S. A. Krasikov

Influence of titanium and molybdenum oxides on the surface and bulk properties of oxide-fluoride slags

The influence of titanium and molybdenum oxides on the surface tension and density of the Al2O3-CaO-CaF2 melt is investigated. It is found that the addition of 4–25 mol % TiO2 and 3 mol % MoO3 to the melt at 1773–1923 K promotes a decrease in surface tension and an increase in density. The manifestation of complexing properties by titanium and molybdenum is found for the studied oxide-fluoride slags, and the sizes and structure of structural units are revealed.

Effect of the intermetallic compound composition of the character of interphase interactions during aluminothermic coreduction of titanium, nickel, and molybdenum from their oxides

The correlation between the sequence of formation of intermetallic compounds and the nature of interphase interactions in the course of aluminothermic coreduction of titanium, nickel, and molybdenum from their oxides is analyzed.

Influence of phase formation on the interphase interactions during the aluminothermic reduction of zirconium from its dioxide

The surface and volume properties of the zirconium–aluminum alloys synthesized by the aluminothermic reduction of zirconium from its dioxide are estimated theoretically and experimentally. The experimental values of surface tension and the metal and slag densities are used to calculate the interfacial characteristics that influence the separation of the products of metallothermic melting.

Effect of zirconium and molybdenum oxides on the surface and volume properties of an aluminocalcium oxide-fluoride melt

The effect of additions of zirconium and molybdenum oxides on the surface tension and density of oxide-fluoride slags is studied by the method of the maximum pressure in a gas bubble. The obtained experimental and calculated results reveal a complex-forming character of the behavior of zirconium and molybdenum in oxide-fluoride slag melts, and they are used to estimate the sizes of the structural units present in the surface layer of the slags.

Effect of zirconium and molybdenum oxides on the viscosity and the electrical conductivity of oxide-fluoride slags

The effect of additions of zirconium and molybdenum oxides on the viscosity and the electrical conductivity of oxide-fluoride slags is studied using a vibration viscometry and an ac bridge.

Effect of titanium and molybdenum oxides on viscosity and electrical conductivity of oxide-fluoride slags

The effect of additives of titanium and molybdenum oxides on the viscosity and electrical conductivity of the Al2O3-CaO-CaF2 oxide-fluoride slag melts at 1750–1950 K is investigated by vibration viscosimetry and the ac bridge method. Crystallization intervals are established depending on the variation in the TiO2 and MoO3 concentrations in the melts from 0 to 25%, and it is revealed that the majority charge carriers are calcium and fluorine ions. These data indicate the complex-forming character of the behavior of Ti and Mo in aluminum-calcium oxide-fluoride melts.

The possibility of oxidation reactions of the sulfides of heavy non-ferrous metals and iron by the chain mechanism

A thermodynamic evaluation of the oxidation of sulfides of heavy non-ferrous metals is carried out. It is shown that, according to the values of the decreasing Gibbs energy for these reactions, the sulfides are arranged in the following series: FeS, Ni3S2, CoS, NiS, ZnS, PbS, CdS, CuS, Cu2 S. The thermodynamic probability that all stages of the chain mechanism of oxidation of sulfides will proceed with the isolation of gaseous oxygen and atomic sulfur is also evaluated.

Viscosity of niobium-containing oxide-fluoride melts

Influence of Nb2O5 on viscosity of the CaF2-based and CaF2-30% Al2O3-based melts was investigated using a vibration viscosimetry method in the range 1523–1873 K. It is found that viscosity of the melts rise and the crystallization range shifts to lower temperatures as the Nb2O5 concentration increases from 0 to 25 wt %. The activation energy of viscous flow increases from 34 to 110 kJ mol−1 and from 56 to 148 kJ mol−1 for the CaF2-based and CaF2-30% Al2O3-based melts, respectively. The obtained data indicate the complexing behavior of niobium in the oxide-fluoride melts.

Effect of a Nonstationary Electric Current on the Oxide Melt–Gas Phase System

The influence of a nonstationary electric current on an oxide melt is studied. A nonstationary energy action is found to change the microstructure of a liquid system and to promote unlikely chemical reactions between an oxide melt and gas components. The division of the gas-phase components into oxidizing and reducing gases becomes rather conventional. It is found that stable application of an electric current can bring the system to a quasi-equilibrium state, which can retard the development of a chemical reaction, and the chemical reaction during the process can generate an electric current.

Surface tension of a titanium-containing oxide–fluoride melt calculated by the polymer theory

The surface tension of an aluminum–calcium oxide–fluoride melt is calculated using the polymer theory. It is shown that, at 15 mol % titanium oxide in the melt, aluminum–fluorine–oxygen complexes mainly form. When the titanium oxide content increases further, these complexes disappear and are partly replaced by titanium–oxygen TiO44- and Ti2O76- anions and titanium–fluorine–oxygen groups.