Method for producing hydrophobic silica aerogel blanket, and silica aerogel blanket

A method for producing a silica aerogel blanket, the method comprising:

• preparing a silica sol containing a water glass solution;
• impregnating the silica sol into a substrate for a blanket;
• preparing a wet gel by gelling the silica sol while the silica sol is impregnated into the substrate for a blanket;
• immersing the wet gel in an acid mixture aqueous solution containing acetic acid and a nitric acid aqueous solution;
• surface modifying the wet gel with an alkyldisiloxane-based compound to prepare a surface modified wet gel;
• and
• drying the surface-modified wet gel,
• wherein after the immersing the wet gel, an acetic acid concentration (w/w) is 30% to 90%, and a nitric acid concentration (w/w) is 5% to 10%.