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By Ping Zhang, Xu Ma

Perturbations from mining operations significantly affect the stability of rock masses, especially with the increase in mining depths. This study uses the discrete element method (DEM) to investigate shear slip failure along discontinuities in an underground mine, aiming to quantify seismic moment and seismic energy to better understand seismic hazards.

May 1, 2023

By William Gleason

The Society for Mining Metallurgy and Exploration (SME) has a long and proud history of being the world?s leading resource for the dissemination for technical information regarding the fields of mining and mineral extraction and processing. That reputation was met, and maybe even exceeded, with the programming for the Society?s 2014 Annual Meeting in Salt Lake City, UT Feb. 23-26. The meeting drew more than 6,700 attendees to the three-day conference that featured more than 90 technical sessions with 670 presentations. These sessions covered the breadth of the mining and minerals industry, but it was the so-called ?softer issues? that were discussed in the keynote session that kicked off the meeting. The keynote session, ?Community Engagement: Building Partnerships for Mining,? brought together some of the leading voices from the mining industry, as well as some of the top voices from nongovernmental organizations (NGOs) that work in the mining sector. The common ground between the panelists was their dedication to working to ensure a social, economic and environmental balance in the development of mines. ?We wanted to bring these NGOs in to begin a dialogue to see how we can work together,? said SME President Jessica Kogel. ?This is a space that SME has not typically operated in, but one in which SME can bring a technical, scientific voice to the discussion. SME wants to play a leadership role in creating partnerships between the technical, social and economic areas that are crucial to the success of any mining project.? In today?s environment, finding mineral deposits and extracting the minerals in an economically viable manner is just one piece of an increasingly complex puzzle. Earning and maintaining a social license to operate requires careful consideration of local and global impacts. The industry often comes under intense scrutiny when a new project is proposed and, therefore, it must strive to meet the highest ethical and environmental standards. Success requires cooperation and collaboration between the industry, community and NGOs.

By Bruce Bryant

Silver ore was discovered at Aspen in 1879, but the district did not reach full production until 1888 after lawsuits were settled and railroads furnished less expensive transportation to the outside world. The boom years were 1888-92; production declined thereafter. From the middle 1920's until 1950, the Midnight mine in the Richmond Hill district furnished most of the output in the Aspen quadrangle. Since 1950, little mining has been done at Aspen. The metals produced were silver, lead and zinc. Native silver dissolved from the sulfide ores was redeposited by waters circulating as deep as 300 m below the land surface, resulting in great secondary enrichment of many of the deposits. Over 100 million ounces of silver were produced in the Aspen quadrangle. Low-grade lead-zinc deposits remain between the old workings locally, and data available suggest that primary ore below levels mined is also of low grade. The ore occurs in the Mississippian Leadville Limestone and the lower part of the Pennsylvanian Belden Formation in sites that were made favorable for deposition by a number of stratigraphic and structural factors.

Jan 1, 1982

Smart defense: that?s what the industry needs to play for the next four years, according to panelists at the 118th Annual Meeting of the Northwest Mining Association (NWMA), which met December 2-7 in Spokane, WA. The conference was well attended, with approximately 2,200 attendees, 244 booths in the two packed exhibition halls, and a rich offering of short courses, field trips, social events and technical sessions. Speakers at the packed legislative session articulated many of the frustrations felt by members of the mining community after the U.S. elections in November, and offered words of advice. Matthew Ellsworth, the new Government Affairs hire at NWMA, stated it best: ?Elections are like Christmas: you find out who?s naughty and nice ? and it?s always going to come again.?

