About

Wencai Zhang is an Associate Professor in the Mining and Minerals Engineering department at Virginia Tech. His research interests include the recovery and purification of rare earth elements from coal-related materials, flotation surface chemistry of various minerals such as rare earth, sulfide, carbonate, silicate, and oxide minerals, as well as the processing and beneficiation of low-grade, finely-dispersed ores. He also focuses on recycling and utilization of industrial and urban wastes, and employs molecular dynamics and DFT simulation techniques to study chemical adsorption on mineral and material surfaces. He holds a Ph.D. in mining engineering from the University of Kentucky, obtained in 2017, a master's degree in mineral processing engineering from Central South University in 2013, and a bachelor's degree in mineral processing engineering from Shandong University of Science and Technology in 2011. Zhang has contributed to numerous publications in the field, exploring topics such as rare earth recovery, flotation separation, and leaching processes. He is involved in teaching courses related to mineral processing and materials handling at Virginia Tech.

Research topics

• Chemistry
• Materials science
• Organic chemistry
• Mineralogy
• Metallurgy
• Waste management
• Environmental science
• Engineering
• Nuclear chemistry
• Inorganic chemistry
• Geochemistry
• Environmental chemistry
• Geology

Selected publications

• Enhanced chalcopyrite flotation via pressurized CO2-assisted grinding

  Journal of environmental chemical engineering · 2025-11-17 · 1 citations

  articleSenior authorCorresponding
  PublisherDOI

• Integrated Transcriptomic and Metabolomic Analyses Reveal Terpenoid and Flavonoid Biosynthesis in High‐Altitude Response of <i>Incarvillea younghusbandii</i>

  Physiologia Plantarum · 2025-11-01

  article

  Incarvillea younghusbandii Sprague is distributed in the sandy meadow and gravelly habitats on the Qinghai-Tibet Plateau (QTP). It is commonly used as a Tibetan herbal medicine to treat weakness, anemia, and other conditions. To date, there are no prior reports on how I. younghusbandii adapts to extreme high-altitude environments or on the differences in the medicinal active ingredients between its various tissues. This study collected leaf and root samples of I. younghusbandii from three altitudes (4100, 4600, and 5200 m) on the QTP, and performed integrated transcriptomic and metabolomic analyses to elucidate the basis for its adaptation to high-altitude extreme environments. A total of 67,375 unigenes and 849 metabolites were identified, including 90 terpenoids and 16 flavonoids. Altitude-associated reprogramming of secondary metabolism was evident, particularly in the terpenoid, flavonoid, and phenylpropanoid biosynthetic pathways. Key biosynthetic genes (such as CHS, F3H, ANS, TPS) were significantly upregulated at higher elevations, correlating with the accumulation of stress-mitigating metabolites such as scutellarein derivatives, diosmetin, luteoloside, α-curcumene, and (S)-oleuropeic acid. These compounds are likely involved in enhancing UV protection, antioxidant capacity and osmotic adjustment. Tissue-specific responses revealed stronger transcriptional and metabolomic shifts in leaves than in roots, reflecting greater exposure of leaves to environmental stressors. Beyond secondary metabolism, altitude-induced modulation was observed in protein processing in the endoplasmic reticulum (RAD23), plant hormone signal transduction (AUX/IAA), and MAPK signaling pathway (WRKY29), indicating a coordinated multi-pathway response. This study reveals a complex regulatory network underlying high-altitude adaptation in I. younghusbandii, provides new insights into alpine plant resilience, and lays a foundation for the conservation and sustainable pharmacological development of Tibetan medicinal resources.

