Article
Engineering, Chemical
Shrey Agrawal, Nikhil Dhawan
Summary: A comprehensive process flowsheet has been developed to recover high-purity products such as alumina, silica, ferrous oxalate, titania, and Sc-Ga containing purified solution from red mud. The overall metal extraction in this proposed flowsheet is higher compared to the direct acid baking process.
MINERALS ENGINEERING
(2022)
Article
Chemistry, Applied
Qingyuan Lei, Dewen He, Kanggen Zhou, Xuekai Zhang, Changhong Peng, Wei Chen
Summary: Selective recovery of scandium and titanium from red mud leaching solution was successfully achieved through neutralization precipitation followed by acid leaching approach. High precipitation and leaching efficiencies were obtained under optimal conditions, contributing to effective separation of titanium from scandium and improvement of metal value.
JOURNAL OF RARE EARTHS
(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
Chemistry, Physical
Andrei Shoppert, Irina Loginova, Julia Napol'skikh, Aleksey Kyrchikov, Leonid Chaikin, Denis Rogozhnikov, Dmitry Valeev
Summary: This study investigates the possibility of selectively extracting cerium from alkali fusion red mud (RMF) using diluted nitric acid as a leaching agent. The results show that under certain conditions, with a leaching solution at pH 2 and 80 degrees Celsius for 90 minutes, the extraction efficiency of cerium reaches 71.2%.
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
Engineering, Chemical
Guangyan Hu, Honghu Tang, Dongdong He, Wei Sun, Li Wang
Summary: In this study, a dry digestion method was introduced for the selective recovery of sodium from red mud, with suppressed formation of silica gel. Under optimized conditions, approximately 85% of sodium was leached out, with silicon dissolution suppressed to 0.7%.
MINERALS ENGINEERING
(2021)
Article
Engineering, Chemical
C. Mohanty, S. S. Behera, B. Marandi, S. K. Tripathy, P. K. Parhi, K. Sanjay
Summary: The extraction and leaching kinetics of V from the spent catalyst containing V, Fe, and Mg was studied using organic citric acid, with citric acid showing the best extraction performance. The leaching of metals was influenced by critical parameters such as citric acid concentration, agitation speed, temperature, S/L, and particle size, and the leaching kinetics followed a diffusion-controlled mode governed by the shrinking core model mechanism.
SEPARATION AND PURIFICATION TECHNOLOGY
(2021)
Article
Engineering, Environmental
Siwei Li, Jian Pan, Deqing Zhu, Zhengqi Guo, Yue Shi, Tao Dong, Shenghu Lu, Hongyu Tian
Summary: This paper proposes a new method to fully recover Fe, Al2O3 and TiO2 from red mud, consisting of pre-reducing-smelting, alkaline leaching and acid leaching procedures. The innovative route aims to achieve comprehensive and clean utilization of red mud by effectively recovering iron, aluminum and titanium.
RESOURCES CONSERVATION AND RECYCLING
(2021)
Article
Engineering, Environmental
Siwei Li, Wei Liu, Deqinq Zhu, Jian Pan, Zhengqi Guo, Congcong Yang, Tao Dong, Shenghu Lu
Summary: This study investigates the extraction of perovskite from red mud alkaline leaching slag and its use in photocatalytic reduction of CO2. The extracted perovskite shows similar performance to pure synthesized perovskite.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Environmental Sciences
Wang Li, Tao Wang, Xiaobo Zhu
Summary: In this study, a high temperature and high pressure water immersion method was developed to selectively remove alkali from red mud by adding Mg-based additives. Experimental results showed that 92% of alkali could be removed from red mud using 12% MgCl2 at 250 degrees C for 60 min. The leaching process was mainly controlled by chemical reactions.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Chemistry, Physical
Andrei Shoppert, Irina Loginova, Julia Napol'skikh, Dmitry Valeev
Summary: The study demonstrates the possibility of selectively extracting scandium from red mud using highly diluted acid in the presence of MgSO4. Under specific conditions, a scandium extraction rate higher than 63% can be achieved, while iron extraction decreased from 7.7% to 0.03% by increasing pH from 2 to 4. The kinetics study indicates that diffusion through a product layer is the rate-limiting step at high temperatures and low pH, while diffusion through the liquid film limits the leaching rate at lower temperatures and higher pH values.
Article
Engineering, Chemical
Shrey Agrawal, Nikhil Dhawan
Summary: The study validates the use of microwave heating for acid baking and leaching of red mud to dissolve metallic values. The process significantly reduces processing time and improves metal dissolution using low pH values. The precipitation and calcination of metallic values can produce a product containing different refractory phases, allowing for separation of iron and titanium values.
MINERALS ENGINEERING
(2021)
Article
Engineering, Chemical
Tingya Cai, Rongxiang Pan, Min Yang
Summary: Red mud, a solid waste from the alumina industry, poses challenges due to its high sodium content. This study investigates the effects of sulfuric acid dealkalization on the physical properties of red mud and explores the mechanism of sodium removal during acid leaching. Various characterization techniques were used to analyze the red mud residues. The results show that increasing sulfuric acid concentration improves sodium removal efficiency and offers a plausible solution for sodium treatment in red mud, reducing environmental contamination.
MINERALS ENGINEERING
(2023)
Article
Engineering, Environmental
Wang Li, Xudong Yan, Zepeng Niu, Xiaobo Zhu
Summary: Selective leaching of vanadium and separation of iron from red mud using oxalic acid and sodium sulfite were studied, showing that over 90% of vanadium could be selectively leached under suitable conditions. The leaching mechanism was analyzed with XRD, SEM-EDS, thermodynamic theory, and leaching kinetics, demonstrating controlled diffusion and chemical reaction processes for vanadium and iron leaching, respectively. The apparent activation energy of vanadium and iron were determined and the presence of stable complexes in the leaching solution was identified.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
Article
Engineering, Chemical
Emmanuel De Gregorio, Alessio Occhicone, Fabio Montagnaro, Giuseppina Roviello, Laura Ricciotti, Claudio Ferone
Summary: Red Mud, a waste product of the Bayer Process, is costly to dispose of and accounts for 5% of the total costs of aluminum production. However, it contains high-value elements such as rare earths and metals. This study focuses on the recovery of iron in the form of Fe(II) oxalate. Hydrochloric acid showed the highest extraction capacity, while sulfuric and phosphoric acid inhibited extraction. Oxalic acid formed a stable complex and allowed for the recovery of iron oxalate. A CHEMCAD plant achieved a yield of over 16% per pass with a purity of up to 96%wt. The proposed process can be used in conjunction with other methods for recovering valuable substances from red mud.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2023)
