Extractive Metallurgist

About Mariana Minerals

Mariana Minerals is a software-first, vertically integrated minerals company on a mission to supply the critical minerals powering modern energy, AI, and defense technologies. We’re reimagining the minerals supply chain by combining deep industry expertise with advanced software, automation, and data-driven decision-making. Join us as we build the future of mining and minerals refining.

The Role

We are seeking an Extractive Metallurgist to join our growing technical team in San Francisco. This role will play a critical part in the development, optimization, and scale-up of mineral processing systems for Mariana’s global operations. The ideal candidate brings strong process engineering and metallurgical expertise, ideally in zinc or copper, and thrives in fast-paced, startup environments where independence, creativity, and problem solving are essential.

You’ll work closely with operations, engineers, machine learning experts, and data scientists to develop innovative solutions that improve efficiency, recovery, and throughput across our projects.

Responsibilities

• Design, test, and optimize mineral processing flowsheets for new and existing projects.

• Lead laboratory, pilot-scale, and plant trials for process validation and improvement.

• Analyze metallurgical data to improve recovery, efficiency, and cost performance.

• Collaborate with engineering teams on process design and scale-up.

• Partner with data scientists and ML engineers to integrate advanced analytics and predictive models into process optimization.

• Support commissioning and ramp-up of new facilities, with significant travel to sites.

• Contribute to Mariana’s culture of continuous improvement, innovation, and safety.

Must Have

• Degree in Metallurgy, Chemical Engineering, or Process Engineering.

• Hands-on mineral processing experience (zinc or copper preferred, broader base considered).

• Proven ability to work independently in dynamic environments, with strong problem-solving skills.

• Experience working in startup or entrepreneurial settings.

Nice to Have

• Background in industrial technology or product development.

• Experience collaborating with machine learning engineers or data scientists.

• Exposure to digitized process monitoring and automation systems.

Location: San Francisco, CA (with significant travel to project sites)

Why Join Us?

At Mariana Minerals, you’ll have the rare opportunity to shape the way critical minerals are responsibly sourced and supplied—combining your metallurgical expertise with cutting-edge software and automation. This is a high-impact role where your work will directly influence the efficiency, scalability, and sustainability of projects powering the future of energy, AI, and defense.

What it's like to work at Mariana Minerals

• Extreme Ownership – We take full responsibility for outcomes, relentlessly driving toward solutions.

• Engineer Out Requirements, then Automate – We simplify, optimize, and then automate for scale.

• Share Your Legos – We collaborate openly, share knowledge, and empower each other to build bigger, better solutions.