Abstract
Calcium compounds affected the trace element leaching concentration from coal fly ash through the addition of suppressing material. Suppressing material which is used in this research is paper sludge and filter cake. Paper sludge (PS) is a waste generated by the paper recycling industries. The kinds of paper sludge which is used in this research is PS3 and PS8. Filter cake (FC) is formed by the substances that are retained on a filter. Filter cake come from lime industry. The determination of calcium compound in coal fly ash and suppressing material have been done by using X-ray Diffraction (XRD) analysis. XRD analysis is an instrument that work based on Bragg`s law and present the result in peaks therefore each compound has peaks suitable with its characteristic. The result from XRD analysis will give good information about the calcium effect which could be used in controlling leaching of trace element from coal fly ash.
