Methods for preparing ceramic fiber filter tubes with high air permeability

A method for preparing a ceramic fiber filter tube with an air permeability, wherein the method comprises:

• mixing silica sol with water to obtain a mixed solution, and adding mullite fibers and glass fibers into the mixed solution;
• wherein a mass ratio of the silica sol, the mullite fibers, and the glass fibers is (30-45):(1.5-9):1, adding an organic forming aid into the mixed solution and stirring, and obtaining a ceramic fiber filter tube green body by a filter-pressing forming process;
• wherein an aspect ratio of the mullite fibers is within a range of (50:1)-(200:1);
• and placing a demolded green body in a refrigerator for freezing for 12 h-24 h, drying a frozen green body at a temperature of (−60° C.)−(−20° C.) for 12 h-24 h, and obtaining the ceramic fiber filter tube by a calcination process, wherein the calcination process includes calcining the frozen green body at a temperature of 800° C.-1400° C., and holding for 1 h-3 h, wherein a heating rate and a cooling rate are controlled at 0.5° C./min-3° C./min.