Red Mud Research Articles

Electrocatalytic activities of iron-supported N-doped porous carbon towards the oxygen/hydrogen evolution reaction

Red mud (RM) disposal has been highly apprehensive due to its environmental impact. The aluminum industry produces large amounts of red mud waste annually, and turning it into a value-added product is a key component of sustainable development. This study combines RM with an N-doped porous carbon (biomass precursor) as an effective electrocatalyst for oxygen evolution and hydrogen evolution reactions (OER and HER). One significant obstacle to anion-exchange membrane (AEM) electrolyzer applications is the development of electrocatalysts that do not require noble metals and are both efficient and effective at HER and OER. The synthesized iron-supported (RM-derived) N-doped porous carbon (RMNPC) exhibits excellent catalytic activities with 276 and 191 mV overpotentials at 10 mA cm−2 for OER and HER, respectively. A two-electrode cell system is designed with an RMNPC/NF electrode as anode and cathode, and it necessitates just 1.82 V to realize 10 mA cm−2 and shows outstanding durability. This study presents a low-cost but effective electrocatalyst for water splitting for renewable hydrogen production, achieving the goal of RM recycling and highlighting the potential of porous carbon electrocatalysts.

An experimental and analytical investigation to determine thermal conductivity of epoxy-filler composites for space applications

Thermal conductivity of epoxy-filler composite based Thermal Interface Materials (TIMs) is of utmost importance for thermal management systems used in space applications. Previous studies have shown that depending on the filler particle mixed into the epoxy, thermal conductivity of the composite can either be increased or decreased. Towards that, we have selected four different filler particles (micron sized) – aluminium, copper, zinc and silver to enhance the thermal conductivity of the base epoxy. Thermal conductivity of these 4 epoxy-filler composites has been determined experimentally using an indigenous developed setup at the temperatures ranging from 4.2 K to 323 K. The values have also been reported at various volume fractions (up to 15 %). In addition, after each preparation as the filler particles are mixed mechanically into the epoxy, they are randomly distributed, and this can affect the composite’s thermal conductivity (for the same volume fraction). The experimental determination of thermal conductivity for all the possible distributions is a time consuming, and cumbersome task. In the literature, thermal conductivity values are usually reported for few possible distributions. Therefore, we have developed a novel analytical model to predict all the possible values of thermal conductivity for a specific volume fraction. The predicted values compare well with our experimental data reported in this work at temperatures ranging between 338 K (above room temperature) to 4.2 K (liquid helium temperature). The predicted values are also in good agreement with the experimental values of different fillers such as red mud, pine wood dust and glass fiber etc. from the literature. Additionally, in comparison to other theoretical models like Lewis-Nielsen, Rule of mixture, and Poisson’s distribution, the present model predicts the thermal conductivity values more precisely. This work will be significant in the designing of components where heat transfer plays an important role towards the safety of the component.

Unlocking the potential of environmentally friendly adsorbent derived from industrial wastes: A review.

With increasing urbanization and industrialization, growing amounts of industrial waste, such as red mud (RM), fly ash (FA), blast furnace slag (BFS), steel slag (SS), and sludge, are being produced, exposing substantial threats to the environment and human health. Given that numerous researchers associate with conventional adsorbents, developing and utilizing industrial wastes derived from adsorption technology still has received limited attention. Utilizing this waste contributes to developing alternative materials with superior performance and significantly reduces the volume of solid waste. The excellent physical and chemical characteristics of these wastes are also investigated in this paper. This review attempts to demonstrate a comprehensive overview of the application of industrial waste-based adsorbent in the adsorption process for removing organic pollutants, dyes, metallic ions, non-metallic ions, and radioactive substances. In addition, industrial waste-based adsorbents are among the most promising and applicable techniques for pollutant removal, offering remarkable adsorption efficiency, rich surface chemistries, reasonable cost, simple operation, and low energy consumption. This review summarizes state-of-the-art advancements in engineered adsorbents (including physical and chemical modifications). It provides a holistic view regarding a comprehensive understanding of the mechanism involved in adsorption for water remediation. The challenges and the prospects for future research in applying these adsorbents are also elucidated, contributing to sustainable waste management and environmental sustainability.