Jan 1, 2013

By J. Noll

There is a need for direct tailpipe sampling of diesel vehicles in mines in order to determine the effects of an emissions-based maintenance program, evaluate control technologies such as diesel particulate filters and identify the worst diesel particulate matter (DPM) emitters in a fleet of vehicles. therefore, this study examined the performance of three portable instruments: a personal dust monitor (PDM) manufactured by thermo Scientific, a prototype elemental carbon monitor (Airtec) manufactured by FLIr and a prototype Ae91 instrument from Magee Scientific. These instruments were evaluated on the basis of their ability to provide direct reading tailpipe analysis for DPM. It was determined that the average bias of the tailpipe results from the PDM and the Airtec were 3±12% and 4±20%, respectively, when compared to the standard method of determining tailpipe particulate concentrations from a diluted exhaust. It was also determined that the Ae91 instrument correlated with the standard method.

Oct 1, 2013

By Ryan C. Stephan, Zach Agioutantis, Christopher Mark

Over the past 15 years, roof fall rates have decreased by two-thirds in U.S. coal mines and by even more in regions where the roof is weakest. This remarkable reduction in the number of roof falls has been accomplished with more effective roof support systems. The purpose of this paper is to present an empirical design methodology that uses real-world data to quantify the basic roof-support concepts that have been successful in the United States. A new computer package, called Analysis of Mine Roof Support (AMRS), implements the design methodology.

By Leping Liu, Sachin Urade, Li-Ting Chen, Pengbo Chu

This study aims to provide industrial perspectives on the current U.S. metal mining engineering education and areas for improvement. An online survey was designed to seek opinions from the U.S. mining industry. Findings indicated a shortage of qualified graduates from the current U.S. metal mining engineering education system. The qualifications that need to be improved include engineering sciences underlying mining methods, mining design experience, mining feasibility study, the connection between theory and practice, and understanding of the overall mining operation. The survey also identified future desired qualifications, such as the ability to acquire and apply new knowledge as needed and sufficient field experience. Respondents recommended enhancing collaborations between industry and academia.

Oct 1, 2023

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 Dominick Mandalari, David Mast, Heather Ullinger, Juan Granja, Amanda Foote

The City of Akron will construct the Northside Interceptor Tunnel project, a U.S. EPA/ DOJ CSO Long Term Control Plan Project. The system will provide at least 10.3 million gallons of storage in a 16.5-foot finished ID and 6,660-foot-long rock tunnel. The system will reduce both overflow volume and number of overflow structures on the Cuyahoga River. The project includes deep drop shafts and more than 3,000 linear feet of 48 to 96-inch I.D. sewers installed by trenchless construction methods. This paper will discuss the project background, ground conditions, and other challenges overcome during the design phases.

Jun 13, 2023

By Staff

Minerals contribute to U.S. gross domestic product (GDP) at several levels ? from mining and processing to the manufacturing of Anished products. In 2009, the estimated real GDP of the United States decreased by 2.4 percent compared with, and the estimated nominal GDP was about $14.2 trillion (Table 1). Trends in various sectors of the domestic economy are often reflected in mineral production and consumption rates. In 2009, the continued decline of the housing market was reflected in reductions in the production and consumption of cement, clays, construction sand and gravel, and crushed stone (those mineral commodities that are used almost exclusively in construction). Production of mineral commodities associated with the manufacture of goods for the housing market, such as ceramic tile, heating and air conditioning equipment, paint, plumbing and sanitaryware, roofing, wiring and wallboard also decreased. Declines in auto-mobile manufacturing resulted in reduced production

May 1, 2010

When it comes to safety in the mining and extractive industries, success is literally a matter of life and death. Anything short of perfection is not acceptable. In recent years, the mining industry in the United States has made tremendous strides in terms of health and safety for its workers. Part of that success has come with an increased focus on the issues of safety, an intense examination of procedures, liberal sharing of best practices and a focus on the synergy between safety, reliability and environment. During his closing keynote address of the Safety Management & System Reliability Conference in Minneapolis, MN on Nov. 15, Joe Driscoll, vice president of Great Basin Gold, showed a calendar from the coal fields in Pennsylvania from the early 1900s. The calendar marked the number of mine-related deaths each month. Some months, the number was as high as 50. It was an illustration of how far things have come, but there is still much more work to be done.

