Research On High-efficiency Recovery Process Of Associated Gold And Silver From Low-grade Copper Ore

The scarcity of copper/gold-silver ore resources and a gradually increase on the demand of these metals through all industries urge our researchers to exploit more efficient and economic technologies to extract them.The purpose of this paper is to upgrade the copper concentrate containing gold and silver from an industrial copper ore mine in Dahongshan,Yunnan.The effort was made to explore new reagents and flow-sheet to achieve the selectivity separation of the copper minerals from the gangues.The mineralogical characteristics of the copper ore samples was investigated,indicating that it assays about 0.4% copper,about 0.09g/t gold,and about 0.9g/t silver,and the oxidation rate of copper is 3.18% and the combined copper oxide accounts for1.59%,which is a typical low-grade copper sulfide ore.In order to further improve the economic benefits of the concentrator,it is an effective way to increase the content of associated gold and silver in the copper concentrate and reach the valued content.Therefore,in this paper,the Dahongshan copper ore in Yunnan is selected as the research object,and the key technology research to increase the gold and silver content associated with flotation copper concentrate is carried out.The research results not only help to improve the economic benefits of the Dahongshan copper mine in Yunnan,but also provide theoretical guidance for the efficient development and utilization of similar ores.In this paper,the chemical composition of the raw ore,the copper phase and the structure and output characteristics of the ore were tested and analyzed by various instruments such as polarizing microscope,X-ray diffractometer,atomic absorption spectrometer and so on.The results of ore process mineralogy show that the ore has the characteristics of complex structure,simple structure,many types of copper minerals,and uneven dissemination size of copper ore.These ore properties will definitely have an adverse effect on flotation.Based on the study of process mineralogical properties and on the premise of ensuring the copper beneficiation index,the effect of grinding fineness,collector type and dosage,frother type,inhibitor type and dosage on the increase of associated gold and silver content in copper concentrate was systematically studied.Through comprehensive analysis of the research results,the best flotation process conditionsand parameters are proposed.The results from batch flotation tests show that a concentrate at a grade of 18.5%Cu,3.08g/t Au,and 22.49g/t Ag with recoveries of 89.57% Cu,61.27% Au,and50.50% Ag,respectively,was obtained by using one-staged roughing,scavenging and cleaning process.The reagents employed in these processes involved 135g/t LBH,650g/t SCF,and 30g/t pine oil at a particle size range of 70% passing 200 mesh.