Liquid–Liquid Extraction of Sulfuric Acid from Aqueous Sulfate Waste Solution using Alamine 336/Kerosene/TBP Solvent

Abstract

Generally the metallurgical industries generate huge amounts of harmful environmental wastes, which may be solids, liquids or gases in their nature. The present study aims to recovery sulfuric acid (227 g/l) from wastes generated during hydrometallurgical digestion of titanium ores with sulfuric acid for TiO 2 production. For this purpose Alamine 336/kerosene solvent was used. Various extraction parameters as Alamine 336 concentration, shaking time, type of diluent, O/A phase ratio were studied and optimized.Under the optimum conditions, Mc-Cabe Thiele diagram results indicated that, after 4 extraction stages the acid concentration in aqueous phase was reduced from the initial value of 227 g/l to about 17g/l. Stripping of the loaded sulfuric acid from the organic phase was done with warm water (60 ºC). Stripping parameters as water temperature, stripping time, A/O phase ratio were studied. Under the stripping the loaded acid concentration in organic phase was reduced from 210 g/l to 6 g/l which matched theoretically by McCabe Thiele diagram.

Sustainable Selective Recovery of Sulfuric Acid and Vanadium from Acidic Wastewater with Two-Step Solvent Extraction

“…The extraction efficiency of the acid was low with a single stage with the Alamine 336 system, but it could reach more than 90% with multistage extraction. Furthermore, the stripping process was difficult to operate, and the stripping efficiency was usually less than 30% . The extraction efficiency of the acid could reach more than 80% by using the TEHA system or the Cyanex 923 system, in which the TEHA system was obviously superior to the Cyanex 923 system due to the fewer extraction stages and higher extraction efficiency .…”

“…Furthermore, the stripping process was difficult to operate, and the stripping efficiency was usually less than 30%. 21 The extraction efficiency of the acid could reach more than 80% by using the TEHA system or the Cyanex 923 system, in which the TEHA system was obviously superior to the Cyanex 923 system due to the fewer extraction stages and higher extraction efficiency. 22 The TEHA system was more suitable for the H 2 SO 4 recovery.…”

Development of a Safe and Environmentally Friendly Sulfate Process for the Production of Titanium Oxide

“…It is estimated that 40% of the sulfuric acid used in the SP is eventually released into the environment . As for the acid recovery from the aforementioned effluent, so far, several methods including solvent extraction, , evaporation, and membrane separation , have been investigated, but none was proved economically viable for the titanium pigment industry.…”

Lithium Enrichment of High Mg/Li Ratio Brine by Precipitation of Magnesium via Combined CO2 Mineralization and Solvent Extraction

“…Solvent extraction of acid is widely applied in acid purification 14 and recovery. 15−17 Extractants such as Cyanex 923, 18 trioctylphosphine oxide, 19 Alamine 336, 20 Aliquat 336, 21 tributyl phosphate (TBP), 22 and tris(2ethylhexyl) amine (TEHA) 23 are typical extractants used in commercial operation. In this work, acid extraction is combined with CO 2 mineralization (ECM) to separate magnesium from high Mg/ Li brine.…”

“…For the dilute salt solution, the extraction requires a highly basic extraction solvent like trioctylamine (TOA). Solvent extraction of acid is widely applied in acid purification and recovery. − Extractants such as Cyanex 923, trioctylphosphine oxide, Alamine 336, Aliquat 336, tributyl phosphate (TBP), and tris­(2-ethylhexyl) amine (TEHA) are typical extractants used in commercial operation.…”