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Liang C, Yang ZD, Tan Y, Ding B. Probing microscale crystallization phenomena: Transforming waste slags into riches. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 186:55-63. [PMID: 38861772 DOI: 10.1016/j.wasman.2024.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 06/04/2024] [Accepted: 06/08/2024] [Indexed: 06/13/2024]
Abstract
Metal smelting and combustion of solid fuels produce significant quantities of waste slag, leading to issues such as land occupation and environmental pollution. Understanding and controlling the microscale crystallization phenomena of these slags during thermal treatment is crucial for transforming waste slags into materials suitable for carbon capture or glass ceramics. Previous research has primarily focused on macroscopic crystallization behaviors, significantly advancing the utilization of waste slags in cement clinker production. However, macroscopic results are inadequate for precisely controlling the microscale crystallization behaviors of waste slags. Here, we employed the single hot thermocouple technique to visually explore crystal growth modes, shapes, sizes, numbers, and translational rates of the crystal growth front in a representative blast furnace slag under various isothermal temperatures. The results revealed that crystals exhibited five modes as the isothermal temperature gradually increased, including equiaxed, equiaxed & columnar, columnar, columnar & planar, and planar. Moreover, the translational rate of the crystal growth front increased from 0.011 μm·s-1 to 43.7 μm·s-1 with an increase in the isothermal temperature. Simultaneously, the number of crystals decreased from around 104 to 100 μm-2. On this basis, correlations between microscale crystallization behaviors and isothermal temperature were established to fill the current gap.
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Affiliation(s)
- Cong Liang
- College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong, China 266510
| | - Zheng-Da Yang
- College of New Energy, China University of Petroleum (East China), Qingdao, Shandong, China 266580
| | - Yu Tan
- School of Mechanical and Power Engineering, Chongqing University of Science & Technology, Chongqing, China 401331
| | - Bin Ding
- College of New Energy, China University of Petroleum (East China), Qingdao, Shandong, China 266580.
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2
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Bishop BA, Ramachandran Shivakumar K, Schmidt J, Chen N, Alessi DS, Robbins LJ. Rare Earth Element Speciation in Coal and Coal Combustion Byproducts: A XANES and EXAFS Study. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 39077826 DOI: 10.1021/acs.est.4c04256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/31/2024]
Abstract
Transitioning to a low-carbon economy, necessary to mitigate the impacts of anthropogenic climate change, will lead to a significant increase in demand for critical minerals such as rare earth elements (REE). Meeting these raw materials requirements will be challenging, so there is increasing interest in new sources of REE including coal combustion byproducts (CCBs). Extraction of REE from CCBs can be advantageous as it involves reusing a waste product, thereby contributing to the circular economy. While a growing body of literature reports on the abundance of REE in CCBs globally, studies examining the key factors which control their recovery, including speciation and mode of occurrence, are lacking. This study employed synchrotron-based X-ray absorption spectroscopy to probe the speciation and local bonding environment of yttrium in coals and their associated CCBs. Linear Combination Fitting identified silicate and phosphate minerals as the dominant REE-bearing phases. Taken together with the results of extended X-ray absorption fine structure (EXAFS) curve fitting, we find there is minimal transformation in the REE host phase during combustion, indicating it is transferred in bulk from the coals to the CCBs. Accordingly, these findings can be incorporated into the development of an efficient, environmentally conscious recovery process.
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Affiliation(s)
- Brendan A Bishop
- Department of Earth Sciences, University of Regina. 3737 Wascana Parkway, Regina S4S 0A2, Saskatchewan, Canada
| | - Karthik Ramachandran Shivakumar
- Department of Earth and Atmospheric Sciences, University of Alberta. 1-26 Earth Sciences Building, Edmonton T6G 2E3, Alberta, Canada
| | - Jamie Schmidt
- Department of Earth Sciences, University of Regina. 3737 Wascana Parkway, Regina S4S 0A2, Saskatchewan, Canada
| | - Ning Chen
- Canadian Light Source Inc., University of Saskatchewan, 114 Science Place, Saskatoon S7N 2V3, Saskatchewan, Canada
| | - Daniel S Alessi
- Department of Earth and Atmospheric Sciences, University of Alberta. 1-26 Earth Sciences Building, Edmonton T6G 2E3, Alberta, Canada
| | - Leslie J Robbins
- Department of Earth Sciences, University of Regina. 3737 Wascana Parkway, Regina S4S 0A2, Saskatchewan, Canada
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3
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Rabbani M, Taqi Rabbani M, Muthoni F, Sun Y, Vahidi E. Advancing phytomining: Harnessing plant potential for sustainable rare earth element extraction. BIORESOURCE TECHNOLOGY 2024; 401:130751. [PMID: 38685517 DOI: 10.1016/j.biortech.2024.130751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 04/26/2024] [Accepted: 04/26/2024] [Indexed: 05/02/2024]
Abstract
Rare earth elements (REEs) are pivotal for advanced technologies, driving a surge in global demand. Import dependency on clean energy minerals raises concerns about supply chain vulnerabilities and geopolitical risks. Conventional REEs productionis resource-intensive and environmentally harmful, necessitating a sustainable supply approach. Phytomining (agromining) utilizes plants for eco-friendly REE extraction, contributing to the circular economy and exploiting untapped metal resources in enriched soils. Critical parameters like soil pH, Casparian strip, and REE valence influence soil and plant uptake bioavailability. Hyperaccumulator species efficiently accumulate REEs, serving as energy resources. Despite a lack of a comprehensive database, phytomining exhibits lower environmental impacts due to minimal chemical usage and CO2 absorption. This review proposes phytomining as a system for REEs extraction, remediating contaminated areas, and rehabilitating abandoned mines. The phytomining of REEs offers a promising avenue for sustainable REEs extraction but requires technological advancements to realize its full potential.