Visible light-assisted S-doped red mud-based Fe-Co PBA derivatives activated PMS for efficient degradation of oxytetracycline from acidic to alkaline conditions: Degradation mechanism, degradation pathways and toxicity evaluation

Building an economically efficient, adaptable, and environmentally friendly advanced oxidation system is crucial for the treatment of antibiotic wastewater. In this study, we prepared a sulfur-doped red mud (RM) based Fe-Co Prussian blue analog derivative material (SRPD) using solid waste RM. Due to the doping of sulfur, SRPD possessed more abundant active sites (Co2+/Fe2+) and superior photocatalytic performance compared to other materials. Therefore, the SRPD/peroxymonosulfate (PMS)/Vis system exhibited the best degradation performance for oxytetracycline (OTC), with good reusability, resistance to impurity anions, adaptability to different water qualities, no secondary pollution, and maintained excellent performance under acidic, neutral, and alkaline conditions. Analysis has shown that the participation of surface S2- species in active sites regeneration was an important reason for achieving satisfactory degradation efficiency under neutral and alkaline conditions. In addition, there were significant differences in the charge transfer ability, surface morphology, and surface composition of SRPD in different pH systems, which affected the amount and types of main reactive oxygen species generated by PMS activation. As a result, the degradation pathways of OTC in SRPD/PMS/Vis systems with different pH values were somewhat different, but the detoxification ability towards OTC was excellent. This study exhibits certain reference significance for improving the degradation performance under neutral and alkaline conditions, and is an excellent candidate system for practical wastewater treatment.

Preparation of a new reusable magnetic organocatalyst to synthesis of polyhydroquinoline derivatives as cytotoxic Agents: Synthesis and biological evaluation

One of the most important ways to practice environmental stewardship is to turn waste materials into useful nanomaterials through ecological recycling. This work introduces a magnetic organocatalyst made from red mud waste, adding to the “greening” of global chemical processes.The new composite (Fe3O4@SiO2@(CH2)3@4-(2-Aminoethyl)-morpholine) is introduced and characterized by different spectroscopic methods such as fourier transform infrared (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), mapping, thermogravimetric analysis (TGA) and vibrating-sample magnetometers (VSM). Catalytic activity of the catalyst was evaluated in production of some polyhydroquinoline derivatives and the results showed efficiency. Nine polyhydroquinoline derivatives were synthesized (M1-M9) and their cytotoxic properties evaluated against two human-cancerous cell lines (Hep-G2 and SW480) by MTT assay. Most of the compounds exhibited high inhibitory activity against two studied cell lines. M2 bearing 2-chloro substitution on phenyl ring was exhibited appropriate activity (IC50 = 14.70 ± 3.11 µM) against SW480 cell line in comparison to cisplatin as positive control.

Lactobacillus pentosus enabled bioleaching of red mud at high pulp density and simultaneous production of lactic acid without supplementation of neutralizers

Heterogenous bioleaching by microorganisms producing organic acids is deemed as a compelling pathway for the recovery of valuable metals from red mud, but it is often performed at low pulp density, making this process not economically competitive. Here, Lactobacillus pentosus was employed to bioleach red mud at high pulp density and simultaneously produce lactic acid. The bioleaching performance of L. pentosus was first compared with Aspergillus niger and Gluconobacter oxydans, two most commonly used bioleaching strains. At 20 wt% pulp density and with pure glucose as a carbon source, L. pentosus could leach 31 % Al from red mud, while the leaching efficiency did not exceed 1 % for other two strains. Increasing the pulp density to even 30 wt% did not compromise the leaching efficiency of L. pentosus. When the enzymatic hydrolysate of rice straw was used to replace pure glucose as a carbon source, a comparable leaching efficiency of 30 % for Al was achieved, demonstrating that rice straw could be a cheap and renewable feedstock for bioleaching. Moreover, the alkali contained in red mud eliminated the addition of costly neutralizer as did in traditional lactic acid fermentation, enabling the simultaneous production of approximately 80 g/L lactic acid. Overall, this study offered a potentially economical and effective pathway for the bioleaching of red mud at high pulp density, and opened a new avenue for the production of lactic acid from lignocellulosic biomass.

