Preparation method of hollow alumina ball thermal insulation refractory material

Abstract

The invention which belongs to the technical field of refractory materials relates to a preparation method of a hollow alumina ball thermal insulation refractory material. The technical scheme of the preparation method is that the preparation method comprises the following steps: 1, adding an organic binder to hollow alumina balls, uniformly mixing, adding water, and stirring to make the surface of the hollow alumina balls be fully wet and adhered by the organic binder; 2, adding mixed powder of clay and alpha-Al2O3 micropowder, and uniformly mixing; and 3, drying the prepared formed product at 100-110DEG C, and carrying out thermal insulation sintering at 1550-1650DEG C. According to the invention, a mullite phase can be easily synthesized from clay and the alpha-Al2O3 micropowder, mullite has the characteristics of low thermal expansion rate, good thermal shock resistance, and good high temperature creep resistance, and the organic binder is adopted to effectively avoid the enrichment of impurities in clay in product drying and sintering processes, so the hollow alumina ball thermal insulation refractory material prepared through the method has the characteristics of uniform distribution of a small amount of the impurities, white appearance, good thermal shock resistance, low volume density, and low thermal conductivity.

Description

technical field [0001] The invention belongs to the technical field of refractory materials, and in particular relates to a method for preparing an alumina hollow sphere heat-insulating refractory material. Background technique [0002] Today, when the price of energy is getting higher, the supply of traditional energy is in short supply, and environmental protection is becoming stricter, while the development of new energy is slow, the most urgent task at present is to develop lightweight porous, low thermal conductivity, good thermal shock resistance, and high refractoriness. , Excellent volume stability at high temperature and high service temperature, which can meet the heat insulation refractory materials required by high-temperature kilns with light structures, so as to change the heavy materials used in traditional high-temperature kilns with large heat capacity, slow heating rate, and high heat dissipation. High conductivity, high kiln surface temperature, high energ...

AI Technical Summary

Problems solved by technology

In the patented technology of "A Preparation Method for Lightweight and High-strength Alumina Hollow Ball Ceramics" (CN 1223547C), α-Al 2 o 3 Micropowder and alumina hollow spheres are used as raw materials, and phosphoric acid solution is used as a binder to prepare lightweight heat-insulating bricks with low volume density and high flexural and compressive strength. However, the heat-insulating bricks prepared by this method only have alumina hollow Balls and α-Al 2 o 3 fine powder, while high-purity α-Al 2 o 3 Micropowder is difficult to sinter at high temperature and needs to be fired at a higher temperature, resulting in higher firing costs. At the same time, the matrix phase of the brick is a dense corundum phase, which leads to its high thermal conductivity and poor thermal shock resistance; and "a In the patented technology of alumina hollow sphere lightweight heat insulation brick and its preparation method (application number: 201110023753.0), α-Al 2 o 3 Micropowder, ρ-Al 2 o 3 Micropowder, silicon micropowder and hollow spheres are used as raw materials, and organic polymers are added to prepare lightweight heat insulation products with low bulk density and high compressive strength, but it uses ρ-Al 2 o 3 Micropowder and silica micropowder synthesize part of mullite in the matrix, while ρ-Al 2 o 3 It is difficult to synthesize mullite from micropowder and silica micropowder, and it also needs to be fired at high temperature, and its raw material cost is high, resulting in high production cost, and its mullite phase content is low