PRODUCTION AND CHARACTERIZATION OF SILICA REFRACTORY FROM RICE HUSK

Rice husk was thought to be a renewable source of good silica, which can help
prevent cracking of silica refractories in the temperature range 100-600°C. The work
reported in this thesis aimed to develop and optimize a fast process for high purity
silica production from rice husk, as well as apply the silica produced from the process
to carry out optimized laboratory scale manufacture of hot-face, stand-alone silica
refractory. Thus, a hydro thermo-baric (HTB) process was developed to aid the fast
production of rice husk silica (RHS). The parameters of the HTB process were
optimized using full factorial design of experiments. The RHS obtained from the HTB
process was characterized in terms of particle size, pore volume, surface area,
structure and morphology. Also, the parameters that affect the production of RHS
refractory using PEG8000 as binder and Ca(OH)2 as dopant (mineralizer) were
investigated and their optimal values obtained using the one-variable-at-a-time
(OVAT) method.