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Affiliation(s)
- Mohsen Rabbani
- Department of Mining and Metallurgical Engineering, Mackay School of Earth Sciences and Engineering, University of Nevada, Reno, USA
| | | | - Frida Muthoni
- Department of Mining and Metallurgical Engineering, Mackay School of Earth Sciences and Engineering, University of Nevada, Reno, USA
| | - Ying Sun
- The Plant Molecular and Cellular Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Ehsan Vahidi
- Department of Mining and Metallurgical Engineering, Mackay School of Earth Sciences and Engineering, University of Nevada, Reno, USA.
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4
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Wen Y, Liu P, Wang Q, Zhao S, Tang Y. Organic Ligand-Mediated Dissolution and Fractionation of Rare-Earth Elements (REEs) from Carbonate and Phosphate Minerals. ACS EARTH & SPACE CHEMISTRY 2024; 8:1048-1061. [PMID: 38774356 PMCID: PMC11103772 DOI: 10.1021/acsearthspacechem.4c00009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 04/10/2024] [Accepted: 04/12/2024] [Indexed: 05/24/2024]
Abstract
Global efforts to build a net-zero economy and the irreplaceable roles of rare-earth elements (REEs) in low-carbon technologies urge the understanding of REE occurrence in natural deposits, discovery of alternative REE resources, and development of green extraction technologies. Advancement in these directions requires comprehensive knowledge on geochemical behaviors of REEs in the presence of naturally prevalent organic ligands, yet much remains unknown about organic ligand-mediated REE mobilization/fractionation and related mechanisms. Herein, we investigated REE mobilization from representative host minerals induced by three representative organic ligands: oxalate, citrate, and the siderophore desferrioxamine B (DFOB). Reaction pH conditions were selected to isolate the ligand-complexation effect versus proton dissolution. The presence of these organic ligands displayed varied impacts, with REE dissolution remarkably enhanced by citrate, mildly promoted by DFOB, and showing divergent effects in the presence of oxalate, depending on the mineral type and reaction pH. Thermodynamic modeling indicates the dominant presence of REE-ligand complexes under studied conditions and suggests ligand-promoted REE dissolution to be the dominant mechanism, consistent with experimental data. In addition, REE dissolution mediated by these ligands exhibited a distinct fractionation toward heavy REE (HREE) enrichment in the solution phase, which can be mainly attributed to the formation of thermodynamically predicted more stable HREE-ligand complexes. The combined thermodynamic modeling and experimental approach provides a framework for the systematic investigation of REE mobilization, distribution, and fractionation in the presence of organic ligands in natural systems and for the design of green extraction technologies.
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Affiliation(s)
| | | | - Qian Wang
- School of Earth and Atmospheric
Sciences, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332, United States
| | - Simin Zhao
- School of Earth and Atmospheric
Sciences, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332, United States
| | - Yuanzhi Tang
- School of Earth and Atmospheric
Sciences, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332, United States
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Bishop BA, Alam MS, Flynn SL, Chen N, Hao W, Ramachandran Shivakumar K, Swaren L, Gutierrez Rueda D, Konhauser KO, Alessi DS, Robbins LJ. Rare Earth Element Adsorption to Clay Minerals: Mechanistic Insights and Implications for Recovery from Secondary Sources. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:7217-7227. [PMID: 38588505 DOI: 10.1021/acs.est.4c00974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
The energy transition will have significant mineral demands and there is growing interest in recovering critical metals, including rare earth elements (REE), from secondary sources in aqueous and sedimentary environments. However, the role of clays in REE transport and deposition in these settings remains understudied. This work investigated REE adsorption to the clay minerals illite and kaolinite through pH adsorption experiments and extended X-ray absorption fine structure (EXAFS). Clay type, pH, and ionic strength (IS) affected adsorption, with decreased adsorption under acidic pH and elevated IS. Illite had a higher adsorption capacity than kaolinite; however, >95% adsorption was achieved at pH ∼7.5 regardless of IS or clay. These results were used to develop a surface complexation model with the derived binding constants used to predict REE speciation in the presence of competing sorbents. This demonstrated that clays become increasingly important as pH increases, and EXAFS modeling showed that REE can exist as both inner- and outer-sphere complexes. Together, this indicated that clays can be an important control on the transport and enrichment of REE in sedimentary systems. These findings can be applied to identify settings to target for resource extraction or to predict REE transport and fate as a contaminant.
