Abstract:
Silica extraction from Palm Oil Mill Fly Ash (POMFA) using sodium hydroxide
solvent was done at temperature above its boiling point in pressurized stainless
steel extractor. The main composition of the POMFA was 39.99% silica and
40.83% unburned carbon. The response surface method (RSM) was applied to
optimize the temperature and the stirring speed. The extract silica was analyzed
using Inductively Plasma Optical Emission Spectroscopy (ICP-OES) to measure
the silica content. At the optimum temperature and stirring speed the effect of the
mass ratio NaOH to POMFA was studied. The optimum conditions were
temperature of 156 oC, stirring speed of 461 RPM and mass ratio of NaOH to
POMFA 0.02. The silica conversion at the optimum conditions was 76.44 ± 0.44
%.