Effects of Different Barium Compounds on the Corrosion Resistance of Andalusite-Based Low-Cement Castables in Contact with Molten Al-Alloy

Synthesis of Al6Si2O13-BaAl2Si2O8-ZrO2-based composites and their wettability by molten Al and an Al-Si alloy

“…The most common solution is the use of additives to reduce wettability of aluminosilicate refractories by molten aluminum alloys enhancing the corrosion resistance [4]. Additives that have been used are: Na 3 AlFe 6 [5,6], Al 2 TiO 5 [7], SiC [8], CaF 2 [4,[9][10][11][12], BaSO 4 [4,9,10,[13][14][15][16], AlF 3 [4,9], CeO 2 [17] or a combination of them [4].…”

“…There are others alternatives for improving the corrosion resistance of aluminosilicate refractories using BaSO 4 or BaCO 3 [15,16]. The formation of compounds such as BaO•6Al 2 O 3 fills the refractory pores and channels reducing porosity and penetration of molten aluminum [13].The negative effects of free silica content in a silicoaluminate refractory can be eliminated when baryte (BaSO 4 ) is used as non-wetting agent, demonstrating an improvement in the corrosion resistance of mullite ceramics [23] or high-alumina refractories [14], due to the formation of BaCelsian.…”

“…The formation of compounds such as BaO•6Al 2 O 3 fills the refractory pores and channels reducing porosity and penetration of molten aluminum [13].The negative effects of free silica content in a silicoaluminate refractory can be eliminated when baryte (BaSO 4 ) is used as non-wetting agent, demonstrating an improvement in the corrosion resistance of mullite ceramics [23] or high-alumina refractories [14], due to the formation of BaCelsian. The addition of barium oxide and barium sulfate (BaO and BaSO 4 ) resulted in great improvements on the corrosion resistance of andalusite low cement castable (LCC) due to the formation of hexacelsian in the refractory matrix [16].…”

Effects of Different Boron Compounds on the Corrosion Resistance of Andalusite-Based Low-Cement Castables in Contact with Molten Al Alloy

“…The method of preparing the test samples and the procedure for the Alcoa cup test are listed in our previous publications. [7,8] All raw materials for the tests were provided by Amol Refractory Industries Company, Iran, and were of industrial purity. Figure 1 shows the images of the sectioned samples after testing at different temperatures.…”

“…The phenomena involved in the severe corrosion of this sample have been addressed previously. [7] Figure 2 (left column) shows the XRD patterns of refractories containing B 2 O 3 as additive, prefired to 873 K to 1373 K (600°C to 1100°C). Broad peaks of B 2 O 3 suggest its partly amorphous structure because it is produced from H 3 BO 3 at 623 K (350°C).…”