Covalent Lithium is preparing for a new era, with Stuart Macnaughton set to succeed Ross Martelli as chief executive officer as the company advances the ramp-up of its integrated Western Australian lithium operations.
Macnaughton will join Covalent on July 1 and formally succeed Martelli, who will retire at the end of the year after leading the company from project inception through the successful development of the Mt Holland mine and concentrator and the Kwinana lithium hydroxide refinery.
Covalent chairperson Ian Hansen said Macnaughton’s three decades of experience across global mining operations, downstream processing and project development made him the ideal successor.
“Stuart is a proven leader with a strong track record supporting multinational workforces through complex operational and external conditions, while improving performance, safety and long-term sustainability,” Hansen said.
“We are confident his values-based performance focus will position Covalent strongly for the future.”
Macnaughton has extensive experience in critical minerals, base metals and hydrometallurgy, having led complex mining and refining operations around the world.
His appointment comes as Covalent continues ramping up production at its Mt Holland mine and Kwinana lithium hydroxide refinery, with both operations receiving positive assessments from joint venture partners.
The Mt Holland operation has progressed through commissioning and ramp-up and is currently achieving nameplate capacity with reliable performance. Meanwhile, the Kwinana refinery achieved first lithium hydroxide production in July 2025 and continues advancing through its ramp-up.
Joint venture partner Sociedad Química y Minera de Chile S.A. (SQM) said in its 2025 earnings report that Mt Holland delivered strong operational results while the Kwinana refinery continued progressing through ramp-up, with excess spodumene concentrate sold into the market.
“We observed a price inflection in spodumene concentrate beginning in early November 2025,” SQM said.
“As is typical in the lithium market, prices have remained volatile, although within a stronger overall pricing environment.
“Looking ahead to 2026, we expect to maintain full production at the mine and concentrator, continue advancing the ramp-up of the Kwinana refinery, and further progress our exploration initiatives both in Australia and internationally.”
Wesfarmers also highlighted the project’s performance in its 2026 half-year report, saying WesCEF’s earnings benefited from a positive contribution from its lithium business, supported by strong mine and concentrator performance and an improved pricing environment.
Construction of the Kwinana refinery was completed below initial cost estimates, with commissioning producing high-quality lithium hydroxide. Engineering works to address intermittent odour issues are scheduled for completion by mid-2026, with excess spodumene concentrate continuing to be sold profitably during the extended ramp-up.
Hansen also paid tribute to Martelli, who has spent almost 45 years with Covalent and the Wesfarmers Chemicals, Energy and Fertilisers division.
“From early project development through to the successful delivery of the Mt Holland mine and concentrator, as well as the construction and commissioning of the Kwinana refinery, Ross’ knowledge and insights have been instrumental in guiding project delivery and operations at each stage,” Hansen said.
“Ross has left an indelible mark on Covalent and will depart with the gratitude and best wishes of Covalent; joint venture partners SQM and Wesfarmers; and the broader team.”
Martelli said building an integrated lithium business from the ground up had been a career highlight.
“It is not often you have the opportunity to build an integrated operation from the ground up, end-to-end. It has been a significant undertaking and a rewarding one,” Martelli said.
“The business is in a solid operating position, with a clear path forward and a strong foundation in place for future growth.”
The leadership transition comes as Australia’s lithium refining sector continues to face mixed conditions.
Earlier this year, US-based producer Albemarle placed its Kemerton lithium hydroxide processing plant in Western Australia into care and maintenance amid prolonged lithium price volatility, while Covalent continues progressing the ramp-up of its integrated Mt Holland and Kwinana operations.
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