Article
Engineering, Chemical
A. Shikika, F. Muvundja, M. C. Mugumaoderha, St. Gaydardzhiev
Summary: The alkaline roasting of coltan ore from the Numbi deposit in the DRC was studied, focusing on the extraction kinetics of Ta and Nb. Experimental results showed that optimal conditions for roasting include particle size range, KOH to ore ratio, roasting temperature, and duration. Kinetic data analysis revealed that the process is controlled by a chemical reaction at the particle surface, with estimated activation energies for Ta and Nb.
MINERALS ENGINEERING
(2021)
Article
Environmental Sciences
Min Huang, Ke Hu, Xiang Li, Yun Wang, Jinbo Ouyang, Limin Zhou, Zhirong Liu
Summary: The recovery of radionuclides from tantalum-niobium slag is important for sustainable development, and roasting at 500 degrees Celsius proves to be an effective method for improving the leaching ratio of uranium and thorium.
Article
Green & Sustainable Science & Technology
A. Shikika, F. Zabene, F. A. Muvundja, M. C. Mugumaoderha, M. Aatach, St Gaydardzhiev
Summary: A novel HF-free treatment route for extracting tantalum and niobium from coltan ore has been proposed in this study, involving alkaline roasting, water leaching, precipitation, and oxalic acid leaching. An extraction efficiency of approximately 75% for tantalum and 84% for niobium can be expected from the entire process.
JOURNAL OF SUSTAINABLE METALLURGY
(2022)
Article
Engineering, Chemical
Ahmad Nawab, Xinbo Yang, Rick Honaker
Summary: This study introduces a new method for recovering rare earth elements (REEs), especially heavy rare earth elements (HREEs), from coal at lower acid concentrations. Different treatment methods, including roasting and direct acid baking, were investigated and compared. The results showed that direct acid baking at a lower temperature provided the best recovery of both light rare earth elements (LREEs) and HREEs. Roasting followed by acid baking also achieved high recovery rates. The improved recovery was attributed to the dehydroxylation of clay minerals and subsequent release of REE-bearing minerals.
MINERALS ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
Zihu Lv, Dengkui Zhao, Qiliang Sun, Changmiao Liu, Hongwei Cheng, Fei Yang, Bo Zhang
Summary: This study investigated the simultaneous extraction of uranium (U) and niobium (Nb) from a low-grade natural betafite ore using a novel technique called sulfatizing roasting coupled to sulfuric acid leaching process. The sulfatizing roasting process altered the properties of the raw ore and converted valuable elements into soluble sulfate compounds. The extraction of U and Nb was significantly improved using sulfatizing roasting compared to extraction without roasting. The optimal conditions for leaching U and Nb were determined through systematic investigation of various parameters, and the novel technique showed promising results with high leaching rates.
HIGH TEMPERATURE MATERIALS AND PROCESSES
(2023)
Article
Engineering, Chemical
Steven Ghambi, Sergio Sanchez-Segado, Vitalis Chipakwe, Animesh Jha
Summary: This research introduces a novel chemical process for the extraction and refining of columbite and tantalite concentrates, resulting in a purified mixture of oxides of Nb2O5 and Ta2O5. By reducing and magnetically separating iron oxides in the concentrates, the process successfully reclaim alkali complex formed during the roasting process as a purified mixture of Nb2O5 and Ta2O5 oxides.
MINERALS ENGINEERING
(2021)
Article
Green & Sustainable Science & Technology
Jing Zhao, Bo Li, Xiaolin Wei
Summary: The paper introduces a dry exhaust gas treatment technology different from the traditional wet spraying process for rare earth roasting, successfully implemented in a roasting kiln to achieve dust removal, cooling, and acid condensation from exhaust gas while converting waste heat into steam. Compared to wet spraying, the dry process offers advantages including operational simplicity, small footprint, low energy consumption, low maintenance cost, and no wastewater production.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Metallurgy & Metallurgical Engineering
Zeng Chu-xiong, Guan Qing-jun, Sui Ying, Yu Wei-jian, Bu Yong-jie, Liu Chu-feng, Zhang Zhen-yue
Summary: This study explored the leaching kinetics of rare earth elements (REEs) from phosphogypsum (PG) in nitric acid at different temperatures. The experiments showed that Y had the highest leaching rate and a new shrinking core model (SCM) was deduced to fit the leaching process. The study provides theoretical basis for the utilization of REEs resources in phosphogypsum.
