Sustainable lithium mining: Taupō’s economic future?


The Geo40 factory in Ohaaki
Photo: Supplied / Geo40

Taupō is home to the country’s largest lake, excellent trout fishing and – now – innovative and sustainable lithium mining technology.

The government recently announced that the Ohaaki-based company Geo40 would receive $2 million in funding from the Regional Economic Development and Investment Unit, Kānoa, to expand its lithium operations.

So what makes the Geo40 process so groundbreaking, what’s hot about lithium, and what does it mean for the wider region?

Why is lithium such a sought-after product?

Geo40 chief executive John Worth said the green revolution, particularly the push for electric cars, has propelled the mineral into high demand.

“Lithium has become one of the basic minerals for battery technology,” he says.

“The price has, for a while, been around $10,000 [per tonne] ($15,000 NZD). But due to supply shortages, we are seeing extraordinary spot prices, especially the Chinese spot price, where it is now hitting $50,000 per ton for the first time. »

How does Geo40 work differently?

Traditional lithium extraction methods are harmful to the environment.

Each tonne of lithium extracted by hard rock mining generates approximately 15,000 tonnes of carbon dioxide.

Lithium can also be extracted from brine, which is an extremely salty liquid found underground. The brine is pumped to the surface in large ponds and left for a few years for the water to evaporate, leaving behind lithium salts.

This uses two million liters of water for every ton of lithium produced.

But Geo40’s method is different, and they’ve already tried it with another compound – silica, which is used for things like densifying concrete and cement.

The company extracts the fluid from underground, separates the minerals from the water, then returns the fluid – sometimes even using waste from the geothermal power plant. Worth says they only emit about 200 kg of carbon dioxide per tonne of silica.

“We are the first company in the world to extract colloidal silica from geothermal fluid on a large scale,” says Worth.

The company is using a similar process for lithium and will soon conduct a life cycle assessment of the mineral’s carbon footprint.

Is this a game-changer for Taupō’s economy?

Taupō Mayor David Trewavas thinks so.

He says Covid-19 is starting to hit the region hard.

“For fiscal year 2021, until last December, we were absolutely in a boom period,” he says.

“But just in the last two months I can feel it in the air – things are starting to wind down a bit.”

Trewavas says Geo40 produces a “wonderful product” and also attracts highly skilled professionals to the area.

“We have international scientists there, about 40 staff on site and luckily they have the salary range to go with it and the downward flow effect, most of them buy locally.”


Photo: .


Comments are closed.