Process of carbothermal self-recovering of disperse Fe-C waste materials of metallurgical production modelling

Investigation of carbothermic self-recovering kinetics of metallurgical production Fe-C waste materials has been continued in this work for model monodisperse wustite-carbon and magnetite-carbon samples. On the strength of the results of differential thermal analysis the temperature of the beginning of the interaction in polydisperse material was determined. It should be more than 960oC. Kinetic curves of carbothermic self-recovering at 970oC and 1050oC were obtained on monodisperse model samples. During the study of high-temperature processing kinetics of Fe-C waste materials the amount of removed oxygen was determined from the volume and composition of the emitted gas phase. The method comprising simultaneous volume - dynamic and gas analyses was used. Analysis of the results showed that with increase in temperature the maximum rate of oxygen removal was achieved faster and had greater value. Analysis of the gas phase showed that at the initial stage of the process CO content was low over the whole operating temperature range. Then it increased and CO/CO2 ratio remained constant till the experiment was over. The concentration of CO for all temperatures being studied was about 75%, the rest was CO2. It convincingly indicated that the process is out of equilibrium with the gas phase and shifting towards CO2 formation. It was found that the completion of the first stage of the process is characterized by virtually zero magnetic properties of the material, i.e. by obtaining pure wustite. The obtained results confirmed the two-stage scheme of carbothermic process of dispersed Fe-C waste materials self-recovering and its topochemical nature. Studies of electrophysical and magnetic properties of the samples after the carbothermic self-recovering have been made. We found that for the studied materials the value of the specific saturation magnetization keeps growing during the process, reaching 179 A?m2/kg for wustite-carbon sample. The obtained value of the specific electric resistance varies slightly from 1,7?10-4 to 2,7?10-4 Ohms?m