High-temperature-resistant low-shrinking-percentage nano-scale microporous heat insulating material for steel ladle and preparation method therefor

Abstract

The invention relates to a high-temperature-resistant low-shrinking-percentage nano-scale microporous heat insulating material for a steel ladle and a preparation method therefor. The heat insulating material is prepared from the following raw materials in percentage by weight: 0-60% of nano-scale silica powder, 0-50% of zirconium silicate micropowder, 5-10% of high silica fiber and 0-50% of gamma-alumina micropowder. Through adding a high-temperature antishrinking agent (alpha-alumina micropowder or gamma-alumina micropowder) into the formula, the high-temperature shrinkage resistance of the heat insulating material is improved, the linear shrinkage ratio (at the temperature of 950 DEG C) is not higher than 2%, the high-temperature shrinkage is reduced, and the safety is improved when the heat insulating material is applied to steel ladle equipment; according to the prepared nano-scale microporous heat insulating material, the service temperature is 1,100 DEG C, the coefficient of thermal conductivity at the temperature of 800 DEG C is not greater than 0.045, the linear shrinkage ratio at the temperature of 950 DEG C in 4 hours is not higher than 2.0%, and the compression strength (at the compression ratio of 10%) is not lower than 0.6MPa; and the high-temperature-resistant low-shrinking-percentage nano-scale microporous heat insulating material for the steel ladle, prepared by the preparation method, has the advantages of high service temperature, small coefficient of thermal conductivity, high compressive strength and low high-temperature linear shrinkage ratio and is applicable to high-temperature equipment with space limitations such as steel ladles for steelmaking, rotary kilns and the like.

Description

technical field [0001] The invention belongs to the technical field of nano thermal insulation materials, and in particular relates to a high-temperature-resistant low-shrinkage nano-scale microporous thermal insulation material for ladles and a preparation method thereof. Background technique [0002] Thermal insulation material, also known as thermal insulation material, is a material that can block the transfer of heat flow. There are many types of insulation materials, including fiberglass, asbestos, rock wool, silicate, airgel felt, vacuum panels, etc. The nano-scale microporous thermal insulation material adopts special nano-scale inorganic refractory powder, the contact between nanoparticles is extremely small point contact, and the thermal resistance of point contact is very large, so that the heat transfer effect of the material is very small, resulting in nano-scale The conduction and heat transfer coefficient of microporous thermal insulation materials is very sm...

AI Technical Summary

Problems solved by technology

[0004] The temperature of molten steel in the ladle is 1600°C~1700°C. At this high temperature, the current nano-scale microporous thermal insulation material has a large shrinkage rate. It is extremely risky and low in safety to apply it to such high-temperature equipment. Based on the above The disadvantages seriously restrict the application of nano-scale microporous thermal insulation materials in high-temperature equipment. Therefore, it is an urgent problem to develop a kind of high-temperature-resistant ultra-low thermal conductivity and low shrinkage nano-scale microporous thermal insulation materials for ladles.