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 a highly motivated Mechanical Engineering Manager / Lead to work on building the critical minerals supply chain to support the world’s energy transition.

In this role, you will lead the mechanical engineering function across pilot and commercial-scale refining projects. You will be responsible for technical direction, team leadership, and successful delivery of mechanical scopes from early concept through commissioning and handover to operations.

You will oversee development of first-of-its-kind chemical refining systems, guide mechanical design standards, mentor engineers, and ensure engineering rigor across solids-handling and process systems. This role combines deep technical expertise with organizational leadership and cross-functional coordination to deliver modular and site-built processing facilities safely, efficiently, and on schedule.

What You’ll Do

Technical Leadership & Strategy

• Own the mechanical engineering strategy across pilot and modular commercial refining plants

• Establish and maintain mechanical engineering standards, best practices, and design guidelines

• Provide senior technical oversight on solids-handling, process mechanical systems, and plant layout

• Drive technical decision-making on equipment selection, system architecture, and risk mitigation

• Lead design reviews, HAZOP participation, constructability reviews, and value engineering efforts

Project & Scope Ownership

• Lead mechanical scopes across project phases—from concept and feasibility through detailed design, procurement, fabrication, installation, commissioning, and ramp-up

• Ensure alignment of mechanical deliverables with cost, schedule, operability, and safety requirements

• Oversee preparation and review of equipment specifications, data sheets, requisitions, and bid evaluations

• Serve as the primary mechanical interface with EPC partners and vendors

• Manage technical risk registers and resolve complex cross-disciplinary design challenges

Team Leadership & Development

• Build, mentor, and manage a high-performing mechanical engineering team

• Provide coaching and technical guidance to engineers across experience levels

• Establish workload planning, resource allocation, and performance expectations

• Foster a culture of engineering excellence, accountability, and continuous improvement

Cross-Functional & Operational Integration

• Collaborate closely with process, structural, piping, electrical, controls, and construction teams

• Support development of 3D models and plant layouts, ensuring constructability and maintainability

• Provide executive-ready technical summaries and recommendations to leadership

• Partner with operations to ensure smooth commissioning, ramp-up, and long-term reliability

Construction & Commissioning Support

• Oversee field engineering support during construction and startup

• Guide resolution of RFIs, field changes, and vendor technical issues

• Ensure successful mechanical system commissioning and handover to operations

Desired Qualifications

Technical Expertise

• Deep understanding of mechanical engineering fundamentals and their application in industrial process environments

• Extensive experience with solids-handling and material-conveyance systems, 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

• Strong experience preparing and reviewing mechanical specifications and vendor documentation for both greenfield and brownfield projects

• Familiarity with relevant codes and standards such as CEMA, ASME, API, and material-handling design practices

• Experience in mining & mineral processing, cement/aggregate, chemical manufacturing, power generation, or other heavy industrial sectors

Leadership & Delivery

• Demonstrated experience leading engineering teams or managing technical groups

• Proven ability to manage competing priorities across multiple concurrent projects

• Experience interfacing with EPC firms and managing vendor relationships

• Strong decision-making capability in ambiguous, fast-moving environments

• Ability to balance hands-on technical depth with strategic oversight

Tools & Analytical Skills

• Proficiency in mechanical design software such as AutoCAD (experience with 3D modeling platforms preferred)

• Experience with first-principles modeling and equipment sizing

• Familiarity with fluids, thermal, and multiphysics CFD simulations is a plus

Why 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.