Potassium is an important mineral for biological functions. In this study, potassium was recovered from a low-grade potash mineral, feldspar through chlorination roasting followed by water leaching. NaCl and CaCl2 were used as additives for chlorination roasting independently. The characterizations throughout the studies were carried out using a series of analytical and spectral techniques like XRD, SEM, FTIR, and Raman spectroscopy. The effects of various experimental parameters such as particle size, roasting temperature, amounts of additives, and water leaching on potassium extraction were evaluated. Water leaching was found to be independent of leaching time, temperature, and agitator speed. During roasting, the formation of water-soluble phase was evident; this phase subsequently disappeared on water leaching. The potassium extraction kinetics in the presence of both the additives was satisfactorily corroborated by Ginstling-Brounshtein model. The activation energies for CaCl2 and NaCl roasting were calculated to be 90 and 122 kJ/mole, respectively. Under the same experimental conditions, 86% of potassium extraction (as potash value) was accomplished using CaCl2 as the additive, whereas the extraction in presence of NaCl was only up to 44%. The mechanism of potassium extraction was elucidated; the superior effectiveness of CaCl2 over NaCl in the extraction process was also explained.
Heping X, Yufei W, Yang J, Bin L, Jiahua Z, Ru Z, Lingzhi X, Tao L, Xiangge Z, Hongmei Z, Chun L, Houfang L, Chinese Sci. Bull., 58, 128, 2003
Jena SK, Dhawan N, Rath SS, Rao DS, Das B, Sep. Purif. Technol., 161, 104, 2016
Nayak R, Rao JR, Suryanarayana A, Nayak BB, J. Sci. Ind. Res., 56, 173, 1997
Ladeira PLG, World Intellectual Property Organisation, International Publication No - WO2013/061092 A1 (2013).
Liu SK, Han C, Liu JM, Li H, RSC Adv., 113, 5, 2015
Kumanan M, Sathya G, Nandakumarand V, Berchmans LJ, Extraction of potash from K-feldspar mineral by acid and molten salt leaching process, July - Special Edition, www.iaset.us (2016).
Malik WU, Tuli GD, Madan RD, Selected Topics in Inorganic Chemistry, New Delhi - India (2010).
Anorthite, https://www.mindat.org.
Beherens H, Muller G, Miner. Mag., 59, 15, 1995
Lingdi Z, Jiugo G, Nianhua Y, Liyun L, Sci. China Ser. D., 40, 159, 1997
Zhang M, Salje EKH, Carpenter MA, Parsons I, Kroll H, Reed SJB, Graeme-Barber A, Am. Miner., 82, 9, 1997
Bendel V, Schmidt BC, Eur. J. Miner., 20, 1055, 2008
Freeman JJ, Wang A, Kuebler EK, Jolliff BL, Haskin LA, Can. Miner., 46, 1477, 2008
Vitz E, Moore JW, Shorb J, Resina XP, Wendorff T, Hahn A, https://chem.libretexts.org/Ancillary_Materials/Exemplars_and_Case_Studies/Exemplars/Geology/Silicon_Dioxide_in_Earth's_Crust (2019).
Skorina T, Allanore A, Green Chem., 17, 2123, 2015