Recovery and Concentration of Strong Mineral Acids From Dilute Solutions Through Llx. II.REVERSIBLE Extraction With Branched-Chain Amines

An overview of the recovery of acid from spent acidic solutions from steel and electroplating industries

“…They found that diluent did not seem to influence the acid extraction although they observed the formation of a third phase with aliphatic diluents with 10-20% Cyanex 923 and above an aqueous acid concentration of 3 M. They also found that the extent of extraction decreased with the increase in temperature. While working with tris-2-ethylhexylamine (TEHA), Eyal et al [167][168][169] and Gottlibsen et al [170] showed that absence of a modifier gave poor extraction of acid by TEHA. When octanol was added as a modifier, the extraction was significantly improved.…”

Value Addition to Sulfate Waste Pickle Liquor of Steel Industry Using Hydrometallurgical Processes

“…Several solvents have been investigated to recover acid from a variety of acidic solutions. [4][5][6][7] It is well known that high-molecularweight amines such as Alamine 336 (Cognis, Monheim, Germany), [8,9] tris 2-(ethyl hexyl) amine, [10,11] and neutral organophosphorus solvents such as tributyl phosphate [12][13][14] are capable of extracting acid from aqueous solutions. Also, solvation extractants can extract acids from solutions in the same manner as amines, i.e., by sharing a pair of electrons with a donor atom.…”

Extraction of hydrochloric and nitric acid with 1-{[2-(2,4-Dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl]-methyl)-1H-1,2,4-triazole and (RS)-1-(4-Chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4-triazol-1-yl-methyl)-pentan-3-ol

“…The reagents under study have very low basicity (pK a 1.09 for propiconazole [15]). As known, the decrease in the basicity of an extractant shifts the area of effective extraction of strong mineral acids to the side of their higher concentrations in the water phase [7,16]. The moderately and strongly basic aliphatic amines effectively extract mineral acids according to the neutralization mechanism from the low acidic solutions (at the acidity of water phase 0.1-0.5 M amines are completely protonated in the organic phase) [16,17], but the extraction of nitric acid with propiconazole from the solution with the concentration of acid 0.…”

“…As known, the decrease in the basicity of an extractant shifts the area of effective extraction of strong mineral acids to the side of their higher concentrations in the water phase [7,16]. The moderately and strongly basic aliphatic amines effectively extract mineral acids according to the neutralization mechanism from the low acidic solutions (at the acidity of water phase 0.1-0.5 M amines are completely protonated in the organic phase) [16,17], but the extraction of nitric acid with propiconazole from the solution with the concentration of acid 0. By means of the shift of the extraction equilibrium it was established that in the range of equilibrium concentrations of HNO 3 in water phase 0.48-1.98 M and the extraction with propiconazole and in the range of equilibrium concentrations of HCl 1.54-3.08 M (extraction with propiconazole) and 1-3.03 M (extraction with tebuconazole) the value of the solvate number is equal to 1 (Fig.…”