Plant Supervisor

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 Operations Supervisor to join our San Francisco Pilot Plant team. You will oversee a team of high performing technicians who support the design, deployment, and operation of first-of-its-kind refining processes for critical minerals, while also supporting development of software for automated plant optimization. This position is highly hands-on and will play a critical role in bridging R&D and Operations, ensuring processes are robust, safe, cost-effective, and suitable for commercial production.

What You'll Do

Serve as the direct lead for a team of high performing operations technicians

Help drive performance reviews, scheduling, training, and hiring

Collaborate with engineers, R&D scientists, and the technicians to operate and monitor mineral extraction chemical processes

Provide off-hours support on evenings and weekends to plant upsets and high priority projects

Create and sustain EHS programs and policies regarding chemical handling, hazard assessment, high risk activities, PPE and waste management compliance

Ensure high-quality data capture from the plant via sampling, basic laboratory measurements, instrument uptime, and MarianaOS usage

Own plant cleanliness and organization, ensuring work areas, tools, and equipment are well-maintained and ready for operations

Create and maintain procedures, experimental records, shift reports, and other critical operations documents

Desired Qualifications

2+ years of experience in a supervisory or lead role

5+ years of experience operating pilot plant or commercial scale industrial equipment in the minerals processing, chemicals, specialty materials, oil & gas, biotech, or similar industry

Demonstrated leadership in core plant safety work processes such as Lockout/Tagout (LOTO), hot work permitting, confined space entry, and safe work permitting systems

Experience using human–machine interfaces (HMIs) and plant software systems to monitor, control, and adjust process operation

Experience overseeing hands-on equipment installation, modification, and troubleshooting

Knowledge of basic process chemistry (pH, reaction stoichiometry, etc)

Experience using engineering documents such as PFDs, control narratives, and P&IDs

Excellent written and verbal communication skills

Climb stairs, stand for extended periods of time, and safely lift up to 50 lbs

Our culture is built on four principles:

Everyone Gets Home Safe. We never put speed or cost ahead of people.

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!