A gold mine in Namibia turned a decade of waste into ore

Navachab has preconcentrated more than 10 million tonnes of low-grade waste rock using dry sensor sorting — and just installed the technology's next generation.

The Navachab gold mine, in Namibia, has been operating STEINERT dry sensor sorters since 2016 to preconcentrate low-grade ore stockpiles — material that, without this sorting, would fall below the economic cutoff of the CIP (carbon-in-pulp) plant. Over the past decade, more than 10 million tonnes of that material have already been processed and converted into economically usable ore. The mine has just completed installation of the equipment's next generation, the STEINERT KSS EVO 6.0, designed to further cut operating costs and future-proof the technology on the plant.

What's worth understanding here isn't the sorting itself, but what it does to the concept of a mineral reserve: low-grade ore treated as waste on a given date can become viable resource again years later, with no new mining, just more precise sorting of what was already extracted. That's different from stretching a mine's life by opening a new pit — it's recovering value from material that was already on the surface, with far less capital investment than a conventional expansion. The technology processes 200 tonnes an hour, requires a minimum of water — a relevant environmental advantage in operations in Namibia, one of the driest countries in the world — and its modularity allows integration into existing circuits without redesigning the entire plant.

For process engineers and operations managers with old low-grade stockpiles sitting in the yard, this case shows that part of a mine's lost value isn't in ore still underground, but in material already extracted and discarded for lack of sufficiently precise sorting technology at the time. Reassessing those stockpiles with newer sensors can be a faster, cheaper return project than searching for new reserves — a geometallurgy skill that should grow in relevance as high-grade deposits become rarer.