Process for preparing a lightweight expanded silicate aggregate from rice hull ash

摘要

Disclosed is a process for making a lightweight silicate aggregate. The process includes the steps of mixing together dry rice hull ash, an alkali metal hydroxide, boric acid, and water; heating the mixture to a temperature sufficient to initiate reaction; curing the composition at a temperature less than the boiling point of water until the reaction is complete; comminuting the cured product and heating the comminuted product to form the expanded aggregate.