Extraction of Gold and Copper from a Gold Ore Thiosulfate Leachate by Use of Functionalized Magnetic Nanoparticles

摘要

Gold and copper thiosulfate adsorption from an alkaline gold ore leachate was investigated by using polyethylenimine-coated iron oxide magnetic nanoparticles (NPs). The ore, sourced from a mine in Nevada, USA, was leached with calcium thiosulfate for 48 h in the presence of Cu(II) at a pH of 8 and a temperature of 50 degrees C. A response surface methodology was used to analyze the effect of adsorbent dosage, adsorption time and solution temperature on the recovery of gold and copper from the solution. The results showed that the gold adsorption was nonlinearly dependent on the adsorbent dosage only. In contrast, the recovery of the copper depended on all three predictors, including interaction between the temperature and adsorbent dosage. The optimal conditions for maximal gold adsorption was 35 g/L adsorbent dosage, 55 min time and a temperature of 23 degrees C. The selective elution of loaded metals on the NPs was also successfully achieved.