Comparison of Economics of Cementation and Solvent Extraction for Recovery of Copper from Tarom Sofla Oxidized Copper Leach Solutions

The Tarom Sofla copper ore zone includes several oxidized copper ore deposits, the most famous being Cheeseh, Aghdarreh and Yamaghan deposits. In view of the diversity of reserves and productivity of ore deposits in the area, two production capacities (high: 2000 tpd and low: 90 tpd), two leaching processes and two methods of recovery were considered to compare the economics of cementation vs. solvent extraction for recovering copper from leach solutions of these ores. Taking all the three parameters (production capacity, leaching processes and methods of recovery) into consideration eight alternatives were evaluated. Capital costs were estimated by employing order of magnitude calculations while operating costs were estimated by scaling up lab- scale costs. Economic comparison was made by the NPV method. The results showed that the NPV of the high capacity model was higher than the low capacity model while vat leaching has a lower NPV than agitation leaching. Similarly it was shown that cementation for the low capacity model has a higher NPV than solvent extraction while for the high capacity model the order is reversed. Hence it is concluded that for capacities less than or equal to 90 tpd cementation is the economically preferable method for recovering copper from leach solutions but for capacities greater than or equal to 2000 tpd solvent extraction is the better option.