Mechanical Engineer

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 seeking a Mechanical Engineer to join our team. The ideal candidate will lead the development and deployment of innovative chemical refining processes, support software for project execution and plant optimization, and design, build, and commission mineral processing and metallurgical refining equipment.

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
• 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
• Demonstrated ability to prepare and review mechanical equipment specifications, vendor documentation, and engineering deliverables for both brownfield modifications and greenfield facilities
• Experience completing 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

Why Join Us?

We are 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.

Company Culture

• 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.

Compensation Range

$140K - $175K