Recuperação de zinco de efluente do beneficiamento de caulim utilizando-se a técnica de membranas líquidas surfatantes

• Ano de defesa: 2010
• Autor(a) principal: Samuel Rodrigues Castro
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Engenharia química; Engenharia quimica
• Link de acesso: http://hdl.handle.net/1843/BUOS-8WCMVG

In this work, the process of zinc recovery from kaolin treatment plant effluent was studied, with the general objective of evaluating the selective removal of zinc from this effluent. The study aimed at the extraction of this metal, by using an adequate separation process, with the evaluation of the effect of some important parameters and the definition of adequate conditions for the operation of these variables. So, liquid membrane surfactant technique was chosen for zinc removal study from this effluent. The studied variables were: permeation time, membrane composition (extracting and surfactant composition) and pH of the external phase. In order of composing the membrane phase, six different concentrations of CYANEX® 301 (1, 2, 3, 5, 7 and 10% w/v) and two different concentrations of the surfactant ECA 4360 (1,0 and 1.5% w/v) were investigated. ESCAIDTM 110 was the diluent used. The internal phase was composed by 1,0M sulfuric acid solution and lithium sulfate, this reagent used as tracer in a concentration of 0.05M, with the objective of evaluating the membrane breakup in the process. The external phase was composed by the effluent from kaolin treatment plant and three different pH conditions were investigated (0.5, 1.0 and 1.5, the last one corresponding to the natural pH of the effluent). Concentrated sulfuric acid was used for pH correction, when necessary. The best results for the extraction and reextraction were obtained for a permeation time of 20min, a membrane composed by 7.0% w/v of CYANEX® 301, 1.0% w/v of ECA 4360 and 92% w/v of ESCAIDTM 110, and with a pH of the external phase equals to 1.5, as said, the natural pH of the effluent. The results for the aforementioned conditions, with respect to an initial zinc concentration in the external phase of 718mg.L-1, were: an extraction yield of 59% in mass and a zinc concentration in the internal phase of 2,382mg.L-1, meaning an enrichment of 386%. This condition implied in a final zinc concentration in the external phase of, approximately, 310mg.L-1, in a single stage extraction.