Appian appoints new CEO of critical minerals
Investment adviser to long-term value-focused private capital funds investing in companies in metals, mining and adjacent industries, Appian Capital Advisory has appointed Paulo Castellari as CEO of critical minerals, strengthening the company's operating capabilities as it scales its critical minerals portfolio.
He will lead Appian’s critical minerals portfolio, overseeing its existing investments across graphite, mineral sands and rare earths, as well as future critical minerals investments, as the firm continues to scale its exposure to commodities essential for energy security, key industries and future-focused technologies.
He will also be responsible for sourcing and evaluating new opportunities across the sector.
Castellari joins Appian from Eramet, where he served as CEO. He brings over 30 years of experience across mining and metals projects in the Americas, Europe and Africa, with a strong record in operations, disciplined capital allocation, responsible practices and complex project delivery.
He previously served as CEO of Appian Capital Brazil from 2019 to 2025. Under his leadership, the business brought three mines into production, integrated them into local communities, and implemented innovative, safe and responsible mining practices.
Before joining Appian in 2019, Castellari built a distinguished executive career spanning multiple industries and geographies. At Anglo American, he held senior leadership roles across marketing, business development and operational leadership of key commodity businesses. In 2016, he transitioned to the energy sector serving as deputy CEO and CFO of CEMIG, one of Brazil's leading electric power companies. He subsequently became CEO of Guinea Alumina Corporation at Emirates Global Aluminium.
His appointment bolsters Appian’s investor-operator model, which combines the sourcing capabilities to identify economically and technically viable projects with in-house technical and operational expertise to responsibly bring them into production, integrating upstream, midstream and downstream activities.
This approach underpins Appian’s $1-billion partnership with the World Bank’s International Finance Corporation, aimed at accelerating the responsible development of critical minerals projects across emerging markets in Latin America and Africa. The partnership offers a blueprint for governments and sovereign funds seeking to secure access to critical minerals through public-private partnerships, amid growing global demand.
“Paulo is a highly respected operating leader with a strong record of delivering complex mining projects to the highest performance and safety standards. His deep technical expertise, disciplined approach to capital allocation, and ability to build and scale complex operations will further strengthen Appian’s operating capabilities. As we continue to grow our critical minerals portfolio, Paulo’s experience will play a pivotal role in advancing our projects and unlocking long-term value for all our partners,” comments Appian founder and CEO Michael Scherb.
“I am delighted to be rejoining Appian to work across its global critical minerals portfolio. Appian has built a strong reputation for operational excellence and disciplined investment, and I look forward to working with the team to further strengthen these capabilities. Together, we will continue to focus on safely and efficiently advancing our projects, building resilient operations and delivering value for all stakeholders while supporting the growing global demand for critical minerals,” says Castellari.
