Di-n-butyl carbamoylphosphonate as an extradant of inorganic ions from hydrochloric acid solutions

The extraction of 33 elements by a 0.1M solution of di-n-butyl carbamoylphosphonate in chloroform has been investigated as a function of hydrochloric acid concentration. The results show that this new extradant readily extracts most of the elements in a high oxidation state, including the trivalent rare earths, from hydrochloric acid at concentrations greater than 6 M.     

Polysulfobetaines as extractants for Sr(II) ions from its aqueous solutions

In the present paper, we communicate sorption of Sr(II) ions on novel polysulfobetaines. N‐vinyl imidazole was modified by crosslinking it with four different crosslinkers: N,N‐methylene bisacrylamide, ethylene glycol dimethacrylate, divinyl benzene, and tripropylene glycol diacrylate. All the crosslinked networks were treated with sodium 2‐bromoethane sulfonate to obtain novel polysulfobetaines. The polymers were characterized by FTIR, elemental analysis and SEM to find evidence of network formation and quaternization. These polymers were used as Sr(II) sorbents. Sr(II) uptake was determined by using a colorimetric method using Rose Bengal anionic dye and 0.1 N HCl as the eluent. SEM‐EDS analysis of Sr(II)‐loaded polymers as well as after elution on treatment with 0.1 N HCl was recorded to ascertain the uptake of Sr(II) ions. The experimental isotherm data were analyzed using the Freundlich and Temkin equations. The experimental data also were analyzed using pseudo‐second order sorption kinetic model. Results show that the equilibrium data fit well in the Freundlich isotherm. Copyright © 2010 John Wiley & Sons, Ltd.     

An equation of state for hydrochloric acid solutions

Gibbons, R.M. and Laughton, A.P., 1984. An equation of state for hydrochloric acid solutions. Fluid Phase Equilibria, 18:61–68.A modified Redlich-Kwong-Soave (RKS) equation is presented for hydrochloric acid solutions. It is shown that the equation with one binary parameter predicts the azeotropic behaviour of the system accurately and the heats of solution within 10%. These results suggest that the new equation can be applied to a wide range of polar systems.     

The microchemical electrolytic analysis of alloys in hydrochloric acid solutions : White metals and solders

The microchemical electiolytic analysis of alloys employing the methods of SAND and LINDSEY for potential control have been extended to include white metals and solders. The methods, employing from 5 to 20 milligrams of material, may be completed in about 2 hours (excluding the time necessary to bring the sample into solution) and are especially useful in circumstances where only a few milligrams of sample are available.     

Thin-layer chromatographic separation of noble metals on ECTEOLA-cellulose in hydrochloric acid and aqueous chloride solutions

Summary The thin-layer chromatographic behaviour of the noble metals on ECTEOLA-cellulose has been examined in HCl and aqueous chloride solutions of Li, Na, Mg, Ca, Sr and Al. The R_f-values decrease in the order Ir(III) Rh(III) > Ru(III) > Pd(II) > Pt(IV) > Ir(IV) > Au(III) in all of the media of higher chloride concentrations (3M to 5M), in which there are sufficiently large differences in R_f-values of adjacent metals to resolve them clearly. Especially, the HCl solutions with or without H₂O₂ are very suitable for multi-component separations of the noble metals.

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DC-Trennung von Edelmetallen auf ECTEOLA-Cellulose in salzsauren und wäßrigen Chloridlösungen

Zusammenfassung Das Verhalten von Edelmetallen wurde in salzsauren Lösungen sowie in Lösungen der Chloride von Li, Na, Mg, Ca, Sr und Al geprüft. Die R_f-Werte nehmen in allen Medien mit höherer Chlorid-konzentration (3M bis 5M) in folgender Reihenfolge ab: Ir(III) Rh(III) > Ru(III) > Pd(II) > Pt(IV) > Ir(IV) > Au(III). Die Unterschiede in den R_f-Werten sind groß genug, um eine deutliche Trennung zu gewährleisten. Salzsaure Lösungen mit oder ohne H₂O₂-Zusatz sind besonders gut für die Trennung von Vielkomponenten-Gemischen geeignet.

     

New solid extractants for preconcentrating noble metals

New solid extractants are synthesized with the use of imidazolium and phosphonium ionic liquids for preconcentrating noble metals. Ionic liquids are selected and conditions for their immobilization on various solid matrices are found. The adsorption properties of the synthesized solid extractants for platinum(IV) in hydrochloric acid solutions are studied. The solid extractants obtained by binding 1-hexadecyl-3-methylimidazolium bromide and trihexyltetradecylphosphonium chloride to polymeric matrices and multiwall carbon nanotubes possess good kinetic properties and selectivity in 1 M HCl, and can be used to preconcentrate Pt(IV), Pd(II), and Au(III) in combined methods of their determination.     

