A study of chromite carbochlorination kinetics

Ndue Kanari (1) , I. Gaballah (1) , Eric Allain (2)

1 LEM - Laboratoire Environnement et Minéralurgie
2 Missouri S&T - Missouri University of Science and Technology

The carbochlorination of a chromite concentrate was studied between 500 °C and 1000 °C using boat experiments. The reaction products were analyzed by scanning electron microscopy (SEM), x-ray diffraction (XRD), and chemical analysis. The carbochlorination of a chromite concentrate at about 600 °C led to the partial selective elimination of iron, thus increasing the Cr/Fe ratio in the treated concentrate. Total carbochlorination of the chromite concentrates and volatilization of the reaction products was achieved at temperatures higher than 800 °C. The kinetics of the chromite carbochlorination was studied between 750 °C and 1050 °C using thermogravimetric analysis (TGA). The results were discussed in terms of the effects of gas flow rate, temperature, partial pressure of Cl2+CO, and Cl2/CO ratio on the carbochlorination process. It was observed that the temperature effect changed significantly with the progress of the reaction. The initial stage of the carbochlorination was characterized by an apparent activation energy of about 135 and 74 kJ/mol below and above 925 °C, respectively, while a value of about of 195 kJ/mol was found for the remainder of the carbochlorination process.

Domaines: Chimie; Chimie inorganique; Matériaux; Planète et Univers [physics]; Sciences de l'environnement

Ndue Kanari, I. Gaballah, Eric Allain. A study of chromite carbochlorination kinetics. Metallurgical and Materials Transactions B, 1999, 30 (4), pp. 577-587. ⟨10.1007/s11663-999-0018-5⟩. ⟨hal-01508076⟩