A design of experiments investigation into predispersed solvent extraction of nickel (II)
from dilute solutions
Aysan Molaei; Kristian E. Waters
Department of Mining and Materials Engineering, McGill University, 3610 University St, Montreal,
Québec, Canada, H3A 0C5
Abstract
Solvent extraction is one of the most common techniques for recovering metal ions from aqueous
systems; however, it is not efficient in extraction of nickel ions from dilute streams. Predispersed
solvent extraction is an alternative method for solvent extraction which utilises colloidal liquid
aphrons as extracting agents, where there is an increase in the specific surface area of extractant
and lower reagent consumption. This work investigated important parameters in predispersed
solvent extraction of nickel ions from dilute aqueous solutions by use of a fractional factorial
design of experiments. Four experimental parameters including initial extractant concentration,
initial surfactant concentration, equilibrium pH, and phase volume ratio (organic to aqueous
ratio) were investigated, and the important parameters were determined as well as the important
interactions between these parameters. It was found that phase volume ratio and equilibrium pH
are two important experimental parameters; however, the interaction between extractant
concentration and surfactant concentration was determined to be an important interaction in the
extraction process.
Keywords: Predispersed solvent extraction, nickel, design of experiments