Extending mine life, improving efficiency, and accelerating more sustainable critical mineral production
Tomra’s advanced sensor-based sorting technology is being utilised to help mining companies recover valuable resources once considered waste, extending mine life, improving efficiency, and accelerating more sustainable critical mineral production
Globally, mines hold a largely untapped aggregate opportunity. Operations generate volumes of waste rock that are left to be monitored for decades after being hauled long distances, stockpiled or dumped, becoming a financial, environmental, and operational burden.
Mines also import aggregate for haul roads, plant foundations, tailings dams and closure works. In remote regions, transporting suitable construction materials can be expensive, posing operational and financial challenges for these infrastructure projects.
The paradox is that much of the waste rock already has the strength and durability needed for construction. Sulphides and acid-forming material have historically limited its use, but once these are removed, the waste rock becomes a clean, stable material that can be managed, reused, or turned into a new revenue stream. This is what Tomra Mining’s sensor-based sorting hopes to achieve.
Creating value from waste rock
Tomra Mining’s sensor-based sorting enables mines to remove acid-forming material from waste rock early in the process. Using X-ray Transmission (XRT) sorting, the technology can create a detailed image of each rock, highlighting fine-grained inclusions such as base-metal sulphides.
Mines can also retain coarse material that would otherwise be crushed away as sorters operate on defined-size fractions, enabling waste to be managed in a form suitable for placement while preserving processing capacity for mineralised material.
Sorting also helps to create certainty. When waste rock is certified as low in sulphides, operators can simplify environmental licensing, reduce monitoring requirements, and strike that material from the records as a future risk.
Turning waste into a manageable resource
At Bluestone’s Renison Bell operation in Tasmania, Australia, the value of sorting lies in the confidence and control it provides. XRT sorting separates non-acid-forming (NAC) from potentially acid-forming (PAC) waste, enabling the operation to manage material based on its long-term environmental behaviour.
Bluestone Mining Tasmania Joint Venture said, "By separating non-acid-forming waste using TOMRA XRT sorting, we are able to place a large portion of our waste rock directly in long-term storage, reducing both environmental risk and the need to place underground."
This segregation can simply waste management and closure planning by ensuring only chemically stable material is placed in long-term storage, while PAF material is isolated and managed appropriately.
At Kensington Mine in Alaska, US, XRT sorting strengthens the same principle- clean waste is usable waste. High-density particles containing sulphide minerals and associated gold are recovered into the concentrate stream, while low-density diorite pebbles, virtually devoid of sulphides, are rejected as waste. This process enhances gold recovery and produces a barren waste fraction with minimal acid-generating potential, supporting environmentally responsible tailings management.
Jordan Rutledge, area sales manager at Tomra Mining, said, “In the latest publicly available technical report, 4,216 ounces of gold were recovered from the pebble sorting operation in one year. At January 2026, gold prices that represents almost US$20 million in recovered value, while still producing a clean, low-sulphide waste stream that can be safely placed or reused. That combination is what makes sorting so compelling for customers.”
Aggregate as a revenue stream
The Mt Carbone operation in far north Queensland, Australia, is a strong proof point for waste-to-aggregate sorting. At the EQ Resources operation, ore sorting has redefined waste management by using Tomra XRT sorters to process tungsten-bearing ore, generating a barren waste stream that is repurposed as aggregate for sale.
Kevin MacNeill, CEO of Mt Carbine mine, EQ Resources, said, “Normally, you would grind the waste down to 6mm and put it through the jigs, but by putting it through the Tomra sorters, we are able to keep a whole range of aggregates on the coarser size fractions. The sorters remove any material containing acid-forming sulphides and the waste rock that comes out is incredibly clean. We are therefore able to use it in making all kinds of different quarry products – from road bases to concrete aggregates. It’s a perfect example of a circular economy.”
MacNeill added, “Selling these green aggregates adds a significant portion to our business – about 5 million Australian Dollars a year – and that’s all because of the Tomra sorters. In fact, we’ve probably paid for each machine from this revenue 5 times over.”
Based on these results, a third sorter is now planned.
Wolfram Bergbau Mittersil in Austria has also unlocked value from its waste by turning it into material for its infrastructure and for sale. Between 25 and 40% of run-of-mine material is removed as coarse waste through XRT sorting.
Alexander Mosser, operations engineer at Wolfram Bergbau und Hütten AG, said, “Coarse barren material produced by XRT sorting at Wolfram Bergbau Mittersill is used for road construction at the tailings dam and in the mine, crushed as aggregate in shotcrete in the mine and local aggregate supply.”
Every tonne rejected before crushing and flotation is a tonne that does not enter the tailings facility, helping extend mine life when tailings capacity is the primary constraint.
A second business
Traditionally, operations have operated on a simple equation: ore generates profit, waste generates cost. But sensor-based sorting can change that.
By removing sulphides and producing clean, stable material, Tomra Mining allows mines to reduce liabilities, simplify compliance, extend mine life, and create a profitable aggregate business alongside metal production. It can improve processing performance and help mines unlock a second business within the mine, where waste is no longer defined by cost but by value.
