Some Effects of Microwave Heating of Chromite Ore for Fe-CrAl Alloys by Aluminothermy

Abstract

Processes and prime materials involved in Fe-Cr-Al alloys production by aluminothermy are presented having in view new possibilities to produce them more ecological and more efficient, using energy of microwave field. The capacity of heating pieces of chromite ore containing 56.52 %mass Cr2O3 and a ratio (% massCr2O3/ %massFeO) = 2.622 in a domestic microwave oven is evaluated at the maximal power of the microwave field of 700 W where a maximal temperature about 260 oC was obtained after 16 minutes heating. A rapid cooling from this temperature to 20 oC, by water immersion induces an increasing of the internal voids due to new cracks and the development of pre-existing cracks of about 0.15-0.29 %, which helps to reduce the energy consumption in chromite comminution. The final heating temperatures show a low possible contribution to the reduction of energy consumptions in direct metallurgical processes on the account of chromite ore heating in microwave field.

Keywords

• chromite ore
• microwave heating
• internal voids
• cracks