Improved recovery of a low-grade refractory gold ore using flotation–preoxidation–cyanidation methods  

作　　者：Faraz Soltani Hossna Darabi Rezgar Badri Piroz Zamankhan 

机构地区：[1]Mineral Processing Department, Faculty of Engineering, Tarbiat Modares University [2]Mineral Processing Department, Faculty of Engineering, Tehran University [3]School of Engineering, University of Kwazulu-Natal, Durban,South Africa

出　　处：《International Journal of Mining Science and Technology》2014年第4期537-542,共6页矿业科学技术学报（英文版）

摘　　要：In this work, different flotation–preoxidation–cyanidation methods are considered for treating a lowgrade refractory gold ore. On the one hand, the results of selective flotation show that 22% and 31.1%of total Sb and As, respectively, remained in the final tailings and only about 28% of the total Au remained for further cyanidation processes. On the other hand, in bulk method of flotation the maximum Au recovery of 90.6% achieved after 60 min of flotation at the grind size with K80 of 146 micron. In addition, the bulk flotation method resulted in the concentrate with low concentrations of Sb and As elements. To improve the recovery of low-grade refractory gold ores, flotation should be followed by roasting, biological, or pressure oxidation processes so that the gold could be liberated prior to cyanidation processes. It is also found that the pressure oxidation pre-treatment of the concentrates prior to cyanidation may yield high gold recoveries of over than 83%. In these processes, recoveries are controlled by the temperature and the oxygen partial pressure in the solvent. However, by utilizing the bio-oxidation technique, the oxidation of sulfur to sulfate cannot be completed and, consequently, the gold recovery may be limited to only 72.2%.In this work, different flotation-preoxidation-cyanidation methods are considered for treating a low- grade refractory gold ore. On the one hand, the results of selective flotation show that 22% and 31.1% of total Sb and As, respectively, remained in the final tailings and only about 28%; of the total Au remained for further cyanidation processes. On the other hand, in bulk method of flotation the maximum Au recov- ery of 90.6% achieved after 60 min of flotation at the grind size with K80 of 146 micron. In addition, the bulk flotation method resulted in the concentrate with low concentrations of Sb and As elements. To improve the recovery of low-grade refractory gold ores, flotation should be followed by roasting, biolog- ical, or pressure oxidation processes so that the gold could be liberated prior to cyanidation processes. It is also found that the pressure oxidation pre-treatment of the concentrates prior to cyanidation may yield high gold recoveries of over than 83%. In these processes, recoveries are controlled by the temperature and the oxygen partial pressure in the solvent. However, by utilizing the bio-oxidation technique, the oxidation of sulfur to sulfate cannot be completed and, consequently, the gold recovery may be limited to only 72.2%.

关 键 词：Low-grade refractory gold ore Pre-treating Flotation Pre-oxidation 

分 类 号：TD923[矿业工程—选矿]