About

The Department of Mining and Minerals Engineering at Virginia Tech is a diverse community of professionals committed to teaching and research that train students to address the critical energy and sustainability needs of the future. The faculty are widely recognized for their pioneering work in clean coal technology, sustainable mining, critical minerals recovery, mine safety, and environmental engineering, and their commitment to student success.

Research topics

• Chemistry
• Mineralogy
• Environmental science
• Metallurgy
• Materials science
• Engineering
• Inorganic chemistry
• Waste management
• Organic chemistry
• Chemical engineering
• Nuclear chemistry
• Physical chemistry
• Environmental engineering
• Mining engineering
• Environmental chemistry
• Geology

Selected publications

• Optimizing Flotation Circuit Using a Model that Can Predict Both Grade and Recoveries

  2025-01-01

  book-chapter
  PublisherDOI

• Letter from the Editors

  New York History · 2024-12-01

  letterSenior author
  PublisherDOI

• Cleaning and Utilization of Waste Coal for Graphite Applications

  2024-01-01 · 1 citations

  article1st authorCorresponding
  PublisherDOI

• Augmenting a Simulation Campaign for Hybrid Computer Model and Field Data Experiments

  Technometrics · 2024-04-19 · 2 citations

  articleOpen access

  The Kennedy and O’Hagan (KOH) calibration framework uses coupled Gaussian processes (GPs) to meta-model an expensive simulator (first GP), tune its “knobs” (calibration inputs) to best match observations from a real physical/field experiment and correct for any modeling bias (second GP) when predicting under new field conditions (design inputs). There are well-established methods for placement of design inputs for data-efficient planning of a simulation campaign in isolation, that is, without field data: space-filling, or via criterion like minimum integrated mean-squared prediction error (IMSPE). Analogues within the coupled GP KOH framework are mostly absent from the literature. Here we derive a closed form IMSPE criterion for sequentially acquiring new simulator data for KOH. We illustrate how acquisitions space-fill in design space, but concentrate in calibration space. Closed form IMSPE precipitates a closed-form gradient for efficient numerical optimization. We demonstrate that our KOH-IMSPE strategy leads to a more efficient simulation campaign on benchmark problems, and conclude with a showcase on an application to equilibrium concentrations of rare earth elements for a liquid–liquid extraction reaction.

  PublisherOA PDFDOI

• Influence of Mesh Design and Surface Treatments on Particle Transport and Fate in a Vibration-Enhanced Flooded Bed Dust Scrubber

  Mining Metallurgy & Exploration · 2024-05-23

  articleOpen accessSenior author

  Abstract Respirable coal mine dust (RCMD) is one of the biggest occupational health hazards for underground coal miners. Dusty mining environments can cause long-term health problems, including pneumoconiosis and progressive massive fibrosis. The Mine Safety and Health Administration (MSHA) has recently revised regulations promoting enhanced dust mitigation technologies, which have sparked renewed interest in the development of dust mitigation technologies. The flooded bed dust scrubber (FBS) is one of the most widely used technologies; however, it is limited by technical challenges, the most notable being the potential to clog. Recent studies have shown that applying vibration to filter mesh can improve the overall efficiency of the scrubber and that the system can be readily integrated to existing continuous mining equipment using an energy harvesting approach. In this follow-up study, the impact of mesh design and surface modification on system efficiency was examined using different vibrating liquid-coated stainless-steel mesh panels in a laboratory-scale FBS. Based on the two-way interaction data from a multi-factor experimental design, the results show that the performance of the system can be optimized by using hydrophilic 20- or 30-layer filters and by excitation frequencies between 67 and 134 Hz. This laboratory study suggests that a 20-layer mesh screen with hydrophilic surface applications and optimized vibration parameters can perform similar to that of a 30-layer static mesh, which is typically used in industrial units.

  PublisherOA PDFDOI

• A Preliminary Study on the Beneficiation and Recovery of Valuable Metals from Municipal Solid Waste Incineration Bottom Ash

  Mining Metallurgy & Exploration · 2024-04-27 · 2 citations

  article
  PublisherDOI

• American Relics and the Politics of Public Memory by Matthew Dennis (review)

  New York History · 2024-12-01

  article1st authorCorresponding
  PublisherDOI

• Terrorism in American Memory: Memorials, Museums, and Architecture in the Post-9/11 Era by Marita Sturken (review)

