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 seeking a highly motivated Staff Mechanical Engineer to support our next-generation minerals processing pilot plant in Houston. You will lead the design, integration, and deployment of pilot-scale mechanical systems and processing equipment used to demonstrate and scale innovative refining technologies for critical minerals. This role is highly hands-on and will play a key role in building and maintaining a first-of-its-kind pilot plant. You will work closely with process engineers, technicians, and cross-functional teams to design, install, commission, and improve pilot-scale equipment while ensuring systems are reliable, safe, and scalable to commercial production.
What You’ll Do
Design, specify, and deploy mechanical systems and equipment for pilot-scale mineral processing operations
Work closely with process engineers to translate process requirements into practical mechanical and plant designs
Support installation, troubleshooting, and maintenance of pilot plant equipment including pumps, piping systems, reactors, separators, filtration systems, and material handling equipment
Develop and maintain mechanical design documentation including equipment specifications, layout drawings, piping schematics, and CAD models
Identify opportunities to improve equipment reliability, maintainability, and operational performance
Coordinate with vendors, fabricators, and contractors during equipment procurement and installation
Support safe plant operations by contributing to hazard reviews, equipment safety design, and mechanical integrity programs
Desired Qualifications
B.S., M.S., or PhD in Mechanical Engineering or a related field
9+ years of experience in operations, process scale-up, or plant design in minerals processing, chemicals, specialty materials, oil & gas, or related industries
Demonstrated experience driving equipment design, commissioning, operations, and reliability
Experience designing and maintaining furnaces, pumps and fluid handling systems, pressure vessels and reactors, piping systems and valves, filtration and separation equipment, and materials handling systems
Ability to work closely with cross-functional teams including process engineering, operations, and project execution
Strong troubleshooting and problem-solving skills in hands-on plant environments
Strong commitment to Health, Safety, and Environmental compliance and mechanical integrity standards
Excellent technical writing, communication, and teamwork skills
Comfortable working in fast-paced environments, wearing multiple hats, and managing ambiguity
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.