Study On Thermo-mechanical Properties And Behavior Of Slag Corrosion Resistance Of β-Sialon Containing MgO Based Castables

MgO based castables used in the test are prepared with following raw materials: fused MgO as aggregate, fused MgO fines, fused alumina, α -Al₂O₃ ultra fine powder and micro silica as matrixes, MgO-SiO₂-H₂O as bonding system. In the castable bauxite based β -Sialon as additives with varying contents substitute corresponding contents of fused alumina fines respectively.Main contents in the investigations include: (1) The influences of β -Sialon addition on thermo-mechanical properties (HMOR, TSR) and microstructure of MgO based castables. (2) Oxidation resistance of Sialon containing MgO based castables has been studied by the methods of oxidation index and thermal weight test. (3) The influences of β -Sialon addition on slag corrosion resistance have been studied by static crucible method (1600℃ ×3h) in reducing and air atmosphere respectively, and two kind of slags------high basicity slagwith 3.5 in the ratio of CaO/SiO2 and low basicity slag with 1.2 in the ratio of CaO/SiO2 were selected; Slag corrosion interface topography was investigated with fractal method, and their microstructure and phase composition have been analyzed by SEM, EDAX, EPMA, XRD. (4) The influences of additives such as Sialon, graphite pellets on slag corrosion resistance in dynamic condition have been studied by revolution dipping method in reduction furnace with high basicity slag (3.5 in the ratio of CaO/SiO₂).The results show that: 1. β -Sialon addition would be contributel to improve thermo-mechanical properties:(1) HMOR at 1400℃ of MgO based castables improves noticeably with the increase of Sialon additon, it increases 2.6 times (2.90Mpa→ 7.36Mpa) with Sialon addition from 0 to 10%. Relationship between HMOR-T show that the specimens' Tm (the temperature while the maximum MOR is) without Sialon addition is 600℃ While it is up to 800℃ with Sialon addition, and HMOR is better than that of the specimens without Sialon addition.(2) Appropriate Sialon addition would lead to improvement of thermal shock resistance...