The process for preparing nano SiO2 powder is characterized by that it adopts chemical precipitation microwave drying process, uses sodium silicate and hydrochlroic acid as raw material, adds proper quantity of stabilizing agent (non-ionic surfactant) and dispersing agent to obtain the nano SiO2 powder body with excellent property under the condition of proper pH value and temp. Its optimum technological condidition is: temp. is 20-40 deg.C, pH is 6, reaction liquor mass concentration is P1 20/L, P2 1.20 g/L and reaction time is 15 min. The result shows that the grain size of the prepared nano SiO2 is 30-50 mn, its specific area is large, dispersion preparty is good and quality is good, |