Advanced Study on Additives for Controlling As, Se, B, and F Leaching Concentration from Coal Fly Ash

摘要

Addition of calcium takes an important role in trace elements leaching mechanism. The application of paper sludge ashes as the additives in controlling the leaching of trace elements indicated satisfying effect. In the previous study, PS ash 3 could suppress the arsenic, selenium and boron leaching concentration simultaneously from a coal fly ash, then calcium oxide consisting in PS Ash 3 considered as the calcium compounds that affected the leaching mechanisms. So that, this study aims to verify the effect of suppressing material in leaching mechanism by the addition another kind of paper sludge ashes into two different coal fly ashes. PS ash 8 as the single additives and the mixture of PS Ash 8 with blast furnace cement (BFC) and calcium hydroxide (Ca(OH)2) as the mixture additives have been tested into coal fly ash C and coal fly ash H. The result from ICP-AES analysis, ion chromatography, analysis, XRF analysis and pH meter determined that the mixture additive is more applicable in the decreasing of leaching As, Se, B and F from coal fly ashes.