LLC Giproniсkel Institute, Saint Petersburg, Russia

I. V. Klimenko, Chief Researcher of the Nickel Refining Technologies Sector of the Laboratory of Hydrometallurgy, email: KlimenkoIV@nornik.ru
U. V. Аbramova, II Grade Engineer of the Nickel Refining Technologies Sector of the Laboratory of Hydrometallurgy
М. B. Greyver, Head of the Nickel Refining Technologies Sector of the Laboratory of Hydrometallurgy

JSC Kola MMC, Monchegorsk, Russia.
I. S. Platonov, Chief Engineer of Nickel Electrolysis Workshop

The desire of JSC Kola MMC to produce high-quality nickel products of the Plating Grade and High Purity grades, characterized by strict requirements for the iron content (<40 ppm and <30 ppm, respectively), as well as a change in the composition of incoming raw materials towards an increase in the iron content in it, requires a significant intensification of the existing iron refining capacities of JSC Kola MMC. The search for opportunities to increase the efficiency of purification of nickel solutions from iron and the selection of optimal modes and parameters for conducting this process in industrial practice is possible provided a deep understanding of the ongoing processes, their qualitative and quantitative assessment. To collect this data, JSC Kola MMC initiated work on modeling the process of iron purification of nickel chloride solutions in order to find ways to increase the productivity of iron purification processing. In the first part of the article published earlier, some of the results obtained in the framework of the conducted research were described, including an assessment of the effect of mixing intensity, information on the order of the oxidation reaction of iron by oxygen and iron, as well as consideration of the temperature effect on the process. In the second part of the article, a method for conducting laboratory experiments is presented, the effect of the solution composition is evaluated: oxygen solubility, ionic strength, the ratio of chloride and sulfate ions, the effect of copper on the oxidation of iron with oxygen is also shown, and the reaction order for copper is determined. The effect of pH changes in the solution on the kinetics of iron oxidation is studied and data on the solubility of Fe³⁺ at different levels of acidity of a concentrated nickel solution are presented. The information will be of interest to a wide range of specialists in the field of nickel hydrometallurgy and chloride hydrometallurgical technologies in general.

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