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The recycling of metals from electronic equipment waste (e-waste) is of great concern today. The work described in the article focuses on the application of ionic liquids (ILs) to selectively recover of precious metals (Ag and Au) from the anodic slime obtained at the anodic dissolution of cast ewaste. The ingots obtained from molten and cast anodic slime were selectively dissolved in ILs. Silver and gold compositions of the ingots: 39.7 wt.% and respectively 18.9 wt.%. The IL used was an eutectic mixture of choline chloride with ethylene glycol in a 1:2 molar ratio. As catalytic/oxidizing agent, there was used pure iodine in a concentration of 0.1-0.2 moldm -3 at 298-303 K. Cyclic voltammetry was employed for the determination of the electrochemical windows of ILs as well as of the dissolution and electrodeposition potentials of principal metals present in the ingot (anode). For Ag and Au, the deposition potentials determined were 0.074 V and respectively 0.696 V. The XRD and SEM-EDX analyses revealed that the content of precious metals in the cathodic deposits was 99 wt.% for Ag and respectively >70 wt.% for Au. We demonstrated that ILs electrolytes could be a solution to selective recovery of precious metals from e-waste.

A new ternary Ti-15Zr-5Nb alloy was elaborated with the aim to satisfy the most stringent requirements of a good implant material. The alloy has a þ b bi-phase microstructure (by XRD and optical microscopy) and presents a proper combination between Young's modulus, elasticity and good ultimate tensile strength and 0.2% yield strength (from stress-strain tensile curve), indicating a good suitability as implant material. Electrochemical behaviour in artificial Carter-Brugirard saliva of different pH values (3.96, 7.84, and 9.11) and composition (un-doped and doped with 0.05 M NaF) that simulate the severe functional conditions in the oral cavity was evaluated. All electrochemical parameters of the new alloy revealed more favourable values than those of the CP Ti and Ti-6Al-4V ELI alloy, showing a more compact, resistant passive film formed on the new alloy surface. The corrosion rates and corresponding ion release rates for the new Ti-15Zr-5Nb alloy exhibited very low values (hundreds of times smaller) in comparison with similar commercial biomaterials. Electrochemical impedance spectra distinguished bi-layered passive film formed by inner, barrier layer and outer, porous layer. X-ray photoelectron spectra and scanning electron microscopy (SEM) observations proved that in time, protective compounds were deposited from saliva on the alloy surface, enhancing its corrosion resistance.

The cathodic reduction processes of cobalt (II), tungsten (VI) and molybdenum (VI) in Na2WO4 melts are discussed. Electrochemical behavior of cobalt in a tungstate melt, as well as the effect of electrolysis conditions on the composition and structure of Co-W and Co-Mo alloys deposits from tungstate-molybdate melts is also studied. With a decrease in the concentration of cobalt ions and an increase in the concentration of molybdenum (tungsten) ions in the melt, the phase composition of cathodic deposits is shown to change from individual cobalt to individual molybdenum (tungsten) via a series of cobalt-molybdenum (tungsten) compounds of various compositions.