HUMBOLDT COUNTY — Lithium Nevada’s Thacker Pass project recently announced the Bureau of Land Management (BLM) has deemed its Plan of Operation complete.
Lithium Nevada — the wholly-owned subsidiary of British Columbia, Canada-based Lithium Americas — filed the plan with the BLM in August 2019. The mining company expects to acquire all major permits for Phase 1 operations by the end of 2020.
The Thacker Pass project is located about 60 miles northwest of Winnemucca in Humboldt County.
According to the technical report, the project is a “one-of-a-kind” deposit that “requires an alternative approach that would reduce overall operational and capital costs and leverage the physical properties of the soft claystone.”
According to Lithium Nevada, operations will create approximately 1,000 jobs during construction of the $1.3 billion project and will employ more than 275 people.
The company anticipates permits to be issued by the end of 2020 and for Phase I construction to begin shortly thereafter. Phase I production is expected to begin sometime in late 2022.
A UNIQUE MINING PROCESS
On a recent tour in Lithium Nevada’s process testing facility in Reno, Vice President of Engineering Brett Rabe laid out the unique aspects of the project.
“The uniqueness of the process is really a function of the ore body,” he said. “In developing our extraction method, we aren’t doing anything that hasn’t been done for, in many cases, 100 years.”
The lithium deposit sits in the McDermitt Caldera, which could possibly be the oldest caldera in a sequence of calderas that were formed by the Yellowstone Hotspot about 16 million years ago.
“What traditionally happens,” Rabe explained, “is that when you have a super eruption, the edges (of the caldera) would collapse, and all of the minerals that were at one time in the magma basically wash out to the ocean.”
However, the McDermitt Caldera is unique because it didn’t collapse; instead, a lake formed that contained the magma and deposited lithium in layers embedded within soft clay sediment. Typically, over millions of years, additional sediment would then be deposited over the lithium.
Instead, Rabe said, “Normally, this (ore) is hundreds and hundreds of feet below the surface and it would not be economically mined. But what happened is about 300,000 years after the first eruption, the magma chamber does an uplift and it pushed the center of that caldera, so all of the overburden was washed away through erosion and exposed that lithium to the surface.”
Rabe said the Thacker Pass project’s mining operation won’t focus on removing large amounts of overburden. He said that by the 40th year of operation, the pit will only be about 120 meters (393 feet) deep.
“By Nevada standards that is a very, very small pit,” he said.
BREAKING DOWN THE PROCESS
The way the lithium deposit is laid down, it creates an ore body of soil-like material, which means that the extraction process is also unique to this mine.
“Due to the nature of the deposit, it’s basically a soil,” Rabe explained. “There’s no drilling. There’s no blasting. We’re basically going in with earth moving equipment and digging it up.”
The company’s Reno testing facility was constructed to determine if the extraction process was feasible.
“You have to consider how the ore was formed because the extraction process is the reverse process of the how the ore was formed,” said Lithium Nevada President of North American Operations Alexi Zawadzki.
According to the company, the ore was formed under water. By adding water, it then reverses process, and the ore falls apart and turns to a slur. This slur gets transported by a gravity feed pipeline to an attrition scrubber to break it apart further so the lithium can be upgraded.
“There’s certain parts of the ore that don’t have a lot of lithium in it,” Zawadzki said. “So, what we’re doing is upgrading the ore in a process called ‘beneficiation.’ We’re upgrading that ore into a slurry and that’s what makes the process unique.
“You can upgrade (the ore) even though we started with a high concentrate of lithium …. We actually increase that concentration simply by adding water to it and do the evaporation process.”
Lithium Nevada will not have to build ponds and wait two or three years for enough water to evaporate out to have a high enough lithium concentration.
“We can crystalize it. We get to use steam from our sulfuric acid plant, and it evaporates the water off it immediately,” Rabe said during the tour. “We’re not waiting on Mother Nature or crossing our fingers hoping to get good sun.”
EMBRACING A RAPIDLY GROWING INDUSTRY
The most expensive part of the process is producing sulfuric acid, since the process requires massive amounts of it, Rabe said.
Lithium Nevada intends to build its own sulfuric acid plant, promising it won’t be anything like any other sulfuric acid plant.
“If you were to drive up to our plant site after it’s been constructed, this is probably going to be the largest building that stands out there,” Rabe said. ” … It will not look like any mine or mill facility you see in Nevada. It’s going to look like a good-sized chemical plant.”
The sulfuric acid plant will produce enough steam to produce electricity that the company will be able to sell up to 15 mega-watts to NV Energy.
Zawadzki added that this process has been proven in the phosphate industry, and Lithium Nevada is applying this method to the extraction process. The slurry goes through a neutralization process and at that point, Zawadzki says what is left is a high purity lithium sulfate.
According to the company, the Reno testing facility has taken samples from the Thacker Pass location and produced over 3,000 kg of high-quality lithium sulfate solution. From this lithium sulfate solution, the company can make two main battery chemicals that are used in the lithium-ion battery industry.
The first is called lithium hydroxide, which is what Panasonic uses in its batteries, and the other one is lithium carbonate.
Zawadzki said that some lithium mining operations can produce only one of these lithium products, but from “our process from lithium sulfate, we can make either lithium hydroxide or lithium carbonate. This is what gives us the flexibility and makes it unique to respond to market needs.”
The lithium market has been a relatively non-descript industry until recently. But with the development of electric vehicles, the demand for lithium batteries has soared. The demand for lithium is expected to grow more than 500% by 2025, industry officials have said.
The Thacker Pass mine has the potential to produce approximately 25% of global demand with a 40-plus-year lifespan.
“This is an industry that’s growing rapidly,” Zawadzki says. “Electric vehicles are something that everyone is going to have. There are laws changing across the world right now that you have no choice. Certainly, in Europe, they’re banning internal combustion engines in major cities by 2030 … so you’re not going to have a choice.
“You’re going to have to have an electric vehicle.”