Mt Marion

Location

Mt Marion is located 590km east of Perth on the Traditional Owner land of the Marlinyu Ghoorlie People. The closest major town is Kalgoorlie, 70km to the north.

Overview

Mining began at Mt Marion in 2016 and is an open-pit lithium mine. MinRes operates Mt Marion under a life-of-mine, build-own-operate, mining services contract as part of a 50-50 joint venture with one of the world’s largest lithium producers, Jiangxi Ganfeng Lithium.

The major infrastructure on site includes:

• multiple open pit mines, waste dumps, Run of Mine pad and tailings storage facilities
• crushing and processing plant via Dense Media Separation (DMS) concentrator
• workshops, offices, grid connection and diesel power generation and bore fields
• FIFO camp accommodation that can house up to 500 people.

Mining

Production to date has been by open pit methods using the conventional drill, blast, load and haul mining cycle. The host rock geology is predominantly formed from mafic and ultramafic rocks with minor occurrence of meta-sediments. These are heavily weathered in the upper 15-40 metres of the pit profile and transition to hard and competent rock below that.

The fresh waste rock has a density similar to or higher than spodumene, hence the mining method needs to ensure minimal dilution to avoid impacting the product specification in the DMS circuit.

While Mt Marion has significant open-pit reserves there are also substantial tonnes of ore at depth that can be more economically extracted via underground mining methods. MinRes began an underground exploration decline development in 2024 before the underground was placed into care and maintenance in December 2024 as a response to market conditions.

Processing

The Mt Marion crushing plant delivers crushed ore onto a stockpile where it is reclaimed into the DMS circuit. The DMS plant produces three product streams based on size splits with an annual production capacity of approximately 600,000 tonnes of spodumene concentrate at two different grades which are typically 5% and 3.5% Li2O. The fine tailings are pumped to wet tailings storage while the coarse tailings are blended with waste rock.

Spodumene concentrate at Mt Marion is transported to the Port of Esperance for export to global markets.