Their direct recovery technology (DLE) encountered corrosion problems. Its also reported that California has a new lithium tax.
Berkshire has geothermal assets nearby which might have provided heat, but article says negotiations with feds over a grant and details like patent ownership failed to be resolved. So they withdrew.
DLE technology extracts lithium from the brine and returns treated brine to the source avoiding waste steams for disposal. Other DLE projects funded by Koch Industries using Schlumberger technology at Great Salt Lake seem to be moving forward.
China currently dominates the purified battery grade lithium business. But most crude lithium is mined in South America, especially Chili, ir Australia. Shipping crude lithium to China for purification and then to the US to make batteries is inefficient. Better to do purification close to the US.
Several companies have projects in the works. A domestic lithium business would be good. Competing with China is always risky. Recall rare earths and others. Solar panels. Some say semiconductors.
From what I understand, BRK is continuing to build out their lithium extraction plant at the Salton Sea, hoping to overcome the problems with extracting lithium from the brine using DLE. They found it too difficult to produce lithium hydroxide, though, which was specified in their grant application. So, when they turned to making the more common and easier to synthesize lithium carbonate instead of lithium hyroxide, the US withdrew the grant, since that was a primary goal of the project.
From the Reuters story linked in the OP:
The U.S. Department of Energy had chosen Berkshire … for a $14.9 million grant to study how Salton Sea-region lithium could be used to make lithium hydroxide, a specialized type of the metal that produces more efficient and longer-lasting EV batteries…
… Berkshire said it had planned to develop “a first-of-its-kind demonstration plant to produce lithium hydroxide” but “subsequently decided to use a commercially proven process” to produce lithium carbonate instead…
Making hydroxide requires extra processing… If and when Berkshire is able to extract the lithium from the Salton Sea brine, making carbonate would be less complicated and expensive than making hydroxide.
Wikipedia reports the standard route to lithium hydroxide is to add lime (calcium hydroxide slurry) to lithium carbonate precipitating calcium carbonate (limestone). The calcium carbonate is a messy waste stream. But it can be recycled to lime by heating in a lime kiln (releasing carbon dioxide).
Both sodium and potassium hydroxide are made by electrolysis of the corresponding chloride salt. I’m surprised that method is not used for lithium hydroxide. Fewer by-products (hydrogen and chlorine) and they are salable.