The preparation and characterization of silica from coconut husk

Abstract

Agriculture wastes, especially ash containing silica, are auspicious sources of silica for synthetic amorphous silica production. In this research, coconut husk ash (CHA) was employed as a raw material to produce silica. Coconut husk was charred inside a furnace in controlled environment at 900 ºC. To extract silica, the formed ashes were treated with two separate chemical treatments. 5N H2SO4 was used in acid treatment while 2.5N NaOH followed by titration of 5N H2SO4 was used in alkali treatment. The prepared products were characterized by the Fourier-transform infrared spectroscopy (FTIR). The data from FTIR characterization of coconut husk ash exposed that the presence of SiO2 increased after both chemical treatments especially in alkali treatment. The silica recovered from acid treatment was found between 25% to 68% while alkali treatment was at 76%.