Experimental Kinetic Analysis of Potassium Extraction from Ultrapotassic Syenite Using NaCl-CaCl2 Salt Mixture

Pegah Haseli; Peter Majewski; Farid Christo; Mark Raven; Steve Klose; Frank Bruno

doi:10.1021/acsomega.0c00549

Experimental Kinetic Analysis of Potassium Extraction from Ultrapotassic Syenite Using NaCl-CaCl₂ Salt Mixture

ACS Omega. 2020 Jun 26;5(27):16421-16429. doi: 10.1021/acsomega.0c00549. eCollection 2020 Jul 14.

Authors

Pegah Haseli¹, Peter Majewski², Farid Christo³, Mark Raven⁴, Steve Klose⁵, Frank Bruno²

Affiliations

¹ Academic Unit STEM, University of South Australia, Mawson Lakes SA, 5095 Adelaide, Australia.
² Future Industries Institute, University of South Australia, Mawson Lakes SA, 5095 Adelaide, Australia.
³ School of Engineering, Deakin University, Geelong Waurn Ponds Campus Victoria, 3216 Melbourne, Australia.
⁴ Commonwealth Scientific and Industrial Research Organisation, Urrbrae SA, 5064 Adelaide, Australia.
⁵ Centrex Metals Limited, Adelaide SA, 5000 Adelaide, Australia.

Abstract

This kinetic experimental analysis reports on the application of a eutectic NaCl-CaCl₂ salt system for the extraction of potassium from ultrapotassic microsyenite. The reaction parameters, time, temperature, salt composition, and salt to ore ratio, were systematically analyzed. It was found that a salt mixture increases the potassium cation extraction in comparison with using either pure NaCl or pure CaCl₂. It was also found that adding CaCl₂ into pure NaCl has a considerably stronger effect on increasing the potassium recovery than adding NaCl to pure CaCl₂. The salt as a melting agent offers a reduction in the reaction temperature due to its lower melting temperature when compared to pure salts (NaCl or CaCl₂). Approximately 70% of K⁺ in the deposit was extracted at 650 °C. Different characteristic methods have been used to understand the reaction mechanism of the salt mixture and ore, as well as to qualify and quantify the end product mineral phases.