The Effect of Hydrothermal Treatment on Olivine Nano-Silica

Abstract

This paper provides an overview of the effects of ripening the olivine nano-silica to form particles with a lower specific surface area for optimal use in high performance concrete. The nano-silica was ripened using a hydrothermal treatment in a mixed batch reactor at 90 °C, pH ranging from 8 to 10 and a silica weight percentage of three and six percent. The specific surface area of the olivine nano-silica can be reduced by 62 percent by Ostwald ripening in 22 hours. This reduction corresponds to a 80 percent drop of the micropore surface area and a 57 percent drop of the external surface area. The different hydrothermal conditions did not affect the final specific surface area at the equilibrium. However, the use of a high energy mixer reduced the specific surface area by 52 percent in only five minutes. Despite the reduction in specific surface area, the aggregates of the original olivine nano-silica are not dissolved during the ripening process. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3491