Ausenco engineers developed a multi-stream process designed to maximize recoveries from all available resources within the Copper Creek mineral deposit. Through strategic planning and flowsheet ingenuity, our team optimized placement of infrastructure on private land, seamlessly aligning with the best engineering outcomes, while reducing the environmental footprint and maximizing project economics.
The Challenge
Copper Creek is a potential open pit and underground project located in Pinal County Arizona directly adjacent to BHP’s historic San Manuel Mine. The vast, 3-kilometer-long porphyry copper deposit has a rich history of exploration and mining over the last hundred years and contains multiple styles of Laramide copper dominant deposits.
Faraday Copper engaged Ausenco to evaluate and strategize the flow sheet for their Copper Creek copper/molybdenum project, to help advance the project to the Preliminary Economic Assessment stage. To maximize the base case project economics, engineers determined a process design that leveraged available metallurgical data to achieve high metal recoveries via conventional floatation and included dry stack tailings to minimize water requirements and reduce the infrastructure footprint. We also investigated stockpiling strategies, streamlining of materials handling, extracting value from oxide material upfront and opportunities for project capital staging.
The Better Way
Ausenco engineers undertook a series of mine-to-mill trade-off studies to determine the ideal process circuits and optimal physical layout for the site, given the pursuit to prioritize private land usage and variability of the ore bodies being processed throughout the life of the mine. We developed multiple process lines – two concentrate streams, one for copper/gold/silver, the second for molybdenum and a heap leaching process for copper cathode recovery.
These circuits were designed to make optimal use of existing topography – using gravity wherever possible while keeping the major process infrastructure on private patented claims or adjoining state lands. Project capital staging was considered by capturing value from the oxide material upfront and deferring installation of a molybdenum circuit once grades in mill feed warranted commissioning.
A water reduction inspired solution was to implement dry stack tailings within the flow sheet which also offered added benefits of reducing the net tailings footprint. Since heap leaching would not extend the full life of mine, it was conceptualized to be kept within the tailings footprint, and later covered with dry stack tailings, contributing to even greater protection against further leaching at mine closure.
The Outcome
Ausenco’s optimized design approach has confirmed the economic viability of the Copper Creek project and has established a technically robust base case for which the project is expected to continue to enhance via exploration drilling and value engineering.