Comparison of Processes for Producing Better Rice Husk Silica Produced from a Field-scale Incinerator

Abstract

Aim: The “amorphous” state of silica is the critical characteristic necessary for its use in various applications.  Extensive experimentation has determined that the highest quality rice husk ash is obtained after treating the ash in two steps: a burning step followed by a curing step.  The purpose of this study was to determine how to conduct these two steps such that the highest quality silica possible could be obtained from the ash. Study Design: Using the solubility of silica as an indicator of the amorphous state, the quality of silica in rice husk ash produced by three treatment processes was evaluated; after all, rice husks were incinerated as a basic treatment. Location and Duration of Study: The experiments were conducted from 2013 to 2016 at Toyama Prefectural University. Methodology: Three treatment methods for the curing step were evaluated: a heating drum, insulating drums, and a sink within the incinerator system. Results: As a result, the highest solubility silica was obtained from the sink, which produced silica with more than 70% solubility, compared to about 40% in other treatments. Conclusions: It can be concluded that the ash should be treated within the incinerator system without being exposed to cold temperatures outside.