  New York History · 2023-12-01

  article1st authorCorresponding

  Reviewed by: Terrorism in American Memory: Memorials, Museums, and Architecture in the Post-9/11 Era by Marita Sturken Aaron Noble (bio) Terrorism in American Memory: Memorials, Museums, and Architecture in the Post-9/11 Era By Marita Sturken. New York: New York University Press, 2022. 336 pages. $89.00 hardcover, $29.00 paperback. A professor of media, culture, and communication at New York University, Marita Sturken has published several works exploring the power of memory and memorialization in American culture. In her most recent work, Terrorism in American Memory: Memorials, Museums, and Architecture in the Post-9/11 Era, Sturken returns to the subject of memorialization and September 11, 2001. This work explores American memorial culture and its role in shaping—and challenging—national narratives and identities in an era that Sturken bookends between the foreign terrorist attacks of September 11, 2001, and the domestic terrorist assault on the U.S. Capitol on January 6, 2021. In the intervening years, Sturken identifies an evolution in memory projects that, she argues, define memorialization in the post-9/11 era. Sturken takes readers on a journey from an "overabundance of 9/11 memory" (4) in the wake of the attacks, in which she details an "obsessive proliferation of 9/11 memorials and the construction of the 9/11 museum, almost all of which deployed memory as a form of national unity" (223); to memory projects for the wars in Afghanistan and Iraq, which seek to create visible reminders of the costs of war that Sturken argues have been erased from American cultural memory (178); to her concluding chapters focused on the Legacy Museum and Memorial in Montgomery, Alabama, which Sturken identifies as the end of the era "with a memorial and museum that demand a rewriting of the national narrative to demonstrate how racism and terrorism [have] been integral to the national fabric" (223). Sturken successfully weaves her main argumentative thread—and her central critique of 9/11 memory—throughout the book: that "terrorism has been narrativized in US culture [End Page 453] as a foreign threat visited upon the US from elsewhere" (219) in a manner that allows for the retention of a dominant narrative of national innocence that was violently interrupted on September 11, 2001. Her turn to an examination of the work of the Equal Justice Initiative in the creation of the Legacy Memorial and Museum provides a jarring, but effective juxtaposition to the impact of memorialization on public consciousness. Throughout the book, Sturken is an advocate of "deploying memory as a form of social change" (220). Her examination of the Legacy Memorial offers a case study on the ways that memorialization can "potentially be transformed into social justice activism in the present" by confronting visitors with a counternarrative that engages in dialogue about the nation's "history of enslavement and native genocide and of lynching and segregation" as a means of promoting national reckoning (264). Sturken's examination of memorialization at the National September 11th Memorial in New York City; at the Pentagon in Arlington, Virginia; at the Flight 93 Memorial in Shanksville, Pennsylvania; and at the Legacy Memorial emphasizes the role and importance of architecture—minimalist architecture in particular—in establishing the desired narrative at these sites of memory. Sturken explores how the "narrative of absence" (51) created by many of the 9/11 memorials evokes powerful emotional responses, yet does not require visitors to probe deeper questions about the meaning of 9/11 or its broader historical contexts. By contrast, the Legacy Memorial seeks to confront and to directly challenge visitors and the preconceived notions of the American story in a way that creates "an experience for visitors that aims to go from confrontation to hope" (246). The book also highlights the tension and conflict that confront museums in their role as sites of memory and in their mission as educational institutions. In her analysis of the National September 11th Museum, Sturken concludes that the "memorial function of the museum to honor those who died inevitably restrains and restricts its capacity for historical interpretation" (82). She argues that the power and immediacy of the artifacts displayed in the museum create an emotive resonance that enables...

