Abstract:
An improved methodology is presented for assessing the economic feasibility and effectiveness of recycling
MgO-C and Al2O3-MgO-C refractory bricks, which are widely used in the steelmaking industry. Since
approximately 28 Mt of refractory bricks are discarded each year, it is logical to recycle them. When furnaces
and ladles are relined, the spent refractory bricks become mixed up, and need to be sorted before recycling.
This study examined the use of a hand-held X-ray fluorescence analyser (HH-XRF) to distinguish between
spent oxide-based and oxide-carbon-based refractory materials, with special emphasis on spent MgO-C (MC)
and Al2O3-MgO-C (AMC) bricks. HH-XRF analysis was conducted on 18 oxide-carbon refractory bricks as
well as on MgO-chromite and bauxite-based refractories. X-ray diffraction, reflected light optical microscopy,
and scanning electron microscopy with energy dispersive spectroscopy were used to characterize the MgO-C
and Al2O3-MgO-C bricks to confirm the accuracy of the HH-XRF analyses.
This study also underlined the importance of calibrating the HH-XRF analyser for the refractory bricks to
be sorted. The HH-XRF was successful in distinguishing between the different oxide-carbon-based refractory
bricks both before and after cleaning. This result is important as it proves that HH-XRF provides a method
whereby spent MC and AMC bricks can be sorted quickly and reliably.
