Talking Rocks with Albemarle's Mineral Process Expert

Sept. 14, 2024

As a metallurgist specializing in energy storage resources, Albemarle’s Henry Walqui is an expert in mineral processing.  

But why is mineral processing important for hard-rock lithium deposits such as the one in Kings Mountain, NC? It’s an essential sequence of liberation and separation. 
Albemarle's Kings Mountain site boasts one of the world’s richest lithium-bearing-ore deposits. But that ore, which in the case of Kings Mountain is predominantly a mineral known as spodumene, has a low concentration of lithium.  

As Albemarle progresses with plans to potentially restart mining operations at the Kings Mountain Mine, Walqui and his team are anticipating how to turn millions of tons of mined ore into spodumene concentrate that contains about 6% lithium oxide.  

“I see my role as playing with rocks and mud,” says Walqui, who has been with Albemarle since October 2021.  

The two basic steps in mineral processing are liberation and separation— one deals with the mined rocks that are blasted and hauled out of the mine pit, and the other involves the slurry that is created later when separating the minerals from the ore.  

Liberation, says Walqui, is how you break apart the particles in the ore so that the valuable spodumene mineral is no longer associated with the non-valuable minerals. Separation is the process of recovering the valuable portion out of the non-valuable portion. 

To support those steps, the proposed Kings Mountain Mine will feature an onsite mineral processing facility designed to process about 8,900 tons of mined material per day. It’s here where Walqui and the team take material that’s been mined and crushed into quarter-inch pieces and transform it into a concentrated, powder-like form of spodumene.  

Walqui notes that his expertise lies in determining what processes can be used to concentrate the ore into a sellable product.  

“We characterize the ore by understanding what the physical properties are of that material. Once we know that, we try different separation techniques to find the method(s) most economically viable to extract the spodumene concentrate,” he says. “We try to take advantage of differences in physical characteristics which may include how heavy the particle is, does it like water, does it have magnetic properties — things like that.” 

In addition, the process must also use natural resources responsibly. Walqui notes that while mining is typically considered a water- and energy-intensive industry, Albemarle works to conserve as much of those resources as possible.  

“We designed our mineral processes to minimize energy consumption by sorting ore early in the process, removing impurities and reducing the amount of valuable material that needs to be processed,” says Walqui. “We also use a filtered tailings process designed to remove most of the water within the material until it resembles something like moist beach sand. Our tailings management processes allow us to maximize the recovery of water.” 

“We are part of an industry that produces a material used in products that drive development and innovation in society,” Walqui says. “But our part is early in the process.”  

After it is separated from the ore, the spodumene concentrate can be transferred to an offsite conversion facility for further refinement. Ultimately the concentrate can be used as an essential element in applications such as batteries for electric vehicles and smartphones, used to strengthen glass or steel alloys, or for defense applications. 

The material is considered so essential to the U.S.’s plans to grow its supply chain of the lithium, the mine’s mineral processing facility received a $150 million grant from the U.S. Department of Energy as part of the recent Bipartisan Infrastructure Law to expand the domestic manufacturing of batteries for electric vehicles and the electric grid.  

After the proposed Kings Mountain Mine and mineral processing facility is fully permitted and constructed, the mine and facility are expected to produce 420,000 tons of spodumene concentrate per year. That is enough material to support the initial manufacture of 1.2 million electric vehicles per year. 

Learn more about our work in Kings Mountain.