Article
Engineering, Environmental
Ghazaleh Shakiba, Roozbeh Saneie, Hadi Abdollahi, Ehsan Ebrahimi, Ali Rezaei, Mohsen Mohammadkhani
Summary: In this paper, deep eutectic solvents (DESs) were applied as a green replacement for conventional solvents in the leaching process of REEs from monazite. The DES comprised of 2ChCl:1PTSA exhibited the highest extraction efficiency.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Geochemistry & Geophysics
Harry Watts, Tonya Fisher
Summary: Monazite is a poorly soluble rare earth phosphate mineral that is difficult to break down in industry processes using concentrated sulphuric acid or caustic soda. A new method has been developed for a direct and rapid breakdown of monazite through simple dissolution under milder conditions, avoiding the use of strong acids/bases and reducing the risk of dust exposure from fine grinding particles.
Article
Materials Science, Multidisciplinary
Zhili Li, Zhihao Xie, Jie Deng, Dongsheng He, Hengqin Zhao, Huan Liang
Summary: The leaching of rare earth elements from phosphate rock follows a shrinking core model with two distinct stages: a fast reaction stage and a slow reaction stage. The leaching rate in the fast reaction stage is controlled by solid product layer diffusion, while in the slow reaction stage, both solid product layer diffusion and chemical reaction play a role.
Article
Environmental Sciences
Sabrina F. Lutke, Marcos L. S. Oliveira, Samuel R. Waechter, Luis F. O. Silva, Tito R. S. Cadaval, Fabio A. Duarte, Guilherme L. Dotto
Summary: This study investigates the leaching conditions and mechanisms of rare earth elements (REE) from phosphogypsum (PG). Through experimental design and optimization, high leaching efficiency values were obtained using sulfuric acid at a concentration of 2.9 mol L-1, a solid/liquid ratio of 1.7/20 g mL(-1), and a temperature of 55 C. The leaching kinetics results indicated that most REE reached equilibrium in about 20 minutes, and the mechanism investigation suggested that surface chemical reaction and diffusion through the boundary layer controlled the leaching process.
Article
Metallurgy & Metallurgical Engineering
Sabrina Hedrich, Anja Breuker, Mirko Martin, Axel Schippers
Summary: Sands from the German Baltic Sea coast are recovered as construction material and contain heavy minerals enriched with zircon, garnet, ilmenite, rutile, magnetite, and monazite. Gravity and magnetic separation can be used to concentrate the heavy minerals. Bioleaching experiments were conducted on zircon concentrates and eudialyte concentrates containing rare earth elements (REE), but the results showed limitations in the extraction of REEs from heavy minerals through bioleaching.
Article
Chemistry, Multidisciplinary
Zhili Li, Zhihao Xie, Dongsheng He, Jie Deng, Hengqin Zhao, Hongqiang Li
Summary: The study found that under specific operation conditions, the leaching efficiencies of rare earth elements and phosphorus can be very high, with most soluble substances decomposed within 30 minutes. The leaching efficiencies of minerals increased in a specific order, providing guidance for enhancing leaching efficiency.
GREEN PROCESSING AND SYNTHESIS
(2021)
Article
Metallurgy & Metallurgical Engineering
Adrian Carrillo Garcia, Mohammad Latifi, Jamal Chaouki
Summary: The study investigated the calcination process of a rare earth carbonatite ore from Niobec in Quebec, Canada, focusing on the decomposition of bastnasite and monazite. A global kinetic model was developed to represent the calcination kinetics of the whole ore based on individual calcination kinetics of the minerals nested in the ore. Initially developed for small particles, the model was later adapted to larger particle sizes by including coefficients based on physical particle size parameters.
Article
Engineering, Chemical
Wei Liu, Zhongqing Xiao, Subodh Das, Wencai Zhang
Summary: This study conducted direct acid leaching to recover rare earth elements from an allanite ore, and examined the effects of operational variables on the extraction efficiency. The results showed that under certain conditions, the extraction efficiency of rare earth elements was high.
