Article
Materials Science, Multidisciplinary
Basudev Swain
Summary: Rare earth metals (REMs) play a critical role in strategic applications such as consumer electronics and clean energy. However, the REM supply chain heavily relies on primary resources, while secondary resources like red mud (RM) containing REMs remain largely unexplored. The current research shows a significant amount of REM oxide in RM, indicating the potential to unlock this resource through efficient technology and research, transforming the supply chain bottleneck into an abundant source.
Review
Engineering, Chemical
Shrey Agrawal, Nikhil Dhawan
Summary: Red mud as an industrial waste generated during alumina production poses environmental risks and high disposal costs, prompting the utilization of valuable minerals from it. Recovering metallic values from red mud can significantly improve process efficiency, reduce industrial liability, and minimize waste generation, offering potential strategic advantages for resource-deficient nations.
MINERALS ENGINEERING
(2021)
Article
Engineering, Chemical
Hossein Habibi, Mohammad Mokmeli, Sina Shakibania, Dorna Pirouzan, Ziaeddin Pourkarimi
Summary: In this study, a complete process for the recovery of titanium and rare earth elements (REEs) from red mud was developed. The process consists of four main stages: sample preparation, leaching, hydrolysis, and solvent extraction. The proposed process showed high efficiency in the dissolution and concentration of titanium and Sc, with the potential to be considered industrially due to its simplicity, high recovery yield, and utilization of low-cost reagents.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Article
Metallurgy & Metallurgical Engineering
Shrey Agrawal, Nikhil Dhawan
Summary: The current study investigated alkali baking and leaching processes to extract valuable elements such as Al, Fe, Ti, Sc, and Ga. Sodium hydroxide was used for baking, followed by water and sulfuric acid leaching. The research demonstrated that alkali baking formed sodium metal oxide phases, which enhanced the dissolution of metals in sulfuric acid. The study also determined the optimal parameters for the process, achieving high dissolution rates for various elements. Carbonation and thermal hydrolysis were utilized to obtain pure alumina and titania products, respectively. The proposed process showed efficient extraction and generation of valuable products.
Article
Metallurgy & Metallurgical Engineering
Abhilash, Sabrina Hedrich, Axel Schippers
Summary: The study demonstrated that bioleaching of scandium from red mud using Gluconobacter oxydans microorganism can be highly effective. Under specific conditions, the solubilization of Sc in Indian and German red mud reached 83% and 94%, respectively. Additionally, the total amount of gluconic acid excreted by the bacteria increased with an increase in pulp density.
Article
Metallurgy & Metallurgical Engineering
Wei Ding, Shenxu Bao, Yiming Zhang, Junhui Xiao
Summary: This study explores the highly selective process steps for extracting Scandium from red mud, and achieves high leaching efficiency under optimal conditions. The sulfation-roasting-water leaching process proves to be a promising and commercially viable technique.
MINERAL PROCESSING AND EXTRACTIVE METALLURGY REVIEW
(2023)
Article
Metallurgy & Metallurgical Engineering
Ding Wei, Xiao Jun-Hui, Peng Yang, Shen Si-Yue, Chen Tao, Zou Kai, Wang Zhen
Summary: This study proposes a theory of red mud segregation roasting ore phase reconstruction, which recovers iron from red mud and enriches scandium in magnetic separation tailings. By studying the factors affecting the leaching of scandium in magnetic separation tailings, the optimal leaching process conditions and kinetics of scandium leaching were determined.
MINERAL PROCESSING AND EXTRACTIVE METALLURGY REVIEW
(2022)
Article
Metallurgy & Metallurgical Engineering
Li Wang, Liu Yue, Zhu Xiao-bo
Summary: The study found that D2EHPA (P204), tri-butyl-phosphate (TBP), and sodium chloride (NaCl) were attractive for the selective extraction of scandium from acid leaching solution of red mud. By investigating extraction parameters and analyzing the extraction mechanism, effective separation of scandium and iron was achieved.
