Investigations on the hydrolysis behavior of AlN in the leaching process of secondary aluminum dross

摘要

In this paper, the hydrolysis behavior of AlN in the leaching process of secondary aluminum dross was studied through thermodynamic analysis, leaching tests, X-ray Fluorescence (XRF), X-ray diffraction (XRD) and Scanning Electron Microscope (SEM). The effects of reaction temperature and time on the AlN hydrolysis process in deionized water were studied. The leaching results showed that the solution pH and nitride change increased with the increase of leaching temperature and time. The XRD and SEM results showed that the morphology of hydrolysis process includes the AlN surface exposure, the form of amorphous aluminum hydroxide, boehmite, and precipitation of bayerite. The thermodynamic calculation demonstrated that the hydrolysis of AlN could proceed spontaneously. For practical significance, AlN can easily hydrolyze because of the moist air and exo-thermic chemical reactions, especially in summer which the ambient temperature is pretty high. Taking the environmental impact into consideration, the dross can be pretreated by water leaching to decompose the AlN before landfilling.