Extraction of uranium from hydrochloric acid solutions by alkylated crown ethers

The extraction recovery of uranium from 1–10 mol/L hydrochloric acid solutions into solutions of alkylated crown ethers di-tert-butyldibenzo-18-crown-6 (DTBDB18C6) and di-tert-butyldicyclohexyl-18-crown-6 (DTBDCH18C6) in organic solvents (nitrobenzene, 1,2-dichloroethane, chloroform, 1-octanol) was studied. It was found that with increasing HCl concentration, the value of the distribution coefficients of uranium (D) between the organic and aqueous phases increased to a maximum value at 9 mol/L HCl for DTBDB18C6 and 6–7 mol/L HCl for DTBDCH18C6. The properties of the solvent also greatly affect the values of D, reaching a maximum in the application of nitrobenzene, dichloroethane, or their mixture. Under these conditions, D for a 0.01 mol/L solution of DTBDCH18C6 in nitrobenzene is 830, which is the highest of known values. It was determined by the slope method and the complete saturation method that the extracted complexes of the studied alkylated crown ethers with uranyl ions have the 2 : 1 composition. Thus, new supramolecular extractants of uranium from hydrochloric acid solutions have been studied, having an extremely high extraction capacity, which can be used in the analytical and preparative chemistry of uranium.     

Iridium(IV) extraction with petroleum sulfoxides from hydrochloric acid solutions

Iridium(IV) extraction with petroleum sulfoxides (PSO) from hydrochloric acid solutions is studied. Optimum conditions of extraction are chosen. It is shown that in the investigated extraction systems for a phase contact time of 30 min, iridium(IV) is extracted by the ion-associative mechanism. Electronic, ¹H NMR, and IR-spectroscopy, and elemental analysis are used to establish the structure of the extracted compound.     

Palladium(II) extraction from hydrochloric acid solutions with diacylated triethylenetetramine

Extraction of palladium(II) with diacylated triethylenetetramine hydrochloride (with chloroform as diluent) from hydrochloric acid solutions was studied. Palladium(II) extraction from 3 mol/L HCl solutions occurs via anion-exchange mechanism. Concentrational constants were calculated and thermodynamic parameters of extraction were estimated.     

Extraction of rhodium(III) with sulfoxides from hydrochloric acid solutions

Extraction of rhodium(III) from hydrochloric acid solutions with dihexyl sulfoxide (DHSO) and with petroleum sulfoxides (PSOs) was studied, and the optimal conditions for its recovery were found. At a phase contact time of up to 0.5 h, the extraction of rhodium(III) with sulfoxides occurred mainly by an ionassociation scenario. If the phase contact time exceeds 0.5 h, a mixed extraction scenario predominated to form the extracted complexes (L · H⁺) · [RhCl₄L₂]-(DHSO)_o and PSO (LH⁺) · [RhCl₄(H₂O) · L]⁻. The protonation of the extraction agents occurred at the donor oxygen atoms of the sulfoxide group. When rhodium was extracted with PSOs, the coordination of the extractant molecule in the inner coordination sphere of the acido complex to the metal ion occurred through the donor sulfur atom of the sulfoxide group, while with the use of DHSO, through the donor atoms of sulfur and oxygen of the sulfoxide group. Electronic, ¹H NMR, and IR spectroscopy and elemental analysis were used to determine the composition of the extracted compounds and suggest their structure.     

Rapid extraction of microamounts of protactinium from hydrochloric acid solutions by morin-isoamylol

A new extractant for protactinium has been studied. This paper describes the extraction behaviour of Pa from HCl system by morin-isoamylol. The whole procedure can be completed in 100 sec., yield of extraction is 99.2%.     

Sildenafil citrate (Viagra) as a corrosion inhibitor for carbon steel in hydrochloric acid solutions

Abstract  

The inhibition effect of sildenafil citrate (Viagra) on the corrosion of carbon steel in 1 M HCl was studied by weight loss, polarization, electrochemical impedance spectroscopy, and UV–Vis spectrophotometry. The results showed that sildenafil citrate is a good corrosion inhibitor for carbon steel in acidic media and acts as mixed type (cathodic/anodic) inhibitor. The adsorption of the inhibitor was well described by the Langmuir adsorption isotherm. Some thermodynamic parameters such as adsorption heat, adsorption entropy, and adsorption free energy were calculated. Kinetic parameters such as the apparent activation energy and pre-exponential factor were calculated and discussed.     

The study of a membrane for extracting gold(III) from hydrochloric acid solutions

A membrane is described consisting of Aliquat 336 chloride immobilized in poly(vinyl chloride) (PVC) which extracts gold(III) selectively from hydrochloric acid solutions in the presence of a 500-fold higher concentration of copper(II). Gold is recovered from the membrane by stripping with a thiourea solution. The stability of the membrane is reported in terms of the extent of leaching of the reagent from the membrane in aqueous solutions.