Aleksandra Wojciechowska

Recovery of Nickel(II) Ions from Sulphate/Chloride Solutions Using Hydrophobic Pyridylketoximes

In this study, the extraction of nickel(II) ions from sulphate and sulphate/chloride solutions with 2-, 3-, and 4-pyridylketoximes was investigated. The effect of different variables influencing the extraction of nickel(II) ions such as the extractant structure and the concentration of hydrogen ion, sulphate, and chloride ions have been studied. The shaking time and temperature also influenced metal ion removal. It was found that the hydrophobic 2-pyridylketoximes are the most effective extractants for nickel ions from sulphate/chloride solutions. The discussion also includes the mechanism of nickel(II) complexation by the hydrophobic pyridylketoximes and the speciation of nickel(II) in the presence of chloride and sulphate ions.

Equilibrium studies of cobalt(II) extraction with 2-pyridineketoxime from mixed sulphate/chloride solution

In present paper the equilibrium of cobalt extraction with 1-(2-pyridyl)tridecan-1-one oxime from the chloride/sulphate solutions was studied. The presented results indicated that extraction depends on a number of process variables, including the pH, metal and Cl− concentration in the aqueous feed, and concentration of the oxime in the organic phase. The created cobalt-complexes with the 2-pyridine ketoxime were stable and only concentrated HCl was found to be a suitable stripping agent for coordinated metal. The separation of Co(II) from Zn(II), Ni(II) and Cu(II) was also studied, but the selective recovery of the metals was possible using the multi-stage stripping process.

Selective Removal of Cobalt from Nickel Sulphate Solutions Using Oxime of 1-(2-Pyridyl)tridecan-1-one

In the present study the selective recovery of cobalt(II) ions from nickel(II) sulphate solution by oxime of 1-(2-pyridyl)tridecan-1-one has been investigated. The studies focused on evaluating the influence of several experimental parameters, such as pH of aqueous solutions, temperature of the process, aqueous/organic phase ratio, and separation factors for cobalt and nickel extraction on the selective recovery of cobalt ions. Based on the results, the flow-sheet for the selective recovery of cobalt ions from nickel sulphate solution was proposed.