Separação de Cd e Ni presentes em bateria de Ni-Cd por um método ambientalmente seguro utilizando sistema aquoso bifásico

• Autor(a) principal: Lacerda, Vânia Gonçalves
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2067
• topic: Bateria de Ni-Cd; Sistema aquoso bifásico; Extração líquido- líquido; Iodeto de potássio; Cádmio; Níquel; Ni-Cd battery; Aqueous two-phase system; Liquid-liquid extraction; Potassium iodide; Cadmium; Nickel; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ANALITICA

This work, was done a revision of what has been done in the area of recycling of Ni-Cd batteries, since the disposal of these materials is regulated in several countries, including Brazil, through the resolution CONAMA no 257, because the potential polluter. The recycling is a solution to the disposal of exhausted Ni-Cd batteries, which can not be done with the household waste. One of the techniques used in the stage of separation of metals present in these batteries is the solvent extraction. It was developed in this work a hydrometallurgical process for separation of metals Cd and Ni from Ni-Cd batteries using aqueous two-phase system, ATPS, in the stage of separation of metals. The separation of Cd and Ni was performed in ATPS formed by copolymer L35, lithium sulfate and water. The influence of the amount of extractant added (potassium iodide) in ATPS, tie line length (TLL), mass ratio between the phases of the ATPS, leaching and the dilution factor of battery samples was investigated. A maximum extraction of Cd (99.2 ± 3.1 %) and Ni (10.6 ± 0.4%) was obtained when the batteries were leached with HCl and the parameters TLL, concentration of KI, mass ratio of the phases and the dilution factor of the battery sample were equal to 62.53% (m/m), 50.00 mmol kg-1, 0,5 and 35, respectively. The proposed method proved to be efficient to separate the metals in question and also has the advantage of being environmentally safe, as the ATPS used are made of a biodegradable copolymer and consisted mostly of water. This new method is strategic and green chemistry approach, because do not use organic solvent and it is recyclable.