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A review of acid recovery from acidic mining waste solutions using solvent extraction
Author(s) -
Kesieme Uchenna,
Chrysanthou Andreas,
Catulli Maurizio,
Cheng Chu Yong
Publication year - 2018
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.5728
Subject(s) - phosphoric acid , data scrubbing , chemistry , extraction (chemistry) , nitric acid , stripping (fiber) , mineral acid , effluent , solvent extraction , reuse , waste management , nuclear chemistry , pulp and paper industry , inorganic chemistry , chromatography , organic chemistry , materials science , aqueous solution , engineering , composite material
The minerals industry is increasingly being forced by regulatory and cost pressures to reduce the amount of liquid acidic waste they produce. This requires a strong focus on waste reduction by recycling, regeneration and reuse. Four mineral acids were examined for recovery from waste acidic solutions including H 2 SO 4 , HNO 3 , HCl, and H 3 PO 4 . The selection of the optimal extractant for acid recovery was based on extraction, stripping and scrubbing efficiencies. The extractants suitable for the recovery of H 2 SO 4 and HCl are in the order of TEHA > Cyanex 923 > TBP > Alamine 336. TEHA has the highest degree of acid extraction and stripping compared with Cyanex 923 and almost 99% of the acid can be stripped. Alamine 336 can extract higher acid (for H 2 SO 4 and HCl systems) than Cyanex 923 and TBP. However loaded acid for Alamine 336 system cannot be stripped using water at 60°C. For the recovery of nitric and phosphoric acids from acidic waste effluents, TBP was the best option. This work clearly demonstrates that extractant suitable for acid extraction may not be suitable for its recovery. However such extractant may be applied for the removal of acid from any waste acidic solution sacrificing the back extraction of the loaded acid. The effective implementation of options for acid recovery was examined to improve sustainability in the mineral industry. © 2018 Society of Chemical Industry