About Mariana MineralsMariana 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 RoleMariana Minerals is seeking a highly motivated Process Engineer to support our next-generation minerals processing pilot plant in Houston. You will help design, deploy, and operate first-of-its-kind refining processes for critical minerals. This role is highly hands‑on and will play a key role in bridging R&D and plant operations, helping scale technologies from laboratory development through pilot demonstration and ultimately to commercial production. You will work closely with technicians, engineers, and cross‑functional teams to ensure processes are robust, safe, and ready for industrial deployment.What You'll DoLead equipment and process design from concept through procurement, fabrication, installation, commissioning, and startupOperate, troubleshoot, and improve pilot‑scale processing equipment in collaboration with pilot plant techniciansDesign and execute pilot‑scale experiments to evaluate process performance, recovery, throughput, and product qualityDevelop and maintain key process documentation including PFDs, P&IDs, mass and heat balances, operating procedures, and control narrativesAnalyze experimental and operational data to identify opportunities for process optimization and scale‑upSupport development of automated plant monitoring and optimization tools in collaboration with software and machine learning teamsEnsure safe operations by supporting EHS, hazard assessments, risk management, and management of change processesWhat You'll BringB.S., M.S., or PhD in Chemical Engineering or a related field10+ years of experience in operations, process scale‑up, or plant design in minerals processing, chemicals, specialty materials, oil & gas, or related industriesDemonstrated experience driving equipment design, commissioning, and plant operationStrong understanding of relevant unit operations and equipment such as kilns, furnaces, ion exchange, solvent extraction, solid liquid separation, leaching, electrowinning, or similar technologiesAbility to design experiments, troubleshoot complex processes, and analyze operational datasetsStrong commitment to Health, Safety, and Environmental complianceExcellent technical writing, communication, and teamwork skillsComfortable working in fast‑paced environments, wearing multiple hats, and managing ambiguityWhy 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.Compensation$140K – $175K, Offers Equity#J-18808-Ljbffr