Separation of Platinum(IV) and Iron(III) with Liquid Membranes under Electrodialysis Conditions

The recovery of platinum(IV) from hydrochloric acid solutions containing an excess amount ofiron(III) with liquid tri-n-octylamine-1'2-dichloroethane membranes under conditions of galvanostatic dialysiswas studied. The influence exerted by the current density, by the composition of aqueous solutionsand liquid membranes on the rate of platinum(IV) transport and efficiency of separation of the metals wasanalyzed and the optimal process conditions were determined.     

Membrane extraction and electrodeposition of silver(I) in systems with di(2-ethylhexyl) hydrogen phosphate

Extraction of silver(I) from nitric acid solution by electrodialysis with liquid membranes containing di(2-ethylhexyl) hydrogen phosphate with addition of tri-n-octylamine in 1,2-dichloroethane is studied. The effects of the composition of aqueous solutions and liquid membranes as well as of the basic parameters of electrodialysis on the Ag(I) transport and electrodeposition rates are examined, and the process conditions are optimized.     

Electrodialytic recovery of cobalt(II) with liquid membranes based on di(2-ethylhexyl)phosphoric acid

Electrodialytic transfer of cobalt(II) from sulfuric acid solutions across liquid membranes containing di(2-ethylhexyl)phosphoric acid with addition of tri-n-octylamine in 1,2-dichloroethane was studied, with the metal electrodeposited from dilute solutions of various acids. The influence exerted by the electrodialysis current density and by the composition of aqueous solutions and liquid membranes on the rate of cobalt(II) transport and electrodeposition was examined.     

Electrodialysis Separation of Copper(II) and Platinum(IV) with Liquid Membranes Based on Di(2-Ethylhexyl)Phosphoric Acid

Separation of copper(II) and platinum(IV) in extraction from binary acid chloride solutions with liquid membranes containing technical-grade di(2-ethylhexyl)phosphoric acid with addition of tri-n-octyl amine in 1,2-dichloroethane under the conditions of the galvanostatic electrodialysis was studied. The influence exerted by the current density and composition of aqueous solutions and liquid membranes on the rate and selectivity of copper(II) extraction was analyzed. The optimal conditions of metal separation were determined.     

Electrodeposition of gold(III) from cyanide-free electrolytes in membrane systems

Possibility of electrodeposition of gold(III) from dilute solutions of various mineral acids and ammonia by membrane electrolysis in recovery of gold from hydrochloric acid solutions was studied. The effect of the composition of the cathode solution and main electrolysis parameters on the rate of transport and electrodeposition of gold(III) was examined. The optimal process conditions were determined.     

Electrodialytic separation of cobalt(II) and nickel(II) using liquid membranes based on tri-n-octylamine and trialkylbenzylammonium chloride

Electrodialytic separation of Co(II) and Ni(II) in the course of their transfer from 3–4 M HCl solutions into dilute solutions of various acids using liquid membranes that contain anion-exchange carriers was studied. The influence exerted on the metal transport rate and separation efficiency by the compositions of the feed and receiving aqueous solutions and of liquid membranes and by the electrodialysis current density was examined. Under optimal conditions, in metal recovery from a solution containing an equimolar mixture of 0.01 M CoCl₂ and NiCl₂, the separation factor β_Co/Ni is 147; when nickel in the feed solution is in excess, it reaches 330, and when cobalt(II) is in excess, it exceeds 400.     

Electrodialytic recovery of chromium(VI) from hydrochloric acid solutions with liquid membranes based on tri-n-octylamine

A study of the process of electrodialytic recovery of chromium(VI) from a solution of 0.01 M K₂Cr₂O₇ in 0.1 M HCl with liquid membranes containing tri-n-octylamine with addition of di(2-ethyl hexyl)phosphoric acid in1,2-dichloroetrhane to dilute solutions of various acids determined the optimal process conditions: electrodialysis current density and the composition of the starting and receiving aqueous solutions and liquid membranes. It was found that all the liquid membranes studied provide a complete recovery of chromium(VI) anions from the starting solution.     

Electrodialytic recovery of iron(III) with liquid membranes based on diphenylthiocarbamide in the presence of palladium(II)

Separation of iron(III) and palladium(III) in recovery from binary hydrochloric solutions with liquid membranes containing diphenylthiocarbamide in 1,2-dichloroethane was studied under galvanostatic electrodialysis conditions. The effect of the current density, process duration, and compositions of the receiving solution and liquid membrane on the iron(III) recovery rate was examined.     

Electrodialysis Extraction and Electrodeposition of Lead(II) in Systems with Liquid Membranes

The extraction of lead(II) ions from nitric acid solutions through liquid membranes under galvanostatic electrodialysis with metal electrodeposition from the receiving solution of perchloric, nitric, or acetic acids is studied. The solitons of di(2-ethylhexyl)phosphoric acid with additives of tri-n-octylamine in 1,2-dichloroethane are used as liquid membranes. The effect of the current density of the electrodialysis and the composition of the initial aqueous solution and receiving solution (catholyte), as well as the composition of liquid membranes on the rate of membrane transport and electrodeposition of the lead(II) ions, is investigated. The optimal conditions of the process are determined. Fine-grained and highly adherent lead deposits are obtained on a platinum cathode during the deposition from perchloric acid solutions. It is shown that the degree of extraction of lead(II) ions from the initial aqueous solution is higher than 90% in the process, while the degree of electrodeposition amounts to 60% within 5 h of electrodialysis.

     

Recovery of manganese(II) by electrodialysis with liquid membranes based on di(2-ethylhexyl)phosphoric acid

Electrodialysis membrane extraction of manganese(II) from sulfuric acid solutions with liquid membranes containing di(2-ethylhexyl)phosphoric acid and tri-n-octylamine in 1,2-dichloroethane was studied. The effect of the electrodialysis conditions and the composition of the organic phase and aqueous solutions on the transport rate of manganese(II) ions was examined. The conditions of quantitative recovery of the metal from a 0.01 M MnSO₄ solution were determined.