Empty warehouse transformed into state-of-the-art metal refining facility

A Christchurch tech company has opened a potentially groundbreaking metal refining facility, which can extract zinc and other critical minerals from industrial byproducts.

The 2500-square-metre facility by clean-tech firm Zethos is aimed at large-scale demonstration, with the company hoping it will pave the way for a commercial production in the future.

"Everyone is better off when critical minerals are abundant, and we need smarter refining technology to make that a reality," chief executive Jonathan Ring said.

Zethos said the plant in Bromley was New Zealand's only domestic source of high-grade zinc, while also producing copper, nickel, manganese and other valuable co-products.

The company has scaled rapidly since its founding in 2021 from laboratory research to pilot operations, and now a large-scale demonstration facility, and has raised $16 million in funding.

"Less than a year ago this was an empty warehouse," Ring said. "Today it is the world's first scale facility producing low-cost low-carbon zinc from steel mill dust."

Speaking to RNZ, Ring described the facility as a "very large pilot" at near commercial scale.

"If this is successful we would then go on to be building commercial plants around the world."

He said currently there were numerous ways of refining each individual mineral, but they could broadly be split into two categories.

"The first is where you use a coal-based smelting technology or furnace technology, and the other one is a high pressure acid leach, where you essentially dissolve everything up and separate out the critical minerals."

Both technologies were energy intensive and highly polluting, which is where Zethos came in.

"We've developed a technology where we can selectively break down the minerals that contain the critical mineral within it, and eject that critical mineral, so we can then selectively dissolve it and then refine them separately."

Ring said the technology used 70 percent less energy than existing methods, with up to 50 percent lower operating costs and up to 95 percent lower carbon emissions compared to conventional methods.

Zethos also announced a partnership with New Zealand Steel, which would see Zethos process byproduct from NZ Steel's new electric arc furnace facility.

Ring said the demonstration facility is aimed to give investors and partners confidence to move forward with the technology.

He expected the plant to operate for around 18 months, where it would test various key performance indicators.

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