Separação de metais, em meio sulfúrico, por extração líquido-líquido, a partir de mistura multicomponente

Abstract

In this work, a study of purification of a multicomponent pregnant solution rich in nickel was developed by the use of liquid-liquid extraction technique. The main contaminants present in the nickel solution (concentration of 4.3g/L), which were primarily removed, are iron (concentration of 33.9 g/L) and aluminum (concentration of 5.5g/L). In order to remove them, two purification routes were evaluated. In the first route, the purification was performed using the liquid-liquid extraction technique in two steps. The aim of the first step was to remove iron and it was performed in six contact stages of 20 minutes each, temperature of 60 oC, pH 1.2 - 2.3, and a solvent composed of 30% v/v of Cyanex® 272, 30% v/v of TBP and 40% of Escaid 110. The aim of the second step was to remove aluminum by the use of four contact stages of 15 minutes each, temperature of 60oC, pH 3.0 - 3.7 and a solvent composed of 20% v/v of Cyanex® 272, 5% v/v of TBP and 75% of Escaid 110. In order to find the most suitable conditions, which would lead to the best extraction results, parameters as temperature, contact time and extractant concentration were investigated. In the second route a single liquid-liquid step was used to remove both iron and aluminum by the use of six contact stages of 20 minutes each, temperature of 60 oC, pH 1.2 - 3.0 and a solvent composed of 30% v/v of Cyanex® 272, 30% v/v of TBP and 60% of Escaid 110. The results showed that the two alternatives fulfill the purpose of purifying the multicomponent solution presented.