Extraction of Potassium from Feldspar by Roasting with CaCl<sub>2</sub> Obtained from the Acidic Leaching of Wollastonite-Calcite Ore

Potassium, which is included in certain contents in the structure of K-feldspar minerals, has a very important function in the growth of plants. Turkey hosts the largest feldspar reserves in the world and is by far the leader in feldspar mining. The production of potassium salts from local natural s...

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Bibliographic Details
Main Authors: Tülay Türk, Zeynep Üçerler, Fırat Burat, Gülay Bulut, Murat Olgaç Kangal
Format: Article
Language:English
Published: MDPI AG 2021-12-01
Series:Minerals
Subjects:
Online Access:https://www.mdpi.com/2075-163X/11/12/1369
Description
Summary:Potassium, which is included in certain contents in the structure of K-feldspar minerals, has a very important function in the growth of plants. Turkey hosts the largest feldspar reserves in the world and is by far the leader in feldspar mining. The production of potassium salts from local natural sources can provide great contributions both socially and economically in the agriculture industry along with glass production, cleaning materials, paint, bleaching powders, and general laboratory purposes. In this study, potassium extraction from K-feldspar ore with an 8.42% K<sub>2</sub>O content was studied using chloridizing (CaCl<sub>2</sub>) roasting followed by water leaching. Initially, to produce wollastonite and calcite concentrates, froth flotation tests were conducted on wollastonite-calcite ore after comminution. Thus, wollastonite and calcite concentrates with purities of 99.4% and 91.96% were successfully produced. Then, a calcite concentrate was combined with hydrochloric acid (HCl) under optimal conditions of a 1 mol/L HCl acid concentration, a 60 °C leaching temperature, and a 10 min leaching time to produce CaCl<sub>2</sub>. To bring out the importance of roasting before the dissolution process, different parameters such as roasting temperature, duration, and feldspar—CaCl<sub>2</sub> ratios were tested. Under optimal conditions (a 900 °C roasting temperature, a 60 min duration, and a 1:1.5 feldspar—CaCl<sub>2</sub> ratio), 98.6% of the potassium was successfully extracted by the water leaching process described in this article.
ISSN:2075-163X