone mobile equipment HVAC.The history of GHGs and climate changeIn 1896, Svante Arrhenius first claimed that the combustion of fossil fuels may eventually result in enhanced global warming, but not until 1955 did Gilbert Plass draw global attention to global warming by summarizing that adding carbon dioxide to the atmosphere would intercept infrared radiation and thus warm the earth. Then in the early 1960s, Charles Keeling developed modern technology to produce concentration curves for atmospheric CO2 (Fig.1).In 1988, the Intergovernmental Panel on Climate Change (IPCC) was founded by the United Nations after acknowledgment of a rising global annual temperature. The IPCC consists of more than 2,500 scientific and technical experts from more than 60 countries. Because climate change could not be solved by a single country, the Kyoto Protocol was negotiated in 1998, requiring all participating countries to reduce their GHG emissions by at least 5 percent from the 1990 levels. The Protocol was signed by 186 countries in 2001 (since then several countries have retreated from the agreement, including the United States). In 2002, the Bush administration announced a policy for climate change relying on domestic, voluntary actions to reduce the "greenhouse gas intensity" of the United States economy by 18 percent by 2012. The U.S. still attends the Kyoto conference of parties (COPs) but does not participate in negotiations, as it is not bound by its terms."

Jan 1, 2014

By Greg Ford

Each year, companies spend millions of dollars on safety training and on safe equipment, money that is generally well spent. Despite that, we still make mistakes. What happens if the mistakes are made not because of inadequate training, but because we are hard-wired to act in a certain way? If you read any of the ?Because of Human Error? text boxes in this document, situations like these may look familiar in your own workplace. ?The issues of risk, health, safety and the environment are getting more attention now than ever before, at all levels of the organization,? said Calvin Price, vice president of Global Health and Safety at LNC-Lavalin Inc., a company with 21,000 workers worldwide. Most would agree with Price that attention to safety is increasing because responsible companies care about their workers and the workers? colleagues, families and communities. However, cynics might say that the safety spotlight is powered by the corporate bottom line. Direct costs created by workplace injuries total $51.8 billion annually and include workers? compensation payments, medical expenses, civil liability damages and litigation expenses. This sum represents a staggering one quarter of each dollar of pretax corporate profits. Indirect costs may run as much as 20 times the direct costs of on-the-job accidents and illnesses. Examples of indirect costs include training replacement employees, investigating the accident and implementing corrective measures, lost productivity, repairing damaged equipment and property, and costs associated with lower employee morale and absenteeism. What?s interesting is that up to 90 percent of incidents are due to human error, not faulty equipment or other factors.

Aug 1, 2013

By Valois R. Shea-Albin

Increasing pressure from State and Federal agencies to mitigate mining-induced subsidence damage to overlying structures has presented a unique problem to the coal industry in the western United States. Because sandstone escarpments are an environmental issue, millions of tons of coal reserves that underlie these escarpments risk being classified as unminable by regulatory agencies. At this time, the effect of subsidence on escarpments has not been well documented or characterized. The Bureau of Mines is using numerical modeling techniques to analyze escarpment response to longwall mining. Two- and three-dimensional finite element models have been constructed for a study area near Price, Utah, where longwall panels were mined near an escarpment. This status report includes preliminary results showing that the pattern of subsidence surrounding the escarpment can be simulated through numerical modeling. Models that include such structural details as joint and fracture patterns will better simulate subsidence patterns .and magnitude. By locating longwall panels strategically in relation to the escarpment, stability may be preserved throughout the mining process. Numerical modeling provides a method to analyze relatively quickly the effects of longwall panel location and resulting subsidence on escarpment stability. The goal is to provide a relatively accurate predictive tool for mine planning to determine if escarpment stability can be maintained while maximizing extraction of the coal reserves.

Jan 1, 1986

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

By G. Arpa

Ventilation survey using tracer gas measurement is one of the techniques for mine ventilation design, monitoring and investigation of movement of fresh air and contaminants. However, there has been little research into using both tracer gas monitoring and numerical simulation. In this research, tracer gas technique was used for quantitative assessment of airflows through narrow vein shrinkage stopes with various opening shapes and friction factors. SF6 was used as a tracer gas to monitor airflow through three narrow vein shrinkage stopes in order to obtain diffusion concentration curves against elapsed time. The mine ventilation simulator, MIVENA Ver.6, was used to construct the entire ventilation network of the mine to monitor airflows through the stopes. The diffusion concentration curves against elapsed time were simulated with a numerical model. The result shows that the concentration-time curve is unsymmetrical and is skewed to the front of the flow direction. From the results of history-matching between the measured and the simulated curves, volume flow rates of airways and stopes were evaluated. Importantly, the tailing effect of the concentration-time curve between the measured and simulated is greatly improved by reconstructing an equivalent airflow route to represent unused mine openings, dead end drives and other open spaces. Finally, it can be concluded that openings, dead end drives and other open spaces have no relation on flow rates, but affect the airflow quality provided from the inlet portal as shown by tracer gas diffusion characteristics.

Jan 1, 2009

By X. Shi

This paper presents design and implementation details of a fuzzy-behavior-based controller for an automated excavator. The robotic excavator is equipped with sensors, actuators and an embedded control system. The excavator controller uses neural-networks to interpret forces and torques gathered during the excavation process from bucket-mounted force sensors. Implementation details card experimental results using the fuzzy-behavior-based excavation controller are given for several excavation tasks. These excavation tasks demonstrate some of the complex skills that are essential for an autonomous mining-excavator controller.

Jan 1, 1997

By J. J. Gusek

The Riley Pass strip mine is an abandoned uranium-bearing lignite deposit in Harding County, South Dakota, covering about 150 acres of highwalls, pit floor and mine spoils exhibiting elevated levels of radioactivity. Six reclamation design alternatives were developed, ranging from doing nothing to reclaiming to approximate original con-tour. The alternatives were evaluated for expense, site stabilization, and mitigation of public safety hazards. A comparative economic evaluation on three of the alternatives was completed for the Forest Service in selecting an alternative and substantiating federal funding requests. This evaluation included economic impacts associated with physical and radiologic health hazards, affects on recreational users, socioeconomic impacts and environmental improvement.

Jan 1, 1995