Abstract

MUNOZ-ARROYO, Rita et al. Magnesium Removal from Molten Aluminum Alloys Injecting Zeolite and Cenospheres. Ing. invest. y tecnol. [online]. 2016, vol.17, n.4, pp.491-497. ISSN 2594-0732.

The use of both cenospheres, and mixtures of mineral zeolite is implemented in the process of submerged injection, in order to improve the removal of magnesium at 750 °C (from 1 wt% to a value equal to or less than 0.1 wt%) of an aluminum bath of A332 alloy automotive use, using Ar as carrier gas. Selected for testing were injection parameters: powder flow dust 16.2 g / min, 4.4 L gas Ar / min for a load of 8 kg aluminum at a temperature of 750 °C. Decreased magnesium content was analyzed during injection spark emission spectrometry, taking samples every 10 minutes to complete the test. The slag produced for each experiment was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The characterization of the reaction products and the use of reaction thermodynamic predictions using FactSage® and data base can corroborate the reaction mechanism between the powder and the liquid aluminum bath to remove magnesium, where the main product is the spinel (MgAl2O4). Comparatively, the cenospheres are less than the zeolite efficiency. The injection of mixtures zeolite:cenospheres in percentages 70:30 and 50:50, produced better results regarding single cenospheres. However, the zeolite was the one with a better magnesium removal efficiency from 1-0038wt%.

Keywords : aluminum alloys; magnesium; cenospheres; zeolite; slag; inert gas.