JSC «RPA «CNIITMASH» (Moscow, Russia):

L. Ya. Levkov, Dr. Eng., Head of the Special Electrometallurgy Laboratory, e-mail: LYaLevkov@cniitmash.com, 6758745@mail.ru

Lomonosov Moscow State University (Moscow, Russia):
D. А. Pankratov, Cand. Chem., Leading Scientific Researcher, Chemical Dept., e-mail: pankratov@radio.chem.msu.ru

Development of significant provisions of the slag melts theory made it possible to substantiate a change in the average oxidation state (o.s.) of iron in the slag phase, and also to determine the conditions and limits of such changes. It is shown that the value of the equilibrium oxygen partial pressure, P_o2 as a value available for measurements is possible to be taken as a measure of slag redox potential of, taking into account its electronic system performance (the Fermi level). It is established a functional relationship between the average o.s. of iron in the oxide-fluoride melted slags, Po2 value and the temperature. Taking into account the structural peculiarities of the external iron electron shells, a kind of dependence of its average o.s. in the slag phase on Р_о2 was proposed and it was experimentally established that a decrease in Р_о2 from 10^–6 to 10^–10 Pa at 1873 K leads to a decrease in by o.s. approximately a factor of 2. An increase in the iron content in a slag leads to a monotonous increase in its average o.s. The study of Mössbauer absorption spectra of quenched slag samples confirmed the possibility of simultaneous presence of iron in the slag in oxidation states from 0 to +3.

The paper was completed with the financial support of the Ministry of Education and Science of the Russian Federation within the framework of the Agreement on granting a subsidy for the implementation of the applied scientific research on the issue with Unique identifier of the applied research and experimental development: RFMEFI57916X0134. We are thankful to D. A. Shurygin and D. K. Terekhin (JSC “RPA “CNIITMASH”) for their assistance in discussing and preparing the material for the article and conducting experiments.

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