The invention relates to a
silicon dioxide
aerogel material and a preparation method thereof. The method comprises the following steps: by using water glass as
silicon source, adding an acid-containing
organic solvent free of
chlorine ions and
fluorine ions to generate a precipitate of
sodium ions,
potassium ions and other
metal salt ions, filtering to remove the precipitate to obtain high-purity silica
sol, carrying out a
sol-gel process, aging, acidifying, modifying, and
drying to obtain the
silicon dioxide
aerogel material. The acidification before modification enhances the
surface reaction activity of the silicon gel, thereby obviously enhancing the modification effect and efficiency. The method has the advantages of low cost and simple and efficient technique, is beneficial to
mass high-efficiency production, is free of
chlorine ions and
fluorine ions in the whole technical process, and enhances the equipment
operation safety and reliability; and the product can be used for heat preservation and
thermal insulation of
nuclear power and
liquefied natural gas equipment and pipelines with higher requirement for
corrosion resistance, and can also be used for
thermal insulation in the field of
aerospace,
petrochemical engineering, track transportation, ships, automobiles, construction and the like.