Metal Removal from Coal Ashes and Wastes

摘要

Laboratory-scale tests and preliminary engineering economic analyses have been performed to evaluate several processes for the recovery of aluminum and other metals from fly ash. Preliminary tests have also been made on two coal conversion ashes. The processes examined include: direct acid leach, lime-sinter, lime-soda sinter, and two new sinter-leach processes (calsinter and salt-soda sinter). The Calsinter process involves sintering with limestone and gypsum or flue gas desulfurization sludge at 1000 to 1200 exp 0 C, followed by sulfuric acid leaching. Each of the new sinter-leach processes recovers more than 95% of the aluminum along with substantial percentages of the other metals present. The recovered metals can be converted to a number of potentially saleable products. (ERA citation 04:053410)