Techno-economic assessment of a water- and energy-efficient future copper processing flowsheet

Rising water and energy constraints, declining copper ore grades, and increasing orebody complexity are placing growing pressure on conventional copper concentrator design. Under these conditions, flowsheet innovation matters not only for technical performance but also for project-level economic value. This thesis evaluates whether a water- and energy-efficient Future copper processing flowsheet can create incremental after-tax value relative to a conventional Base case. The Future flowsheet integrates six technical pillars: bulk ore sorting to improve mine-to-plant routing and capture value from waste rock; particle ore sorting to reject gangue before energy- and water-intensive processing; high-pressure grinding rolls (HPGR) crushing; coarse stirred milling; coarse particle flotation to reject gangue before fine grinding; and enhanced tailings dewatering to limit water loss. The benefits of these technologies are usually assessed individually; this thesis instead quantifies the cumulative economics of the combined flowsheet. The study applies a transparent Future − Base techno-economic framework. Both cases are evaluated on a consistent technical and economic basis, and CAPEX is assessed using a Greenfield comparison in which both flowsheets are costed as complete conceptual plants. Technical deltas in copper production, downstream feed, energy intensity, water intensity, operating requirements, and capital are integrated into an Excel-based after-tax discounted cash flow model developed on a scoping-level Class 4/5 basis, using benchmark costs, capacity scaling, project-level adders, and contingency. The results show that the Future flowsheet is a value-creating alternative to the Base case. The incremental Greenfield CAPEX is US$188.80 million, and the flowsheet generates an after-tax NPV of US$625.97 million, an IRR of 41.22%, and a payback period of 2.53 years. Value is driven mainly by higher copper production, lower energy intensity, and lower water make-up demand. Sensitivity results identify copper price and CAPEX as the dominant drivers, with NPV reaching zero at a copper price of about US$2.65/lb and a maximum CAPEX of about US$816.89 million. Overall, an integrated Future flowsheet can improve both resource efficiency and project economics within a transparent Future - Base framework.