Non-respirable, polycrystalline, aluminosilicate ceramic filaments, fibers, and nonwoven mats, and methods of making and using the same

A method of making a nonwoven web, comprising:

• flowing an aqueous ceramic precursor sol through at least one orifice to produce at least one substantially continuous filament, wherein the aqueous ceramic precursor sol comprises at least one of alumina particles or silica particles dispersed in water, and further wherein the aqueous ceramic precursor sol further comprises at least one of a hydrolysable aluminum-containing compound or a hydrolyazable silicon-containing compound;
• removing at least a portion of the water from the at least one substantially continuous filament to at least partially dry the at least one substantially continuous filament;
• passing the at least partially dried filament through an attenuator to draw the filaments to a diameter not less than or equal to three micrometers;
• and
• collecting the at least partially dried filaments as a nonwoven web on a collector surface.