A NEW THERMAL PROCESS FOR THE RECOVERY OF METALS FROM ZINC-CARBON AND ALKALINE SPENT BATTERIES
Girolamo Belardi, Roberto Lavecchia, Franco Medici, Luigi Piga and Antonio Zuorro
DOI : 10.3844/ajassp.2014.1566.1573
American Journal of Applied Sciences
Volume 11, Issue 9
The aim of this study is the thermal recovery of manganese and zinc from a mixture of zinc-carbon and alkaline spent batteries containing 40.9% of Mn and 30.1% of Zn after a preliminary physical treatment. Separation of the metals is carried out on the basis of their different phase change temperatures, the boiling point of zinc being 906Â°C and 1564Â°C that of Mn3O4, the main Mn-bearing phase in the mixture. After wet comminution and sieving to remove the anodic collectors and most of the chlorides contained in the mixture, chemical and X-Ray Powder Diffraction (XRPD) analyses were performed. The mixture was heated in CO2 atmosphere and the temperature raised, thus permitting the zinc oxide to be reduced to metallic zinc by the carbon present in the original mixture. Other tests were carried out by addition to the mixture of activated charcoal (95% C) or of the automotive shredder residue (fluff) containing 45% C.A zinc product was obtained suitable, after refining, for the production of new batteries. The treatment residue consisted of manganese and iron oxides that could be used to produce manganese-iron alloys. From these results, an integrated process for the recovery of the two metals was proposed.
© 2014 Girolamo Belardi, Roberto Lavecchia, Franco Medici, Luigi Piga and Antonio Zuorro. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.