Extraction Equilibrium of Pyrocatechol by Sulfuric Acid Salts of Trioctylamine

Liquid-liquid extraction of scandium(III) from sulfuric acid solution using bis(2-ethylhexyl) phosphinic acid (PIA-8) in toluene has been studied. The extraction of scandium(III) was found to be quantitative with 0.03 M PIA-8 in toluene in the acidic range of 0.1?0.5 M and 6.0?8.0 M H2SO4. The effect of the reagent concentration and other parameters on the extraction of scandium(III) was also studied. The stoichiometry of the extracted species of scandium(III) was determined on the basis of the slope analysis method. The extraction reaction proceeds via the cation exchange mechanism in the H2SO4 concentration range of 0.1?0.5M and the extracted species is ScR3.3HR. However, at higher acidity (6.0M?8.0M H2SO4) it proceeds by solvation. The extracted species is HSc(SO4)2.4HR. The temperature dependencies of the extraction equilibrium constants were examined to estimate the apparent thermodynamic functions (?H, ?S and ?G) for the extraction reaction.

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Regulation of the Surface Microrelief of Titanium Hydride by Solutions of Sulfuric Acid Salts

Lecture Notes in Civil Engineering - Environmental and Construction Engineering: Reality and the Future ◽

10.1007/978-3-030-75182-1_8 ◽

2021 ◽

pp. 51-58

Author(s):

A. I. Gorodov ◽

R. N. Yastrebinsky ◽

A. A. Karnauhov ◽

A. V. Yastrebinskaya

Keyword(s):

Sulfuric Acid ◽

Titanium Hydride ◽

Surface Microrelief ◽

Acid Salts

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Extraction of phenol using sulfuric acid salts of trioctylamine in a supported liquid membrane

Industrial & Engineering Chemistry Research ◽

10.1021/ie00028a019 ◽

1994 ◽

Vol 33 (4) ◽

pp. 914-921 ◽

Cited By ~ 28

Author(s):

Maw-Ling Wang ◽

Kwan-Hua Hu

Keyword(s):

Sulfuric Acid ◽

Liquid Membrane ◽

Supported Liquid Membrane ◽

Acid Salts

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Extraction of Tungsten with Trialkylamine - Effect of pH

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20011407 ◽

2001 ◽

Vol 66 (9) ◽

pp. 1407-1419

Author(s):

Jaroslav Procházka ◽

Aleš Heyberger ◽

Jan Horáček ◽

Eva Volaufová ◽

Jitka Voborská ◽

...

Keyword(s):

Sulfuric Acid ◽

Sodium Tungstate ◽

High Concentration ◽

Tungsten Atom ◽

Extraction Equilibrium ◽

Alkyl Chains ◽

Flat Part ◽

High Concentration Range ◽

Hydrolysis Of ◽

Extraction Isotherms

Extraction equilibrium in the system aqueous solution of sodium tungstate-solution of trialkylamine in a mixed diluent was investigated. A tertiary amine with C7-C9 straight alkyl chains was dissolved in a mixture of tributyl phosphate and kerosene and presaturated with sulfuric acid to give normal trialkylamine sulfate. Extraction isotherms at 25 °C and at several constant values of equilibrium pH were measured in a broad range of aqueous tungstate concentrations. pH 2.0-6.0 was adjusted by addition of sulfuric acid during equilibration. The equilibrium tungstate and sulfate contents in both phases were determined. A typical tungstate isotherm exhibits a steep ascending part in the low concentration range, corresponding to the region of anion exchange, and a flat part in the high concentration range, where the acid content in the organic phase is virtually exhausted. The level of the flat part decreases with growing pH, corresponding to the increasing number of negative charges per tungsten atom in the tungstate polyanions extracted. At pH > 5, also the effect of hydrolysis of amine sulfate could be detected.

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