Strength analysis and microstructural characterization of calcined red mud based-geopolymer concrete modified with slag and phosphogypsum

This research aims to comprehensively investigate the combined use of calcined red mud (RM), calcium sulfate dihydrate (CSD), and ground granulated blast furnace slag (GGBFS) in geopolymer concrete (GC), demonstrating how their optimized proportions improve GC's fresh, mechanical, durability, and microstructural properties. This study investigated the influence of partially replacing calcined red mud (RM) with GGBFS and Phosphogypsum or CSD in GC. The test program included tests on the fresh, mechanical, and durability properties of these blends, including slump value, compressive strength, ultrasonic pulse velocity, water absorption and porosity, rapid chloride penetration, electrical resistivity, mass loss due to freeze-thaw cycles, and resistance to sulfate attack. Material characterization of the GC blends was conducted using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential thermogravimetric analysis (DTG). One-way ANOVA analysis was also used to examine the significance of variation between the results due to the replacement of calcined RM with GGBFS and CSD. The results showed that the mix R40-G45-C15, with 40% calcined red mud, 45% GGBFS, and 15% CSD, demonstrated the highest density at 2401 kg/m³, 15.93% greater than the R70-G15-C15 mix, and achieved a compressive strength 73.40% higher at 28 days. Additionally, R40-G45-C15 showed superior durability, with water absorption and porosity reductions of 87.42% and 83.86%, an 85.78% reduction in charge passed at 7 days, and a 40.94% lower mass loss from freeze-thaw cycles compared to R70-G15-C15. SEM analysis confirmed the formation of N–A–S–H and C–A–S–H gels in the blends, contributing to improved density and strength. XRD tests indicated the nominated peaks of calcite, quartz, and portlandite in the blends, with increased portlandite intensity due to higher RM content. These results indicate that partially substituting the calcined RM with CSD and GGBFS in GC could be a viable alternative option, offering potential contributions to sustainable construction with improved structural performances.

Characterization of Phosphogypsum Blended Red Mud as Geo-material

Red mud (RM) is a toxic material discarded after extraction of aluminum from the Bauxite and is disposed of in the form of slurry or as low-water content cake as stacking. Either form of disposal is a threat to the environment due to the alkaline nature of RM and also consumes vast tracts of land. Occasional failure of the dyke of the RM pond causes a slurry flooding over a large area, which creates geo-environmental problems. The highly alkaline nature of the RM restricts its bulk utilization, as the high pH value supports the leaching of the heavy metals. On the other hand, phosphogypsum (GYP) is an acidic (pH < 7) material produced from the phosphate industry, blending of which can reduce the alkalinity of the mixture. In the present study, an attempt has been made to use GYP blended RM as a resource geomaterial. The GYP is mixed with RM in 5%, 10%, and 15% on a dry basis to evaluate the chemical, physical, and mechanical properties of the newly developed resource material after 3, 7, and 28 days of curing period. The addition of 5% and 10% GYP lowered the maximum dry unit weight, however, 15% GYP increased the maximum dry unit weight upto 15.47 kN/m3. The 28-days strength of 5%, 10%, and 15% GYP blended RM was found as 433.57 kPa, 592.44 kPa, and 711.53 kPa, respectively, which further increased to 752.11 kPa, 1120.38 kPa, and 1371.80 kPa, respectively, after alkali activation.

Developing alkali-activated controlled low-strength material (CLSM) using urban waste glass and red mud for sustainable construction

Using industrial waste in controlled low-strength material (CLSM) offers many benefits and addresses waste management issues. However, identifying optimal CLSM design while balancing environmental impacts and engineering properties poses a notable challenge. Herein, new alkali-activated CLSM formulations based on urban waste glass and red mud (RM) are proposed for the first time with systematic investigations into the material properties and sustainability. The formulations involve the ternary blends of slag, glass powder (GP) and RM as the binders and crushed glass as aggregate. Our observations show RM has a clay-like texture with complex crystalline phases rich in Al and Fe. Increasing the proportion of RM to GP notably decreases the flowability, extends the setting time and impairs the mechanical properties. Nevertheless, red mud demonstrates a crucial role of reducing bleeding level especially for the mixtures with high proportions of glass aggregate. The standard leachate tests as per toxicity characteristic leaching procedure (TCLP) show the heavy metals leached from the CLSM are below the concentration limits and exhibit low mobility. The microstructural and thermodynamic analyses reveal the precipitation of calcium-(sodium-)aluminosilicate hydrate (C-(N-)A-S-H) as the major binding material. The reactive Fe and Al in red mud most probably contribute to the formation of hydrogarnet phases. Moreover, the suggested CLSM formations typically exhibit reduced carbon emissions and lower costs compared to the traditional CLSM produced with cement and fly ash, underlining their environmental sustainability and cost-effectiveness. This study provides a potential guideline for the flowable fill construction in the regions with bauxite producers.

