Argosy Minerals (ASX:AGY) said the process design program for the Rincon lithium project in Argentina is nearing completion following systematic evaluation and design refinement works, according to a Thursday Australian bourse filing.

The firm's concentrated lithium brine was utilised to produce a high-purity lithium chloride concentrate using the selected process technologies, with test work results confirming a lithium recovery of 96%.

The optimized process flowsheet validation testing advanced to continuous pilot plant scale operations in Argentina, per the filing.

Its shares jumped 4% in recent trading on Thursday.