Ekstraksi Silika (SiO2) dari Mineral Tanah Napa Pesisir Selatan

— Silica is a mineral with potential for use in a variety of industries. Silica can be produced an extraction process using natural materials such as Napa Soil from the South Coast as the raw material. In this study, the extraction method used is a modification of the alkali fusion and hydrothermal methods. The Napa soil was calcined at 750°C for 4 hours, then reacted with NaOH (2; 4 ; 6; and 8) M at 95°C to form Na silicate, then 6M HCl was added to form silicic acid and finally the silica gel was dried to form SiO 2 . The extracted silica was also characterized using XRF which showed the silica purity level increased to 61.84%. The maximum extraction yield was obtained with an 8 M NaOH concentration of 30.78 %, according to the data. The extracted silica was also analyzed using XRF, which confirmed that the purity level of the silica had enhanced to 69.85 %.