Studying On Preparation And Properties Of Alumina Light Weight Insulation Materials With High Strength And Low Thermal Conductivity

Energy-saving problem of industrial furnaces has been an important issue for metallurgy, machinery, chemical and other large energy consumption, the small volume density, low thermal conductivity of light weight insulation materials for lining is one effective way to solve this problem. Light-weight Alumina material is one of the ideal choices As the advantages of high temperature furnaces lining material has high strength, resistance to acid and alkali erosion, using high temperature etc. At present, Light-weight Alumina material always was prepared by compression molding process with alumina hollow ball, which had some disadvantages such as large energy consumption, big volume density and thermal conductivity. So how to prepare the light-weight alumina material with higher strength, smaller volume density and thermal conductivity by new process had became an important research direction for refractory workers.In this paper, two feasible methods to synthesize the light weight alumina insulation materials have been explored. And effects of process parameter on structure and properties of light weight alumina insulation materials were the main research content. The main contents in this paper include two parts. (1) Light weight alumina insulation materials were prepared by two step process, and effects of raw materials, molding pressure, porogen contents and sintering temperature on the properties and structure of light-weight alumina materials were explored; (2) Light weight alumina insulation materials were prepared by foam casting process, and effects of raw material composition, foam addition and firing temperature on the properties and microstructure of alumina light materials were explored.The main conclusions were as follows:(1) In two step process, when adding 15 wt% of a-Al2O3 powder addition,35 wt% of porogen contents, molding by 10MPa pressure, sintering at 1550℃癈, the properties of light-weight alumina materials were best, the cold compressive strength is 1.54MPa, the thermal conductivity is 0.17W/(m·K)(300℃) and the bulk density is 0.94g/cm3.(2) In foam casting process, when adding 30 wt% of alumina micro powder,2 wt% of micro-silicon,600 ml/kg of foam and sintering temperature is 1600℃, the properties of light-weight alumina materials were best, the cold compressive strength is 22.6MPa,the thermal conductivity is 0.29 W/(m · K) (300 ℃) and the bulk density is 0.94g/cm3.