  PublisherDOI

• Letter from the Editors

  New York History · 2023-12-01

  letterSenior author

  Letter from the Editors Robert Chiles, Devin R. Lander, Jennifer Lemak, and Aaron Noble Dear Readers, Before this issue went to print, we were saddened to hear of the passing of Dr. Wendell Tripp. Dr. Tripp was a legend within the New York State history community and was an accomplished educator, researcher, and author. He was also the prolific editor of this journal for decades, having served in that capacity for an amazing 148 issues. Our thoughts are with his family and with all the historians and authors who worked with him over the years. Among the treasures of state-level histories is the fact that they often uncover the idiosyncratic experiences and particular agendas of communities and individuals. These idiosyncrasies often complicate and humanize well-known historical events while providing new interpretations of old historical themes. This issue of New York History offers a panoply of studies in how regional scholarship adds nuance to well-known stories while also furnishing revised interpretations of the past. Articles by Amy M. Cools and Chris Fobare each reveal the relationship between activist strategies among African Americans in nineteenth-century New York and broader national controversies and trends. In "Association of Ladies," Cools explores the essential roles of Emeline Bastien and Fanny Tompkins among New York City activists to reveal the forms of community leadership available to African American women. In "A Full Measure of Citizenship," Fobare charts the evolving strategies of African Americans in Gilded Age Oneida County, analyzing how initial hopes for collaborative work toward social and political equality were replaced by an inward-facing pragmatism emphasizing economic uplift and social respectability once white Republicans abandoned the promises of Reconstruction. The contributions by Michael Haggerty, Mark A. Smith, and Colin Williams all demonstrate that exploring how individual motivations interfaced with broad national trends provides a space for revisionist interpretations of major historical problems. In "The Blackwell's Island Candidate," Haggerty engages the rhetoric and experiences of New York congressman Mike Walsh to argue that frustration with the sprawling carceral state was an essential component of northern working-class politics in the antebellum period. In "The Curious Case of Clancy Collins," Smith uses the Civil War service record of one Irish-immigrant New Yorker to explore the complex mix of financial and ideological concerns motivating both enlistments in and desertion from the Union army. In "Persuasion Politics," Williams reassesses the career of Governor George Clinton, portraying New York's first and longest-serving chief executive less as a factional partisan than as a builder of stability and prosperity. [End Page vii] Meanwhile, exciting revisionist articles complicate our views of famous pieces of Empire State History such as the 1918 influenza pandemic, the rise of Coney Island, and the status of New York State as nineteenth-century America's immigrant destination par excellence. In "The Supervisors Are Carrying the Bag," Eric C. Cimino provides an insightful microhistory of New York City's Nurses' Emergency Council (NEC)—an umbrella group of settlement houses and municipal organizations formed in response to the 1918 flu—to show how the institutional experiences of key figures like NEC chair Lillian Wald allowed the city to keep death rates among the lowest in the eastern United States. In "Coney Island Babies," Meggie Crnic and John Parascandola tell the story of Gilded Age Children's Aid Society health homes at Coney Island—elevating the perspectives of the largely impoverished and immigrant mothers, who preferred these institutions to hospitals, while adding a new dimension to memories of Coney Island as a site not only of spectacle and play but also of recuperation and rest. In "French-Canadian Settlement and Community Formation in Pre–Civil War New York State," Patrick Lacroix systematically demonstrates how mass-emigration from Quebec spurred significant institution-building and cultural development and shaped the economies of many upstate cities and towns. Lacroix's essay simultaneously reorients the story of immigrant New York northward from Gotham and that of French-Canadian America westward from New England. This issue is also an opportunity to announce both beginnings and endings. This volume is the last produced with our intern Zachary Deibel. Zac, who is pursuing his PhD at Binghamton, has been...

  PublisherDOI

• Physical, Chemical, and Mineralogical Characterizations of MSWI Ash Product and Recommendations for Downstream Processing