MINERALS ENGINEERING
(2024)
Article
Environmental Sciences
Nathalia Luiza P. Wyatt, Vinicius C. Costa, Jefferson R. de Souza, Merisnet Ferde, Floriatan S. Costa, Jordan B. Neris, Geisamanda P. Brandao, Wesley N. Guedes, Maria Tereza W. D. Carneiro
Summary: The Brazilian coast is rich in monazite, a mineral found in beach sand deposits. This study focused on the composition of monazite sands from beaches in the State of Espirito Santo, Brazil. The concentrations of rare earth elements, thorium, and uranium were determined and found to exceed established limits, indicating an elevated radiological risk and higher risk of developing cancer compared to the world average.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Metallurgy & Metallurgical Engineering
Raphael Cruz Alves, Marisa Nascimento, Jessica Frontino Paulino, Julio Carlos Afonso
Summary: This work focuses on processing a monazite concentrate containing iron mineral phases to recover rare earth elements, with the alkaline conversion route showing the best combined recovery and selectivity results for lanthanum and iron. Various experimental designs were used to determine the key variables for each processing route, with temperature playing a significant role in all three routes.
Article
Engineering, Chemical
Wei Liu, Xu Feng, Aaron Noble, Roe-Hoan Yoon
Summary: Rare earth elements can be extracted from low-grade monazite concentrates under relatively mild conditions, which is advantageous over acid leaching.
MINERALS ENGINEERING
(2022)
Article
Metallurgy & Metallurgical Engineering
Luver Echeverry-Vargas, Nestor Ricardo Rojas-Reyes, Luz Marina Ocampo-Carmona
Summary: This paper investigates the leaching conditions of hydrochloric acid and sulfuric acid for the maximum extraction of cerium, lanthanum, and neodymium from a dephosphorized monazite concentrate. The experiments showed that sulfuric acid performed better in terms of extraction efficiency. The addition of hydrogen peroxide further enhanced the dissolution of rare earth elements in sulfuric acid. The recovered rare earths can be converted to oxides through precipitation with oxalic acid and subsequent calcination.
Article
Environmental Sciences
Xiaolin Ou, Zhibiao Chen, Xiuling Chen, Xiaofei Li, Jian Wang, Tianjing Ren, Haibin Chen, Liujun Feng, Yikai Wang, Zhiqiang Chen, Meixia Liang, Pengchang Gao
Summary: Mining activities have significant impacts on the distribution and chemical speciation of rare earth elements, posing serious risks to the environment.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Metallurgy & Metallurgical Engineering
Laura Castro, Helena Gomez-Alvarez, Manuel Carmona, Felisa Gonzalez, Jesus A. Munoz
Summary: The aim of this study was to investigate the solubilization of monazite and recovery of REE using Burkholderia thailandensis, and the influence of the rhamnolipids produced by the bacteria on REE mobilization. B. thailandensis grown in nutrient broth with 1% monazite (w/v) achieved a REE concentration of 8.3 mg center dot l-1 after 15 days. Rhamnolipids were produced by B. thailandensis grown in medium supplemented with 10% glycerol, and the critical micelle concentration (CMC) was determined to be 94.45 mg center dot l-1 for commercial rhamnolipids and 60.41 mg center dot l-1 for purified rhamnolipids. The maximum REE solubilization was achieved at CMC, with 9.36 mg center dot l-1 for commercial rhamnolipids and 5.13 mg center dot l-1 for rhamnolipids produced by B. thailandensis E264.
Article
Engineering, Chemical
Bin Ji, Qi Li, Rick Honaker, Wencai Zhang
Summary: The leaching recovery of rare earth elements (REEs) from kaolinite samples was significantly increased by pretreatment through calcination, likely due to the liberation of encapsulated REE-bearing minerals and conversion to more soluble forms. This study also found that the REEs were primarily associated with REE-bearing minerals within kaolinite aggregates, with only a small fraction occurring in an ion-adsorption form. The research suggests that the modes of occurrence and association characteristics of REEs with kaolinite are complex.
