Materials Engineer

marianaminerals· Process Development
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📍 San Francisco HQFullTime💰 USD 100K–140K

About this role

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 highly motivated Materials Engineer to join our R&D and product development team. The successful candidate will be responsible for designing, developing, and optimizing processes for novel material synthesis - from lab-scale proof-of-concept to pilot and commercial scale implementation. This position will play a critical role in translating laboratory discoveries into scalable, economically viable production processes.


What You’ll Do

  • Conduct lab-scale and pilot scale wet chemical synthetic experiments to validate proof-of-concept ideas and develop new material formulations.

  • Design and execute experiments to establish reaction parameters, yield optimization, and reproducibility.

  • Evaluate and select equipment and process configurations for pilot-scale and commercial-scale operations.

  • Develop process flow diagrams (PFDs), process and instrumentation diagrams (P&IDs), and mass/energy balances.

  • Collaborate with multidisciplinary teams including R&D scientists, operations, and external vendors to ensure smooth scale-up.

  • Support process safety reviews, risk assessments, and environmental compliance planning.

  • Collect and analyze process data to identify areas for optimization, cost reduction, and performance improvement.

  • Prepare technical documentation, reports, and presentations for internal and external stakeholders.

  • Work closely with cross-functional teams including lab technicians, pilot plant engineers, process engineers, project execution teams, and more to scale designs from lab through to commercial scale

  • Work closely with the software and machine learning teams to automate capital project execution workflows and develop reactor and plant optimization algorithms

     

What You’ll Bring

  • MS degree in Materials Science, Chemistry, Materials Engineering, or Chemical Engineering (PhD preferred).

  • Hands-on experience in materials synthesis (e.g., solid-state, hydrothermal, precipitation, or other chemical synthesis techniques).

  • Proficiency with materials characterization tools such as XRD, SEM, TEM, BET, TGA/DSC, and spectroscopic methods.

  • Experience with process design, equipment specification, and scale-up of laboratory processes to pilot or production scale.

  • Strong analytical and problem-solving skills with a data-driven approach.

  • Excellent communication and teamwork skills in a multidisciplinary environment.

  • Familiarity with process simulation tools (e.g., OLI systems or equivalent) is a plus.

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.

Frequently Asked Questions

What is the salary for the Materials Engineer role at marianaminerals?
The listed salary for this Materials Engineer position at marianaminerals is USD 100K–140K. This is an FullTime role.
Where is the Materials Engineer position at marianaminerals located?
This Materials Engineer role at marianaminerals is based in San Francisco HQ. The position is listed as on-site or hybrid. Check the full job description or apply directly to confirm the work arrangement.
Is the Materials Engineer role at marianaminerals full-time or part-time?
This is listed as a FullTime position. It is posted as a Materials Engineer role in the Process Development department at marianaminerals.
Which team or department does the Materials Engineer at marianaminerals belong to?
This Materials Engineer position is part of the Process Development department at marianaminerals. See the full job description for more information about the team structure and responsibilities.
How do I apply for the Materials Engineer position at marianaminerals?
Click the "Apply Now" button on this page. You will be redirected to marianaminerals's official application portal hosted on ashby where you can submit your application directly.
When was the Materials Engineer job at marianaminerals posted?
This Materials Engineer position at marianaminerals was posted on Aug 5, 2026. Apply as soon as possible — early applications are often reviewed first.
Materials Engineer
marianaminerals · 💰 USD 100K–140K
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You'll be redirected to marianaminerals's official application page on Ashby ATS.