  2023-11-17

  reportOpen access

  The primary objectives of this project are to (1) systematically characterize MSWI ash, and (2) based on characterization findings, design preliminary flowsheets for downstream processing. To achieve these objectives, a total of ten tasks were completed, including sample collection, physical separation tests, liberation tests, synthetic MSWI ash preparation, elemental composition analysis, sequential chemical extraction, mineralogical characterization, pozzolanic activity characterization, thermal stability characterization, processing flowsheet design, TEA and T2M, and project performance reporting. Many useful findings and conclusions were obtained from the exhaustive efforts of this project from several different aspects, including: a) Valuable Metals in MSWI Ash: MSWI ash contains a diverse array of valuable metals. Based on potential recoverable values, the most valuable metals present in MSWI ash include Fe, Ti, Mn, Cu, Zn, V, Co, Ni, Sr, Sn, Ag, Mo, and Sc. Some of these metals have been identified as critical minerals by DOE and DOI, suggesting that MSWI is a promising feedstock for critical mineral recovery. Noticeable graphical and seasonable variations in the valuable metal content of MSWI ash were observed. Nevertheless, it was challenging to discern any clear, definitive patterns for conclusions from those observations. Compared with bottom ash, fly ash contains more volatile metals, such as Zn and Sn, but less nonvolatile metals, such as Fe, Mn, Cu, Zn, Co, and Ni. Mineralogical analyses showed that MSWI ash contains a substantial amount of calcium minerals, such as portlandite, lime, gypsum, and calcite. In addition, it was found that different types of valuable metals often exist in the same particles. b) Physical Separation of MSWI Ash: Both dry sieving and wet sieving were performed on MSWI ash. A notable disparity in the size distribution of the same material was observed when using the two different sieving methods. The disparity is due to the agglomeration of small particles. For the valuable metals investigated, no significant enrichment in a specific size fraction was observed, suggesting that it is challenging to preconcentrate the valuable metals through size fractionation. Due to the presence of ferromagnetic materials, such as Fe, most of the materials reported to the magnetic products obtained by dry magnetic separation. However, the enrichment effect is minimal due to the existence of particle agglomerates. Density separation at a cut-off density of 2.7 SG or higher led to noticeable enrichment of selected valuable metals, particularly Ti. The unburned carbon present in MSWI ash was effectively removed by flotation using diesel as the collector. A novel reagent scheme, Na2S plus cationic collectors, that can efficiently beneficiate nonferrous metals plus Co was developed. c) Liberation Tests: The particle size of MSWI ash was effectively reduced by grinding, and as a result, the encapsulated valuable metal particles (if any) were liberated to a certain degree. However, particle size reductions did not noticeably enhance the beneficiation performance using the physical separation methods, primarily due to the inefficiency of these methods in processing fine particles and/or a possibility that insufficient liberation is not a limiting factor for achieving satisfactory physical separation performance. Valuable metals were classified into water leachable, ion-exchangeable, acid soluble, reducible, oxidable, and insoluble forms. It was found that the distributions in the different categories, i.e., the occurrence modes of the valuable metals, were not affected by the particle size. d) Leaching Characteristics of Metals from MSWI Ash: Most of the valuable metals were extracted from the fly ash samples when using 1 M HCl or HNO3 as the lixiviant. The leaching reaction is a very fast process, which can reach equilibrium within the first 5 min. The releasing of Co, Ni and Ag are sensitive to leaching temperature, a higher recovery value could be obtained when using relatively higher leaching temperatures. The leachability of the valuable metals present in MSWI bottom ash is relatively lower than that of fly ash. Leaching recoveries increased with elevations in the acid concentration. Relatively high leaching recoveries were obtained for REEs, Mn, Co, Ni, Cu, and Zn using 1 M HCl or HNO3 as the lixiviant. Elevations in the reaction temperature noticeably increased the leachability of the valuable metals, whereas the leachability was barely influenced by oxidizing and reducing agents. Similar to fly ash, leaching valuable metals from bottom ash is a rapid process, with most of the leaching reaction completed within the first 5 minutes. e) Combusted iPhones: The original structure of iPhones was remained after treating at 400 ºC and 600 ºC, while after being treated at 800℃, the screen bent, and the back cover of iPhone melted. Increasing the combustion temperature to 1000℃, the screen scattered, and most of the components turned into ashes. Combustion enhanced the leachability of REEs, while the leachability of the other valuable metals, except for Zn, was barely affected. Most of the REEs present in the original iPhones occurred as oxidizable forms. With elevations in the combustion temperature up to 600 ºC, the oxidizable REEs were transformed to acid soluble forms. However, further elevations in temperature resulted in decreases in the acid soluble fraction and corresponding increases in the reducible and oxidizable forms. Additionally, combustion temperature also significantly altered the occurrence modes of other metals present in the iPhones. f) Synthetic MSWI Ash: It was found that in the absence of hydrogen peroxide, all the elements except for Si were leached to certain degrees. It is noteworthy that approximately 80% of Zn was leached with 1.2 M HCl. When hydrogen peroxide was added to the reaction system, noticeable increases in the leaching recovery of Fe, Mn, Co, Ni, and Cu were observed. The leaching recovery of Al and Si was barely affected by adding hydrogen peroxide. These results suggested that the majority of Zn in the synthetic MSWI ash existed as metal oxide, a portion of Fe, Mn, Co, Ni, and Cu existed as metal oxide, and Al and Si are associated with glasses which are difficult to leach. Additionally, the remaining Fe, Mn, Co, Ni, and Cu in the metallic form were efficiently oxidized in the presence of hydrogen peroxide. g) Pozzolanic Activity and Thermal Stability of MSWI Ash: MSWI fly ash has higher pozzolanic activity compared to the bottom ash sample, which indicates that the fly ash sample consumed more portlandite because of its smaller particle size as reactivity fundamentally relates to reaction surface area. However, after the recovery of valuable elements, the pozzolanic activity of both the valuable elements fraction and the less valuable elements-rich products decreased significantly, which means that the valuable elements recovery lowers the Ca(OH)2 consumption, thus leading to the low activity of SCM. h) Flowsheet Design for Metal Recovery from MSWI Ash: Based on the results of the comprehensive physical separation and acid leaching tests, circuits that enable the beneficiation of the valuable metals were developed. In these circuits, the valuable metals are recovered into nonferrous, ferrous, and other valuable metal concentrates, which are processed separately in the acid leaching step. The subsequent separation and purification steps are simplified due to the physical beneficiation step. In addition, the overall recovery cost is reduced since physical beneficiation is much cheaper compared with chemical processing. Using different technologies, such as selective precipitation and solvent extraction, a comprehensive hydrometallurgical circuit was designed, and compounds of Cu, Zn, Mn, Co, and Ni with a purity close to or even higher than 95% were successfully generated.

  PublisherDOI

Frequent coauthors

• Paul Ziemkiewicz

  West Virginia University

  12 shared

• Rick Honaker

  University of Kentucky

  11 shared

• Roe‐Hoan Yoon

  11 shared

• Seyed Hassan Amini

  10 shared

• Wencai Zhang

  Virginia Tech

  10 shared

• Christopher R. Vass

  West Virginia University

  6 shared

• G.H. Luttrell

  Virginia Tech

  6 shared

• Gerald H. Luttrell

  5 shared