S. A. Denisova

Phase equilibria in water-alkali metal (ammonium) sulfate-Oxifos B systems

Solubility in the H2O-(NH4)2SO4 (Li2SO4, Na2SO4)-Oxifos B (potassium bis(alkylpolyoxyethylene) phosphate, [CnH2n + 1O(C2H4O)m]2POOK, n = 8−10, m = 6) ternary systems at 25°C is reported. A two-phase liquid-liquid equilibrium in the systems is observed in a wide pH range (at inorganic acid concentrations of 2 to 10 mol/l). These separating systems are suggested for use in liquid-liquid extraction of metal ions.

Phase equilibria in the water-alkali metal or ammonium sulfate-synthanol systems

Solubility was studied for the first time in ternary aqueous phase-separating systems containing synthanol DS-10 or ALM-10 (polyethylene glycol monoalkyl ethers based on primary fatty alcohols, CnH2n − 1O(C2H4O)mH, where m = 8–10 and n = 10–18 (synthanol DS-10) or 12–14 (synthanol ALM-10)) and inorganic salt (NH4)2SO4, Na2SO4, or Li2SO4 at 25°C. The boundaries of two-phase liquid equilibrium regions were determined. It was proposed to use the studied phase-separating systems for liquid extraction of metal ions.

Phase and Extractive Equilibria in the Water-Inorganic Salting-out Agent-Polyethyleneglycol Alkyl Ether Systems

AbstractThe solubility isotherms were constructed for the ternary systems H2O-DS-10 synthanol-(NH4)2SO4 and H2O—ALM-10 synthanol-KSCN at 298 K. The regions of two-phase liquid equilibrium were revealed. The interphase distribution of some metal ions was examined. It was established that cobalt(II) and zinc ions were quantitatively extracted into the phase of the surface-active substance in the system with potassium thiocyanate.

Solubility in the water-Catamine AB-(alkali metal or ammonium chloride) systems

Solubility in ternary aqueous stratifying systems containing Catamine AB (alkylbenzyldimethylammonium chloride [CnH2n + 1N+(CH3)2CH2C6H5] · Cl, a cationic surfactant, where n = 10–18) and LiCl, NaCl, KCl, and NH4Cl inorganic salts was studied for the first time at 25°C. The boundaries of two-phase liquid equilibrium fields were determined. The studied stratifying systems were proposed for use in the liquid extraction of metal ions.

Phase and extraction equilibria in the water-ammonium chloride-Sintamid-5 system

The solubility isotherm of the H2O-NH4Cl-Sintamid-5 ternary system at 298 K was constructed on the basis of refractometer measurements. It was found that the region of two-phase liquid equilibrium existed over a wide pH range at inorganic acid concentrations from 10 to 2 mol/l. The distribution of some metal ions between the phases was studied. Conditions for quantitative extraction of thallium(III) and gallium were determined.

Phase and extraction equilibria in water-syntamide-5-ammonium sulfate and water-syntamide-5k-ammonium sulfate systems

Phase equilibria in ternary aqueous layering systems containing a commercial nonionogen surfactant (Surf.) syntamide-5 or syntamide-5k and an inorganic salting-out agent ammonium sulfate were studied. The potential application of the systems for liquid extraction of metal ions was assessed.

Phase and extraction equilibria in water–polyethyleneglycol ethers of monoethanolamides of synthetic fatty acid–ammonium chloride systems

Phase equilibria in layering systems of water, polyethyleneglycol ethers of monoethanolamides of synthetic fatty acids (SFAs) (synthamide-5), and ammonium chloride are studied. The possibility of using such systems for the liquid extraction of metal ions is evaluated. The effect the nature of salting-out agents has on the processes of segregation of the systems has been considered.

Extraction of metal thiocyanate complexes in a water-potassium bis (alkylpolyoxyethylene) phosphate-ammonium sulfate segregating system

Dependence of Fe(III), Zn(II), Co(II), Cu(II), Cd(II), and Mo(VI) extraction at concentration of 0.01 mol/L in a water-potassium bis-(alkylpolyoxyethylene) phosphate (Oxyphos B)-ammonium sulfate system on NH4SCN and H2SO4 concentration was studied. Conditions for the quantitative recovery of Fe(III), Zn(II), Cu(II), Co(II), and Mo(VI) were found. Spectrophotometric characteristics of extracted Cu(II), Co(II), and Fe(III) thiocyanate complexes were studied.

Extraction of scandium by diantipyrylalkanes from naphthalene-2-sulfonate solutions in the extraction systems of different types

The extraction of scandium by diantipyrylmethane, diantipyrylbutane, and diantipyrylheptane from naphthalene-2-sulfonic acid solutions in the systems of different types, including those without an organic solvent, was studied. The composition of extracted scandium complexes was determined. The constants of scandium extraction with 0.1 M solutions of diantipyrylalkanes in a 10% solution of isopentanol in chloroform were calculated. Diantipyrylmethane exhibited a maximum extraction capacity. A procedure for the extraction-chelatometric determination of scandium was developed with the use of the water-diantipyrylmethane-naphthalene-2-sulfonic acid segregable system.

Phase and extraction equilibria in the antipirin-pyrocatechol-water system

Solubility isotherms of the antipirin-pyrocatechol-water ternary system at 25 and 50°C were constructed. A field where two liquid phases are present in equilibrium which results from the protolytic interaction between the components was revealed. The various-composition chemical compounds that formed were isolated preparatively. Interphase distribution of a series of metal ions was studied. The half-extraction pHs of rare-earth metals were found to be linearly related to their ionic radii.