The shift towards district-scale, or ‘hub-and-spoke,’ mining configurations within the industry has reignited the key question of financial risk: does centralisation of processing facilities act to diminish financial risks by spreading them out, or does it create new risks of a technical nature? While centralisation certainly reduces capital costs by removing the need for duplication of infrastructure costs, the data suggests that this is balanced by an increase in project risks which offset this advantage.
The key advantage of the centralised hub and satellite facility is that economies of scale can be achieved by directing ore from multiple small satellite deposits into a single facility. This allows companies to spread the significant capital costs associated with construction and development across a broader base of production. This structure allows miners to achieve cash flow more quickly by developing satellite deposits rather than waiting a decade or more for production to begin from a single large deposit. It can thus act to significantly reduce the financial barrier to entry associated with the long lead times associated with mine development.
The centralised hub-and-spoke model does, however, introduce a key technical risk: ore variability. While satellite deposits may be within the same district, there can exist subtle or significant variations in ore type. As Simon Jowitt of the University of Nevada, Reno explains, the key question is whether “the processing plant works with everything.” If the plant is designed to work with a certain type of ore, the introduction of ore with significantly different metallurgical properties may require complex blending strategies to achieve desired outcomes, which can act to diminish the overall financial advantage of this approach.
Additionally, the financial viability of a project, be it centralized or otherwise, is now largely dictated by factors other than geology. In the current capital-scarce environment, for example, the financing risk is paramount, and projects that have otherwise demonstrated good metallurgical results and project economics have had difficulty accessing capital in the absence of off-take agreements. Centralization of processing will therefore not protect a project from macro-financial forces, including fluctuating energy costs and increasing capital costs, which have seen significant budget blowouts in the industry.
In conclusion, while a centralized processing plant provides a viable solution for reducing upfront costs and maximizing asset value, it is essential to understand that it does not reduce risk; it merely redistributes it. The risk profile now changes from a traditional financial risk to a sophisticated mix of metallurgical and inflexibility risks. To be successful, it requires rigorous metallurgical testing and a flexible design that ensures that the hub is not a bottleneck.