  PublisherDOI

• Investigating CO2 mineralization of fine mafic minerals: Insights into reaction characteristics and physicochemical attributes

  Journal of environmental chemical engineering · 2025-04-27 · 3 citations

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• Review of CeO₂ Nanostructure/Carbon Composite Catalysts for Wastewater Treatment

  ACS Applied Nano Materials · 2025-05-12 · 7 citations

  article1st author

  This review systematically summarizes recent advancements in cerium dioxide (CeO2) and carbon-based nanocomposite catalysts, focusing on their potential applications in environmental catalysis and wastewater treatment. First, the unique structural and chemical characteristics of CeO2 and carbon materials are discussed. CeO2 is noted for its distinctive redox properties and abundant oxygen vacancies at the nanoscale, while carbon materials are recognized for their high surface area and excellent chemical stability, which are enhanced by their nanostructured forms. These properties synergistically improve the pollutant degradation efficiency when combined in composite materials. Subsequently, the review explores key synthesis methods, including hydrothermal, sol–gel, and in situ techniques, analyzing their roles in controlling the morphology and catalytic activity of the composites at the nanoscale. Furthermore, the applications of CeO2/carbon nanocomposites in removing complex contaminants─such as dyes, pharmaceutical residues, and heavy-metal ions─are discussed in detail, highlighting their potential in improving the efficiency of industrial wastewater treatment. In conclusion, these composite catalysts, with their nanoscale-enhanced properties, exhibit excellent environmental compatibility and reusability, providing a theoretical foundation and practical guidance for the development of efficient and sustainable catalytic materials in the future.

  PublisherDOI

• Fabrication of physically multi-crosslinked sodium alginate/carboxylated-chitosan/attapulgite-base aerogel modified by polyethyleneimine for the efficient adsorption of organic dye and Cu(II) contaminants

  International Journal of Biological Macromolecules · 2025-05-15 · 10 citations

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• Unlocking the carbon mineralization capacity of produced water: Optimization and phase transformation

  Journal of Cleaner Production · 2025-07-02 · 5 citations

  articleSenior authorCorresponding
  PublisherDOI

• MSRS: Evaluating Multi-Source Retrieval-Augmented Generation

  ArXiv.org · 2025-08-28

  preprintOpen access

  Retrieval-augmented systems are typically evaluated in settings where information required to answer the query can be found within a single source or the answer is short-form or factoid-based. However, many real-world applications demand the ability to integrate and summarize information scattered across multiple sources, where no single source is sufficient to respond to the user's question. In such settings, the retrieval component of a RAG pipeline must recognize a variety of relevance signals, and the generation component must connect and synthesize information across multiple sources. We present a scalable framework for constructing evaluation benchmarks that challenge RAG systems to integrate information across distinct sources and generate long-form responses. Using our framework, we build two new benchmarks on Multi-Source Retrieval and Synthesis: MSRS-Story and MSRS-Meet, representing narrative synthesis and summarization tasks, respectively, that require retrieval from large collections. Our extensive experiments with various RAG pipelines -- including sparse and dense retrievers combined with frontier LLMs -- reveal that generation quality is highly dependent on retrieval effectiveness, which varies greatly by task. While multi-source synthesis proves challenging even in an oracle retrieval setting, we find that reasoning models significantly outperform standard LLMs at this distinct step.

  PublisherOA PDFDOI

• Microwave-assisted leaching of olivine: Investigation of leaching characteristics and kinetics of Mg, Si, Fe, Co, and Ni

  Minerals Engineering · 2025-04-23 · 20 citations

  articleOpen accessSenior authorCorresponding

  • Leaching of Mg, Si , Fe, Co, and Ni was enhanced by microwave-assisted leaching. • Microwave-assisted method enabled lower acid consumption within a very short time. • The Avrami model governed the leaching kinetics of elements. • Activation energy values confirmed the diffusion-controlled leaching process. Olivine, a silicate ultramafic rock, has been a promising primary resource of nickel and cobalt for the past years. Microwave-assisted leaching of selected elements, namely magnesium (Mg), silicon (Si), iron (Fe), cobalt (Co), and nickel (Ni) from olivine was compared with the conventional leaching method. Also, the effects of acid type, sulfuric acid concentration, solid-to-liquid (S/L) ratio, reaction time, and reaction temperature were investigated. Approximately 100 % of selected elements were extracted from olivine under suitable conditions of 0.5 M sulfuric acid concentration, 2.5 % S/L ratio, 20 min, and 160 °C. Microwave-assisted leaching enabled the leaching process to be conducted with high efficiency, with lower acid consumption within a very short time. Leaching kinetics modeling suggested that the microwave-assisted leaching of selected elements is governed by the Avrami model, while the surface reaction shrinking core model governs the conventional leaching kinetics. The morphology study of solid residues resulting from microwave-assisted leaching experiments indicated that the microfractures and cracks facilitate the leaching efficiency of selected elements by providing a higher reaction solid–liquid interface. This study reveals valuable insights into the leaching characteristics and kinetics of major and critical elements from olivine using microwave-assisted leaching.

