METHOD FOR PROCESSING COAL ASH, AND CURED PRODUCT OF COAL ASH RESIDUE OF THE PROCESSED PRODUCT

摘要

PROBLEM TO BE SOLVED: To provide a processing method including extracting high purity silica components from coal ash and then utilizing the residue with a rich almina content after processing.SOLUTION: The method for processing coal ash includes extracting silica components as alkaline silicate from coal ash and manufacturing an artificial aggregate from the residue after extraction. The method comprises: a first step of exuding silica components as sodium silicate from coal ash using a solution of NaOH at a concentration higher than 25 wt.% heated at 70°C to 150°C for separation into a sodium silicate solution and an Al-rich residue having a ratio: Si/Al3; and a second step of manufacturing an artificial aggregate by directly heating and solidifying the Al-rich residue having a surface to which sodium silicate generated in the first step is attached for molding, or by adding cement and water to the Al-rich residue for granulation molding.