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.

The Role

Mariana Minerals is looking for a highly motivated Mechanical Maintenance Technician to join our San Francisco Pilot Plant team. You will support the design, installation, and maintenance of first-of-its-kind refining processes for critical minerals. This position plays a critical role in bridging R&D and Operations, ensuring our equipment and work processes are robust, safe, cost-effective, and suitable for commercial production.

What You’ll Do

• Perform preventive and corrective maintenance on plant equipment including pumps, valves, piping systems, filtration units, and other process equipment.

• Troubleshoot and repair mechanical issues to maintain safe and reliable plant operations.

• Assist with fabrication, installation, modification, startup, and commissioning of new equipment and pilot plant systems.

• Read and interpret engineering drawings, P&IDs, and equipment manuals to support maintenance and installation work.

• Safely perform maintenance activities following plant safety procedures including Lockout/Tagout (LOTO), hot work permitting, and confined space entry.

• Identify and maintain critical spare parts for the pilot plant

• Champion the site Computerized Maintenance Management System (CMMS) system

Desired Qualifications

• Associate degree, technical certificate, or equivalent hands-on experience in industrial maintenance, mechanical technology, millwright work, or a related field.

• 3+ years of experience maintaining industrial or pilot-scale equipment in the minerals processing, chemicals, specialty materials, oil & gas, biotech, or similar industries.

• Hands-on experience with maintenance tasks such as pump repair, valve replacement, and instrument troubleshooting

• Hands-on experience fabricating, modifying, and/or constructing industrial equipment

• Familiarity with core plant safety practices including Lockout/Tagout (LOTO), hot work permits, confined space entry, and safe work permitting systems.

• Ability to read and interpret engineering drawings such as P&IDs, equipment diagrams, and mechanical layouts.

• Experience documenting maintenance activities using CMMS or maintenance tracking systems.

• Experience working with rotating equipment, filtration systems, and industrial piping is a plus.

• Ability to climb stairs, stand for extended periods of time, and safely lift up to 50 lbs.

Why Join Us?

At Mariana Minerals, you’ll be part of a mission-driven team reshaping the way critical minerals are sourced and supplied globally. You’ll have the autonomy to make big decisions, the tools to innovate, and a culture that values ownership, smart automation, and collaboration.

Our culture is built on three principles:

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.

Join us as we build the future of responsible mineral sourcing and supply.

Mariana is an Equal Opportunity Employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. We do not discriminate on the basis of race, color, religion, sex, sexual orientation, gender identity, national origin, age, disability, veteran status, or any other protected status.