Mariana Minerals
Manufacturing & IndustrialDirect Ashby career site

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

Location
Houston, TX · On-site
Job type
Full-time
Level
Lead / Staff
Experience
8+ years
Education
Bachelor's degree
Listed
23 days ago

Skills & highlights for this role

  • P&ID development
  • hydraulic modeling
  • process equipment sizing
  • HAZOP

Also useful

  • SmartPlant P&ID
  • AVEVA P&ID
  • Plant 3D
  • lithium extraction
  • copper solvent extraction

The Role

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.

What You’ll Do

  • 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
  • Size and specify process equipment such as pumps, control valves, relief devices, heat exchangers, tanks and agitators, filters, thickeners, mixer-settlers, crystallizers, and solid-liquid separation
  • Write the control narratives and functional descriptions with support from the controls engineering team
  • Represent process in PHAs and HAZOP.
  • Coordinate across detailed engineering disciplines. Such as equipment lists and loads to mechanical, motor and instrument lists to electrical and controls, and layout, access, and maintenance clearances with piping and civil-structural
  • Support construction and commissioning. RFI and field change resolution, P&ID walkdowns and field verification, loop checks and functional testing, water and first-feed startup, and as-built closeout

Desired Qualifications

  • 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 on at least one greenfield or major brownfield project
  • BS in Chemical, Metallurgical, or Process Engineering. PE preferred

Preferred, but not required

  • Lithium - direct lithium extraction, spodumene leaching, crystallization, and battery-grade product specifications
  • Copper - heap and tank leaching, solvent extraction and electrowinning, tankhouse and electrolyte circuits
  • Slurry and solids handling - thickeners, filters, pulp and tailings piping, and settling and erosion design
  • Data-centric P&ID platforms - SmartPlant P&ID, AVEVA P&ID, or Plant 3D P&ID - where the drawing is a database, not a picture

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.

Our Culture Is Built on Four Principles

Everyone Gets Home Safe. We never put speed or cost ahead of people.

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!

Read the original posting

From Mariana Minerals's careers page, first listed on Rolev.ai on October 17, 2026. Rolev.ai is not the employer.

How Rolev.ai helps with this application

Rolev.ai is a job search and application tool for US job seekers. For this Sr./Staff Process Engineer - Detailed Engineering and Plant Design role at Mariana Minerals, it shows how your resume fits, tailors your resume to the posting, and prepares the application for you to review.

  • See how you fit

    Openings from employer career sites are ranked against your whole resume—and searchable inside Claude, ChatGPT, and Cursor via Rolev.ai MCP.

  • Tailor without inventing

    Every change to your resume is checked against your original. New experience goes in only with your yes—zero fabricated claims.

  • Draft the full kit

    Tailored and Full Match resumes, role-specific cover letters, and answers to employer screening questions are prepared in seconds.

  • 1-Click Extension Autofill

    The Chrome extension fills the employer's Greenhouse, Workday, Lever, or Ashby form in 1 click. You review it and press Submit.

Common questions

Where is the Sr./Staff Process Engineer - Detailed Engineering and Plant Design job at Mariana Minerals located?

This Sr./Staff Process Engineer - Detailed Engineering and Plant Design position at Mariana Minerals is located in Houston, TX (On-site). Always check Mariana Minerals's application page for specific state eligibility or relocation policies.

What qualifications are required for Sr./Staff Process Engineer - Detailed Engineering and Plant Design at Mariana Minerals?

For the Sr./Staff Process Engineer - Detailed Engineering and Plant Design role, Mariana Minerals highlights 8+ years of relevant experience; a bachelor's degree; experience with P&ID development, hydraulic modeling, process equipment sizing, HAZOP. Rolev.ai can score your existing resume against these requirements and show any skill gaps before you apply.

How do I apply for the Sr./Staff Process Engineer - Detailed Engineering and Plant Design position at Mariana Minerals?

This listing links directly to Mariana Minerals's Ashby application page. You can apply directly on Mariana Minerals's site, or use Rolev.ai to check your resume fit, generate a zero-hallucination tailored resume and cover letter for this posting, and autofill the Ashby application form in 1 click with the Rolev.ai Chrome extension. You always review the form and press Submit yourself.