JOURNAL OF CENTRAL SOUTH UNIVERSITY
(2021)
Article
Environmental Sciences
Ali Dawood Salman, Tatjana Juzsakova, Moayyed G. Jalhoom, Thamer Adnan Abdullah, Phuoc-Cuong Le, Sebestyen Viktor, Endre Domokos, X. Cuong Nguyen, D. Duong La, Ashok K. Nadda, D. Duc Nguyen
Summary: The aim of this study was to develop a new technique for the selective separation and recovery of Sc and Fe from Hungarian bauxite residue waste material. Solvent extraction was used to extract high purity Sc and Fe from real RM leachates. Different extractants and extraction conditions were evaluated, and efficient separation and recovery of Sc and Fe were achieved.
ENVIRONMENTAL POLLUTION
(2022)
Article
Metallurgy & Metallurgical Engineering
Vladimir Rychkov, Maxim Botalov, Evgeny Kirillov, Sergey Kirillov, Vladimir Semenishchev, Grigory Bunkov, Denis Smyshlyaev
Summary: Bauxite residue is a promising source of scandium, with nearly 150 tons of this trace metal appearing annually in waste dumps in the aluminum plants of the Ural region, Russia. A method of red mud carbonization by carbon dioxide has been described, resulting in scandium leaching and decrease of toxicity. Methods to increase scandium leaching degrees, such as ultrasonic treatment and mechanical activation, were evaluated. It was suggested that carbonated red mud had high sorption activity, causing secondary loss of scandium in the carbonate treatment process.
Article
Engineering, Environmental
Xue Zhang, Rong Huang, Yijun Cao, Chongqing Wang
Summary: The innovative strategy of rapid conversion of red mud into soil matrix by cohydrothermal carbonization effectively neutralizes the alkalinity, improves soil properties, and verifies the feasibility and practicality of the process, promoting future application of phytoremediation of red mud at full field scale.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
Article
Metallurgy & Metallurgical Engineering
L. A. Pasechnik, V. M. Skachkov, A. Yu Chufarov, A. Yu Suntsov, S. P. Yatsenko
Summary: Storage of red mud, a byproduct of bauxite processing, can lead to environmental issues due to its high alkalinity and particle dispersity. Scandium, the most valuable component of red mud, is poorly commercialized because of extraction costs, however, new efficient extraction technologies promise to reduce costs significantly. By sulfatising scandium concentrate extracted from red mud, silica can be separated from water-soluble sulfates, while crystallization of scandium and ammonium sulfates offers a selective separation method with high solubility in water.
Article
Green & Sustainable Science & Technology
Shrey Agrawal, Nikhil Dhawan
Summary: This study focuses on the hydrogen reduction of red mud and subsequent acid leaching to recover valuable elements. The results show that reduction at 450°C for 30 minutes yields 10% metallization of magnetite, while increasing the temperature to 900°C results in 97% metallization of metallic iron. The hydrogen-reduced products at 900°C can be used for efficient extraction of iron, gallium, and scandium. Rating: 8/10
JOURNAL OF SUSTAINABLE METALLURGY
(2023)
Article
Metallurgy & Metallurgical Engineering
Shrey Agrawal, Nikhil Dhawan
Summary: The study investigates the recovery of valuable metals in red mud through the microwave acid baking-water leaching process, optimizing the dissolution of titanium and scandium. Key parameters identified include microwave power, acid ratio, and exposure time. The generation of microcracks by microwave irradiation enhances metal dissolution.
Article
Metallurgy & Metallurgical Engineering
Jie Zhou, Shuyi Ma, Yedan Chen, Shunyan Ning, Yuezhou Wei, Toyohisa Fujita
Summary: A synergistic process for co-recovery of scandium was proposed in this study, utilizing acid titanium white waste acid to leach red mud for scandium recovery and then extracting scandium using a P204-TBP-sulfonated kerosene system. The final enriched scandium product had a purity of 17.4% and a total recovery yield of 68.6%.
