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By Gerald G. Griswold, James O. Greenslade, Cherie Tilley, Richard Reseigh

INTRODUCTION The Harrison Western Corporation, a leading Denver based mine contracting and engineering concern, is presently engaged in sinking two 1,006 m (3,300 ft) shafts for the Phillips Uranium Corporation at their Nose Rock Project, approximately 13 miles northeast of the small community of Crownpoint in McKinley County, New Mexico. The Nose Rock Project is the first attempt by the Phillips Uranium Corporation to tap the deep uranium reserves in what has become known as the Grants Mineral Belt. (See Figure 1) Project Description Phillips Uranium Corporation's plan for the large 2700 metric ton per day (2950 tons/day) mining facility calls for a series of deep access and ventilation shafts ranging from 4.27 m (14 ft) to 5.49 m (18 ft) in diameter to approximate depths of 1,006 m (3,300 ft). The initial pair of shafts consists of one production shaft and one ventilation shaft separated by a distance of 91 m (300 ft). The interbedded layers of sedimentary sandstones and shales to be penetrated by the shafts contain several major water producing aquifers, the deepest being the mineralized zone called the Westwater Canyon Member of the Morrison Formation.

Jan 1, 1981

By Anthony Harding

In a world of technology and electronic communication, it is easy to forget what engineers do best with a problem: sitting around a table, exchanging views and ideas with sketches and respecting everyone?s view. This was the approach adopted in the project to arrive at a solution for the cross passage opening sup-port for the Seattle University Link Extension. Schedule and space constraints usually impede concurrent cross passage excavation and tunnel boring machine (TBM) operation. And where the space is constrained, opening support solutions that maximize available cross sections are of great benefit. While there are a number of solutions that minimize space, some of these solutions can require expensive steelwork and extensive drilling and fixing. However, following a detailed round-the-table discussion of the options and constraints, it was identified that a shotcrete shell would not only limit obstruction of the space during installation, but also permit easy installation, particularly around services, and avoid costly steelwork and drilling and fixing.

By Mike O'Driscoll

The future for the industrial minerals sector, and of mining in general, is being shaped by a new order of geopolitical and environmental factors. Last year’s foreword focused on an example of the former (U.S. tariff impact). Here, we shall focus on the latter, and in particular on mineral recycling. Mineral recycling is one of the two missions of the mineral industry right now; the other is decarbonization. Get these right and the industry will be more resilient to the challenges to come, plus making much-needed improvements to our environment. But mineral recycling should not be viewed as simply responding to environmental pressures, a checkbox on the corporate portfolio to allay fears and protests of damage to the environment, leading to charges of so-called greenwashing. While mineral recycling will be an important contributor to the circular economy and assisting in climate protection, it will also evolve as an essential alternative source of raw materials, presenting opportunities in mineral recycling project developments, and increased innovation and supply of pertinent processing and sorting technologies. This new era of industrial mineral recycling is already underway and gaining momentum. But it is not plain sailing, mindsets need to be adopted and correct processes employed. Key questions raised include: • How to go about getting involved in this sector? • Whether to vertically integrate? Invest for an in-house business/plant? • How much and how far to invest? What kind of processing/sorting technology is required? • Partner with/acquire an independent recycler? Join forces with same-sector end-use players? • What kind of logistics are involved? Permits for handling/transport? Costs? • Crucially: making grade acceptable, consistent and economic for customers?

Jul 1, 2026

By Diego A. Dávila Novoa

The United States is correctly recognizing copper as a strategic material increasingly tied to artificial intelligence (AI) infrastructure such as data centers, grid modernization, electricvehicle (EV) charging stations, electrification, defense manufacturing, industrial reshoring, energy security and long-cycle economic competitiveness. Recent years have seen rising concern around future copper deficits, accelerating electrification demand, geopolitical fragmentation and the strategic vulnerability associated with concentrated mineral supply chains. As a result, significant volumes of copper cathodes have increasingly flowed into the United States through a combination of Comex positioning, arbitrage opportunities relative to the Shanghai Futures Exchange (SHFE), inventory relocation, tariff anticipation and broader long-term supply-security considerations. However, an important structural distinction is beginning to emerge inside the system — one that remains materially underrecognized across portions of industry, finance, policy, government and institutional planning frameworks. Accumulating copper cathodes inside the United States is not automatically the same as expanding the country’s ability to industrially utilize copper at scale. That distinction matters enormously because the cathodes themselves are not the final product. Their strategic relevance only materializes once the material is transformed into qualified conductive systems capable of supporting real electrical infrastructure deployment across the broader economy. Copper cathodes inside warehouses may improve availability. But availability alone does not automatically create executable electrical infrastructure. The strategic value emerges only once conductive material becomes integrated into functioning industrial systems capable of supporting AI infrastructure; grid infrastructure; utility modernization; electrification; heating, ventilation and air-conditioning (HVAC) systems; EV charging infrastructure; defense manufacturing and broader industrial deployment. This increasingly shifts the discussion away from copper availability alone and toward a broader question of industrial synchronization involving conductive transformation capacity, fabrication capability, electroplating ecosystems, original equipment manufacturer (OEM) qualification, manufacturing scalability, logistics integration, workforce capability, permitting timelines and downstream deployment infrastructure. The challenge emerging inside the United States is therefore not necessarily geological scarcity. Rather, the bottleneck increasingly appears to be migrating downstream into the industrial interfaces required to convert material availability into executable infrastructure deployment, particularly as domestic transformation, fabrication, plating, qualification and deployment ecosystems attempt to scale under infrastructure constraints, long industrial lead times and evolving tariff structures affecting portions of the downstream conductive value chain.