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Affiliation(s)
- Brendan A Bishop
- Department of Geology, University of Regina, 3737 Wascana Parkway, Regina, Saskatchewan S4S 0A2, Canada
| | - Md Samrat Alam
- Geological Survey of Canada, Natural Resources Canada, Québec, Quebec G1K 9A9, Canada
| | - Shannon L Flynn
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - Ning Chen
- Canadian Light Source Inc., University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan S7N 0X4, Canada
| | - Weiduo Hao
- State Key Laboratory of Continental Dynamics, Shaanxi Key Laboratory of Early Life and Environment, Department of Geology, Northwest University, Xi'an 710069, P. R. China
- Department of Earth and Atmospheric Sciences, University of Alberta, 1-26 Earth Sciences Building, Edmonton, Alberta T6G 2E3, Canada
| | - Karthik Ramachandran Shivakumar
- Department of Earth and Atmospheric Sciences, University of Alberta, 1-26 Earth Sciences Building, Edmonton, Alberta T6G 2E3, Canada
| | - Logan Swaren
- Department of Earth and Atmospheric Sciences, University of Alberta, 1-26 Earth Sciences Building, Edmonton, Alberta T6G 2E3, Canada
| | - Daniela Gutierrez Rueda
- Department of Earth and Atmospheric Sciences, University of Alberta, 1-26 Earth Sciences Building, Edmonton, Alberta T6G 2E3, Canada
| | - Kurt O Konhauser
- Department of Earth and Atmospheric Sciences, University of Alberta, 1-26 Earth Sciences Building, Edmonton, Alberta T6G 2E3, Canada
| | - Daniel S Alessi
- Department of Earth and Atmospheric Sciences, University of Alberta, 1-26 Earth Sciences Building, Edmonton, Alberta T6G 2E3, Canada
| | - Leslie J Robbins
- Department of Geology, University of Regina, 3737 Wascana Parkway, Regina, Saskatchewan S4S 0A2, Canada
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Dos Reis GS, Srivastava V, Taleb MFA, Ibrahim MM, Dotto GL, Rossatto DL, Oliveira MLS, Silva LFO, Lassi U. Adsorption of rare earth elements on a magnetic geopolymer derived from rice husk: studies in batch, column, and application in real phosphogypsum leachate sample. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:10417-10429. [PMID: 38200192 DOI: 10.1007/s11356-024-31925-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 01/04/2024] [Indexed: 01/12/2024]
Abstract
There is a growing need to develop new strategies for rare earth element (REE) recovery from secondary resources. Herein, a novel approach to utilize biogenic silica (from rice husk) and metakaolin was employed to fabricate magnetic geopolymer (MGP) by incorporating metallic iron. The fabricated MGP adsorbent material was used to uptake Ce3+, La3+, and Nd3+ from synthetic solutions and real phosphogypsum leachate in batch and column modes. The MGP offers a negatively charged surface at pH above 2.7, and the uptake of REEs rises from pH 3 to 6. The kinetic study validated that the kinetics was much faster for Nd3+, followed by La3+ and Ce3+. A thermodynamic investigation validated the exothermic nature of the adsorption process for all selected REEs. The desorption experiment using 2 mol L-1 H2SO4 as the eluent demonstrated approximately 100% desorption of REEs from the adsorbent. After six adsorption-desorption cycles, the MGP maintained a high adsorption performance up to cycle five before suffering a significant decrease in performance in cycle six. The effectiveness of MGP was also assessed for its applicability in recovering numerous REEs (La3+, Ce3+, Pr3+, Sm3+, and Nd3+) from real leachate from phosphogypsum wastes, and the highest recovery was achieved for Nd3+ (95.03%) followed by Ce3+ (86.33%). The operation was also feasible in the column presenting suitable values of the length of the mass transfer zone. The findings of this investigation indicate that MGP adsorbent prepared via a simple route has the potential for the recovery of REEs from synthetic and real samples in both batch and continuous operations modes.
