A. Warshawsky et al., Ion exchange resins for gold cyanide extraction containing a piperazine functionality, 2 study of the gold extraction reaction, MACRO MAT E, 286(5), 2001, pp. 285-295
Ion exchange technology is offered as an alternative to activated carbon fo
r gold cyanide recovery A new type of ion-exchange resin (PS-PIP) recovery
a piperazine group, linked to a styrene-divinylbenzene. macroporous network
, is described. The extraction of Au(CN)(2)(-) and other metal cyanides wit
h the PS-PIP resin involves three modes of metal extraction: the protonated
secondary amine groups of the resin (at acidic pH conditions), the free am
ine groups of the resin (at neutral and basic pH values) and the small port
ion of the quaternary ammonium groups participate in the gold extraction me
chanism. The gold cyanide extraction reaction on the polymeric piperazine w
as studied by a combination of metal extraction data, from batch experiment
s and IR and XPS spectroscopic analysis of the metal loaded polymres. Exrac
tion isotherms of gold cyanide show that gold bindign is possible from 40-6
0 mg Au/g of resin in alkaline solutions, up to 150 mg Au/g of resin in aci
dic solutions. Efficient stripping of gold from the resin was achieved usin
g ethanol/water solutions of sodium hydroxide, or 0.5 mol/l thiurea in sulf
uric acid solutions.