--- title: Sr. Staff Mechanical Engineer at Mariana Minerals description: Mariana Minerals is hiring for the Sr. Staff Mechanical Engineer role in San Francisco, CA. See the full description and apply. type: job url: https://www.foundrole.com/jobs/sr-staff-mechanical-engineer-at-mariana-minerals-01a118c2-596c-712c-bb24-69d76ecd0490 date: 2026-10-08T00:15:46Z og_description: Join Mariana Minerals as Sr. Staff Mechanical Engineer in San Francisco, CA. Pays $140K–$175K per year. Full-time, on-site role. og_image: https://www.foundrole.com/og/wntnk8.png breadcrumbs: - label: Home url: https://www.foundrole.com/ - label: Search url: https://www.foundrole.com/jobs --- | | | |---|---| | **Company** | Mariana Minerals | | **Location** | San Francisco, CA | | **Salary** | $140K/yr - $175K/yr | | **Type** | Full Time | | **Posted** | Oct 07, 2026 | ## Description # **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. # **Role Overview** Mariana Minerals is looking for a highly motivated Sr./Staff Mechanical Engineer to work on building the critical minerals supply chain to support the world’s energy transition. As a Mechanical Engineer at Mariana Minerals, you will lead the development and deployment of first-of-its-kind chemical refining processes, while also supporting development of software for project execution and plant optimization. You will design, build, and commission mineral processing and metallurgical refining equipment, develop first-principles-based models of refining equipment and processes, and lead equipment scopes from concept through to design, installation, commissioning, ramp, and handover to the operations team. This is a hands-on, first-principles role for an engineer who wants to help build the world’s most advanced minerals refining facilities. # **What You’ll Do** - Lead mechanical engineering scopes across project phases—from concept and feasibility through detailed design, procurement, fabrication, installation, and commissioning - Manage vendors throughout the equipment lifecycle—from specification, RFQ, and technical bid evaluation through drawing review and approval, fabrication expediting and inspection (ITP/FAT), delivery, installation and commissioning support, and warranty close-out - Develop site-wide and area-level plant layouts, optimizing equipment arrangement, maintainability access, constructability, safety, and integration with other disciplines - Prepare mechanical equipment specifications, data sheets, and requisition packages for a range of process and solids-handling equipment, and support technical bid evaluations and vendor selection - Perform static equipment design of tanks, silos, bins, pressure vessels, and other stationary equipment, including mechanical sizing, wall/shell thickness, and structural load calculations ensuring code compliance - Conduct finite element analysis (FEA) to validate equipment and component designs for stress, fatigue, thermal, and operational loading conditions - Design, evaluate, and integrate solids-handling and material-conveyance systems, including silos, bins, hoppers, feeders, conveyors, bucket elevators, chutes, and dust-control systems - Support development of 3D models and piping/mechanical interface layouts, ensuring alignment with process, structural, civil, and electrical engineering requirements - Review vendor drawings and calculations, ensuring mechanical design compliance with project requirements, codes, standards, and operability/maintainability expectations - Collaborate with multidisciplinary EPC teams—including process, structural, piping, electrical, instrumentation, and construction management—to deliver cohesive and constructible engineering packages - Provide mechanical engineering support during construction and commissioning, including responding to RFIs, reviewing field changes, and assisting with equipment installation and start-up # **What You’ll Bring** - Bachelor’s degree in Mechanical Engineering or a related engineering discipline - Strong understanding of engineering fundamentals and demonstrated ability to leverage that understanding to solve challenging problems - Experience preparing and reviewing mechanical equipment specifications, vendor documentation, and engineering deliverables for both brownfield modifications and greenfield facilities - Demonstrated ability to complete static equipment design of tanks, silos, bins, vessels, and other stationary equipment, including code-based mechanical and structural calculations - FEA capabilities—proficiency with finite element analysis tools to validate equipment and component designs for stress, fatigue, and thermal/operational loading - Working knowledge of relevant industry standards and codes, such as ASME and API - Ability to work effectively with cross-functional teams, manage competing priorities, and deliver high-quality engineering packages under schedule constraints - Proficiency in mechanical design software such as AutoCAD # **Preferred** - Hands-on experience with solids-handling and conveyance equipment, including: Silos, bins, hoppers, chutes, and bulk storage systems | Feeders (vibratory, belt, screw, rotary, apron) | Conveyor systems (belt, screw, drag/chain, pneumatic, bucket elevators) | Screens, crushers, and material-transfer equipment - Experience with pyrometallurgical processes and equipment, such as rotary kilns, electric arc furnaces, converters, dryers, and flash kilns - Familiarity with industrial and process-industry environments, such as: Mining and mineral processing | Cement, aggregate, or bulk-materials handling | Chemical or industrial manufacturing facilities | Power generation or heavy industrial sectors - Experience with fluids, thermal, and Multiphysics CFD simulations ## **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!** ## Skills - Storage Systems - Equipment Installation - Material Handling - Construction - Structural Calculations - Inspection - 3D Modeling - Load Calculations - Request for Quotation (Rfq) - Vendor Selection - Brownfield Development - Mechanical Design - Inspection and Test Plan (Itp) - Fatigue (Material) - Pipe (Fluid Conveyance) - Constructability - Expediting - Quality Engineering - Power Generation - Equipment Design - Detailed Design - Commissioning - Computational Fluid Dynamics (Cfd) - Mechanical Equipment Maintenance - Kilns - Finite Element Analysis (Fea) - AutoCAD - ASME Standards - Request for Information (Rfi) - Procurement - Software Maintainability - Pneumatics - Simulations - Dust Control - Fabrication - TANKS - Drawing - Construction Management - Electrical Engineering - Pressure Vessel - Shell Script - Bid Evaluation ## Related - [Engineering jobs](https://www.foundrole.com/careers/engineering?utm_source=ai_markdown)- [Mechanical & Related Engineering jobs](https://www.foundrole.com/careers/engineering/mechanical-and-related-engineering?utm_source=ai_markdown)- [Mechanical Engineer jobs](https://www.foundrole.com/careers/engineering/mechanical-and-related-engineering/mechanical-engineer?utm_source=ai_markdown)- [Browse all companies](https://www.foundrole.com/companies?utm_source=ai_markdown) ## Explore this job market - 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