Jan 1, 2013

By Andrew J. Petruska, Austin F. Oltmanns

The paper proposes a capacitive load cell for detecting changes in material and tool wear conditions for conical picks used in underground mining. The current process is dangerous and subjective, relying on human operators near the cutting interface. The new sensor aims to improve worker safety by allowing operators to perform their functions from a greater distance.

Aug 1, 2023

By G. ALBORNOZ, S. Utili, A. AGOSTI, C. VALDERRAMA, R. PELL

The steepness of an openpit mine’s slopes has a substantial influence on the mine’s financial return. This paper proposes a novel design methodology where overall steeper pitwalls are employed without compromising the safety of the mine. In current design practice, pitwall profiles are often planar in cross section within each rock layer: that is, the profile inclination across each layer tends to be constant. Here, instead, a new geotechnical software, OptimalSlope, is used to determine optimal pitwall profiles of depth-varying inclination. OptimalSlope seeks the solution of a mathematical optimization problem where the overall steepness of the pitwall, from crest to toe, is maximized for an assigned lithology, geotechnical properties and factor of safety (FoS).

By JOHN HOMER, KATHLEEN STABRYLA, JACOB L. CARR, JONATHAN K. HRICA, JENNICA L. BELLANCA

Given the recent focus on powered haulage incidents within the U.S. mining sector, an appraisal of collision avoidance/warning systems (CXSs) through the lens of the research literature is timely. This paper aims to evaluate the maturity of CXS technology through the application of a technology readiness assessment (TRA) to research literature identified by systematic search methods. Results indicate that much of the evidence for CXS performance is at lower levels of maturity: that is, components and prototypes tested in a laboratory and in relevant environments. Less evidence exists for CXS performance at higher levels of maturity — that is, systems evaluated within operational environments — despite the existence of commercial products in the marketplace. This lack of evidence at higher maturity levels within the scientific literature highlights the need for more peer-reviewed research to evaluate CXS technologies. Additionally, results of the review reveal that most of the literature relevant to CXS technologies is focused on vehicle-to-vehicle interactions, which contrasts with haul truck fatal accident statistics that indicate most are due to vehicle-to-environment interactions, such as traveling through a berm. Lastly, the relatively small number and segmented nature of relevant studies suggest there is a need for more incremental research that would better facilitate the improvement of CXS technologies. This progression could be achieved through continued long-term interest and support for CXS technology research.

Mar 1, 2023

By W. A. Wright

The use and abuse of social media restate common employee relations issues. Business solutions to these issues require advanced preparation. Employers should establish and enforce social media policies to guide their reactions to employees? social media posts that reflect on the employer and its business.

Jan 1, 2011

By Liming Yuan, Isaac Zlochower, RICHARD THOMAS, Thomas H. Dubaniewicz, Teresa Barone

Mining vehicle manufacturers are developing lithium-ion (Li-ion) battery electric vehicles as an alternative to diesel-powered vehicles. In gassy underground mines, explosion-proof enclosures are commonly used to enclose electrical ignition sources to prevent propagation of an internal methane (CH4)-air explosion to a surrounding explosive atmosphere. Li-ion batteries can create pressurized explosions within sealed enclosures due to thermal runaway. Researchers at the U.S. National Institute for Occupational Safety and Health (NIOSH) measured thermal-runaway pressures of lithium iron phosphate (LFP) cells as a function of free space within sealed enclosures and observed an inverse power relationship. A well-confined cell produced 4260 psia (294 bar) of pressure during a thermal runaway, far exceeding minimum pressure containment specifications for conventional explosion-proof enclosures. Results indicate that adding enough free space surrounding LFP cells can reduce thermal-runaway pressures to levels below that expected for CH4-air ignitions. Measured thermal-runaway temperatures were below the minimum autoignition temperature of CH4-air.

