Aqueous colloidal dispersion of fumed silica, acid and stabilizer

An aqueous high solids fumed silica colloidal dispersion product prepared by the process of:

• providing a volume of water defining at least a portion of the continuous aqueous phase of said colloidal dispersion product;
• preselecting the concentration of fumed silica to form the discontinuous phase of the colloidal dispersion product, said preselected concentration being at least 40% by weight thereof;
• mixing a mineral or organic acid into said volume of water in an amount corresponding to between about 0.0025% and about 0.5% by weight of the fumed silica required to provide said preselected concentration, thereby to preacidify said volume of water;
• dispersing fumed silica into said preacidified volume of water in an amount at least sufficient to provide said preselected concentration and under sufficiently high shear mixing conditions as to form an acidic aqueous colloidal dispersion of said silica;
• mixing a pH raising stabilizer into said acidic aqueous colloidal dispersion of said silica in an amount sufficient to being the pH of the dispersion to between about 7.0 and about 12.0;
• and
• collecting the resulting stabilized aqueous colloidal fumed silica dispersion as product;
• wherein the dispersion will not gel for a period of at least 1 day, has a viscosity of below about 1000 centipoise, and is non-dilatant.