Research On Refractory Thermal Insulation Material Of Obturator Perlite

In the insulation material advocate of environmental protection and energy saving "green refractories" trend, obturator perlite as a lightweight, insulated, high temperature, environmental protection, thermal insulation material,is widely used in the insulation materials. In this paper, obturator perlite was used as insulation aggregate, bauxite as refractory aggregate, Through orthogonal test method to study the effect of phosphate, potassium feldspar, kaolin, pyrophyllite on the the material strength, thermal conductivity, water absorption.and to analysis the material microstructure and physical phase formation by scanning electron microscopy, X diffraction.Through the experiment obtained the following results:(1)In the study of phosphate system refractory thermal insulation material,after high temperature sintering, the phosphate through a series of reactions,and the material has certain compressive strength and thermal shock resistance by chemical combination. When the obturator perlite content increased, density and thermal conductivity of the material is reduced, thermal insulation performance is improved, strength is decreased, the absorption rate is increased. Within a certain range of phosphate, the compressive strength and thermal shock resistance of the materials are improved. With the increase of the sintering temperature, the compressive strength and bulk density of the materials are increased, the water absorption and thermal conductivity are decreased, and the thermal shock resistance of the material is increased.(2)In the study of feldspar as sintering agent, The increase of the amount of sodium bentonite, the increase of the strength of the material,But when the added amount more than 30%, the sample will appear cracks in the drying process. Compressive strength, density and thermal conductivity of the materials will be improved, water absorption will be decreased when the feldspar increased. With the increase of sintering temperature, the compressive strength of the material is increased, the density, thermal conductivity and water absorption are decreased.When the sintering time reached 120 min, the material is basically sintering completed.(3)In the study of Kaolinite and pyrophyllite as additives, after high temperature sintering,the new phase of mullite and quartz are formed what can significantly improve the material compressive strength and thermal shock resistance. Within a certain range, the higher the amount, the better the thermal shock resistance of the material. Mullite phase is increased and the thermal shock resistance of materials is improved when increasing the sintering temperature. The optimal test performance of the materials is compressive strength 3.36 MP,bulk density 1.211 g /cm3,water absorption 23.2%,thermal conductivity 0.257 W /(m ? K),thermal shock resistance more than 20 cycles(800?).