Red Mud Neutralisation by CO2 Promotes Alkali Recovery and Higher Scandium Extraction

Red Mud Neutralisation by CO2 Promotes Alkali Recovery and Higher Scandium Extraction

Toughening Mechanism of CaAl12O19 in Red Mud–Al2O3 Composite Ceramics

The utilization of red mud in the production of ceramic products represents an efficient approach for harnessing red mud resources. Composite ceramics were prepared from Al2O3, red mud, and Cr2O3 by atmospheric pressure sintering, and the phase composition and microscopic morphology of the composite ceramics were investigated by XRD, SEM, and EDS. The flexural strength and fracture toughness of composite ceramics were measured by three-point bending and SENB methods. The results showed that the composite ceramics sintered at 1500 °C with the addition of 1.5 wt.% Cr2O3 had a flexural strength of 297.03 MPa, a hardness of 17.44 GPa, and a densification of 97.75% and fracture toughness of 6.57 MPa·m1/2. The addition of Cr2O3 helps to improve the low strength of red mud composite ceramic samples. The CaAl12O19 phase can form a similar “endo-crystalline” structure with Al2O3 grains, which changes the fracture mode of the ceramics and thus significantly improves the fracture toughness. The wettability tests conducted on Cu and RM–Al2O3 composite ceramic materials revealed that the composites exhibited non-wetting behavior towards Cu at elevated temperatures, while no interfacial reactions or elemental diffusion were observed. Composites have higher surface energy than Al2O3 ceramic at high temperatures. The present study provides a crucial foundation for enhancing the comprehensive utilization value of red mud and the application of red mud ceramics in the field of electronic packaging.

An Experimental Investigation on the Hydraulic and Mechanical Properties of Red Mud Amended with Monovalent and Divalent Bentonites

An Experimental Investigation on the Hydraulic and Mechanical Properties of Red Mud Amended with Monovalent and Divalent Bentonites

Valorization of Residue from Aluminum Industries: A Review

Recycling and reusing industrial waste and by-products are topics of great importance across all industries, but they hold particular significance in the metal industry. Aluminum, the most widely used non-ferrous metal globally, generates considerable waste during production, including dross, salt slag, spent carbon cathode and bauxite residue. Extensive research has been conducted to recycle and re-extract the remaining aluminum from these wastes. Given their varied environmental impacts, recycling these materials to maximize residue utilization is crucial. The components of dross, salt slag, and bauxite residue include aluminum and various oxides. Through recycling, alumina can be extracted using processes such as pyrometallurgy and hydrometallurgy, which involve leaching, iron oxide separation, and the production of alumina salt. Initially, the paper will provide a brief introduction to the generation of aluminum residues—namely, dross, salt slag, and bauxite residue—including their environmental impacts, followed by an exploration of their potential applications in sectors such as environmental management, energy, and construction materials.

Synthesis of Porous Red Mud/Slag-Based Spherical Geopolymers for Efficient Methylene Blue and Ni2+ Removal from Water.

To reuse red mud and slag wastes as raw materials, a green type of porous spherical red mud/slag-based geopolymer (RSG) was synthesized by utilizing suspension curing and foaming techniques. Because methylene blue (MB) and nickel ion (Ni2+) were common and difficult to treat in wastewater, the adsorption characteristics of MB and Ni2+, as well as the phase and microstructure of the porous RSG spheres prior to and after adsorption, were thoroughly investigated. The porous RSG spheres showed a stable and mesoporous structure with a BET surface area of 31.36 m2/g. The spheres achieved the maximum removal efficiencies of 99.81% (MB) and 99.01% (Ni2+) at dosages of 16 and 10 g/L, respectively. The pseudo-second-order kinetic model and the Langmuir model could match the adsorption data of these spheres, with predicted maximum adsorption capacity (Qmax) values of 19.88 mg/g for MB and 12.39 mg/g for Ni2+, respectively. After three adsorption-desorption cycles, porous RSG spheres demonstrated good recycling capability with removal efficiencies of 98.10% (MB) and 54.60% (Ni2+). The spheres were also effective in adsorbing additional dyes (methyl orange (MO), crystal violet (CV), and malachite green (MG)) and heavy metal ions (Cd2+, Pb2+, Zn2+, and Cu2+). The spheres have potential use in water treatment.

