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Mariana Minerals is a software-first, vertically integrated minerals company focused on supplying critical minerals for modern energy, AI, and defense technologies. The company reimagines the minerals supply chain by combining deep industry expertise with advanced software, automation, and data-driven decision-making.
As a Senior Process Engineer, you will execute detailed engineering deliverables including P&IDs, line and instrument valve lists, control narratives, hydraulic models, equipment specifications, and procurement packages. You will produce these deliverables in-house, own their technical content and revision history, and carry them through procurement, construction, and commissioning phases.
Key responsibilities include:
- Own the process design basis for assigned areas, including design cases, margins, turndown analysis, utility and reagent demands, and first-principles assumptions
- Develop PFDs, heat and material balances, and P&IDs using smart drafting and modeling software such as Plant 3D
- Develop comprehensive P&IDs from concept through IFC, including equipment, instrumentation, control loops, isolation and relief philosophy, drains, vents, sample and utility stations, sloping and tracing notes, and tie-ins
- Manage and develop automated workflows for process data behind line, instrument, and valve lists (line numbers, sizes, service conditions, design and test pressures/temperatures, pipe class selection, insulation, heat tracing, and instrument process data)
- Build and maintain hydraulic models, including line sizing, pressure drop analysis, pump and blower curves, NPSH margin, control valve and orifice sizing, slurry and two-phase line handling, and gravity/launder/vent flow evaluation
- Size and specify process equipment including pumps, control valves, relief devices, heat exchangers, tanks, agitators, filters, thickeners, mixer-settlers, crystallizers, and solid-liquid separation equipment
- Write control narratives and functional descriptions with support from controls engineering
- Represent process engineering in PHAs and HAZOPs
- Coordinate across detailed engineering disciplines (mechanical, electrical, controls, piping, civil-structural)
- Support construction and commissioning phases including RFI resolution, P&ID walkdowns, loop checks, functional testing, startup activities, and as-built closeout
Requirements:
- 8+ years of process engineering delivering detailed design for industrial process facilities in an EPC/EPCM, owner's engineer, or in-house capital projects environment
- Detailed-engineering cycle experience on at least one greenfield or major brownfield project
- BS in Chemical, Metallurgical, or Process Engineering (PE preferred)
Preferred qualifications (not required):
- Lithium processing experience (direct lithium extraction, spodumene leaching, crystallization, battery-grade specifications)
- Copper processing experience (heap and tank leaching, solvent extraction, electrowinning, tankhouse and electrolyte circuits)
- Slurry and solids handling expertise (thickeners, filters, pulp and tailings piping, settling and erosion design)
- Data-centric P&ID platform experience (SmartPlant P&ID, AVEVA P&ID, or Plant 3D P&ID where drawing functions as database)