Sep 1, 2026

By D. Morgan Warren, David Hanson, Alice Alex, Tom Meuzelaar, Heather Lawson, Sam J. S. Wright

Dynamic failures, or “bumps,” are a category of ground failure occurring in underground coal mines that involve the sudden expulsion of coal and rock debris into a working area of an active mine. They are an imperative safety concern for the global coal industry. Dynamic failure events have occurred in nearly every coal mining nation of the world, and there have been an estimated greater than 30,000 fatalities as the result of dynamic failure events globally (Bodziony and Lama, 1996; Kidybinski, 2011). Kidybinski (2011) describes them as “the most dangerous natural phenomenon creating a threat to life and health of miners working in hard coal mines.” In the United States, dynamic failures are significantly less common than in many other coal mining countries. However, when they do occur, they result in a proportionately extremely high rate of accidents and fatalities, with more than 60 percent of cases reported to the U.S. Mine Safety and Health Administration (MSHA) resulting in worker injury up to and including death (MSHA, n.d.). The driving mechanisms behind these events are not yet fully understood. Research aimed at optimizing pillar design and mining practices has resulted in a significant decrease in ground control related fatalities including dynamic failure occurrence over the past three decades (Mark, 2024). However, events continue to occur, and new research focused on engineering controls has failed to yield continued, measurable results. It is likely that to produce a further reduction in the rates of dynamic failure accident occurrence, novel research must be pursued. Recent research performed by the National Institute for Occupational Safety and Health (NIOSH), Spokane Mining Research Division (SMRD) has sought to address this need through a focus on the complex interaction between mining induced stressors and risks innate to the host rock mass through improved incorporation of geologic variables into hazard assessment.

Jun 1, 2026

By Carrie Smith

Inside a mountain in Idaho Springs, CO, a century-old mine is taking on a second life. The Edgar Experimental Mine (EEM), once a key producer of valuable ore, now trains engineers and soon may host quantum experiments that could reshape computing. Edgar began as a working underground operation where miners extracted ore from narrow veins deep in the rock. What once produced silver, lead and gold now generates something less visible. In 1921, the Colorado School of Mines (CSM) transformed the mine into an educational facility for mining students, preserving the underground workings as a hands-on training environment. More than a century later, the same tunnels built for extraction are supporting a different kind of industry. Instead of chasing mineral deposits, researchers are using the mine’s depth to study quantum systems, particle physics and train engineering students. Today, a growing network of research laboratories operate inside Edgar. Among them, a new quantum facility is taking shape, where the Colorado Underground Research Institute (CURIE) will turn the mine into a hub for high-scale physics research. The development of the new underground facilities would not have been possible without the hard work of the CSM’s mining engineering department. Over the course of a year, the department worked tirelessly to create a suitable space for future experiments. “The mining engineering department provided the mining expertise, planning and student labor necessary to excavate and prepare the underground spaces required for the quantum laboratory,” said Lee Fronapfel, mine manager of the Edgar Experimental Mine. That work included drill-and-blast excavation, ground support installation, shotcrete application, concrete floor placement, ventilation systems and electrical infrastructure, among other necessary adjustments. “To support quantum research activities, larger underground excavations were created in areas of the mine with the greatest depth of rock cover,” Fronapfel said. “These locations were selected to help minimize environmental interference and provide the stable underground conditions required for sensitive quantum experiments.” Unusual coordination between physicists and mining personnel occurred. Two fields that rarely intersect worked together to create an underground environment capable of tackling some of science’s most complex questions. Now, these departments collaborate closely to ensure all work is carried out effectively. “Because the laboratories are located in relatively isolated areas of the mine, vibration and noise impacts are generally limited,” said Fronapfel. “However, occasional coordination is required to manage activities that could affect sensitive experiments. This is handled through direct communication between mine personnel and quantum researchers.”

