Xonotlite compound super insulating material and preparation method thereof

Abstract

The invention relates to an xonotlite compound super insulating material and a preparation method thereof. The xonotlite compound super insulating material comprises the following mixed raw materialsby weight percentage: 40 to 80 percent of SiO2 aerogel, 5 to 40 percent of infrared opacifier and 0 to 25 percent of reinforcing fiber. The preparation method comprises the following steps: adopting secondary particles which are provided with surface loose structures and are formed by mutual winding of xonotlite fiber with ultrafine diameters and SiO2 aerogel precursor prepared by adopting industrial water glass as silicon source to carry out compounding in advance; filling the SiO2 aerogel precursor in loose accumulation body of secondary particles of vacuum-dehydrated xonotlite, and drying after gelatinization and surface modification; filling the aerogel at the inner parts and the shells of the secondary particles of the xonotlite to form xonotlite-aerogel compound powder; and then mixing the xonotlite-aerogel compound powder with the infrared opacifier and the reinforcing fiber evenly, pressing the mixture in forming equipment with a negative pressure device and forming to obtain the xonotlite compound super insulating material. The invention has simple technique and low cost; and the prepared xonotlite compound super insulating material has excellent performance and can be used for insulation of a heating power device and a high-temperature pipeline.

Description

technical field [0001] The invention belongs to the field of inorganic non-metallic materials, in particular to a xonotlite composite super heat insulating material and a preparation method thereof. Background technique [0002] At present, the high temperature insulation materials used above 500℃ mainly include: ① aluminum silicate fiber and its products; ② rock wool, slag wool and its products; ③ glass wool products (alkali-free ultra-fine glass wool); ④ expanded vermiculite and Its composite materials; ⑤ asbestos products (foamed asbestos). For a long time, during the use of the above-mentioned thermal insulation materials, a large number of problems and defects have been exposed, mainly including: [0003] 1) Poor thermal insulation performance: the thermal conductivity at room temperature is 0.06-0.2W / m·K, and it rises rapidly with the use temperature. For example, the thermal conductivity of high-quality glass wool blanket is 0.13W / m·K at 400°C. The high thermal cond...

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Problems solved by technology

[0004] 2) Moisture absorption, corrosion of pipelines and equipment: Fiber insulation materials are prone to moisture absorption and deliquescence (water absorption rate above 97%) in ocean and high-temperature and high-humidity environments, and are not easy to disperse, resulting in damage to pipelines, thermal equipment, valves, etc. Premature corrosion will affect its service life and performance, resulting in a substantial increase in maintenance costs

[0005] 3) Harmful to the human body: What's more serious is that during the main