Solid state reduction of titanomagnetite concentrate by graphite

Abstract

Titanomagnetite concentrate was reduced by graphite isothermally under argon gas in thermogravimetry system at 1 373 to 1 623 K. The influences of reductive conditions on the reduction and metallization degree including reduction temperature, reduction time and C/O molar ratio were studied. And the characteristics of reduced samples were analyzed by XRD, BES and EDS. Results shown that in the temperatures range of 1 423 to 1 623 K, initially the reduction proceeded rapidly and after 30 min only a slow increase in reduction was observed. The low reduction degree was owing to the high impurities oxides content such as magnesium oxide in titanomagnetite concentrate and the reduction and metallization degree increased with the C/O molar ratio until up to 1.0 at 1 623 K. Above 1 373 K, the reduction path is suggested as follow: Fe 3-xTixO4 → (x + y - 1)FeO + Fe 4-2x-yTixO4-y → (x + y - 1)Fe + Fe 4-2x-yTixO4-y → (3 - x)Fe + xTiO 2 (0