Preparation and characterization of potassium chloride from the roast-leaching treatment of a Nigerian quartz-rich muscovite ore

Abstract

This study extracts potassium from quartz-rich muscovite ore via roast-leaching, employing CaCl₂ derived from periwinkle shells as additives. Various analytical and spectral techniques, including XRD, XRF, and SEM, were utilized for characterization throughout the research. The impact of experimental parameters such as CaCl₂ salt quantities, roasting temperature, leaching duration, and particle size on potassium extraction was thoroughly investigated. Under established conditions (ore to salts mass ratio of 1:5, temperature of 850 °C, particle size − 63 + 56 µm), 99.7% of the potassium was dissolved within 30 min. The roast-leaching process exhibited a reaction order of 1.178, and the estimated activation energy of 33.78 kJ/mol suggested a diffusion-controlled reaction through the product layer as the rate-limiting step for potassium extraction. The multiple regression analysis supports the data reported. To selectively recover potassium from the leach liquor, sodium perchlorate was introduced to precipitate potassium as KClO₄, subsequently thermally decomposed to yield high-purity potassium chloride. This innovative approach demonstrates a sustainable and cost-effective method for potassium recovery from its ore.

Graphical Abstract