Kinetic study of the carbothermic reduction of zinc ferrite for the recycling zinc

Reference	Presenter	Authors (Institution)	Abstract
06-217	Leidy Julieth Hernández Buitrago	Hernández Buitrago, L.J.(Universidades de Sao Paulo); Lenz e Silva, G.F.(Escola Politécnica da Universidade de São Paulo); Amaral-Labat, G.(University of São Paulo);	Most zinc recycling processes of electric arc furnace (EAF) dust employ carbon as a reducing agent of iron and zinc oxides in the dust. In the present work, the reduction reaction of frankilinite (ZnO.Fe2O3) with different carbon sources was studied. The effects of temperature and the reducing agent on the kinetics of the reduction reaction of pellets of EAF dust and the carbon source were studied at the temperature range of 1123-1323K under argon atmosphere, through a)fractional factorial design of experiments type 3III(4-2) The variables were: type of binder (borax, sodium metasilicate and a cane molasses with Ca(OH)2 mxture); Binary Basicity (0.5 - 3.5), isothermal reduction temperature and reducing agent type( petroleum coke and, charcoal with total carbon content of 86.88 and 76.195 %, respectively). According to the reduced-time method the kinetic model that best fit the overall reduction process is the exponential model of continuous reaction (kt = -Ln (1-Fr)).. From the experimental results, it was found that the variation of the activation energies for carbon gasification is mainly due to the type (reactivity) of the reducing agent and its porosity, and it ranged from 170 to 350kJ/mol. Characterization by X-ray diffraction, laser granulometric analysis, elemental analysis of carbon, nitrogen and hydrogen as well as percentage of volatile matter, fixed carbon and ash were employed.
<< Back