抄録
Reaction between molten oxide containing iron oxide and CO-CO2 gas is the essential reaction in numerous metallurgical smelting processes and the refining speed depends on this reaction rate. Therefore, the mechanism and kinetics for this reaction give us important information for the analysis, simulation and control of processes, and development of new refining systems. Many investigations have been done for clarification of reaction mechanisms between molten oxide containing iron oxide and CO-CO2 gas, however the direct measurement of oxygen exchange rate controlled by chemical reaction has not been conducted because of experimental difficulties. In the present work, oxygen exchange reaction rate between molten iron oxide and CO-CO2 gas has been measured by means of isotope exchange technique using C18O2-enriched CO2 gas. Isotope exchange technique is a useful method because the chemical reaction rate between gas and liquid phases could be measured directly without any influence of mass transfer in gas or liquid phases. The effects of temperature and CO2/CO ratio on the exchange rate have been investigated. It was clarified that the exchange rate was determined by interfacial reactions at first, and then by diffusion of 18O in liquid iron oxide.