High temperature co-processing of stainless-steel slag and red mud: Towards a selective Cr immobilization and harmless treatment

Stainless-steel slag and red mud are bulk metallurgical wastes, which are difficult to reuse due to the complex composition and high environmental risk. To realize their harmless and resource utilization, a collaborative treatment of the stainless-steel slag (AOD slag) and red mud at high temperature was proposed in this study. The influence of the stainless-steel slag to red mud ratio on spinel phase precipitation and crystallization, Cr enrichment and immobilization in the mixed slags were systematically investigated. The results demonstrated that when the stainless-steel slag to red mud ratio was 6:4, the enrichment degree of Cr in spinel phase was 94.12 wt%, and the precipitation amount of spinel reached the highest, 20.98 wt%. In this case, only small amounts of other mineral phases existed, the crystal particle size of spinel phase was larger, and the self-wrapped spinel phases were formed in the stage of cooling. The outer Cr-poor spinel could avoid the abrasion and erosion of the inner Cr-rich spinel in the subsequent physical separation process, thus reducing the risk of Cr6+ dissolution. In the toxic leaching test, the total Cr concentration leached from the mixed slag (stainless-steel slag to red mud ratio was 6:4) was far lower than the national leaching concentration limit of Cr-related ions. The Cr and Fe-rich spinel phases separated from the mixed slag of stainless-steel slag and red mud can be used as the raw material for the production of stainless steel, while the residual Cr-poor slag rich in Ca, Si and Al can be applied in the field of construction.

Manufactured soil: A new use for bauxite residue

Bauxite processing residue produced at an Alumina refinery was used to produce manufactured soil. The residue was first acidified and then leached to remove excess salts. Green waste compost was added at rates of 5 and 10 % w/w, with or without the addition of 20 % w/w dune sand. The products were dried, crushed and sieved and the chemical, physical and microbial properties of the materials characterized. Products had an electrical conductivity and pH of 1.0–1.1 dS m−1 and 8.0–8.1 respectively in 1:5 soil:water extracts and corresponding values in saturation paste extracts were 5.4–5.7 dS m−1 and 7.4–7.5. The effective cation exchange capacity was 202–351 mmolc kg−1, exchangeable Na percentage was 41–46 %, Colwell-extractable P was 108–119 mg kg−1 and the Toxicity Characteristic Leaching Procedure showed that extractable metal concentrations were an order of magnitude below regulatory limits so the material can be considered as non-hazardous. Diethylenetriaminepentaacetic acid-extractable Cu, Zn and Mn were below reported critical levels. Addition of compost lowered concentrations of extractable Cr, As and V and drying the material further reduced extractable levels. When the material was dried it shrunk and solidified and the aggregates produced had a low macroporosity and high microporosity and water holding capacity compared with dune sand. Aggregates were very stable as measured by wet sieving. Compost addition increased organic C content, and the size (microbial biomass C) and activity (basal respiration and the activity of enzymes involved in C, N, S and P mineralization) of the soil microbial community. It was concluded that the materials produced had soil-like chemical, physical and microbial properties and could potentially be used as a soil substitute.

Applicability of Waste from Al Industry toward Dephosphorization of Hot Metal in Primary Steel Making

Managing industrial waste is a global challenge. Red mud is a byproduct of the aluminum industry posing serious concerns. The presence of FeO and CaO in red mud makes it a potential DeP flux. Red mud has been utilized as a DeP flux in previous studies, but these studies deal with low Si content and no P2O5 content in the red mud. However, certain steel makers have high initial Si content (0.6–0.7 wt%) in the hot metal, and with increasing demand for low P steel, new dephosphorization fluxes need to be explored. Addressing this gap, this study investigates red mud's potential as a flux for dephosphorization in hot metal with elevated Si levels. Conducting slag–metal equilibrium experiments at 1350 °C, using red mud‐based fluxes, the research achieves a 40% dephosphorization degree under optimized conditions of double deslagging and fluxing. Analysis via wet chemical methods and inductively coupled plasma mass spectrometry confirms the effectiveness of the approach. Furthermore, thermodynamic calculations highlight the influence of O2 partial pressure and Si content on dephosphorization efficacy. Through laboratory experiments and theoretical insights, this study provides a valuable roadmap for leveraging red mud as a sustainable flux in hot metal dephosphorization processes, contributing to both waste management and steel production efficiency.

