Green Technology Metals (ASX:GT1) said that a study that evaluated the Root lithium project in Canada on a standalone basis confirmed favorable economics across different mine development scenarios, including both open pit and underground mining, according to a Wednesday Australian bourse filing.

The optimized preliminary economic assessment considered the recently updated project mineral resource estimate, revised pit optimizations, and mine development options, as well as changed lithium market conditions.

The study considered a project length of 10 years, with a processing rate of 1.5 million tonnes per annum, delivering an after-tax net present value of $668 million.

The firm will now proceed to a prefeasibility study, focusing on mine geotechnical, metallurgical testwork, and flowsheet optimization.

Green Technology Metals' shares fell past 5% in recent trading on Wednesday.