A version of this article was first published by AusIMM, August 2026. Reprinted with permission.
As ore bodies change and market pressures intensify, many mining operations are looking for ways to get more value from the assets they already have.
For some, the challenge is an ageing plant that was designed for a different orebody. For others, it is a constrained footprint, changing mineralogy, declining grades, different ore hardness, spare capacity in one part of the circuit, or bottlenecks in another. In many cases, the answer is not a major expansion or a new plant, the opportunity lies in rethinking their flowsheet.
We are seeing more clients ask how they can increase throughput, improve recovery, process new ore sources or extend mine life without committing to large capital projects, long shutdowns or complex new approval pathways. That requires more than simply adding equipment. It requires a clear understanding of where value is being lost, where capacity exists, and which modifications will deliver the best return over the remaining life of the asset.
There is no standard solution. Every orebody, flowsheet, site and business case is different. But in many operations, there are practical ways to unlock hidden value from existing infrastructure.
Breathing new life into existing operations
For mines with ageing assets, even incremental changes to the flowsheet can have a significant impact on throughput, recovery or operating cost.
The right intervention depends on the constraint. A flotation circuit may benefit from additional capacity or improved selectivity, using high-intensity flotation cells such as Jameson Cells. A comminution circuit may be able to achieve higher throughput through better control, classification or circuit balancing. Coarse particle flotation may also help increase concentrator throughput without adding milling capacity, while ore sorting may allow for increased metal production without increasing concentrator capacity by rejecting low-grade material prior to milling. In other cases, improvements to tailings or water management, including filtered tailings stacks, can help extend the operating life of the site.
The key is to start with the business objective, not the technology.
In one recent project, a client needed to increase milling throughput but was constrained by both footprint and existing equipment. A new standalone circuit would have required significant capital and was unlikely to be economically feasible. Instead, our team developed a hybrid two-stage arrangement that unlocked capacity within the existing comminution equipment. The primary mill cyclones were repurposed from a classification duty to managing mill loading and density, while final size classification was shifted to the secondary mill circuit, removing the key constraint on primary mill operation. This has allowed the client to progress the expansion to the next stage of engineering without defaulting to a new milling circuit.
In another case, an operation had historically turned off one of their mills when ore grades were high to reduce energy costs. As grades declined and mineralogy changed, the same operating philosophy was no longer delivering the best outcome. By revisiting recent operating data, our team identified that restarting the mill would provide additional liberation, significantly improve metal recovery and generate a positive financial return after accounting for additional power, media and maintenance costs. This type of opportunity is often overlooked. Processes that made sense earlier in a mine’s life may no longer be fit for purpose as the orebody changes. Revisiting old processes and operations with a fresh set of eyes can reap unexpected improvements, sometimes at minimal expense.
Finding new value in existing assets
The opportunity is not limited to improving current operations. Many mine owners have untapped potential in their older assets and are looking for ideas and solutions that can turn what seems like the end of the road into new sources of value.
In some cases, reduced access to ore has left processing plants operating below capacity. Our team recently worked with a client that owned an underutilised base metals plant and had another base metals deposit nearby. The challenge was to reconfigure the flowsheet so the plant could switch between two different ore streams, each with different throughput requirements, hardness and grind sizes. Through targeted piping changes and modifications to the milling and classification circuit, the team enabled the plant to process ore from either deposit. This filled spare processing capacity and allowed the client to begin generating revenue from the second asset with limited additional approvals.
Our team have also supported clients to move entire processing plants or circuits to new ore bodies, often reorganising the flowsheet to improve throughput and extend equipment life. In other cases, the team have helped clients repurpose equipment from one site to improve performance at another or reviewed post-closure assets to identify opportunities to recover value from waste materials, reuse land and support future community outcomes.
These examples show that the value of an asset is not always limited to its original design intent. With the right technical and commercial assessment, existing infrastructure can often be adapted to support a different operating strategy that will provide better value to the owner.
From ideas to value
Innovation is important, but ideas alone are not enough. Some options may be technically possible but commercially unattractive. Others may require too much capital for the remaining mine life, create unacceptable downtime, trigger permitting challenges, increase operating complexity or fail to meet community and environmental expectations.
That is why flowsheet modification needs to be assessed through a lens of value. When we work with clients, the objective is not simply to generate a list of ideas. It is to identify, test and prioritise the options that can deliver the strongest return over the life of the asset.
That means understanding the impact of each option on throughput, recovery, operating cost, product quality, downtime, labour, energy, approvals and future flexibility. It also means recognising that the best solution may not be the most technically ambitious one. Often, the highest-value outcome comes from a targeted change that removes a bottleneck, improves stability or allows the plant to process a broader range of feed with the shortest downtime.
At Ausenco, we take a multidisciplinary approach, bringing together all relevant expertise to help clients find practical ways to achieve their objectives. We work closely with operations teams to understand the realities of the site and to develop options that are innovative, technically sound and commercially realistic, regardless of the stage the operation is in.
For many mine owners, there is significant value still to be unlocked from existing investments. The opportunity lies in challenging legacy assumptions, using current data, and rethinking the flowsheet in line with today’s orebody, market and operating conditions.
Matthew Swanson is speaking on this topic at the MetFest! Tasmania event in November. Get your tickets here.