Combined Decarbonizing Technologies for Treatment of Bauxite Residues
Abstract
This study explores both pyrometallurgical and hydrometallurgical methods for decarbonizing and recovering valuable metals from bauxite residue, with hydrogen plasma reduction and direct acid leaching as the primary approaches. The goal is to offer innovative techniques for extracting metals from bauxite residue, a by-product of the Bayer process, which cannot be disposed of in an environmentally sustainable manner. Additionally, reducing the volume of bauxite residue through combined treatments is a key objective. In contrast to traditional carbon-based reductive melting, which generated significant CO2 emissions, hydrogen is now being investigated as a cleaner alternative. Through hydrogen plasma reduction, approximately 99.9% of iron is recovered as crude metallic iron, which can be easily separated from the slag containing other valuable metals. Thermochemical analysis was used to predict slag formation and chemical analysis of slag during hydrogen reduction. To further recover metals like aluminum and titanium, the slag is subjected to sulfuric acid leaching under high-pressure of oxygen in an autoclave avoiding silica gel formation. The results demonstrated a leaching efficiency of 93.21% for aluminum and 84.56% for titanium, using 5 mol/L sulfuric acid at 150 °C, with almost complete iron recovery. Assisted ultrasound leaching of slag with sulphuric acid under atmospheric pressure leads to 54% leaching efficiency of titanium.
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BibTeX
@article{stopic2026combined,
title = {{Combined Decarbonizing Technologies for Treatment of Bauxite Residues}},
author = {Srecko Stopic and Richard Schneider and Duško Kostić and Isnaldi Filho and Mitar Perušić and Elif Emil-Kaya and Bernd Friedrich},
journal = {Waste},
year = {2026},
month = sep,
doi = {10.3390/waste3020011},
url = {https://hal.science/hal-05748890v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Combined Decarbonizing Technologies for Treatment of Bauxite Residues
AU - Srecko Stopic
AU - Richard Schneider
AU - Duško Kostić
AU - Isnaldi Filho
AU - Mitar Perušić
AU - Elif Emil-Kaya
AU - Bernd Friedrich
PY - 2026
DA - 2026/09/14
JO - Waste
DO - 10.3390/waste3020011
UR - https://hal.science/hal-05748890v1
AB - This study explores both pyrometallurgical and hydrometallurgical methods for decarbonizing and recovering valuable metals from bauxite residue, with hydrogen plasma reduction and direct acid leaching as the primary approaches. The goal is to offer innovative techniques for extracting metals from bauxite residue, a by-product of the Bayer process, which cannot be disposed of in an environmentally sustainable manner. Additionally, reducing the volume of bauxite residue through combined treatments is a key objective. In contrast to traditional carbon-based reductive melting, which generated significant CO2 emissions, hydrogen is now being investigated as a cleaner alternative. Through hydrogen plasma reduction, approximately 99.9% of iron is recovered as crude metallic iron, which can be easily separated from the slag containing other valuable metals. Thermochemical analysis was used to predict slag formation and chemical analysis of slag during hydrogen reduction. To further recover metals like aluminum and titanium, the slag is subjected to sulfuric acid leaching under high-pressure of oxygen in an autoclave avoiding silica gel formation. The results demonstrated a leaching efficiency of 93.21% for aluminum and 84.56% for titanium, using 5 mol/L sulfuric acid at 150 °C, with almost complete iron recovery. Assisted ultrasound leaching of slag with sulphuric acid under atmospheric pressure leads to 54% leaching efficiency of titanium.
SN - 2813-0391
ER -