Jun 1, 2026

By Carrie Smith

As demand for copper continues to climb alongside the rapid expansion of artificial intelligence (AI), electrification and advanced manufacturing, the United States faces growing pressure to secure domestic supplies of the metal. Analysts expect global copper demand to increase sharply over the next two decades, as the production of electric vehicles, renewable energy and AI data centers ramps up. At the same time, new copper mines have become increasingly difficult to develop. In central Arizona, one project is taking a different approach. Located in the town of Florence between Phoenix and Tucson, Florence Copper recently became the first major new source of U.S. copper in more than a decade. In early 2026, the project began commercial operations after spending years developing its copper recovery process at a test stage. Rather than relying on an openpit or an underground mine, the operation uses in situ copper recovery (ISCR), a process that extracts copper from underground without blasting, hauling or constructing tailings facilities. The project is the world’s first greenfield commercial ISCR copper project and produces London Metal Exchange (LME) Grade A copper cathode on site, which allows the finished product to move directly to U.S. manufacturers without off-site smelting. Not only is Florence Copper a new copper operation that will help strengthen domestic mineral supply chains, but it is also a testament to whether certain copper deposits can be developed using a lower-impact approach. Traditional copper mining typically involves removing large volumes of rock from an openpit or underground workings before processing and transporting concentrate to a smelter. However, Florence Copper’s in situ process eliminates many of those steps. “Rather than extracting and processing massive quantities of mineralized rock, the ISCR process at Florence Copper leaches copper minerals into solution below ground before pumping a copper-rich solution to surface and processing it into pure copper cathode sheets on site,” said Sophie Dessart, manager of communications and public affairs at Florence Copper. The process takes place between 122 and 365 m (400 and 1,200 ft) below the surface within a naturally fractured copper oxide deposit saturated with groundwater. Operators inject a mildly acidic solution, comparable in acidity to household vinegar, through a series of wells. As the solution moves through the orebody, it dissolves copper minerals before recovery wells pump the copper-rich solution back to the surface. At the surface, the solution enters a solvent extraction and electrowinning (SX/EW) plant, where it is refined into LME Grade A copper cathodes. Once the copper has been removed, the remaining solution is recycled back into the wellfield, creating a closed-loop process that repeats throughout the life of the operation. Although Florence Copper only began commercial production this year, development of the deposit stretches back more than five decades. Copper was first identified on the property in 1969 after geologists recognized evidence of mineralization near Poston Butte. Its initial investigations focused on conventional mining methods before companies began evaluating the site’s potential for in situ recovery during the 1990s. In 2014, Trekor Metals (formerly Taseko Mines) acquired the project, and in 2017, construction of a production test facility began. Two years later, the pilot operation produced its first copper cathode using ISCR. Over the next several years, the facility safely produced more than one million pounds of copper while generating operational data that helped engineers refine commercial design. “The production test facility played a critical role by allowing Florence Copper to demonstrate the safety, effectiveness, compliance with permit conditions and overall environmental responsibility of the ISCR process while also generating valuable operational data to optimize performance at commercial scale,” said Dessart. The company completed construction of its production facility in fall 2025 and produced its first copper cathode in February 2026. Dessart said the project reached its construction and commissioning phase on schedule and within roughly 4 percent of budget. Florence Copper now expects to reach full production in 2027, with the capacity to produce 85 million pounds of copper annually. Over its projected 22-year mine life, the operation is expected to produce more than 1.5 billion pounds of copper cathode. At full production, the project is expected to increase U.S. copper cathode output by 5 percent compared with 2025 levels and make the country’s third-largest copper cathode producer. The timing of Florence Copper’s commercial launch coincides with a period of growing concern about future copper supply. According to S&P Global’s 2026 report, “Copper in the Age of AI: The Challenges of Electrification,” global copper demand could increase roughly 50 percent by 2040, reaching 42 Mt/a (46 stpy). The report projects that AI infrastructure alone will require significant volumes of copper, with a single hyperscale data center consuming as much as 50 kt (55,000 st). Without substantial new investment, the report warns the world could face a copper supply deficit approaching 10 Mt (11 million st) by 2040. But with the addition of Florence’s production, the U.S. could add a significant amount of the critical mineral to its domestic supply. “Florence Copper is emerging as a critical new source of U.S.-produced refined copper at a time when global demand is accelerating significantly,” said Dessart. “We are proud to serve as a new domestic source of U.S. copper, helping strengthen supply chains, support economic growth and ensure that the materials essential to electrification, innovation and national security are produced here at home.”

