Improvements of properties of alumina-silica refractory castables by alumina-coated aluminum powders

Enhanced performance of Al2O3–SiC–C castables via in-situ formation of multi-reinforced phases by introducing surface treated composite metal powders

“…Surface treated composite metal powders (STCMPs) were prepared by water vapor corrosion composed of 60 wt.% Al, 10 wt.% Si and 30 wt.% Al-Si alloy, which was referred to microcapsules in the following analysis. The process has been reported in detail in our previous work [21].The ratios of raw materials were determined according to the Andreasen packing model with a distribution coefficient of q=0.21, which is shown in Table 1. The raw materials were mixed with water reducer (FS10, Wuhan Sanndar Chemical Company Co., Ltd, Wuhan,China) and about 5 wt.% water for all the samples, then they were cast into 140 × 25 × 25 mm 3 samples.…”

“…In our previous studies [21], a Al2O3-coated Al powders were prepared and added to a Al2O3-SiO2 refractory castable and its properties were greatly improved after heat-treatment at 1000 °Cin N2 atmosphere. As for the second aspect, the addition of metal powders can not only improve the oxidation resistance of ASC castables, but also enhance its explosion resistance.…”

Gas permeability of alumina–spinel refractory castables bonded with hydratable magnesium carboxylate

“…However, there is still a risk of explosives associated with the setting before gas generation, high curing temperature, and excessive amount addition of metallic powders. 13,14 The chelating agents (e.g., Refpac MIPORE 20 and RefM-OAS) used for MgO-bonded refractory castables may improve the explosive spalling resistance by promoting the formation of permeable paths for water removal at lower temperatures or stepwise dehydration. Nevertheless, the permeability of chelating agents contained in castables has not been tested and the effect of the chelating agents on the permeability of the castables has not been fully understood.…”

“…Common metallic powders (Al, Mg, Si, and alloys) were added to improve the permeability of castables by the release of a mass of hydrogen (H 2 ) to generate the gas paths during the reaction of metallic powders with water. However, there is still a risk of explosives associated with the setting before gas generation, high curing temperature, and excessive amount addition of metallic powders 13,14 . The chelating agents (e.g., Refpac MIPORE 20 and RefM‐OAS) used for MgO‐bonded refractory castables may improve the explosive spalling resistance by promoting the formation of permeable paths for water removal at lower temperatures or stepwise dehydration.…”