HPSIL® Precipitated Silica is obtained by the reaction of an alkaline silicate solution, preferably sodium silicate, and a mineral acid. Sulfuric acid and sodium silicate solution are reacted in an agitated reactor. The reaction products are silica slurry and sodium sulphate solution which would be filtered in a filter press. Then the filter cake is washed and dried on dryer. Finally the product would be milled in a microniser and packed. Through controlling of  agitation, duration of precipitation, the addition rate of reactants, their temperature and concentration, and pH can vary the properties of the silica, so as to increase both the quality and performance of end-products.