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Henan’an, China

Chen H.,Henan Boma Co. | Wang C.,Henan Boma Co.
Naihuo Cailiao/Refractories | Year: 2013

Three castables 0#, 1# and 2# were prepared in order to cut the production cost of ladle nozzle well block. The formulation of 0# castable is 70% (in mass, the same hereinafter) white fused corundum aggregate, 10% white fused corundum fines, 15% (α-Al2O3 micropowder+magnesium aluminate spinel+chrome oxide micropowder), and 5% calcium aluminate cement. For 1# castable, the equigranular Al2O3-Cr2O3 slag was used to completely replace the white fused corundum aggregate based on the 0# castable formulation. For the 2# castable, the Al2O3-Cr2O3 slag fines was used to completely replace the white fused corundum fines based on the 1# castable formulation. After stirring, vibratory compaction, curing, drying, and heating at 1100 and 1550°C, respectively, the density, strength, thermal shock resistance and slag corrosion resistance of the three castables were determined. The results indicate: (1) after drying at 110°C, compared with 0# castable, the bulk density of 1# castable changes a little, the apparent porosity increases slightly, and the modulus of rupture decreases slightly while the crushing strength improves significantly; but the performances of 2# castable decline in different degrees; (2) after heating at 1100 and 1550°C, the performances of 1# castable improve markedly; the hot modulus of rupture increases distinctly, the slag corrosion resistance is good, but the thermal shock resistance reduces; the performances of 2# castable decline evidently except for the hot modulus of rupture. The ladle nozzle upper well blocks prepared using the 1# castable formulation were used on a 60 t ladle in one steel plant, their service life without repair reached 80-90 heats, and the service life reached 110-120 heats after repairing, synchronized with the ladle life. Source

Zhiwang N.,Henan Boma Co. | Hui L.,Henan Boma Co. | Xinhong L.,Henan Boma Co. | Peizhong L.,Henan Boma Co. | And 4 more authors.
Naihuo Cailiao/Refractories | Year: 2013

The metal composite unfired Al2O3-C slide plate specimens were prepared using tabular corun-dum, α-Al2O3 micropowder, flake graphite, aluminum powder and silicon powder as main starting materials, extra adding 4 mass% thermoset phenol formaldehyde resin and modified resin as binders. Effects of modified resin additions (0,1%,2% and 3%.,in mass) on properties of specimens fired at 400-1 000 °C in carbon embedded (graphite) condition and in air, respectively, were investigated. The results show that modified resin can obviously increase the strength at medium and low temperatures,but it has a little negative effect on oxidation resistance of the specimens. The unfired slide plates with 2% modified resin were used in a 120 t ladle and achieved a good effect. The average service life of the developed slide plates is 2.2 heats,and that of normal unfired slide plates without modified resin is 1.3 heats. Source

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