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| Author(s): |
Denise Corrêa de Oliveira
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Escola Politécnica (EP/BC) |
| Defense date: | 2002-04-30 |
| Examining board members: |
Jorge Alberto Soares Tenório;
Jose Deodoro Trani Capocchi;
Arthur Pinto Chaves
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| Advisor: | Jorge Alberto Soares Tenório |
| Abstract | |
Household zinc based batteries contain zinc, manganese and mercury. So, as a municipal waste, their disposal has become and increasing worry. The aim of the present work was to characterize dry batteries scraps and define some possible recycling parameters and stages using the low cost Mineral Processing unit operations. Even with the recent developments on this subject, batteries recycling is not yet a profitable activity, when compared to disposal in landfills. The lower cost treatments are based on Mineral Processing unit operations. The aim of the present work was to define the steps of a recycling system for batteries. Scraps were characterized and the considered treatment were unit operations to remove this kind of residue from municipal solid waste and recover zinc and graphite. The employed methods were hammer mill grinding, magnetic separation, size separation and specific weight separation. Results have shown that the developed process recovered 140kg of zinc 1 ton of spent dry batteries. For alkaline batteries, the system was only efficient until the magnetic separation step. In dry batteries zinc, paper, plastic, steel, graphite and chlorides could be identified. In alkaline batteries steel, plastic, paper and a white paste containing zinc and potassium hydroxide could be identified. Considering the presence of mercury in dry batteries, this work also aimed to remove this element through a pyrometallurgic route. It was possible to eliminate 95% of themercury after two hours at 600´DEGREES´C. The pyrometallurgic route using higher temperatures (900´DEGREES´C and 1000´DEGREES´C), made also possible to recover zinc, and reduce the manganese from Mn´POT.4+´ to Mn´POT.2+´. (AU) | |