Sr./Staff Process Engineer - Detailed Engineering and Plant Design

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.

We are hiring a Senior / Staff Process Engineer to execute detailed engineering deliverables such as P&IDs, line and instrument and valve lists, control narratives, hydraulic models, equipment and bulk specifications, and the procurement packages behind them. Mariana executes process engineering in-house, you will produce these deliverables yourself, own their technical content and revision history, and carry them through procurement, construction, and commissioning.

Own the process design basis for your assigned areas. Design cases and margins, turndown, utility and reagent demands, and the first principles and assumptions basis behind them

Develop PFDs, heat and material balances, and P&IDs. Manage the metadata behind smart drafting and modeling software such as Plant 3D

Develop P&IDs from concept through IFC. Including, but not limited to, equipment, instrumentation and control loops, isolation and relief philosophy, drains and vents, sample and utility stations, sloping and tracing notes, and tie-ins

Manage and develop automated workflows for the process data behind the line, instrument, and valve lists. E.g. line numbers and sizes, service conditions, design and test pressures and temperatures, pipe class selection, insulation and heat tracing, and instrument process data

Build and maintain the hydraulic models. Line sizing and pressure drop, pump and blower curves and duty points, NPSH margin, control valve and orifice sizing, slurry and two-phase lines, and gravity, launder, and vent flow. Evaluate automation opportunities to link this to heat and material balances and Plant 3D datamanger