@Polocook It boils down to economies of scale. As a general...

@Polocook It boils down to economies of scale. As a general point, taken from my post Post #:69711272:

DLE IMO is largely an unproven technology IMO and is probably costlier than typical brine processes - with the difficulty in process is the fact that the 'input' is in varied concentrations, ranging from lithium to deleterious elements as it enters DLE and that is a problem in itself, although if Rio can ever get it to work at scale it would be a good thing (assuming they can further improve on the ESG aspects of the production technique in terms of returning water to the water table). Background is here -Post #:49764761

The embedded post has this image, i.e. at a time comparisons were between Atacama and hard rock, and whilst the numbers may be outdated the relativities remain:


Treating brines is a two step process to hydroxide, whilst hard rock it is a one step process. Point of the above is that I suspect, even if DLE is proven at scale which will take time btw, it will produce carbonate and hydroxide at a greater cost, where comparison is to brines using evaporation techniques of extraction, and hard rock.

My gut feel is the play that Rio is doing is about resource size given its Jadar project is dead in the water IMO - refer Post #:75994058

It is a risky play by Rio on the DLE front, but I suspect it sees risks and reward if it can utilise DLE, and overtime improve the extraction methodology to reduce costs. If others have a view I would be interested as well.

A good article on pro and cons of DLE is this one - it shows the advantages and disadvantages of DLE and main challenges and is a good read IMO and draws out the issues very well IMO:
Lithium Extraction Startup Landscape, role of direct lithium extraction (DLE) in energy transition. | by Anil Achyuta | TDK Ventures | Medium

All IMO