Aug 1, 2026

By Debra Struhsacker

For the last few years, critical minerals have been in the news as policymakers and the media highlight the important role critical minerals play in all aspects of the U.S. economy, technology, infrastructure, manufacturing, energy systems and national defense. These discussions focus on how critical minerals are the foundational inputs to everything modern societies build and use. They even play a role in the foods we eat because some fertilizers consist of minerals like phosphates, potash and lime. Many experts predict that the global demand for lithium, copper, rare earth elements, graphite, nickel and other critical minerals will soar in the next decade as countries pursue electrification objectives, build artificial intelligence (AI) data centers that must have massive amounts of always available electricity, and develop high-tech defense equipment built with rare earth magnets and other critical minerals (International Energy Agency, 2025). The U.S. Congress defined minerals for the first time in the National Materials and Minerals Policy, Research and Development Act of 1980, stating: “The term “materials” means substances, including minerals, of current or potential use that will be needed to supply the industrial, military, and essential civilian needs of the United States in the production of goods or services, including those which are primarily imported or for which there is a prospect of shortages or uncertain supply, or which present opportunities in terms of new physical properties, use, recycling, disposal or substitution, with the exclusion of food and of energy fuels used as such.” (30 U.S.C. § 1601(b)(2)) Although most critical “minerals” are actually metallic elements rather than minerals, this article will refer to them as “minerals” to conform to the congressional definition and the current critical minerals dialogue. Forty years later, Congress enacted the Energy Act of 2020, which amended the 1980 Act to add the following definition for critical minerals: “The term ‘‘critical mineral’’ means any mineral, element, substance, or material designated as critical by the Secretary under section 7002(c) of the Energy Act of 2020.” (30 U.S.C. 1601(2)(b)(1)) The Energy Act of 2020 directs the Secretary of the Interior, acting through the Director of the U.S. Geological Survey (USGS), to identify critical minerals, to develop a Critical Minerals List (CML), and to update the CML at least every three years or more frequently if determined necessary by the Secretary. The USGS published the first CML in February 2022 (USGS, 2022). The 2022 CML identified 50 minerals critical to the U.S. economy and national security. In November 2025, the USGS finalized its 2025 CML (USGS, 2025a, 2025b) to include 60 minerals (Fig. 1), stating: “Critical minerals underpin industries worth trillions of dollars, and import dependence puts key sectors at risk.” In developing the CML, Section 1606(c) of the Energy Act of 2022 directs the USGS to include minerals that: 1. Are essential to the economic or national security of the United States. 2. The supply chain of which is vulnerable to disruption (including restrictions associated with foreign political risk, abrupt demand growth, military conflict, violent unrest, anticompetitive or protectionist behaviors, and other risks throughout the supply chain). 3. Serve an essential function in the manufacturing of a product (including energy technology, defense, currency, agriculture, consumer electronics and health care-related applications), the absence of which would have significant consequences for the economic or national security of the United States. This law also requires the Secretary to consult with the Secretaries of Defense, Commerce, Agriculture, Health and Human Services, and Energy and the U.S. Trade Representative in designating minerals, elements, substances and materials as critical.

Sep 1, 2026

By Christian Connolly

The surface office’s shift change board shows 47 workers heading underground in the next hour. Before any of them descend, a safety manager works through a familiar routine with a clipboard in hand, moving down a printed roster, checking off names, and scanning a wall of safety helmets for current inspection stickers. At the same time, a crew foreman works through a binder searching for a certification card that should have been updated a month ago, while a desk spreadsheet behind them tracks personal protective equipment (PPE) assignments by serial number, last touched by hand. The new-hire onboarding process adds another layer of work. A fresh sticker is peeled and pressed onto the back of a helmet, with the number written on a paper log that will later be entered into the spreadsheet. It takes time, not because anyone is doing it wrong or slowly, but because this is simply how it has always been done. This daily routine represents where PPE management in mining still begins for some operations across North America. The administrative burden it places on safety teams compounds across every shift, crew rotation and piece of equipment that moves through the operation. For mines running multiple shifts across several active headings, with contractors rotating in and out alongside permanent crews, maintaining accurate records through manual systems alone is not just inefficient. It is a compliance liability waiting to surface.

