614 4. LCA RESULTS - ROUGHER CONCENTRATE FEEDSTOCK Rougher concentrate feedstock (19% copper by weight) is produced with a rougher flotation and rougher scavenger. A cleaning flotation and regrind steps are not used. In this scenario, it was found that climate change impact of the process is 3.3 kg CO2 per kg Cu cathode, a reduction in the finished concentrate baseline by 30%. Water use is reduced significantly by removing the cleaning flotation and regrind stages: an 80% reduction in water is estimated. Acidification is also greatly reduced by 50%. These results demonstrate the significant environmental benefit that RACER provides by processing upstream feedstocks. Table 5 – LCA results for rougher concentrate feedstock, including climate change impact, acidification, energy demand for the RACER process only, and water use. Climate Change Impact 3.3 kg CO₂ eq. per kg Cu cathode Water Use 2.65 m³ world eq. per kg Cu cathode Electricity demand 0.57 kWh/kg concentrate Acidification 0.058 mol H⁺-Eq per kg Cu cathode Breaking down climate change impact by stage, impact from RACER remains the same, while upstream impact is reduced (Table 6.) Table 6 – Climate change impact by stage for rougher concentrate feedstock. Stage Share kg CO₂ eq. per kg Cu Cathode Upstream Concentrate (Mining + Comminution + Flotation) 76% 2.87 RACER Process 19% 0.74 SX/EW 5% 0.18 The substantial improvement in the rougher concentrate scenario across impact categories is driven by several compounding factors. Eliminating the cleaner flotation circuits removes significant water, chemical and energy inputs, including calcium oxide and multiple collector reagent stages. Improving total copper recovery reduces the upstream footprint per kg of cathode. 5. RACER FOR BULK SULFIDES — THE ZERO-WASTE VISION The fundamental barrier to new copper mine development is not capital or geology—it is community acceptance. Long permitting timelines, frequently exceeding a decade, are driven in large part by well-founded concerns about the long-term management of sulfidic mine tailings. Even when permits are granted, many mines face legal pushback based on these concerns, which can further delay production by many years. When sulfide minerals in tailings are exposed to oxygen and water, they oxidize to produce sulfuric acid and heavy metal leachate—Acid Mine Drainage (AMD)—a liability that can persist for centuries after mine closure. AMD is one of the most significant sources of water quality impairment from mining globally, and the specific concern most frequently cited in community opposition to new mines and expansions. Still
RkJQdWJsaXNoZXIy MTM0Mzk2