Development of sustainable aluminum alloy‑tungsten carbide hybrid composites using industrial waste - An experimental analysis

The research article focuses on the development of aluminum alloy 6061 sustainable composites with the utilization of industrial waste through the use of the stir casting process. Recycling industrial waste is essential for reducing environmental impact. Thus, the red mud waste came from the aluminum production process, which was considered for producing sustainable metal matrix composites (MMCs). Also, tungsten carbide (WC) microparticles have been used to develop hybrid aluminum composite materials. The concentrations of red mud and tungsten carbide were 2 wt%, 4 wt%, and 6 wt%, respectively, and were used to achieve the desired strength performance of aluminum metal matrix composites. The elemental and bonding analyses of hybrid composites were analyzed using X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) analysis. Mechanical characterizations of aluminum hybrid sustainable composites were also investigated, including tensile, compression, and microhardness testing. The results show that increasing reinforcement by up to 4 wt% increases the mechanical strength of aluminum alloy composites. The tensile, compression, and microhardness of metal matrix composites are increased by 25.24 %, 40.2 %, and 20.6 %, respectively, as compared to the aluminum alloy 6061 alloy. The surface morphology of metal matrix composites was analyzed by utilizing Field emission scanning electron microscopy. The proposed sustainable aluminum composites have the potential to develop structural and automotive components due to their higher strength-to-weight ratio.

The Use of Waste Materials Red Mud and Fly Ash as Road Embankment Fill

This study provides a comprehensive evaluation of red mud as a sustainable material for road base construction, particularly in combination with bottom ash. Red mud, a by-product of the Bayer process used in alumina extraction, is known for its high alkalinity and heavy metal content. For this reason, this waste material causes environmental challenges. Red mud sourced from the Eti Aluminum Factory in Seydişehir, Konya (Turkey), was stabilized with bottom ash. Then, these waste materials were tested through a number of experiments, such as in relation to their Atterberg limits, compaction characteristics, unconfined compressive strength (UCS), California bearing ratio (CBR), and microstructure through a scanning electron microscopy (SEM) analysis. The results highlight that the UCS of stabilized red mud samples significantly improved with the addition of bottom ash and longer curing periods. Specifically, the UCS values increased from 0.5 MPa to 2.5 MPa after 28 days of curing. Moreover, RM specimens stabilized with 25% bottom ash achieved a CBR value of 146.64% after 28 days, far exceeding Turkey’s road fill material requirement, which mandates a minimum unsoaked CBR value of 15%. These findings indicate that red mud stabilized with bottom ash not only meets but exceeds the structural requirements for road base materials. This approach provides a sustainable solution for the environmental management of red mud while contributing to infrastructure development. Through the recycling of these industrial by-products, this study presents a viable method to reduce waste and support economic and environmental sustainability in road construction projects.

A Comparison Study on the Recovery of REEs from Red Mud by Sulfation Roasting–Water Leaching and Citric Acid Leaching

In this study, the recovery of rare earth elements (REEs) from red mud (bauxite residue) was explored through a combination of citric acid leaching and sulfation roasting–water leaching processes, introducing an innovative approach to the field. The research uniquely investigates the influence of citric acid on the leaching behavior of REEs and impurities in both untreated red mud and red mud subjected to sulfation roasting, providing a direct comparison of these methodologies. A novel aspect of this study is the evaluation of solvent extraction efficiency using DEHPA, highlighting the selective recovery of REEs over impurities from both citric acid and water-leaching solutions. Furthermore, a comprehensive phase analysis using X-ray diffraction (XRD) was conducted to track the transformations of minerals during the sulfation roasting process, an original contribution to the literature. The findings revealed that over 85% of REEs and major elements such as Fe, Al, Ca, and Ti dissolved in water after sulfation at 105 °C, while iron and titanium dissolution significantly decreased following roasting at 725 °C. Importantly, terbium, neodymium, and gadolinium extraction efficiencies were notably affected by roasting temperature. Citric acid leaching results demonstrated that the direct leaching of red mud leads to higher leaching efficiency than leaching it after the roasting process. Solvent extraction demonstrated lower terbium and neodymium recovery from citric acid solutions compared to water leaching solution. Finally, stripping experiments illustrated that 6M H2SO4 solution is capable of stripping more than 80% of rare earth elements, except terbium.