Aug 1, 2026

By Rajesh Raitani, Emily Haas

The Society for Mining, Metallurgy & Exploration (SME) MINEXCHANGE SME Annual Conference & Expo hosts innovationrelated content across division sessions each year. The development and integration of automation, robotic systems, artificial intelligence (AI), machine learning (ML), internet of things (IoT), digital twins, drones, remote monitoring and other intelligent systems have regularly been showcased as advancements that can be used to improve safety, efficiency and sustainability across the industry. Although the presence of these conference topics is evident, it is unclear if they are just an expressed interest of industry visionaries and experts or if they may be early indicators of emerging trends. To date, there has not been a systematic analysis of the presence, fluctuation and focus of conference topics over the years. Some sources support the analysis of conference data to help identify emerging trends, opportunities and interests. For example, the International Technology and Engineering Educators Association (ITEEA) completed an analysis of conference programs from 1978 to 2014 to highlight historical milestones and emerging trends within their profession — an effort that assisted with future conferencing planning and other professional events (Reed and LaPorte, 2015). These authors identified several topics that appeared prevalent in the peer and gray literature that were not as prominent in conference offerings. They also indicated that the conference theme had minimal influences on the submission topics (Reed and LaPorte, 2015). In another effort, creators made links between tweets that used conference title hashtags during the Association of College and Research Libraries conferences from 2011 to 2019 as a form of trend analysis (Hennesy et al., 2021). Finally, related efforts have occurred in the text mining of journal article titles to identify latent topics and unique terms in the scientific literature (Ravikumar et al., 2023). Analyzing paper and conference titles has received attention in recent years to help propose and predict research topics (Wang et al., 2022). For example, Wang and colleagues (2022) indicated that trends revealed in paper titles can be useful for proposing more authoritative sessions at major conferences to align with industry trends. Consequently, an abbreviated activity was undertaken by SME’s Industry Innovation Strategic Committee in 2025. The goal was to (1) reveal stable and shifting priorities around innovation, (2) inform respective division planning for subsequent conference sessions and (3) ascertain whether the association is meeting members’ expectations around innovation-related content throughout the year. SME’s Industry Innovation Strategic Committee focused on the identification and dissemination of these tools in the field, and reviewed technical session titles from annual conference programs from 2016 to 2026. Using keyword frequency, theme clustering and division-specific tagging, the committee identified themes that seemed to be gaining traction, fading, remaining consistent, or changing in detail and scope regarding emerging technologies. This short article serves as both a retrospective view and possible planning tool for shaping future conference programming and, if applicable, inform impactful and relevant initiatives.

Sep 1, 2026

By Jim McKinley

With a growing number of mines reaching closure and seeing closure costs materialize, regulators, lenders and banks are observing projects that fail economically by miscalculating these costs. Mine closure costs are often categorized as a type of liability, which is defined as the money owed by the company to offset effects from the project and the money available to pay for those debts, such as bonds. Often, decisions made before the first day of mining — such as co-disposal, dry stack tailings, waste segregation — can significantly change the bond calculation. Once the bond is calculated and funded, operators are encouraged to conduct closure research and use applied science for progressive bond release prior to final closure. However, the author has observed few instances of financially significant progressive bond release, as there are typically no robust procedures for bond return, either before or during closure activities. As a result, many companies decide that entering a state of care and maintenance (C&M) is less risky than attempting to fund closure activities with an unknown bond return mechanism. Although perhaps less risky in the short term, the primary long-term risk with entering C&M is that it increases the chances of the bond not covering the cost of closure and the chances of the government/regulatory agency inheriting the mine closure. Bonds are typically reevaluated on a regular cycle, such as five years, so every mining company goes through this financing challenge eventually.

