O. S. Kudryashova

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.

Effect of the salting-out agent anion nature on the phase separation of a potassium salt–potassium bis(alkyl polyoxyethylene)phosphate–water systems

The effect the salting-out agent anion nature has on the temperature and concentration intervals of the existence of the separation area is established by analyzing the phase diagrams of pseudoternary KCl (KBr, KI, KNO3, K2SO4, K4P2O7)–potassium bis(alkyl polyoxyethylene)phosphate (oxyphos B)–water systems. It is concluded that the anionic salting-out capability is reduced in the order P2O74-> SO42-> Cl− > Br‒> NO74-> SO3-> I−. The thermodynamic parameters of phase separation used to interpret the results are calculated. The observed pattern of a change in the salting-out ability of the investigated salts relative to aqueous solutions of the surfactants is in good agreement with the lyotropic (Hofmeister) series.

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.

Potential of magnesium salt–monoalkylpolyethylene glycol–water systems for use in micellar extraction

Solubilities in MgCl2 (MgSO4, Mg(NO3)2)–syntanol DS-10 (syntanol ALM-10)–water systems have been studied by the visual-polythermal method and the isothermal section method. The liquid–liquid phase separation region was shown to change its topology depending on temperature and the salting-out agent. The salting-out agent anion was shown to influence the cloud point of syntanol solutions. The effect of structure on the ability of syntanol to be salted out by magnesium salts was studied. Optimal temperature and concentration parameters of boron extraction in the studied systems were determined.

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.