Brine based lithium cannot be used in technical grade uses and...

Brine based lithium cannot be used in technical grade uses and in battery usage, brine conversion to lithium carbonate can only yield a maximum of a 99.2% concentrate whereas hard rock can yield as high as 99.9% making the hard rock product better from the outset.

It should be also noted that brine conversion is an extraordinarily complex conversion where as hard rock which is low iron content is relatively simple.

And, China is geared up for processing hard rock, all their plants use hard rock and they will likely have a preference for hard rock lithium for processing.