Aug 1, 2026

By William Gleason

During a mining roundtable at the U.S. Department of State on Aug. 7, President Donald Trump announced that the U.S. Government will invest $3 billion in critical minerals and battery projects as part of a push to increase domestic production, boost national security and support industrial policy. Part of this investment includes $180 million earmarked for education and workforce development for the mining sector, including up to $100 million to strengthen education in critical minerals and materials from the U.S. Department of Energy (DOE) and $80 million from the U.S. Department of War (DOW) for investments in the Colorado School of Mines, South Dakota School of Mines and Technology and Johns Hopkins University. The DOE’s Office of Critical Minerals and Energy Innovation (CMEI) announced a notice of intent for up to $100 million to develop a new program called “Providing Opportunities for Specialized Education in Critical Technologies (PROSPECT).” The DOW investment will be used to build technology innovation hubs, form projectfocused partnerships between students and defense industry, develop new processes and prototypes, and certify hundreds of new students with advanced degrees in mining, geology and metallurgy. Department heads from the 14 ABETaccredited mining schools in the United States attended the meeting held at the Department of State. They were joined by Trump, Secretary of State Marco Rubio, Secretary of the Interior Doug Burgum and Secretary of Commerce Howard Lutnick as well as several industry leaders including James Litinsky, chief executive officer of MP Materials; Vicky Peacey, president of Resolution Copper; Robert Friedland, founder of Ivanhoe Mines; Mitchell Krebs, chief executive officer of Coeur Mining as well as representatives from Rio Tinto, BHP, Energy Fuels and a number of other industry leaders. “I am not aware of another time in history when the leaders of the U.S. mining education community have been brought together with a sitting President, Cabinet officials, and industry leaders to discuss the future of American mining,” said Aaron Noble, Charles T. Holland Professor Department Head - Mining and Minerals Engineering and interim department head - Materials Science and Engineering at Virginia Tech. “Mining education was not on the periphery of the conversation; we quite literally had a seat at the table where national mineral strategy was being discussed. I hope we look back on this as an inflection point for American mining education.” The historic funding announcement comes in response to a critical need for more mining and processing engineers in the United States. The DOE estimates the industry will need 6,000 more mining engineers during the next decade. Noble said U.S. programs currently graduated fewer than 200 mining engineering graduates annually. Meeting that demand has been a challenge for many years. Enrollment in U.S. mining programs has declined by approximately 45 percent since 2015, and data compiled by the Society for Mining, Metallurgy & Exploration (SME) and the Society of Mining Professors show enrollment falling from nearly 1,500 students eight years ago to fewer than 600 in 2023. The investments offer the 14 mining schools an opportunity to expand enrollment, modernize curricula, strengthen industry relationships and build a more stable workforce pipeline. Kray Luxbacher, executive director and head of the University of Arizona School of Mining Engineering and Mineral Resources, attended the roundtable. She said mining school department heads across the country are “fighting to grow enrollment to meet industry demand.” “This funding is an opportunity to change the trajectory of mining,” Luxbacher said, “to bring in students who didn’t grow up around mining, show them what a modern career in this field looks like and give our programs the resources to compete for their attention.”

Sep 1, 2026

By Paul O. Knorr

The Marine Minerals Administration (MMA), a bureau within the U.S. Department of the Interior, has responsibility over both energy and nonenergy mineral development on the U.S. Outer Continental Shelf (OCS) under the OCS Lands Act (OCSLA). The OCS extends beyond the exclusive economic zone (EEZ) and encompasses the federal seabed. These responsibilities include all aspects of the department’s offshore energy and mineral resource management and conservation, safety oversight, environmental enforcement and related activities on the OCS, including activities pertaining to offshore critical minerals. The MMA’s Marine Minerals Program (MMP) is a matrixed program that manages U.S. offshore mineral resources including hard minerals, sand and gravel. As the sole steward of OCS critical and hard minerals, the MMP is responsible for understanding where critical minerals are located, identifying and understanding their environments, managing activities that affect these resources and implementing related federal policies. Several federal laws and regulations, such as OCSLA and the National Environmental Policy Act (NEPA), govern federally authorized or regulated activities. However, there are six U.S. federal rules in the Code of Federal Regulations (CFR) that are particularly pertinent to inform MMP’s procedures: 30 CFR 580 and 280 (prospecting for minerals), 30 CFR 581 (leasing of minerals), 30 CFR 582 and 282 (operations in the OCS related to minerals), and 30 CFR 583 (negotiated noncompetitive agreements for sand).

Sep 1, 2026

By Prashant Dixit, Akhil Singh, Asim Kumar Mukherjee, Sudipta Patra, Veerendra Singh

Phosphorous is an undesired element present in iron ore used in the steel making process. It leads to an increase in overall production cost as well as deteriorated steel quality. The desired phosphorus content in iron ores used in steel making is < 0.1%. Numerous beneficiation studies are mentioned in the literature; however, there is no commercial scale technology established to beneficiate high phosphorous iron. The major phosphorous bearing minerals are apatite (Ca5(PO4)(Cl/F/OH), wavellite (Al3(PO4)2(OH)3·5(H2O)), senegalite (Al2(PO4)(OH)3(H2O), barrandite ((Fe,Al)PO4·2H2O), etc. Ultrafine grinding is required to liberate phosphorous minerals from iron ore minerals and subsequently subject it to flotation, acid leaching, and bioprocessing. The selective flotation of iron ore could successfully reduce the phosphorous content from 0.82% to < 0.20% with the combination of grinding, magnetic separation, and carbothermic reduction. Acid leaching processes are also able to remove ~80% (0.85%→0.16%) of phosphorus; however, these are relatively costly and complex processes. The mechanism of bio-extraction for phosphorous removal is reported as one of the most successful processes. This process is capable of removing more than 80% of the total phosphorous and significantly reducing the phosphorous content from 1.06% to 0.16%. The main disadvantage of this process is that it occurs at a much slower pace. In today’s scenario, ultrafine grinding followed by froth flotation seems to be the most feasible solution for the beneficiation of high phosphorous iron ore in which the concentrate obtained can be utilized for pellet making and ultimately used for steel making processes. Development of additives for leaching, roasting, and bioprocessing can be explored further to make these processes more effective and economically viable.