MINERALS ENGINEERING
(2022)
Article
Geochemistry & Geophysics
Youngeun Kim, Jaesoo Lim, Jaehyung Yu, Sujeong Park, Jin-Young Lee, Sei-Sun Hong, Gyujun Park
Summary: Radiocarbon dating was used to analyze sediment cores from the wetland of the Muljangori volcanic cone on Jeju Island, South Korea, revealing that plant fragments were consistently younger than humic acid samples and showed a long-term change in age difference over the past 8000 years. The study suggests that the trend in age difference may be influenced by long-term climate change, as indicated by carbon/nitrogen ratios and total organic carbon isotope values of the sediments.
Article
Chemistry, Multidisciplinary
Hoil Lee, Jin-Young Lee, Seungwon Shin
Summary: This study investigated sedimentary changes in Deukryang Bay on the southwest coast of Korea in response to sea level changes during the Holocene period. The hydrological and climate changes during the mid-Holocene were influenced by El Nino and La Nina conditions, as well as the weakening of the East Asian Summer Monsoon and changes in sea surface temperature of the Western Pacific Ocean. The study suggests that freshwater input events at 4000-3000 cal yr BP were related to the weakening EASM on the southwest coast of Korea.
APPLIED SCIENCES-BASEL
(2021)
Article
Geosciences, Multidisciplinary
Hoil Lee, Jin-Young Lee, Jaesoo Lim
Summary: This study in Yeosu, Korea, analyzed past hydrologic behavior by examining sediment grain size variability, revealing different sedimentary sequences and linking grain size changes to freshwater input fluctuations. The long-term variations were similar to Asian summer monsoon fluctuations and correlated with past El Nino-Southern Oscillation activity, showing intensified freshwater input during stronger ENSO periods. Severe rainfall events characterized by sand layers were identified as isochronous sedimentary layers on the southern coast of Korea.
GEOSCIENCES JOURNAL
(2022)
Article
Engineering, Environmental
Pyeong-Koo Lee, Jaesoo Lim, Youn-Joong Jeong, Seho Hwang, Jin-Young Lee, Byoung-Young Choi
Summary: This study assessed metal(loid) pollution in Gunsan Reservoir, South Korea, over the last century by analyzing metal(loid) concentrations, Pb isotope ratios, and 210Pb dating of sediments. It was found that contributions of Cu smelting and Asian dust influx to pollution varied over time, highlighting the importance of understanding changes in pollution sources for environmental management.
JOURNAL OF HAZARDOUS MATERIALS
(2021)
Article
Geography, Physical
Jin Cheul Kim, Dong-Geun Yoo, Seok-Hwi Hong, Hyun Ho Yoon, Seungwon Shin, Min Han, Jooah Choi, Daekyo Cheong, Jin-Young Lee, Hanwoo Choi
Summary: The study of six boreholes in the Nakdong River delta area in South Korea revealed fluctuations in sedimentation rates and histories over the past 12,000 years, influenced by sea level changes and climate. In the past 2,000 years, rapid delta progradation in the region was attributed to human activities and monsoonal climatic changes.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Marine & Freshwater Biology
Kota Katsuki, Jaesoo Lim, Jin-Young Lee
Summary: This study examines the relationship between tidal levels and diatom assemblage and grain size distributions in sediments of Jujin Stream, a tributary of Gomso Bay in Western Korea. The results show clear gaps in diatom and grain size distributions between tidal, fluvio-tidal transition, and freshwater zones. Combining diatom and grain size data can provide accurate paleo sea-level information for strongly tidal areas.
ESTUARINE COASTAL AND SHELF SCIENCE
(2022)
Article
Geology
Jin Cheul Kim, Ju Yong Kim, Jin-Young Lee
Summary: The study focuses on the sand layer distribution and aggregate resources in Geumsan-gun, Chungcheongnam-do, mainly within Quaternary sedimentary environments of alluvial and river sedimentation. The research reveals the impact of intruding meandering rivers on aggregate distribution characteristics, where certain areas have lower resource distribution but correspond to river floodplains.
