Effect of heating on speciation of copper in Si/Al/Ca-based environmental matrices

Abstract: X-ray absorption spectroscopy is used to investigate the speciation of sorbed copper in heated fly ash. CuO and Cu(OH)2 are determined to be the principal copper species in the Cu-sorbing fly ash heated at 500°C for 2h. Heating the Cu-sorbing fly ash to 900°C or 1100°C can result in the formation of CuSO4, representing 41% and 32% of the total copper, respectively. Ash sintering and/or co-melting at 900 and 1100°C occur, thereby triggering chemical reaction between CuO/Cu(OH)2 and sulfur compounds. [Copyright &y& Elsevier]