Nickel speciation in aqueous chloride solutions

✍ Scribed by Jinxing Ji; W.Charles Cooper

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 833 KB
• Volume: 41
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(95)00407-6

✦ Synopsis

A series of speciation diagrams for nickel species in chloride solutions at 25°C has been plotted with the effects of the ionic strength on the activity coefficient of the hydrogen ions and the equilibrium quotients being taken into account. It has been determined that the predominant nickel species in the acidic region are Ni' + and NiCl+ in concentrated pure NiCI, solutions and Ni'+, NiCl+ and NiSO, in concentrated sulfate-containing NiCI, solutions. The species NiOH+ is negligible until the NiCI, concentration is lowered to the order of lo-'M. Other nickel species including Ni(OH),,,,,, Ni(OH);, Ni(OH):-, NisOH"+ are negligible both in the acidic and basic regions for the concentrated NiCI, solutions. When pH increases, insoluble Ni(OH),(,, is expected to form in the basic region if NiCI, concentration is higher than 10m6 M. The pH where Ni(OH),(,, starts to form decreases with increasing NiCl, concentration.