Application of aluminum sol in alumina fiber

Alumina fiber as a new fiber refractory material, because of its high temperature resistance, high strength (fiber average tensile strength of 70 ~ 80kg/m2), high modulus, low thermal conductivity, chemical erosion resistance and other advantages are significantly better than ceramic fiber, long-term use temperature of 1200℃ ~ 1500℃, the highest use temperature of 1600℃, It is widely used in large-scale metallurgical industrial furnaces, ceramic firing kilns and ceramic baking furnaces in ceramic industry, high temperature furnaces, etc. At the present stage of production, the sol-gel method is mostly used to prepare raw fiber, and alumina fiber is prepared by high temperature forging and other processes, so that the content of alumina fiber and fiber blanket slag ball is low (the content of slag ball is 70 mesh: < 0.5%), and the thermal conductivity is low (the thermal conductivity of the blanket average temperature of 500℃ is < 0.12W /(m·K)).

The concentration of alumina in the polyalumina sol used for alumina fiber is preferably 15-30%. The preparation method is to mix aluminum powder, hydrochloric acid and distilled water according to the molar ratio of 1.5 ∶1∶20 or 1.7 ∶1∶35, and heat to 80℃ ~ 90℃ reflux reaction for 3 ~ 6 hours to obtain the polyalumina sol. However, the alumina sol prepared by this method has strong acidity, high chlorine content, obvious yellow color, large particle size, long reaction time, and is easy to produce hydrogen and need to be heated in the process, which is prone to safety hazards.

The newly developed nano aluminum sol powder MZT-AH03 by Ningbo Ji Micro Nano New Material Technology Co., LTD., can directly add water to form aluminum sol, without heating, low chlorine content, and has 3 nanometer particle size, about 250m2/g specific surface area, pH value between 4-5, uniform dispersion, transparent, long-term stability without agglomeration and other significant technical advantages. It can be widely used in fiber, ceramics, refractory materials, paper making, textile, catalyst and other fields.