Kajian Pengaruh Konsentrasi Asam Nitrat Terhadap Kemurnian Silika dari Batu Rijang

Abstract

Chert  is stone that contains silica (SiO₂) ≥ 60%. High silica content in chert stones can be used as an alternative source of potential silica in synthesizing sodium silicate (Na₂SiO₃) or other industrial needs. Purification is used to separate silica from other metals contained in the chert stone using HNO₃. The qualitative and quantitative analysis of chert stone with XRF reveal that it contained a small amount of impurity oxide such as Al₂O₃, Fe₂O₃, MgO, K₂O, CaO with the highest contain is SiO₂ about 79.99%. After several purification steps, silica percentage from the chert stone increased to 86.45%. With this increasing percentage of silica, its potential to use it as precursor Na₂SiO₃.