Abstract
Coal fly ash was treated with 3.5 M NaOH water solution by heating to 80-90°C for 24 h. The alkali treatment caused an increase in cation exchange capacity (CEC) from 12-20 me/100 g to 158-360 me/100 g for the fly ash. X-ray powder diffraction analysis showed that hydroxy-sodalite, faujasite and phillipsite formed in the ash after the treatment. The formation of such zeolite was most likely responsible for the increase of CEC. It is possible to apply the zeolitized fly ash tomaterial for soil amendment, removal of NH4+ and heavy metals from waste water, deodorization and moisture desorption. The present results may lead a technologyfor utilization or recycling of the waste coal ash.
