Analisis dan Karakterisasi Kandungan Silika (SiO₂) sebagai Hasil Ekstraksi Batu Apung (<i>Pumice</i>)

Abstract

The study of silica from pumice was done by extraction method using NaOH, H₂SO₄, and HCl. Powder of pumice before extraction was calcined at 450^oC for 4 hours. The extraction powder was calcined at 800 C for 3 hours. The powder before and after the extraction were characterized by XRD and SEM-EDS. Sample also characterized by DTA-TGA analysis before extraction and after extraction was analyzed by TEM. XRD pattern powder of pumice dominated by amorphous silica. The results have been confirmed with SEM-EDS showing that the silica content has the highest percentage, ie 65.88% for the sample before extraction and 78.95% for the sample after extraction. From the TEM observation it shows spherical particles, with particle size of 5.8 0.2 nm. DTA-TGA analysis for pumice powder shows the occurrence of endotherm and exothermic events accompanied by mass shrinkage along with warming temperature rise.