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 an experienced Pilot Plant Operations Manager to lead operations at our DSM Pilot Plant in Houston. The DSM pilot is a first-of-its-kind, fully integrated flowsheet that couples a high temperature pyrometallurgical section with a downstream hydrometallurgical refining section. You will own safe, reliable, round-the-clock operation of both sections and lead the technician team that runs them. This is a highly hands-on leadership role. You will build the operating team from the ground up, take the plant through commissioning and startup, and then run structured campaigns that generate the process data and product samples the company depends on. You will work shoulder to shoulder with process engineers, R&D scientists, maintenance, and the analytical laboratory, and you will be accountable for the safety, quality, and throughput of everything that happens on the floor. The role reports to the Houston site leadership team and carries direct responsibility for people, budgets for consumables and spares, shift structure, and operational readiness. You will set the safety culture for a plant that handles hot solids, molten material, combustion systems, process off-gas, concentrated acids and bases, and organic solvents. What You Will Do - Lead the DSM pilot operations team, including shift leads and technicians across the pyrometallurgy and hydrometallurgy sections. Recruit the team, develop shift leads into supervisors, and own training, qualification, and performance management. - Design and run the shift schedule, including rotation pattern, campaign and turnaround coverage, call-out rotation, overtime and fatigue management, timekeeping, and attendance. - Write and own the plant procedure library: startup, normal operation, shutdown, emergency response, and equipment-specific SOPs. Qualify every operator against them before independent work. - Own safe and reliable operation of the pyrometallurgical section: drying, calcining or roasting, reduction or smelting furnaces, hot solids handling, and off-gas and scrubbing systems. - Own safe and reliable operation of the hydrometallurgical section: leaching, solid liquid separation, solvent extraction or ion exchange, precipitation, crystallization, and effluent treatment. - Manage the interface between the two sections, including intermediate transfer, recycle streams, residues, and waste handling. - Lead commissioning, startup, and campaign execution, including punch list closure, loop checks, pre-startup safety review, and first feed. - Own EHS on the floor: lockout and tagout, hot work, confined space entry, line breaking, chemical handling, PPE, and waste compliance. Serve as incident commander for the plant and drill spill, fire, and chemical exposure response. - Maintain the operating records, inspections, and reporting required under the site air, stormwater, and hazardous waste requirements, and support agency inspections. - Drive troubleshooting and root cause analysis on upsets, equipment failures, and off-specification product, and close out corrective actions through management of change. - Plan campaign execution against the schedule, track feed, reagent, and product inventory, and report daily and weekly on throughput, uptime, consumption, and safety metrics. - Own the CMMS work order and preventive maintenance program, spare parts minimums, and contractor work on site, and manage the operating budget for consumables, reagents, spares, and contract labor. - Provide off-hours support during campaigns and plant upsets. Desired Qualifications - 5 or more years supervising a multi-shift team, and 10 or more years operating pilot or commercial scale process plants in minerals processing, metallurgy, or chemicals. - Hands-on operating experience in both pyrometallurgical and hydrometallurgical processes. Deep experience in one with demonstrated working exposure to the other will be considered. - High temperature equipment experience: kilns, roasters, calciners, or furnaces, including burner management systems, refractory, and hot solids handling. - Wet chemical unit operation experience: leaching, filtration or centrifugation, solvent extraction or ion exchange, precipitation, and crystallization. - Demonstrated safe handling of concentrated acids and bases, flammable solvents, and hazardous process gases. - Proven ownership of core safety work processes: lockout and tagout, hot work, confined space entry, and safe work permitting. - Commissioning and startup experience on new plants or new units. - Fluent with HMI, DCS or PLC systems and historians, and with PFDs, P&IDs, and control narratives. - Associate or Bachelor degree in engineering, metallurgy, or chemistry, or equivalent operating experience. - Startup environment experience preferred, where procedures and systems have to be built rather than inherited. 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!