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Affiliation(s)
- Glaydson Simões Dos Reis
- Department of Forest Biomaterials and Technology, Biomass Technology Centre, Swedish University of Agricultural Sciences, 901 83, Umeå, Sweden
| | - Varsha Srivastava
- Department of Forest Biomaterials and Technology, Biomass Technology Centre, Swedish University of Agricultural Sciences, 901 83, Umeå, Sweden
- Research Unit of Sustainable Chemistry, Faculty of Technology, University of Oulu, 90014, Oulu, Finland
| | - Manal F Abou Taleb
- Department of Chemistry, College of Science and Humanities in Al-Kharj, Prince Sattam Bin Abdulaziz University, 11942, Al-Kharj, Saudi Arabia
| | - Mohamed M Ibrahim
- Department of Chemistry, College of Science, Taif University, P.O. Box 11099, 21944, Taif, Saudi Arabia
| | - Guilherme Luiz Dotto
- Research Group On Adsorptive and Catalytic Process Engineering (ENGEPAC), Federal University of Santa Maria, Av. Roraima, 1000-7, Santa Maria, RS, 97105-900, Brazil.
| | - Diovani Leindecker Rossatto
- Research Group On Adsorptive and Catalytic Process Engineering (ENGEPAC), Federal University of Santa Maria, Av. Roraima, 1000-7, Santa Maria, RS, 97105-900, Brazil
| | | | | | - Ulla Lassi
- Research Unit of Sustainable Chemistry, Faculty of Technology, University of Oulu, 90014, Oulu, Finland
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7
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Wen Y, Hu L, Boxleiter A, Li D, Tang Y. Rare Earth Elements Recovery and Waste Management of Municipal Solid Waste Incineration Ash. ACS SUSTAINABLE RESOURCE MANAGEMENT 2024; 1:17-27. [PMID: 39177103 PMCID: PMC10840445 DOI: 10.1021/acssusresmgt.3c00026] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 10/18/2023] [Accepted: 11/13/2023] [Indexed: 08/24/2024]
Abstract
The advancements in high-tech products and pursuit of renewable energy demand a massive and continuously growing supply of rare earth elements (REE). However, REE production from mining is heavily restricted by technoeconomic limitations and global geopolitical tensions. Municipal solid waste incineration ash (MSWIA) has been recently recognized as a potential alternative for REE recovery. This study applies and optimizes a green modular treatment system using organic ligands for effective REE recovery and concentration from MSWIA with minimal generation of secondary wastes. Citrate extracted >80% of total REE at pH 2.0 and ∼60% at pH 4.0. A subsequent oxalate precipitation step selectively concentrated >98% of extracted REE by ∼7-12 times compared to raw MSWIA. Waste byproducts were upcycled to synthesize zeolites, resulting in an overall solid waste volume reduction of ∼80% and heavy metal immobilization efficiency of ∼75% with negligible leaching, bringing the dual benefits of REE recovery and waste management. This work serves as a pioneer study in REE recovery from an emerging source and provides system level insights on the practicality of a simple three-step treatment system. Compared to existing literature, this system features a low chemical/energy input and a light environmental footprint.
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Affiliation(s)
- Yinghao Wen
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332, United States
| | - Lei Hu
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332, United States
| | - Anthony Boxleiter
- Department
of Geosciences, Georgia State University, 38 Peachtree Center Avenue, Atlanta, Georgia 30303, United States
| | - Dien Li
- Savannah
River National Laboratory, Aiken, South Carolina 29808, United States
| | - Yuanzhi Tang
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332, United States
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Zhang H, Gao Y. Polymeric Materials for Rare Earth Elements Recovery. Gels 2023; 9:775. [PMID: 37888349 PMCID: PMC10606271 DOI: 10.3390/gels9100775] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 09/16/2023] [Accepted: 09/22/2023] [Indexed: 10/28/2023] Open
Abstract
Rare earth elements (REEs) play indispensable roles in various advanced technologies, from electronics to renewable energy. However, the heavy global REEs supply and the environmental impact of traditional mining practices have spurred the search for sustainable REEs recovery methods. Polymeric materials have emerged as promising candidates due to their selective adsorption capabilities, versatility, scalability, and regenerability. This paper provides an extensive overview of polymeric materials for REEs recovery, including polymeric resins, polymer membranes, cross-linked polymer networks, and nanocomposite polymers. Each category is examined for its advantages, challenges, and notable developments. Furthermore, we highlight the potential of polymeric materials to contribute to eco-friendly and efficient REEs recovery, while acknowledging the need to address challenges such as selectivity, stability, and scalability. The research in this field actively seeks innovative solutions to reduce reliance on hazardous chemicals and minimize waste generation. As the demand for REEs continues to rise, the development of sustainable REEs recovery technologies remains a critical area of investigation, with the collaboration between researchers and industry experts driving progress in this evolving field.
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Affiliation(s)
- Hongtao Zhang
- School of Chemistry and Chemical Engineering, Qinghai Normal University, Xining 810008, China;
| | - Yongfeng Gao
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
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