Recovery of gold (III) from solutions by melamine-formaldehyd-thiourea resin

RECOVERY OF GOLD (III) FROM SOLUTIONS BYMELAMINE-FORMALDEHYD-THIOUREA RESINAbdülhakim AYDINSUMMARYKeywords: Melamine-Formaldehyde-Thiourea resin, Chelating resin, Gold (III) ions,Adsorption, EluationIn the present work, melamine- formaldehyde-thiourea (MFT) resin was synthesizedand recovery of gold (III) ions from the solutions including copper (II) and zinc (II)ions was investigated by MFT resin.In the gold (III) sorption studies by batch method, it was found that the optimum pHfor the adsorption of gold (III) was 2 and the adsorption capacity was 0.246 mmolAu3+/g resin or 49 mg Au3+/g resin. Moreover it was seen that gold (III) ions couldbe selectively adsorbed from aqueous solution containing copper (II) and zinc (II)ions by MFT resin.In the column studies, when 100 ppm gold (III) solution was adsorbed onto 1 g resin,it was obtained 99 % adsorption and 230 ppm Au3+ solution after eluation bythiourea + nitric acid solution. In addition, the eluation was studied at 0,2 and3 mL/min flow rates and it was seen that while the adsorption was effective at lowflow rate, the eluation was at high flow rate. The resin was used secondly to adsorpAu3+ ions and it was found that the resin was reuseable.