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Ion Exchange Resins for Gold Cyanide Extraction Containing a Piperazine Functionality, 2. Study of the Gold Extraction Reaction
Author(s) -
Warshawsky A.,
Kaha.,
Kampel V.,
Rogachev I.,
Kautzmann R. M.,
Cortina J. L.,
Sampaio C. H.
Publication year - 2001
Publication title -
macromolecular materials and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.913
H-Index - 96
eISSN - 1439-2054
pISSN - 1438-7492
DOI - 10.1002/1439-2054(20010501)286:5<285::aid-mame285>3.0.co;2-3
Subject(s) - piperazine , extraction (chemistry) , cyanide , inorganic chemistry , ion exchange , thiourea , chelating resin , sodium hydroxide , materials science , ion exchange resin , nuclear chemistry , sulfuric acid , amine gas treating , metal ions in aqueous solution , chemistry , metal , organic chemistry , ion
Ion exchange technology is offered as an alternative to activated carbon for gold cyanide recovery. A new type of ion‐exchange resin (PS‐PIP) incorporating a piperazine group, linked to a styrene‐divinylbenzene macroporous network, is described. The extraction of Au(CN) 2 – and other metal cyanides with the PS‐PIP resin involves three modes of metal extraction: the protonated secondary amine groups of the resin (at acidic pH conditions), the free amine groups of the resin (at neutral and basic pH values) and the small portion of the quaternary ammonium groups participate in the gold extraction mechanism. The gold cyanide extraction reaction on the polymeric piperazine was studied by a combination of metal extraction data, from batch experiments, and IR and XPS spectroscopic analysis of the metal loaded polymers. Extraction isotherms of gold cyanide show that gold binding is possible from 40–60 mg Au/g of resin in alkaline solutions, up to 150 mg Au/g of resin in acidic solutions. Efficient stripping of gold from the resin was achieved using ethanol/water solutions of sodium hydroxide, or 0.5 mol/l thiourea in sulfuric acid solutions.