The Effect of Using Acid on Separation of Metals from Coal Fly Ash as Basis of Zeolite Synthesis

Pengaruh Penggunaan Asam Terhadap Pemisahan Logam dari Abu Layang Batubara Sebagai Bahan Dasar Sintesis Zeolit

Abstract

Fly ash is a by-product in the form of solid waste generated from the burning process of coal in power plants, which contains mostly silica (SiO₂), alumina (Al₂O₃), and iron oxide (Fe₂O₃) compounds. Fly ash has the potential to be used as a base for zeolite synthesis. The presence of impurities in fly ash such as Fe and Ca will affect the purity level of the zeolite obtained. Therefore, this study aims to see the effect of using hydrochloric acid (HCl) on the separation of Fe and Ca metals from fly ash as a basic material for zeolite synthesis. The method used to separate Fe and Ca metals using HCl from fly ash is reflux. In this study, HCl was made with a concentration variation of 4 M; 8 M; and 12 M and X-Ray Fluoerescence (XRF) analysis was performed on fly ash. Based on the results obtained from XRF, it showed that fly ash using 4 M, 8 M and 12 M HCl obtained Fe metal content of 16.29%; 14.03%; 11.98% and Ca 3.59%, 3.30%, and 2.96%. So it can be concluded that the separation of Fe and Ca metal content decreases from fly ash with the greater the HCl concentration.

Key words: fly ash; hydrochloric acid; zeolite