Extraction of copper from acid sulphate solutions by 2-hydroxy-5-(1,1,3,3-tetramethylbutyl)-benzaldehyde,-acetophenone and -benzophenone oximes

2-Hydroxy-5-(1,1,3,3-tetramethylbutyl)-benzaldehyde E-oxime ( 1 ), 2-hydroxy-5-(1,1,3,3-tetramethylbutyl)-acetophenone E-oxime ( 2 ) and 2-hydroxy-5-(1,1,3,3-tetramethylbutyl)-benzophenone E-oxime ( 3 ) were synthesized and used for copper extraction from acidic sulphate solutions. The dissociation constants of the phenolic group of the oximes and the stability constants for their complexes with copper were determined. An extraction model is discussed taking under consideration the association of the oxime and the solvation of the complex. It was found that 1 can extract copper more efficiently from acidic aqueous solutions and at a higher rate than 2 and 3. 1 is a stronger acid than 2 and 3 . However, it is a weaker acid than the Z isomer of 3 . The proposed model fits the experimental data well. When the oxime is used in excess, solvation of the copper complex seems probable.     

RATE OF COPPER EXTRACTION AND INTERFACUL ACTIVITY OF MODEL β-DHCETONES

ABSTRACT

Interfacial tension isotherms and rate of copper extraction were studied for model β-diketones of LIX 54 and of pyrazolone type. The effect of the position and structure of the hydrophobic alky1 group upon interfacial activity and rate of extraction is discussed. The preadsorption of extractant molecules at the water/hydrocarbon interface is not needed to obtain a quick and effective extraction.     

MODIFICATION OF EXTRACTION ABILITIES OF N,N,N'N'-TETRAALKYL-3,5-PYRIDINEDICARBOXAMIDE BY ITS ASSOCIATION WITH ALCOHOL

ABSTRACT

The extraction of copper with N,N,N'N'-tetrahexyl-3,5-pyridinedicarboxamide in the presence of the decanol and the co-association of the amide with alcohol were studied. Alcohol associates with the amide forming hydrogen bonds mainly with the oxygens of the carbonyl group without blocking the chemically active pyridine nitrogen. Hydration occurs in the same way. The effect of the alcohol on copper extraction is relatively small and weaker than the effect of chloride concentration.     

Mathematical Relations Correlating Pluronics Properties with their Chemical Structure

Statistically valid equations correlating properties of ethylene and propylene oxides block copolymers of Pluronic type with molecular mass of polyoxybutylene chain, the content of ethylene oxide and concentration are given. The following properties are considered: density, viscosity, melting point, cloud point, surface and interfacial tension, foaming, wetting and washing ability.     

Extraction and pertraction of phenol through bulk liquid membranes

The extraction and pertraction of phenol through a bulk liquid membrane (BLM) with Cyanex^® 923, Amberlite^® LA‐2 and trioctylamine (TOA) as carriers were studied. Cyanex^® 923 was selected as the best carrier for pertraction. The distribution coefficient of phenol for solvents with carrier and pure n‐alkanes, the individual mass‐transfer coefficient at the extraction interface and the initial flux of phenol through the extraction interface (J_Fo) decreased in the order: Cyanex^® 923 > Amberlite^® LA‐2 > TOA ? pure n‐alkanes. The opposite order was observed for the value of the mass‐transfer coefficient in BLM and the maximum flux of phenol through the stripping interface (J_Rmax). At constant driving forces the maximum fluxes through the extraction and stripping interfaces were similar when amine carriers were used. However, J_Rmax was lower than J_Fo for Cyanex^® 923. Although the kinetics of stripping was the rate‐determining step, the flux of phenol was significantly higher than in pertraction with amine carriers. The adsorption of the carrier at aqueous phase/membrane interfaces was probably responsible for the rapid and slow transfer of phenol through the extraction and stripping interface, respectively. Copyright © 2004 Society of Chemical Industry     

Synthesis of Alkyl (±)-2,3-Di-O-acylglycerates and Attempts Directed to their Conversion into Alkyl (R)-2,3-Di-O-acylglycerates by Enzyme-catalyzed Enantioselective Deacylation Reactions [1]

By screening several lipases and proteases as catalysts for an enantioselective partial deacylation of methyl (±)-2,3-di-O-acylglycerates, it was found that methyl (R)-2,3-di-O-butanoylglycerate can be obtained with an enantiomeric excess of >96% and a yield of 20% related to the racemic starting material. This was prepared from methyl acrylate through dihydroxylation with potassium permanganate at −30°C and a subsequent bisacylation.     

Effect of narrowing oxirane adduct distribution on some properties of ethoxylated alcohol-based sulfosuccinic acid halfesters

Foaming and viscosity build-up properties are presented for sulfosuccinic acid derivatives of ethoxylated alcohols with broad- and narrow-range polyoxyethylene chains. Narrow-range ethoxylated alcohol-based sulfosuccinic acid halfesters show better foaming ability. The effect is especially visible at 50°C. Better viscosity build-up properties, as well as higher electrolyte resistance thereof, are also demonstrated.     

Cloud point extraction of direct yellow

The cloud point separation of Direct Yellow from micellar solution of various nonionic surfactants, containing a polyoxyethylene chain, was studied. The separation of dyes is an important environmental problem. Moreover, such separation can also be considered as a preliminary step for further studies of biochemical recovery. Some dyes can be considered as affinity ligands, which form complexes with biochemicals. The use of dye enabled the observation of the dynamics of surfactant-rich phase separation by means of a color video. It was found that the separation of phases was incomplete. The aqueous phase contained some amounts of surfactant globules with the dye. The surfactant-rich phase was usually more heterogenic than the aqueous phase. The recovery of Direct Yellow was very effective in the presence of electrolyte (NaCl). The distribution coefficients were high and equal to a few hundreds in the presence of sodium chloride. Under optimum conditions 98-99.9% of the dye could be removed in the one step.     

Recovery of zinc(II) from HCl spent pickling solutions by solvent extraction

Recovery of zinc(II) from HCl spent pickling solutions by solvent extraction using CYANEX921, CYANEX923, CYANEX302, tributyl phosphate, and ALAMINE336 extractants was studied. Tributyl phosphate was selected as suitable extractant. It permitted both effective zinc(II) extraction and the stripping from loaded organic phase with water. The presence of iron(II) did not affect zinc extraction, and only negligible oxidation of iron(II) was observed during extraction experiments. CYANEX reagents and ALAMINE336 extracted zinc(II) strongly, but the stripping with water was ineffective. Moreover, a significant oxidation of iron(II) to iron(III) occurred during extraction. Each of three reagents (CYANEX923, ALAMINE336 and TBP) extracted iron(III) very well. Thus, if iron(III) was present in the spent pickling solution, prior to the extraction it had to be reduced to iron(II). The oxidation was low for tributyl phosphate and high for CYANEX923 and ALAMINE336. CYANEX302 was inactive both for zinc(II) and iron(III) and could not be used for extraction of zinc(II) from spent pickling hydrochloric acid solutions.