Impact of the reduction of graphite content in critical properties of MgO–C bricks for steelmaking industry

Abstract

Nowadays, the use of lower amounts of graphite in MgO–C bricks for the steelmaking industry is motivated by several reasons, including the reduction of CO2 emissions. In this work, a MgO–C brick with 12 wt% graphite, was evaluated in comparison with a similar material containing just 8 wt% of this component. The changes induced in the brick by thermal treatments (graphite bed) between 500 and 1400 °C were analyzed comparatively. Moreover, the effect of reducing the graphite content in the mechanical properties at RT, 1000 and 1400 °C (compressive tests, in argon) and the oxidation resistance in air at 1000 and 1400 °C was determined. At 1000 °C, the refractory with 8 wt% graphite exhibited the highest mechanical strength and stiffness. Furthermore, although the decarburized area was larger after treatment at 1000 °C in air in this brick, the mass and carbon losses showed the opposite trend.