Determination of amorphous silica in rice husk ash by a rapid analytical method

A rapid analytical method for evaluating amorphous silica in rice husk ash (RHA) is provided and therefore an assessment of its potential pozzolanic activity. The method is based on bringing the siliceous non-crystalline fraction of the pozzolan into solution as glycerosilicate by treating the test material with glycerol. The titration of the resulting solution is performed with an aqueous glycerol solution of barium hydroxide. Data are compared to those obtained using a standard method and a good concordance is achieved. It is demonstrated that the proposed method can be a useful tool for evaluating amorphous silica in RHA. (C) 2001 Elsevier Science Ltd. All rights reserved.