Mariana Minerals

Process Modeling Engineer

Mariana Minerals · San Francisco, CA
San Francisco, CA was $100K–$160K Closed
Applications are closed for this role. It was originally posted 2026-07-24. It’s no longer accepting applicants — see roles Mariana Minerals is still hiring for →, or browse the live openings below.
Salary
$100K–$160K
Type
Full-time

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 Process Modeling Engineer to support the development of next-generation refining processes for critical minerals — key to enabling the world’s energy transition.

In this role, you will be responsible for developing, validating, and optimizing heat and material balance models using tools such as ASPEN Plus/HYSYS, SysCAD, OLI Studio, or METSIM. You will work closely with R&D, pilot operations, and project execution teams to translate lab and pilot data into robust, scalable process models that drive the design of first-of-a-kind mineral refining facilities.

WHAT YOU’LL DO

  • Develop steady-state and dynamic process models to establish heat and material balances for integrated mineral refinery systems using ASPEN, SysCAD, OLI, or METSIM.
  • Automate equipment and process sizing (reactors, heat exchangers, filters, crystallizers, evaporators, and separators) based on model outputs, linking models to datasheets and other engineering tools
  • Develop and maintain process simulation databases, ensuring consistency and traceability between modeling assumptions, test data, and engineering deliverables.
  • Calibrate and reconcile models using pilot or plant operating data to ensure model fidelity and predictive accuracy.
  • Conduct process optimization studies — evaluating energy/heat recovery, recycle strategies, and material efficiency improvements.
  • Develop dynamic process models to validate PLC and DCS programming and evaluate/optimize buffer sizing throughout the design.
  • Link process models to CAPEX and OPEX estimation tools, automating technoeconomic model development
  • Document modeling methodologies and results, providing clear technical communication for design reviews, techno-economic assessments, and regulatory submissions.

WHAT YOU’LL BRING

  • Bachelor's degree or higher in Chemical Engineering, Mechanical Engineering, Process Engineering, Metallurgical Engineering, or a closely related engineering discipline
  • Proficiency in one or more of the following process simulation tools:
  • ASPEN Plus / HYSYS
  • SysCAD
  • OLI Studio / OLI Flowsheet
  • METSIM
  • Deep understanding of mass transfer, heat transfer, thermodynamics, fluid flow, and reaction engineering.
  • Experience developing material and energy balances for multi-step, integrated process systems.
  • Strong grasp of chemical equilibria and phase behavior in aqueous and non-aqueous systems.
  • Familiarity with data reconciliation, parameter fitting, and model validation using experimental or operational data.
  • Competency with Python or MATLAB for model automation, data processing, and custom calculations is a strong plus.
  • Experience integrating process modeling outputs into EPC deliverables (PFDs, P&IDs, equipment datasheets, control narratives, etc.)

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.

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