Special applications of the carbothermic reduction of metallic oxides

Abstract

The carbothermic reduction of metallic oxides has been used since the ancient times in the metal production, and currently it is the most important process of extractive metallurgy, being the foundation of ironmaking and several non-ferrous metals processes. The team of the present project has worked in different aspects of the carbothermic reduction, and intends to consolidate the acquired knowledge in the development of processes and improvement of the existing ones. The ultimate goal is to contribute to find answers to the demands of the society in a way that the metallurgical processes are energetically efficient, have high productivity, produce with quality and are not aggressive to the environment. The project is divided in 9 sub-projects closely related in the theoretical and technological aspects, covering aspects related to the primary metal attainment, recovery of values of residues, equipment, energy consumption, preparation of raw materials and mathematical modelling. The considered sub-projects are the following ones: 1)direct attainment of nodules of primary iron by carbothermic self-reduction. The objective of this project of research is to establish the best conditions of attainment of separate nodules of iron from the slag by treatment of self-reducing pellets of iron ore and carbon; 2) recovery of the iron from sludge and dusts generated in oxygen steelmaking. The objective of this project is to prove, in a laboratorial scale, that the technology of self-reduction is a possible alternative to the recycling of solid residues of an integrated plant; 3) treatment of oxygen steelmaking slags. This project intends to determine the effect of process parameters of steelmaking slag reduction aiming at the delineation of an industrial treatment that allows the recycling of this type of residue; 4) use of microwave energy in the carbothermic reduction of metallic oxides. The objective is to explore the use of microwave energy as promotional of reactions of carbothermic reduction of metallic oxides, specifically of iron ores, zinc bearing dusts, steelmaking slags and ilmenite; 5) recycling of dust from electric steelmaking employing self-reducing pellets containing petroleum coke. The objective is to analyze the behavior of self-reducing pellets, using petroleum coke, when submitted to different thermal cycles approaching the melting temperature; 6) carbothermic reduction of ilmenite as preparation for the attainment of synthetic rutile. The objective is to study the preparation of synthetic rutile from Brazilian ilmenite (richer in Fe203), through carbothermic reduction followed by separation of the metallic iron; 7) carbothermic reduction of chromite and chromium bearing residues. It aims the evaluation of the type of reductant on the kinetics of reduction of Brazilian chromites as well as the chromium yield, when chromite composite pellets are added to steel baths; 8) preliminary study on carbothermic reduction of alumina. The objective is to study experimentally the carbothermic reduction of alumina in the presence of a metallic solvent... (AU)