Analisis Karakteristik Penetralan Fly Ash Batubara Terhadap Air Asam Dengan Metode Acid Buffer Characteristic Curve

Abstract

Fly ash or coal fly ash produced by coal combustion is only considered as B3 waste and is very lacking in terms of utilization, in previous studies it was known that fly ash has alkalinity properties that can neutralize acid mine water. This study aims to analyze the neutralization characteristics of coal fly ash against acid water. To analyze the neutralization characteristics of fly ash, the Acid Buffer Characteristic Curve (ABCC) method is used, this method uses a titration system of HCl and H2SO4 (0.5 Molar) acids into the sample with an amount of 0.4 ml for each titration and the titration will continue until pH 2 The dominant fly ash content consists of silica (SiO2) 40.13%, Aluminum oxide Al2O3) 13.71%, Calcium oxide (CaO) 12.50%, Iron oxide (FeO) 20%. The results of the static test of the Acid Neutralizing Capacity value of fly ash are 337.88 kgH2SO4/ton and the NAPP value of -326 kg H2SO4/ton indicates the high alkalinity of fly ash. The ABCC graph shows that the thickening characteristics of fly ash are less than optimal at pH above neutral because the CaO content is not too large so that the buffer capacity in the pH range is not maximal, different from the neutralization characteristics at pH below neutral (6-3) fly ash is very good in the pH range. This is due to the content of gypsum, magnesium, and aluminum oxide which react in that pH range. The results of the ABCC test describe that the neutralization characteristics of fly ash are quite good but have a small buffer capacity at pH 7-10.