By Jerry C. Tien

In 2009 China mined 2.695 billion metric tones (Gt) of raw coal. It is estimated that only 3-5% or roughly 135 million metric tones (Mt) of these were mined from 300 some surface operations. Except for a dozen or so large modern operations, most of China's surface coal operations are small by western standards, with annual production ranging from a few thousand tones to 300,000 metric tones (mt). Depending on the size of operations, equipment used range from small trucks and shovels to large bucket wheel excavators and draglines in sizable pits. This article provides a brief overview of China's surface mineable coal reserves, mining methods commonly used and increasing environmental concerns; introductions of several large surface operations are also provided.

Jan 1, 2012

By Samer Sadek, Brian Hagan

We are thrilled to welcome you to the 2025 Rapid Excavation and Tunneling Conference (RETC), which will be held in Dallas, TX. This year’s conference will showcase the continued trend of strong industry interest, as there will be a record setting 115 papers being presented over the course of three days. The set of papers compiled in this book captures the latest and greatest information on a broad array of topics within our fascinating tunneling industry. We hope that the compilation of selected papers in this book will provide a comprehensive recap of the conference while also providing a source of future reference for contractors, engineers, and anyone in general who is a student of our beloved and unique industry. Since its inception in 1972, RETC has been the preeminent tunneling forum to promote ideas, tell stories, share lessons learned, and promote new technologies. RETC prides itself on its focus towards highlighting real-world experiences and practical ideas, with the intent to help the entire industry learn from one another and grow. The need for us all to stay sharp and remain on the cutting edge of technology has never been stronger – the technology and ideas that have been applied in aerospace are now attempting to mix with tunneling, and the advancement of AI continues to permeate all industries. However, no amount of technology or AI can fully replace the human element, and in our tunneling industry, the human element is key and is what sets us apart. In tunneling, every project is different, because the ground is always different. We can only take what the ground will give us, and we must rely on our past experiences to get through present day challenges. Most importantly, we must rely on each other. This is the heart of what RETC is all about. For those of you attending this conference, we encourage you to attend as many sessions as possible and engage with your colleagues to discuss during the breaks in between sessions. This sharing of ideas is what keeps us connected and helps to expand our industry. Please also try to engage with the scholarship students and the newcomers who will be in attendance, as it is the new ideas and fresh energy from the next generation that will continue to make our industry thrive into the future. The program chairs thank and greatly appreciate the efforts made by our session chairs, co-chairs, authors, the members of the RETC Executive Committee, and most importantly the SME staff towards making this RETC possible.

Oct 1, 2025

By Kristian E. Waters, Hao Ma, Haibei Wang

Heavy metal ions exist in waste effluents including mining tailings, manufacturing discharges, and smelting and metal plating process wastes. Various methods are available to treat industrial effluents containing high levels of metal ions, but when confronted with wastewater that has low metal ion concentration below 500 mg/L, most techniques suffer from low removal or separation efficiency as well as high operating cost. ELM-based techniques can be used to solve these problems.

Apr 1, 2023

By Paul Lynch

"Since being reported to the 2012 UMI in Shanghai, the Cook Islands has been steadily developing for the commencement of it Seabed Minerals sector in its large Exclusive Economic Zone which contain a vast and unique Manganese Nodule resource, estimated at 10 billion tonnes1. At the 2013 UMI in Brazil, it was reported that the Seabed Minerals Act had commenced and all the necessary complex Technical aspects of this developmental work was being undertaken. At the 2014 UMI in Portugal, full details of the final developments leading to the opening of the Tender of Exploration Blocks in the Cook Islands EEZ will be presented in a brief but comprehensive method, using Poster displays, Powerpoint and active Website interaction. This will show the drafted Regulations, prepared on best international standards, to address both Licencing and Environmental requirements, to give clarity and security to the Resources Owner, industry and stakeholders. This work in being coordinated by the Cook Islands Seabed Minerals Authority, with the valuable collaboration of many international, regional and national stakeholders, including the Cook Islands NGOs, Marine Resources, Marine Park and National Environment Service."

Sep 1, 2014