May 28, 2024

By Yaxiong An, Jianwen Yu, Yuexin Han, Peng Gao

This paper presents an industrial verification test, adding a high pressure grinding roll and magnetic separation operation after the third-stage fine crushing operation to reduce the particle size of ball mill feed and improve the processing capacity of grinding operation. The optimal process parameters of high pressure grinding roll and magnetic separation were determined to be a 10 mm of roller surface spacing, a 10.5 Mpa of roller surface pressure, a 14 r/min of roller surface speed, a particle feed size to the magnetic separator of P100 3 mm, and a 3000 Oe of magnetic field intensity. Under the above optimized conditions, the iron grade of magnetic pre-enriched concentrate increased significantly from 28.27% to 36.30%, and the iron recovery was 87.59%. Meanwhile, the yield of coarse tailings was 36.16%, which significantly reduced the amount of ore entering the subsequent ball mill-magnetic separation operation. The ball mill Bond work index Wib of raw materials and the pre-enriched concentrate were 11.76 kW•h/t and 10.46 kW•h/t, respectively. The relative grindability of the pre-enriched concentrate was increased by 34%.

May 31, 2024

By C. Allen, H. Zhang, L. Falk

Shock loss occurs when there is a change in the area of a drift or airflow direction. These shock losses accumulate throughout the ventilation system and will increase the mine resistance as underground development deepens or becomes more complex. Hence, shock losses should be carefully considered when establishing the resistance through a series of branches as they can be a significant contributor to the estimated mine resistance. Using computer software to simulate a ventilation system is common but applying reasonable shock loss factors in the software is not a simple or direct process. Determining shock loss values includes the consideration of historical measurements, application of factors and formulas from literature based on the geometry and complexity of junctions, and the geometry variation at different locations. For example, the shock loss at the bottom of a ventilation raise can be comprised of a 90° bend and a sudden area change. This paper presents an approach for estimating shock loss factors near raise junctions using computational fluid dynamics. Current and future work will also be compared with field measurements. Results from this approach are compared with software defaults as well as classical techniques in published literature and standards.

May 14, 2024

By Ashish Kumar Vishwakarma, Vivek Kumar Himanshu, Kaushik Dey

The accurate prediction of blast-induced ground vibration due to underground ring blasting is a prominent need for ensuring the safety of structures. Different site-specific empirical equations are available for the prediction of ground vibration. These empirical equations are best suited when the monitoring and blasting locations are present in the same medium. The change in the medium alters the behavior of wave propagation. Hence, existing empirical equations have limitations in peak particle velocity (PPV) prediction when the blasting location is an underground hard rock mine and the monitoring location is ground surface. This is because the underground metal mine comprises different levels having void in the form of excavated stope or paste-filled stope. It is very difficult to predict the magnitude of PPV on the surface in such instances. Therefore, this study has been carried out to predict the PPV at surface due to underground blasting. In this paper, PPV data was recorded at surface for 207-ring blasts. Furthermore, the PPV has also been measured at different underground locations for 47-ring blasts. Different empirical equations along with k-nearest neighbor (KNN) and random forest (RF) model of machine learning technique were developed for the prediction of PPV. Most of the empirical models have higher accuracy in the prediction of PPV at an underground location. This shows that scaled distance-based empirical predictors are best suited when the monitoring and blasting media are the same. However, the empirical models do not predict PPV accurately when the monitoring location is ground surface and the blast is conducted underground. The machine learning models are better suited for PPV prediction in such cases. Based on the analysis performed for the case study site, RF model predicts PPV at surface with the highest accuracy. The coefficient of determination and root mean square error for RF model used for predicting PPV at ground surface are 0.94 and 0.438 mm/s respectively. The RF-based model is also the best suited among all the models for predicting PPV at underground locations as well.

