Integrated kinetic–thermodynamic modelling of Fe-Al mineral transformations during high-pressure acid leaching of laterite ores at 265 °C
Abstract
High-pressure acid leaching (HPAL) of laterite ores involves simultaneous mineral dissolution and secondary phase precipitation, both of which strongly influence metal extraction, acid consumption and scale formation. Existing models generally describe these phenomena independently, limiting their ability to predict the dynamic evolution of industrial HPAL systems. This work presents an integrated kinetic-thermodynamic-population balance framework that simultaneously models the dissolution of primary minerals (goethite and gibbsite) and the precipitation of secondary phases (hematite and H-alunite) during HPAL at 265 • C. Equilibrium speciation calculations were coupled with shrinking-core dissolution kinetics and population balance modelling to predict elemental concentrations, supersaturation, nucleation and crystal growth under different solid contents (22-30 wt%) and acid-to-ore ratios (0.25-0.45). The model accurately reproduced the experimental concentration profiles of Ni, Co, Mn, Mg, Fe and Al across the investigated operating conditions. The results demonstrate that increasing acid dosage enhances primary mineral dissolution while simultaneously promoting supersaturation and secondary phase precipitation. Hematite exhibited faster crystal growth, whereas H-alunite showed higher nucleation tendencies, highlighting distinct precipitation mechanisms in HPAL. The proposed framework predicts dissolution-precipitation interactions and provides mechanistic insights for optimising industrial HPAL operation by controlling process parameters to minimise precipitation leading to scale formation.
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BibTeX
@article{dickson2026integrated,
title = {{Integrated kinetic–thermodynamic modelling of Fe-Al mineral transformations during high-pressure acid leaching of laterite ores at 265 °C}},
author = {Okechukwu Vincent Dickson and Thomas Deleau and Fabienne Espitalier and Christophe Coquelet and Julien Lombart},
journal = {Materials \& Design},
year = {2026},
month = oct,
doi = {10.1016/j.matdes.2026.117186},
url = {https://imt-mines-albi.hal.science/hal-05790944v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Integrated kinetic–thermodynamic modelling of Fe-Al mineral transformations during high-pressure acid leaching of laterite ores at 265 °C
AU - Okechukwu Vincent Dickson
AU - Thomas Deleau
AU - Fabienne Espitalier
AU - Christophe Coquelet
AU - Julien Lombart
PY - 2026
DA - 2026/10/07
JO - Materials & Design
DO - 10.1016/j.matdes.2026.117186
UR - https://imt-mines-albi.hal.science/hal-05790944v1
AB - High-pressure acid leaching (HPAL) of laterite ores involves simultaneous mineral dissolution and secondary phase precipitation, both of which strongly influence metal extraction, acid consumption and scale formation. Existing models generally describe these phenomena independently, limiting their ability to predict the dynamic evolution of industrial HPAL systems. This work presents an integrated kinetic-thermodynamic-population balance framework that simultaneously models the dissolution of primary minerals (goethite and gibbsite) and the precipitation of secondary phases (hematite and H-alunite) during HPAL at 265 • C. Equilibrium speciation calculations were coupled with shrinking-core dissolution kinetics and population balance modelling to predict elemental concentrations, supersaturation, nucleation and crystal growth under different solid contents (22-30 wt%) and acid-to-ore ratios (0.25-0.45). The model accurately reproduced the experimental concentration profiles of Ni, Co, Mn, Mg, Fe and Al across the investigated operating conditions. The results demonstrate that increasing acid dosage enhances primary mineral dissolution while simultaneously promoting supersaturation and secondary phase precipitation. Hematite exhibited faster crystal growth, whereas H-alunite showed higher nucleation tendencies, highlighting distinct precipitation mechanisms in HPAL. The proposed framework predicts dissolution-precipitation interactions and provides mechanistic insights for optimising industrial HPAL operation by controlling process parameters to minimise precipitation leading to scale formation.
SN - 0261-3069
SN - 0264-1275
ER -