High-strength thermal-insulating microporous castable and preparation method thereof

The invention belongs to the technical field of refractory materials and particularly relates to high-strength thermal-insulating microporous castable and a preparation method thereof. The high-strength thermal-insulating microporous castable is prepared from raw materials as follows: a-Al2O3 fine powder, SiO2 fine powder, industrial aluminum hydroxide and tetraethoxysilane; the percentage of each raw material is as follows: 30%-40% of a-Al2O3 fine powder, 20%-25% of SiO2 fine powder and 5%-8% of tetraethoxysilane; besides, 2%-7% of a binding agent and 0.05%-0.1% of a coagulation accelerator are added. The preparation method of the high-strength thermal-insulating microporous castable is as follows: firstly, the a-Al2O3 fine powder, the active SiO2 fine powder and industrial aluminum hydroxide are mixed for 1-3 minutes and ground by a ball mill into fine powder, then the binding agent, tetraethoxysilane and the coagulation accelerator are added, the mixture is mixed for 3-5 minutes by a planetary mixer, packaged, transported to the field, added with water and stirred, and the high-strength thermal-insulating microporous castable can be used. The high-strength thermal-insulating microporous castable has uniform pore diameter distribution and a good thermal insulation effect.