Munasir, A. Sulton, Triwikantoro, M. Zainuri, Darminto
An extraction of silica from natural sand has been conducted by means of alkalifusion route using NaOH. The silica sand was mined from Slopeng, Indonesia. This study was designed to obtain amorphous silica. Preliminary study from XRF characterization revealed that the silica sand contains 65.9 wt% SiO2 and and some other compounds in smaller percentages. The alkaliffusion perfomed an optimal result when the sand was immersed in 2M HCl for 10 hours with a composition (in wt%) of 12.5 sand and 87.5 NaOH and sintered at 500 °C for 2 hours. The purity of the silica was 98.9 wt%. XRD patterns indicated that the silica formed amorphous phase. Micro structural profile of the silica by TEM clearly revealed that the particle size was in the order of nano meter (< 100 nm). The geometrical shapes were circular and oval with agglomerated behavior. Furthermore, the XRD analysis was consistently confirmed by the TEM image, i.e. the silica was found in the amorphous phase. © 2013 AIP Publishing LLC.
Department of Physics, Institut Teknologi Sepuluh Nopember, Kampus ITS Sukolilo, Surabaya 60111, Indonesia; Department of Physics, Universitas Negeri Surabaya, Kampus Ketintang, Surabaya 60231, Indonesia