  PublisherDOI

• Enhanced grindability of bastnaesite ore by ex-situ CO2 treatment under the partial pressure of 0–100 psi

  Journal of environmental chemical engineering · 2025-03-06 · 4 citations

  articleOpen accessSenior authorCorresponding

  High grinding energy consumption has long constrained the sustainable development of mineral processing . This study introduces an innovative technology that employs ex-situ CO 2 treatment to enhance the grindability of bastnaesite ore. The grinding aid effect was evaluated under CO 2 partial pressures ranging from 0 psi to 100 psi using particle size distribution and the Bond work index (BWI), while the underlying mechanism was elucidated with various characterization techniques including inductively coupled plasma (ICP), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Brunauer-Emmett-Teller (BET). The optimal grinding aid effect was achieved at 100 psi partial pressure, 50 % slurry concentration, and 3 h reaction duration. Correspondingly, the P 80 of the grinding product decreased from 81.76 μm to 72.73 μm and the BWI of bastnaesite ore decreased from 6.96 kW·h/t to 6.30 kW·h/t, a reduction of 9.48 %. The grinding aid effect primarily resulted from the transformation of sparingly soluble carbonates like calcite and dolomite into more soluble bicarbonates, which created substantial cracks and pores, thereby reducing the ore's hardness and improving its grindability. By significantly saving grinding energy consumption while delivering environmental benefits, this technology exhibits great promise for further optimization and widespread adoption. • Ex-situ CO 2 treatment has improved the grindability of bastnaesite. • Ex-situ CO 2 treatment resulted in partial dissolution of carbonates. • The dissolution caused the ore particles to form more pores and cracks. • More pores and cracks led to a decrease in the hardness of the ore particles.

  PublisherOA PDFDOI

• Impurity Shielding in Li/Al-LDH-Based Lithium Recovery from Produced Water via Activated Carbon Pretreatment

  ACS Sustainable Chemistry & Engineering · 2025-08-25 · 2 citations

  articleOpen accessSenior authorCorresponding

  Produced water (PW), a complex industrial wastewater byproduct, contains diverse organic contaminants and competing ions that hinder lithium recovery via lithium/aluminum-layered double hydroxide (Li/Al-LDH) adsorption. In this study, an activated carbon (AC)-based pretreatment strategy was developed to improve Li+ adsorption efficiency by mitigating impurity-induced interference. Two commercial ACs were screened across three PW sources, with optimal dosage and contact time determined for each. AC pretreatment effectively removed key organic compounds and divalent cations, enhancing the aqueous environment for lithium uptake. More importantly, it preserved the structural integrity of Li/Al-LDH, reducing degradation associated with coadsorbed organics. Adsorption experiments confirmed increased Li+ capacity following AC treatment, while adsorption kinetics remained unchanged. Li+ selectivity was also modestly improved, particularly over Ca2+ and Mg2+. Rather than directly enhancing Li+ adsorption, AC served as a protective pretreatment, indirectly enabling more efficient and stable lithium recovery. This impurity-shielding approach offers a scalable and environmentally benign pathway for critical mineral recovery from PW, aligning with sustainable water treatment and circular economy principles.

  PublisherDOI

Frequent coauthors

• Rick Honaker

  University of Kentucky

  26 shared

• Bin Ji

  Virginia Tech

  24 shared

• Duanling Li

  Beijing University of Posts and Telecommunications

  11 shared

• Aaron Noble

  Virginia Tech

  10 shared

• Jiacan Su

  XinHua Hospital

  10 shared

• Kunmao Li

  10 shared

• Shengfeng Zhou

  Jinan University

  9 shared

• Hongqiang Li

  Wuhan Institute of Technology

  7 shared