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

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.