Effect of mechanical activation on the soda roasting kinetics of chromite

Abstract

Soda roasting kinetics of non-activated and mechanically activated chromite was investigated. It was determined that the reaction was diffusion controlled between 700 – 900°C and chemical reaction controlled between 900 – 1200°C. The activation energy of first step for soda roasting of non-activated chromite was 170 kJ/mol and this value decreased to 141.8 kJ/mol for 30 min activated chromite and 79 kJ/mol for 120 min activated chromite. The activation energies for the second step was calculated as 64.7 kJ/mol for non-activated chromite, 43 kJ/mol for 30 min activated chromite and 25.1 kJ/mol for 120 min activated chromite. Mechanical activation reduced the activation energy for the soda roasting of chromite.

Keywords

• kromit, kromat, soda kavurması kinetiği, mekanik aktivasyon