{"schemaVersion":"jobsearcher.job.v1","id":"b3c345b884772f217dfd7b4f","url":"https://jobsearcher.com/jobs/b3c345b884772f217dfd7b4f","canonicalUrl":"https://jobsearcher.com/jobs/b3c345b884772f217dfd7b4f","title":"Sr. Process Engineer","description":"About Mariana Minerals\n\nMariana 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.\n\nRole Overview\n\nMariana Minerals is looking for a highly motivated Sr. Process Engineer to join our San Francisco Pilot Plant team. You will lead 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.\n\nWhat You’ll Do\n\nWork closely with Pilot Plant Technicians to operate, maintain, troubleshoot, and improve pilot-scale processing equipment\n\nDesign experiments to evaluate process performance, recovery, throughput, and product quality\n\nCreate and maintain key engineering and operational documentation such PFDs, HMBs, P&IDs, Operating Procedures, and Process Control Narratives\n\nLead equipment design scopes from concept, through procurement, fabrication, installation, commissioning, and handover to Operations\n\nWork closely with cross-functional teams including R&D, commercial plant design engineers, project execution teams, and more to scale designs from lab to the pilot to production scale\n\nWork closely with the software and machine learning teams to develop and implement reactor and plant optimization algorithms\n\nTravel to pilot and commercial sites to drive commissioning, startup, and ramp-up alongside operations & plant design teams\n\nWhat You’ll Bring\n\nB.S., M.S., or PhD in Chemical Engineering or related field\n\nMinimum of 5 years of experience supporting R&D scale up, pilot plant operation, and/or commercial production in minerals processing, chemicals, specialty materials, oil & gas, or similar industry\n\nStrong understanding of reaction engineering, solid-liquid separation, leaching, ion exchange, solvent extraction, and/or similar unit operations\n\nHands-on experience designing, commissioning, and operating pilot or commercial-scale process equipment\n\nAbility to design experiments, problem-solve, and analyze complex datasets\n\nStrong commitment to Health & Safety and experience with risk management, management of change, and hazard assessment\n\nExcellent technical writing, communication, and teamwork skills\n\nComfort working in fast-paced, cross-functional environments\n\nOur culture is built on four principles:\n\nEveryone Gets Home Safe. We never put speed or cost ahead of people.\n\nExtreme Ownership. We take full responsibility for outcomes, relentlessly driving toward solutions.\n\nEngineer Out Requirements, then Automate. We simplify, optimize, and then automate for scale.\n\nShare Your Legos. We collaborate openly, share knowledge, and empower each other to build bigger, better solutions.\n\nJoin us as we build the future of responsible mineral sourcing and supply!\n\nCompensation Range: $120K - $140K","company":"Mariana Minerals","rawCompany":"mariana minerals","city":"Millbrae","state":"CA","isRemote":false,"isActive":false,"createdAt":"2026-08-19T12:53:16.209Z","occupations":[{"code":"17-2041.00","title":"Chemical Engineers","slug":"chemical-engineers"},{"code":"17-2199.00","title":"Engineers, All Other","slug":"engineers-all-other"},{"code":"17-2112.03","title":"Manufacturing Engineers","slug":"manufacturing-engineers"}],"industries":[{"code":"541715","title":"Research and Development in the Physical, Engineering, and Life Sciences (except Nanotechnology and Biotechnology)","slug":"research-and-development-in-the-physical-engineering-and-life-sciences-except-nanotechnology-and-biotechnology"},{"code":"541512","title":"Computer Systems Design Services","slug":"computer-systems-design-services"},{"code":"541330","title":"Engineering Services","slug":"engineering-services"}],"jobPosting":{"@context":"https://schema.org","@type":"JobPosting","title":"Sr. Process Engineer","description":"About Mariana Minerals\n\nMariana 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.\n\nRole Overview\n\nMariana Minerals is looking for a highly motivated Sr. Process Engineer to join our San Francisco Pilot Plant team. You will lead 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.\n\nWhat You’ll Do\n\nWork closely with Pilot Plant Technicians to operate, maintain, troubleshoot, and improve pilot-scale processing equipment\n\nDesign experiments to evaluate process performance, recovery, throughput, and product quality\n\nCreate and maintain key engineering and operational documentation such PFDs, HMBs, P&IDs, Operating Procedures, and Process Control Narratives\n\nLead equipment design scopes from concept, through procurement, fabrication, installation, commissioning, and handover to Operations\n\nWork closely with cross-functional teams including R&D, commercial plant design engineers, project execution teams, and more to scale designs from lab to the pilot to production scale\n\nWork closely with the software and machine learning teams to develop and implement reactor and plant optimization algorithms\n\nTravel to pilot and commercial sites to drive commissioning, startup, and ramp-up alongside operations & plant design teams\n\nWhat You’ll Bring\n\nB.S., M.S., or PhD in Chemical Engineering or related field\n\nMinimum of 5 years of experience supporting R&D scale up, pilot plant operation, and/or commercial production in minerals processing, chemicals, specialty materials, oil & gas, or similar industry\n\nStrong understanding of reaction engineering, solid-liquid separation, leaching, ion exchange, solvent extraction, and/or similar unit operations\n\nHands-on experience designing, commissioning, and operating pilot or commercial-scale process equipment\n\nAbility to design experiments, problem-solve, and analyze complex datasets\n\nStrong commitment to Health & Safety and experience with risk management, management of change, and hazard assessment\n\nExcellent technical writing, communication, and teamwork skills\n\nComfort working in fast-paced, cross-functional environments\n\nOur culture is built on four principles:\n\nEveryone Gets Home Safe. We never put speed or cost ahead of people.\n\nExtreme Ownership. We take full responsibility for outcomes, relentlessly driving toward solutions.\n\nEngineer Out Requirements, then Automate. We simplify, optimize, and then automate for scale.\n\nShare Your Legos. We collaborate openly, share knowledge, and empower each other to build bigger, better solutions.\n\nJoin us as we build the future of responsible mineral sourcing and supply!\n\nCompensation Range: $120K - $140K","datePosted":"2026-08-19T12:53:16.209Z","dateModified":"2026-08-19T12:53:16.209Z","hiringOrganization":{"@type":"Organization","name":"Mariana Minerals","sameAs":"https://jobsearcher.com"},"jobLocation":{"@type":"Place","address":{"@type":"PostalAddress","addressLocality":"Millbrae","addressRegion":"CA","addressCountry":"US"}},"identifier":{"@type":"PropertyValue","name":"JobSearcher","value":"b3c345b884772f217dfd7b4f"},"url":"https://jobsearcher.com/jobs/b3c345b884772f217dfd7b4f"}}