The separation of gold by selective extraction of HAuBr4 using a poly(tetramethylene) ether glycol impregnated filter

Abstract

The separation of gold(III) by selective extraction on an organic- impregnated filter (OIF) was studied. Gold was found to be rapidly extracted into the active polytetramethylene ether glycol (polyTHF) layer of the filter from strongly acidic solutions of HBr, as the HAuBr4 complex. Quantitative extraction of gold from solution was obtained with flow rates up to 600 ml min−1 through the 10.75 cm2 OIF and at ng ml−1 concentration levels. The extraction is shown to be dependent on the solution flow rate and HBr concentration as well as the filter pore size, thickness and porosity. Gold can be eluted from the filter by converting it into the AuBr4− complex using a KBr solution. The separation of gold is demonstrated from simple binary metal mixtures involving iron and cadmium, as well as from a more complicated matrix, gold ore solution.