Since completing its prefeasibility last year, the firm tasked Lycopodium and Orway Mineral Consultants to take a pass at various options for improving the process flowsheet before the hard work starts on a definitive feasibility study.
The work suggests a 10% larger plant with a molybdenum recovery circuit tacked on delivers better economics for minimal extra cost.
While the initial project capital costs for the first few years increases from A$1.6 billion to $1.7 billion, scaling up the plant from 27 million tonnes per annum to 30Mtpa in increases average annual copper production by some 5000tpa to 65,000tpa and adds 900,000tpa of molybdenum by-product.
All-in sustaining costs can be cut 14% to US$2.07 per pound.
Pre-tax net present value jumps A$600 million to A$2 billion, and internal rate of return rises to 21%, and net cash flow increases $1 billion to $6.6 billion, with total revenue of $19 billion over the life of the project, a rise of 8%.
Payback falls to just below five years.
As part of the changes the coarse particle floatation would be deferred, reducing process risk and saving $33 million on capex, offsetting a large chunk of the $57 million molybdenum circuit.
Caravel managing director Don Hyma said the aim was to “build it right” from the beginning, and the study results had exceeded expectations even using “modest” pricing assumptions of US$4/lb for copper and $20/lb for molybdenum.
Caravel is now looking to deliver the DFS by mid-2024, had has tapped Lycopodium as its lead engineer.
