ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Eutectic freeze crystallization in the boric acid–water system

Mohammadreza Akbarkermani and Fatma Elif Genceli Güner

Chemical Engineering Department, Istanbul Technical University, Maslak, Istanbul, Turkey

E-mail: egenceli@hotmail.com

Received: 21 February 2023  Accepted: 1 June 2023

Abstract:

Boron compounds are widely used in various industries. Current high rates of boron production/usage generate significant wastes. As an ecologically friendly technology, eutectic freeze crystallization (EFC) has the potential to treat boron wastewater ponds for mineral recovery; however, its feasibility has not been examined before. Here, we determined the eutectic point of boric acid (a major boron compound)-water system to be -0.79 °C and 2.5 ± 0.05 wt%. At the eutectic point, ice and boric acid crystals were isolated from the aqueous solution. The nucleation rate and growth rate of boric acid were considered, as well as the boron content in ice crystals. Our results show that it is feasible to separate boric acid and water from boron waste streams by EFC.

Keywords: Eutectic freeze crystallization; Nucleation rate; Growth rate; Wastewater treatment; Boric acid

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-02907-z

Chemical Papers 77 (10) 5881–5891 (2023)