Extraction of KCl from Potassium Feldspar by Various Inorganic Salts

Abstract

Feldspar, which is one of the main inputs of the ceramic and glass industries, has widespread sources in Turkey and thus forms a large component of the country’s mineral exportation. In addition to this, potassium feldspars are one of the raw materials suitable for the production of potash, which is a vital component of the agricultural industry. In our work, the chlorination technique was used to produce potassium chloride (KCl) from potassium feldspar ore of the Kırşehir-Buzlukdağı region. The aim of this study was to determine the most suitable and economical additive for producing KCl from potassium feldspar ore with high efficiency. The calcination process was used to decompose potassium feldspar and form potassium chloride using different kinds of salts, such as CaCl2, NaCl, and CaSO4, followed by the water-leaching process. While 93.4% K dissolution efficiency was achieved in the tests performed with CaCl2, the same dissolution efficiency (93.7%) was obtained in the experiments with a CaCl2-NaCl mixture by using less CaCl2. Furthermore, the CaSO4-NaCl mixture achieved the highest dissolution efficiency. The recovery of KCl from feldspar, by assaying its 7.21% K2O, was carried out using a 1:1.25:1.5 ratio of feldspar:CaSO4:NaCl at 1000 °C for 60 min, followed by leaching, to obtain KCl with 96.1% potassium dissolution.