Improved corrosion resistance of Al₂O₃‐SiC‐C castables through in situ carbon containing aluminate cement as binder

Abstract

Slag corrosion is one of the main damage modes for refractory castables used in iron and steel metallurgy. The matrix plays vital roles for corrosion resistance of refractory castables. In the present paper, the properties of the Al2O3‐SiC‐C‐based trough castables with in situ carbon containing calcium aluminate cement (CCAC) and ball pitch as carbon sources, respectively, were comparatively investigated. The microstructures of the trough castables after corrosion were observed by field‐emission scanning electron microscopy. The results showed that after being corroded at 1450°C for 3 hours, the corrosion depth of Al2O3‐SiC‐C‐castables with CCAC as binder (A2) was 1.2 mm, 65.71% lower than that of the trough castables with ball pitch as carbon source (A1), though the content of carbon materials in the former was much lower than that of the latter. The reasons for these observations were that the in situ carbon materials of CCAC exhibit improved distribution in the matrices of castables and excellent oxidation resistance, resulting in lower porosity within the castables, and hindered the penetration of the molten slag at high temperatures. In addition, the Al2O3‐SiC‐C‐castables bonded by CCAC displayed good mechanical properties at room temperature and elevated temperature.

Improving the green mechanical strength and thermal shock resistance of colloidal silica‐bonded castables using La2O3

“…Corundum refractory castables, owing to their benefits, including good thermal stability, wear resistance, erosion resistance, thermal shock resistance, corrosion resistance, and high strength, are extensively used in circulating fluidized bed boilers, metallurgy, petrochemical, thermal power, and other industries 1–3 . Calcium aluminate cement (CAC) is the most widely used binder in corundum refractory castables 4–7 . However, the use of CAC has some drawbacks.…”

Particle grading effect on properties of reactive MgO‐bonded castables

“…Refractory castables encompass a broad range of materials that have undergone significant advancements, [1][2][3][4] leading to intricate and technically advanced formulations aimed at fulfilling highly demanding and rigorous industrial applications at elevated temperatures. [5][6][7][8][9][10] The primary features of castables consist of a well-chosen combination of raw materials, including aggregates, fillers, binders, and admixtures, [11][12][13][14][15][16][17][18] which leads to a deliberately designed particle gradation affecting the flowability and density of the mixture, [19][20][21][22][23][24][25] alongside the binder that influences both the green mechanical strength and the high-temperature properties, including phase evolutions. 6,[26][27][28] More recently, reactive MgO (RM) is considered as hydraulic binder to prepare castables with superior properties and performance.…”

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

“…Al2O3-SiC-C (ASC)castables are one of the primary refractory products used for molten iron pretreatment in iron and steel manufacturing process due to its excellent oxidation resistance and slagcorrosion resistance, thermal shockresistanceand good mechanical properties [1][2][3]. With the application and development of pretreatment desulfurization, dephosphorization and desiliconization technologies, higher requirements are demanded for ASC castables.…”