Influence of the Production Process Conditions on the Specific Surface Area of Olivine Nano-Silicas

Abstract

The production of nano-silica by the olivine route is a cheaper and greener method than the commercial methods (neutralization of sodium silicate solutions and the flame hydrolysis) because of the low cost of raw materials and the low energy requirements. The produced olivine nano-silica has a specific surface area between 100-400 m2/g and primary particles between 10 to 25 nm (agglomerated in clusters). The process conditions and the ripening process influence the properties of nano-silica in the following ways i) the cleaner the nano-silica is the higher the specific surface area is; ii) the higher the filtration pressure is the higher the surface area is (unless the pressure is so high that the voids of the material collapse reducing drastically the SSA); iii) the ripening process diminishes the specific surface of nano-silica by two thirds and could be even further reduced. Thus, modifying the process conditions and/or adding an Ostwald ripening process, nano-silicas with different specific surface areas can be synthesized. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/34893