Fatty Imidazolines: A Novel Extractant for the Recovery of Palladium(II) from Hydrochloric Acid Solutions

The extraction of palladium(II) from hydrochloric acid solutions with a novel highly basic extractant, a mixture of homologous 1-[2-(alkanoylamino)ethyl]-2-alkyl-2-imidazolines (AAI) in toluene with 15% (v/v) of n-octanol was studied. Palladium(II) is rapidly and most effectively extracted with AAI hydrochloride at the low hydrochloric acid (chloride ions) concentration (up to 1 M) and can be completely separated from Fe(III), Cu(II), and Co(II). The palladium(II) extraction at the optimum acidity occurs via an anion-exchange mechanism with the formation of ionic associates (LH)₂PdCl₄ (K _ex = (1.5 ± 0.2) · 10⁴ at 0.5 M HCl) and is accompanied by the dimerization of palladium(II) in the organic phase with the formation of ionic associates (LH)₂Pd₂Cl₆ (K _dim = (3.9 ± 0.4) · 10^?4 at 0.5 M HCl). The anion-exchange extraction of palladium(II) at the acidity of 0.5 M HCl is temperature independent in the range 20–49°C. Complete stripping of palladium(II) can be performed using a 5% solution of thiourea in 0.1 M HCl.     

Sizing preparations for complex polyester fibres

Water-soluble polyethers containing 5-sulfoisophthalic acid units and polyethylene oxide blocks in the macromolecules were synthesized. The possibility of using water-soluble copolyethers as sizing preparations for synthetic complex fibres was investigated. It was found that the copolyethers obtained are analogs of the imported preparation Eastman WD with respect to sizing properties.Translated from Khimicheskie Volokna, No. 1, pp. 21–23, January–February, 1995.     

Features of hardening of the heavy rolls of mills for cold rolling of tubing

All-Union Scientific-Research Institute for the Tube Industry, Chelyabinsk Tube Rolling Plant. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 9, pp. 42–43, September, 1989.     

Contamination of the transformer oil of power transformers and shunting reactors by metal-containing colloidal particles

The results of a measurement of the contamination of the oil in 66 transformers by metal-containing colloidal particles, formed as a result of the interaction of the oil with the structural materials (the copper of the windings, the iron of the tank and core etc.), and also the results of measurements of the optical turbidity of the oil in 136 transformers when they were examined at the Power Engineering Research and Development Center Company are presented. Methods of determining the concentration of copper and iron in transformer oil are considered. The limiting values of the optical turbidity factors, the copper and iron content are determined. These can serve as a basis for taking decisions on whether to replace the silica gel of the filters for continuously purifying the oil of power transformers and the shunting reactors in addition to the standardized oil contamination factors, namely, the dielectric loss tangent and the acidity number of the oil.     

Use of local sands in sheet glass production

Study of domestic sands from the Aleksandrovskoe deposit (Saratov Region) revealed the possibility of using these sands in sheet glass production. The use of this sand as the main silicon-containing material in the pilot production of heat-absorbing glass of a wide color spectrum is discussed.     

Entropy generation due to natural convection of a nanofluid in a partially open triangular cavity

A numerical analysis of laminar natural convection with entropy generation in a partially heated open triangular cavity filled with a Cu-water nanofluid has been carried out. Mathematical model including partial differential equations and boundary conditions has been solved by using finite difference method. Particular efforts have been focused on the effects of Rayleigh number, nanoparticles volume fraction and position of the local heater on streamlines, isotherms, local entropy generation as well as local and average Nusselt number, average Bejan number, average entropy generation and fluid flow rate. Obtained results have demonstrated that the heat transfer enhancement and fluid flow attenuation with nanoparticles volume fraction, mainly for high values of Rayleigh number.