Sol for preparing alumina fibers and preparation method of sol

Abstract

The invention provides a preparation method of a sol for preparing alumina fibers. The preparation method comprises the following steps of carrying out stirring and mixing on a polymeric aluminum chloride solution, silica sol, a spinning aid and a defoaming agent, and carrying out reduced pressure distillation to obtain the sol for preparing the alumina fibers. According to the method, powdered polymeric aluminum chloride is taken as an aluminum source for preparation of the sol for the alumina fibers. The low-cost inorganic aluminum source suitable for continuous industrial production is selected, and compared with a sol preparation method using aluminum chloride as an aluminum source, the spinning sol has relatively high spinnability, spinning performance and rheological property and does not pollute the environment. Compared with an aluminum source such as aluminum powder and hydrochloric acid, the energy consumption in the process of producing the aluminum sol is more saved, secondary treatment on hydrogen and volatile acid gas generated in the sol preparation process is avoided, the process is simple and safe, and manpower is saved.

Description

technical field [0001] The invention relates to the field of material technology, in particular to a sol for preparing alumina fibers and a preparation method thereof. Background technique [0002] Alumina fiber is an inorganic fiber with many advantages such as high temperature resistance, high mechanical strength, chemical corrosion resistance, low thermal conductivity, insulation, and noise reduction. Because of its outstanding high-temperature heat insulation performance, it is widely used in various high-temperature furnace linings in the metallurgical industry, automobiles, aerospace and other fields. Its Al 2 o 3 The content is above 67%, or doped with other oxides. Usually, the sol-gel method is used to configure the aluminum source and the silicon source into a spinning solution, which is formed into fibers through spinning process / blowing process / dry extrusion process / electrospinning process, and then undergoes high temperature heat treatment to form a polycryst...

AI Technical Summary

Problems solved by technology

The most commonly used organic aluminum sources are: aluminum isopropoxide, aluminum acetylacetonate, aluminum acetate, etc.; the main advantages of organic aluminum source aluminum sol are uniform chemical composition, high purity, and low process temperature, etc. The disadvantage is that it is greatly affected by the preparation conditions , the alkylaluminum alkoxide is active in nature, the amount of water added, catalyst concentration, reaction time, temperature, etc. all affect the spinnability of the sol, followed by the alkylaluminum alkoxide as an aluminum source is expensive, and the organic matter produced during the reaction pollutes the environment

In short, the cost of industrial production of aluminum sol prepared from organic aluminum sources is relatively high, and the reaction process is not easy to control

[0004] The spinnability of aluminum sol prepared from inorganic aluminum sources such as aluminum powder and aluminum salt comes from the Al13 colloidal particles contained therein, which contain 24 An active -Al-OH bond, with high positive charge and strong bridging ability, helps to form long-chain molecules with other additives containing hydroxyl groups such as acidic silica sol. The advantage of this system is that the cost of raw materials is low, However, dangerous hydrogen is produced during the reaction process, and the spinning performance of the sol prepared by simply using aluminum sources such as aluminum chloride and aluminum nitrate is poor, which does not meet the spinning performance and fiber strength requirements of subsequent fiber formation. The mixed use of organic aluminum sources can achieve the expected effect of the sol

Images