Sr. Plant Manager

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 seeking a highly motivated Sr. Plant Manager to lead the development and operation of our next-generation minerals processing pilot facility in Houston. You will be responsible for establishing and operating a first-of-its-kind pilot plant, including site setup, equipment design, construction, commissioning, start-up, and ongoing operations. You will help build and lead a multidisciplinary team of engineers and technicians to develop, test, and optimize innovative refining processes for critical minerals. This role serves as a critical bridge between R&D and commercial deployment, ensuring technologies are safely and effectively scaled from pilot to industrial production.

What You'll Do

• Lead the design, construction, commissioning, and startup of Mariana's Houston pilot plant facility.

• Oversee day-to-day pilot plant operations to ensure safe, reliable, and efficient execution of minerals refining processes.

• Oversee the design and execution of pilot-scale experiments to validate reaction parameters, optimize yields, and demonstrate process reproducibility.

• Drive the creation and upkeep of process documentation including PFDs, P&IDs, mass/energy balances, and operating procedures.

• Recruit, build, and manage a team of engineers and technicians to support pilot plant development and operations.

• Collaborate with R&D, engineering, and commercial design teams to scale processes from lab development to commercial production.

• Own and manage the site budget, including capital expenditures, operating costs, and contractor/vendor management

• Establish and enforce Environmental, Health & Safety (EHS) and Process Safety Management (PSM) programs and operational standards.

Desired Qualifications

• B.S., M.S., or PhD in Engineering or a related field

• 10+ years of experience in operations, process scale-up, or plant design in minerals processing, chemicals, specialty materials, oil & gas, or related industries

• Demonstrated experience leading equipment design, construction, commissioning, and startup

• Strong understanding of relevant unit operations and equipment such as kilns, furnaces, ion exchange, solvent extraction, solid liquid separation, leaching, electrowinning, or similar technologies

• Experience translating R&D processes into pilot and commercial-scale operations

• Proven experience implementing EHS and Process Safety Management programs

• Strong leadership and project management skills with experience managing technical teams and complex projects

• Comfortable working in fast-paced environments, wearing multiple hats, and managing ambiguity

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.