Apr 20, 2024

By Xiang He, Xinzhong Wang, Ning Li, Bao Cao, Hongyang Bai, Zhigang Du

Revealing the periodic fracture pattern of the main roof and the key influencing factors of the support resistance is crucial for strata control and support selection of the shallow buried working face with large mining height. Based on the cantilever beam theory, an improved step rock beam model, and the measured strata pressure data of the 12,401 working face in Shangwan Mine, the mine pressure behavior law of the shallow buried with a large mining height working face was analyzed. The results show that both ratio of maximum principal stress to load (σ1/q) and ratio of maximum shear stress to load (τmax/q) inside the main roof increase with increasing periodic advancing distance, while the ratio of maximum shear stress to maximum principal stress (K) is the opposite, indicating that the increase rate of σ1/q is higher than that of τmax/q. K is less than 1 when the periodic advancing distance exceeds 8 m, indicating that the periodic fracture of the main roof will be dominated by tensile failure. Support resistance increases with increasing immediate roof thickness, main roof thickness, periodic fracture step distance of the main roof, and mining height, and decreases nonlinearly with increasing friction coefficient of periodic fracture rock block hinge surface. The main roof thickness, the periodic fracture distance of main roof, and the friction coefficient of the hinge surface of the periodic fracture rock block are the key factors influencing the support resistance. The advance breaking of the main roof and increasing the friction coefficient of the hinged surface of the main roof can reduce the support resistance of the working face. The support resistance of the 12,401 working face in Shangwan Mine presents an arch distribution characteristic. The average periodic weighting step interval, average support resistance, and dynamic load coefficient are 15.6 m, 17,552 kN, and 1.3, respectively. Finally, the rationality and validity of the model are verified by comparing the measured and theoretical values of the support resistance in the 12,401 working face of Shangwan Mine and other shallow coal seams with large mining height.

Apr 22, 2024

By Emily Sarver, August Greth, Cigdem Keles, Setareh Ghaychi Afrouz

The characterization of respirable dust on the basis of constituent fractions and particle sizes is increasingly of concern for evaluating exposure hazards. For high-resolution particle analysis, scanning electron microscopy with energy dispersive X-ray (SEM-EDX) can be an effective tool. However, it requires particles to be deposited on a smooth, uniform substrate such as a polycarbonate (PC) filter for optimal results. While direct sampling onto PC is possible, this is not the standard approach in many situations. For example, in coal mines, respirable dust samples have typically been collected onto polyvinyl chloride (PVC) filters because they are intended for gravimetric and/or infrared spectroscopy analysis. Such fibrous substrates are not ideal for SEM-EDX (or other microscopy), but an effective method to recover and redeposit the dust particles could render such samples suitable for the additional analysis. Here, we present a simple method and compare SEM-EDX results for paired samples analyzed directly on PC and following recovery from PVC and redeposition on PC. Both laboratorygenerated dust samples (n = 10 pairs) and field samples of respirable coal mine dust (n = 44 pairs) are included in this study. Although some changes in particle size distributions were observed between samples analyzed directly and those that were recovered and redeposited prior to analysis, the results indicate the dust recovery method generally yields a representative sample in terms of mineral constituents. That said, results also highlighted the effects of high particle loading density on individual particle analysis. Considering all sample pairs, those with similar loading density between the directly analyzed and recovered sample tended to exhibit similar mineralogy distributions. This was generally the case for the lab-generated sample pairs, and the Freeman-Halton exact test of independence indicated that the samples in just three (of 10) pairs were in disagreement in terms of their mineralogy distributions. On the other hand, for the field samples, the directly analyzed sample often had higher loading density than the recovered sample; and the Freeman-Halton test showed that 25 (of 44) pairs were in disagreement. However, the effect of possible particle agglomeration on the directly analyzed samples cannot be ruled out—and exploration of this factor was beyond the scope of the current study.

May 17, 2024

By Ismail Adeniyi Okewale, Hendrik Grobler

Significant factors believed to be responsible for tailings dam failure which can lead to loss of lives, destruction of properties and assets or damage to the environment are the mechanics of material characteristics and static liquefaction. It is therefore essential to understand the tendency for the likely occurrence of liquefaction in tailings dam as well as mechanics behind the behaviour of this tailing materials (inevitable products of ore mining, mineral and metallurgical processes). This study aims to present the mechanical behaviour and susceptibility to liquefaction of a gold tailings sample. Series of oedometer tests were conducted to determine the compression behaviour and the possibility of transitional behaviour or not. Index and physical tests were conducted to determine engineering grading descriptors which was directly linked to compression behaviour and comparisons made with other tailings. Microstructure was studied to understand the effects of fabric on the behaviour of samples and the chemical composition and mineralogy were also investigated. The compression paths slowly converge and the gold tailings might be said to be less transitional. The gold tailing is less dependent on initial state. The loosest gold tailing is more susceptible to liquefaction and compared to other gold tailings, this sample is less susceptible to liquefaction.

Apr 19, 2024