JOURNAL OF CENTRAL SOUTH UNIVERSITY
(2022)
Article
Thermodynamics
Zhongbing Tu, Xiaoping Liang, Chengbo Wu, Yu Wang
Summary: The study investigated the thermal decomposition characteristics and phase transformation rules of low-grade rhodochrosite ore, finding that MnCO3 can be converted to different products under different atmospheres and temperatures, with a higher conversion temperature in a CO2 atmosphere.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Materials Science, Multidisciplinary
Shuhui Zhang, Guanghui Li, Rendong Xiao, Jun Luo, Lingyun Yi, Mingjun Rao
Summary: This study focused on extracting vanadium from low-vanadium grade magnetite concentrate pellets using sodium salt, achieving a high extraction rate under optimal conditions. The research found that part of trivalent vanadium was not completely oxidized during the sodium salt roasting process. By optimizing the sodium salt roasting parameters, the production efficiency of vanadium extraction can be significantly improved.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Metallurgy & Metallurgical Engineering
Jianfang Lyu, Yong Liu, Zhiyuan Ma, Xianjin Lyu, Jikui Zhou
Summary: A stable and continuous leaching process for niobium and tantalum extraction from ferrocolumbium tantalum (FT) has been developed. The leaching rates of Ta, Nb, Fe, and Si were enhanced by increasing acid concentration, grinding fineness, leaching time, and temperature. By optimizing the process conditions, a high niobium extraction rate was achieved.
MINING METALLURGY & EXPLORATION
(2022)
Article
Green & Sustainable Science & Technology
Jinhe Pan, Behzad Vaziri Hassas, Mohammad Rezaee, Changchun Zhou, Sarma V. Pisupati
Summary: A sequential chemical roasting, water leaching, and acid leaching process was developed for the recovery of REEs from coal fly ash. Adding NaOH and Na2CO3 proved to be effective in converting the glassy phases in the ash into water or acid soluble phases, enhancing the recovery of REEs.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Engineering, Environmental
Boyi Xie, Chaxiang Liu, Bohan Wei, Ruixiang Wang, Rushan Ren
Summary: Waste phosphors, containing rare earth and toxic metals, are difficult to extract cerium and terbium due to their unique structure. This study developed a simple process for recovering rare earth elements from waste phosphors. By alkali roasting with NaOH as the additive, the aluminum-magnesium spinel structure was destroyed. A controlled potential reduction leaching process using FeCl2 as the reductant achieved high leaching efficiencies for Y, Eu, Ce, and Tb. This research provides a theoretical and technical basis for the recycling of waste phosphors.
Article
Materials Science, Multidisciplinary
Wen-Cheng Gao, Jian-Kang Wen, Biao Wu, He Shang, Xue Liu
Summary: In this study, a novel approach using a KHSO4-H2SO4 system was experimentally studied for leaching valuable metals from low-grade niobium-bearing ore. The results showed that the roasting KHSO4-H2SO4-ore system is an effective method to extract Nb, Y and Ce with high recovery rates. The leaching kinetics of the calcined Nb-bearing ore in oxalic acid solution was successfully modeled by a chemical reaction model.
Article
Green & Sustainable Science & Technology
Guangshi Li, Wenli Li, Xiaolu Xiong, Zhongya Pang, Qingyun Zhuang, Xingli Zou, Kai Zhu, Hongwei Cheng, Qian Xu, Rongbin Li, Xionggang Lu
Summary: This paper proposes a novel integrated metallurgical process for low-grade Ni-Cu matte, achieving efficient and cleaner metal extraction and preparation of high-value nanomaterials. The process involves temperature-programmed roasting and water leaching, resulting in significant expansion of industrial applications for traditional mineral resources and extractive metallurgy.
JOURNAL OF CLEANER PRODUCTION
(2022)
