AIChE Journal, Vol.54, No.2, 453-463, 2008
Pseudo-emulsion based hollow fiber strip dispersion: A novel methodology for gold recovery
This article presents the study of Au(I) extraction from synthetic cyanide media through pseudo-emulsion based hollow fiber strip dispersion (PEHFSD) containing LIX-79/n-heptane as extractant in the form of a pseudo-emulsion with NaOH. The permeation of Au(I) is investigated as a function of various experimental variables: hydrodynamic conditions, feed pH, LIX-79 concentration in pseudo-emulsion, cyanide concentration in feed phase, NaOH concentration in pseudo-emulsion as a strippant, and initial Au(I) concentration in feed phase. In PEHFSD, pseudo-emulsion is an emulsion that is formed temporarily between organic and stripping solutions. The organic and aqueous solutions are separated when the stirring device is stopped. In this study, feed was circulated through the tube side in counter current mode. The linear flow velocity of the feed was varied between 0.74 and 2.58 cm/s and the linear flow velocity of the pseudo-emulsion was maintained at 0.28 cm/s. The value of the permeation coefficient obtained under standard experimental conditions was 8.19 X 10(-5) cm/s. The selectivity of LIX-79/n-heptane based PEHFSD toward different metal cyanide salts such as Fe(II), Cu(I), Ni(II), Zn(II), and Ag(I) was also examined. (c) 2007 American Institute of Chemical Engineers.