Fracture behaviour and microstructure of refractory materials for steel ladle purging plugs in the system Al2O3-MgO-CaO

Synthesis of Niobium-Alumina Composite Aggregates and Their Application in Coarse-Grained Refractory Ceramic-Metal Castables

“…The envelope density of the fine-grained composite was determined with the Archimedes principle to 5.66 g /cm 3 including 18% open porosity. A skeleton density of 6.73 g /cm 3 was determined with mercury intrusion porosimetry (MIP) resulting in an envelope (bulk) density of 5.78 g /cm 3 and hence an (open) porosity of 16.5% as presented in Table 4.…”

“…The envelope density of the fine-grained composite was determined with the Archimedes principle to 5.66 g /cm 3 including 18% open porosity. A skeleton density of 6.73 g /cm 3 was determined with mercury intrusion porosimetry (MIP) resulting in an envelope (bulk) density of 5.78 g /cm 3 and hence an (open) porosity of 16.5% as presented in Table 4. The total porosity of the fine-grained composite was estimated based on the CT image as shown in Figure 5 to 32.60%, which gives an estimated closed porosity in the range of 10-15%.…”

“…Therefore, the image processing, particulary the binarisation step, is a subject of errors. 3 in % in g /cm 3 in % in g /cm 3 in g /cm 3 in g /cm…”

“…The higher the firing temperature of the castables the more pronounced is the ceramic bonding of the fine matrix. Hence, the high degree of sintering results in lowering porosity and enhancing both modulus of rupture as well as Young s modulus [3]. The open porosity of conventional alumina castables bonded with high alumina cement fired at 1000 °C varies from 20% to 30% depending on the type of aggregates and cement used [4] After firing at 1600 °C, the low cement castables (LCC) and cement-free castables (NCC) based on alumina have an open porosity in the range from 15 to 20% [5].…”

Numerical Investigations on Thermomechanical Behaviour of Purging Plug with Rectangular and Circular Slits

“…In general, the wear of the purging plugs mainly consist of erosion due to intensive liquid steel stirring, corrosion by aggressive iron-oxide rich slag at high temperature and, as well as the spalling of layers from the hot face, which is owing to horizontal cracking. 7) In order to prolong the service life of purging plugs, many efforts have been made by adjusting the chemical components so as to improve the material properties. For instance, Long et al 8) compared the relevant thermomechanical properties of corundum-spinel castables produced with and without calcium aluminate cement.…”