Kutus Bence

Kása Eszter

Sipos Pál

English

University of Szeged

28th International Symposium on Analytical and Environmental Problems  192  THE SYNTHESIS AND NEUTRALIZATION OF HYDROXYSODALITE  Eszter Kása1, Bence Kutus2, Pál Sipos2  1Department of Organic Chemistry, University of Szeged, H-6720 Szeged, Dóm tér 8, Hungary 2Department of Inorganic and Analytical Chemistry, University of Szeged, H-6720 Szeged, Dóm tér 7, Hungary e-mail: eszterorban94@chem.u-szeged.hu  Alumina is typically refined from bauxite ore via the Bayer process, which annually generates more than 2.7 billion tons of red mud/bauxite residue worldwide, and this quantity is still growing by 120 million tons per annum [1]. Currently, almost all bauxite residue is stored indefinitely in land-based red-mud disposal areas, bearing potential environmental risks associated primarily with its alkalinity. Therefore, the decreasing the causticity by means of neutralization is crucial for sustainable alumina production. Sodalite (SOD, Na6[Al6Si6O24]×2NaX, where X can be OH−, Cl−, NO3−, ½CO32−, or ½SO42−) is the dominant phase of all by-products forming during the Bayer process, beside hematite [2]. Although sodalite can contain many different anions (depending on the medium), the isomorph containing OH− is especially important concerning the alkalinity. Hence, this study focuses on the preparation of hydroxysodalite (HS, Na8Al6Si6O24(OH)2) under well-controlled conditions and the neutralization of this aluminosilicate by hydrochloric acid.  Overall, we found a synthesis method that yields hydroxysodalite with unique cubic morphology. Moreover, our findings shed light on the time duration and mechanism of neutralization of this sodalite.  Acknowledgement Eszter Kása thanks for the financial support by the National Talent Program (NTP-NFTÖ-22-B-0064) from the source of Human Resource Support Operator.  References [1] M. Gräfe, C. Klauber, Hydrometallurgy 108 (2011) 46.  [2] J. Vogrin, T. Santini, H. Peng, J. Vaughan, Micropor. Mesopor. Mat. 299 (2020) 110086.   

The synthesis and neutralization of hydroxysodalite : [abstract]

http://acta.bibl.u-szeged.hu/78508/1/proceedings_of_isaep_2022_192.pdf

The synthesis and neutralization of hydroxysodalite : [abstract]

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