Defining the operating conditions of the attrition-leaching process using thermodynamic process modelling

Laurent Cassayre (1) , Florent Bourgeois (1) , Carine Julcour-Lebigue (1) , Imane Benhamed (1) , Jaouher Diouani (2, 1) , Kais Nahdi (2)

1 LGC - Laboratoire de Génie Chimique
2 Laboratoire d'Application de la Chimie aux Ressources et Substances Naturelles et à l'Environnement

The attrition-leaching process aims at improving leaching performance when formation of passivation layers at the surface of leached particles is a severe limiting factor, as discussed recently by Julcour and coworkers (Julcour et al., 2015). This paper proposes a geochemistry-based modelling scheme for deriving the window of possible operating conditions for the attrition-leaching process to match the properties of the processed ore. The rationale is that the attrition-leaching process maintains the surface of reacting particles in an unpassivated state by continuous mechanical removal of surface leach layers, so that the process reactions can be modelled from thermodynamic equilibria throughout the duration of the process. The strength of the proposed modelling approach is that it bridges the gap between the properties of the ore and the process operating conditions. The present paper exemplifies the proposed process modelling route for derivation of the attrition-leaching process operating conditions in the context of the leaching of silicate ores, matching model predictions against controlled laboratory experiments. It is shown how thermodynamic modelling, when used in conjunction with a solid knowledge of the phases present in the system, can assist with deciding upon suitable process operating conditions. As an example, this firstprinciple modelling approach predicted that steel grinding medium would be converted into siderite (FeCO3) under a wide range of operating conditions, which led to questioning this initial choice of grinding medium for the attrition-leaching process under mineral carbonation conditions. It is emphasised that the same approach could be applied to ores of greater economic significance.

Mots clés: Attrition-leaching process; Thermodynamic process modelling; Mineral carbonation

Domaines: Génie chimique; Génie des procédés

Laurent Cassayre, Florent Bourgeois, Carine Julcour-Lebigue, Imane Benhamed, Jaouher Diouani, et al.. Defining the operating conditions of the attrition-leaching process using thermodynamic process modelling. IMPC 2016: XXVIII International Mineral Processing Congress Proceedings, Sep 2016, Québec, Canada. pp. 1-12. ⟨hal-01739538⟩