ECONOMIC AND ENVIRONMENTAL GEOLOGY
(2021)
Review
Geology
Seungyeoun Cho, Gil-Jae Yim, Jin Young Lee, Sangwoo Ji
Summary: Housing prices in metropolitan areas of the UK and Australia are increasing, leading their governments to utilize urban planning systems to develop housing in quarry sites near cities. The development plans include public facilities and affordable housing for local communities, with a focus on sustainable and eco-friendly development for future generations.
ECONOMIC AND ENVIRONMENTAL GEOLOGY
(2021)
Article
Geology
Hoil Lee, Uk Hwan Byun, Kyoungtae Ko, Seung-Jun Youm, Sangwoo Ji, Hwanju Jo, Seungwon Shin, Jin-Young Lee
Summary: Aggregate is a crucial construction material with increasing demand each year. Different regions have varying properties of aggregate, making long-distance supply difficult. Since 1993, regional aggregate resource surveys have been conducted in Korea to stabilize supply and demand. In 2020, a survey in Goyang City revealed ample reserves of deep aggregates, with characteristics closely related to the Han River's activities.
ECONOMIC AND ENVIRONMENTAL GEOLOGY
(2021)
Article
Archaeology
Seungwon Shin, Yong-Hee Park, Jaesoo Lim, Daekyo Cheong, Seung-Yup Choi, Jeong-Heon Choi, Chang-Pyo Jun, Hyoun Soo Lim, Jin-Young Lee
Summary: This study investigated the relationship between the location of Paleolithic sites in Korea and past climate change. The findings suggest that climate conditions are essential in the development of Paleolithic cultural layers.
GEOARCHAEOLOGY-AN INTERNATIONAL JOURNAL
(2022)
Article
Geology
Byoung-Woon You, Jin-Young Lee, Dong-kil Lee, Young-Wook Cheong
Summary: This study evaluated the effect of weathering on the particle size distribution and amount of fine particles generated during the crushing of igneous rock. The results showed that higher weathering degrees led to a smaller particle size distribution and an increased proportion of fine particles.
ECONOMIC AND ENVIRONMENTAL GEOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Jin-Young Lee, Seungwon Shin, Hyun Ho Yoon, Jin Cheul Kim, Yire Choi, Wook-Hyun Nahm, Heejung Kim
Summary: In this study, the researchers analyzed a sediment core from the Hapcheon Basin to investigate the sedimentary facies and the history of the Hapcheon impact crater. The results showed that the impact crater was filled with sediments from the surrounding mountains after the meteorite impact, and the basin transitioned from a lake environment to an alluvial fan setting. The sediment cores also contain important information about volcanic and seismic events on the Korean Peninsula over the past 1.3 million years.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Geology
Sei Sun Hong, Jin Young Lee
Summary: The purpose of this study is to understand the annual production of aggregates and the prospects of supply and demand. In 2021, a total of 135 million m3 of aggregates was produced in Korea, slightly higher than the total production in 2020. Among these, about 47 million m3 of sand and 88 million m3 of gravel were produced. About 46% of the total quantity of aggregates were produced with permission and the rest were produced after declaration.
ECONOMIC AND ENVIRONMENTAL GEOLOGY
(2023)
Article
Geology
Gil-Jae Yim, Jeong-Yun Jang, Dong-Wan Cho, Sangwoo Ji, Young Wook Cheong, Sei-Sun Hong, Jin-Young Lee
Summary: In Korea, aggregate collection in various areas may lead to Acid Rock Drainage (ARD) if the development site contains sulfide minerals, potentially causing environmental pollution. Study on forest aggregate samples showed that most samples have acid-forming potential, with some classified as potential acid-generating samples. Proper management of these forest aggregates is necessary to prevent economic losses and environmental pollution in the future.
ECONOMIC AND ENVIRONMENTAL GEOLOGY
(2021)
Correction
Geology
Sei Sun Hong, Choon Oh Lee, Jaesoo Lim, Jin Young Lee, Ung San Ahn
ECONOMIC AND ENVIRONMENTAL GEOLOGY
(2021)
