Affiliation:
1. Cinvestav Saltillo, Industria Metalúrgica 1062, Ramos Arizpe 25900, Mexico
2. Tecnológico Nacional de México/IT Saltillo, Blvd. V. Carranza 2400 Col. Tecnológico, Saltillo 25280, Mexico
3. School of Engineering, Tecnológico de Monterrey, Campus Monterrey, Eugenio Garza Sada, Monterrey 2501, Mexico
Abstract
The study of aluminothermic reduction in manganese compounds is a complex challenge in preparing Al-Mn alloys. The primary objective of this study was to ascertain the activation energy values for the aluminothermic reduction of MnO and Mn3O4 oxides derived from alkaline batteries. The study melted aluminum found in beverage cans and utilized the technique of powder addition with mechanical agitation. The kinetics of the reaction were studied under the effects of temperature (750, 800, and 850 °C), degree of agitation (200, 250, and 300 rpm), and the initial concentration of magnesium in molten aluminum (1, 2, 3, and 4% by weight). Kinetic measurements for Mn3O4 particles suggest a reaction mechanism that occurs in stages, where manganese undergoes oxidation states [Mn+3] to [Mn+2] until it reaches the oxidation state Mn0, which allows it to dissolve in the molten aluminum, forming alloys with up to 1.5 wt.% of Mn. Therefore, the kinetic of the aluminothermic reduction of MnO is described by the geometric contraction model, while the mechanism of Mn3O4 reduction occurs in two stages: geometric contraction, followed by an additional stage involving the diffusion of chemical species to the boundary layer. In addition, this stage can be considered a competition between the formation of MnO and the chemical reaction itself.
Subject
General Materials Science,Metals and Alloys
Reference39 articles.
1. An overview on the current processes for the recycling of batteries;Romano;J. Power Sources,2004
2. Lindermann, W. (1996). Process for the Recovery of Raw Materials from Presorted Collected Waste, Especially Scrap Electrochemical Batteries and Accumulators. (US5575907A), U.S. Patent.
3. Poinsignon, C., and Lucienne, J. (1994). Method for Electrolytical Processing of Used Batteries. (EP0620607A11997), European Patent.
4. The battery recycling loop: A European perspective;Ahmed;J. Power Sources,1996
5. Vitrification for reclaiming spent alkaline batteries;Ming;Waste Manag.,2009