R&D Metallurgist

San Francisco, CA

About the 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.

The Role

  • The R&D Metallurgist designs, executes, and analyzes experiments to advance Mariana Minerals' hydrometallurgical testing programs. This hands-on laboratory and pilot-scale role focuses on running DOE protocols, operating tank reactors and mining systems, and analyzing data to optimize extraction for critical minerals.

What You'll Do

  • Develop Design of Experiments (DOE) protocols for chemical processing, extraction, and purification

  • Analyze metallurgical and process data to identify trends, root causes, and optimization opportunities

  • Operate tank reactors, filtration systems, separation equipment, and purification units at bench and pilot scale

  • Prepare chemical solutions and reagents according to experimental specifications

  • Monitor and control process parameters: temperature, pH, flow rates, residence time, and reagent dosing

  • Perform systematic sampling and material handling throughout process streams

  • Collect experimental data including process parameters, weights, volumes, and analytical results

  • Analyze data using Excel and statistical tools to evaluate performance and identify optimization opportunities

  • Generate clear data visualizations, charts, and summary reports

  • Maintain detailed laboratory notebooks and digital documentation

  • Support DOE planning and multi-variable optimization studies

  • Perform routine maintenance, calibration, and troubleshooting of processing equipment

  • Follow all chemical handling, PPE, and MSHA/OSHA safety protocols

  • Maintain clean, organized, and safe laboratory environments

  • Conduct hazard assessments for chemical processes and experimental setups

Desired Qualifications

  • Bachelor's degree in Chemistry, Chemical Engineering, Metallurgy, or related technical field preferred

  • 5+ years' experience in chemical processing, hydrometallurgy, or laboratory/pilot plant operations

  • Experience with Design of Experiments (DOE) methodology and statistical analysis highly desirable

  • Hands-on experience with chemical reactors, filtration, and separation equipment

  • Advanced Excel proficiency (pivot tables, statistical functions, data visualization)

  • Understanding of chemical process fundamentals (mass balance, stoichiometry, reaction kinetics)

  • Knowledge of purification techniques (precipitation, solvent extraction, ion exchange, crystallization)

  • Ability to read P&IDs and process flow diagrams

  • Experience with DOE software (JMP, Minitab, Design-Expert) is a plus

  • Exceptional attention to detail and data integrity

  • Strong analytical and problem-solving skills

  • Excellent communication and documentation abilities

  • Self-motivated with ability to manage multiple experiments

  • Unwavering commitment to safety and quality

  • Valid driver's license required

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!

About Mariana Minerals

Mariana Minerals is a software-first, vertically integrated minerals company focused on supplying the minerals critical to modern energy, AI, and defense technologies. It engineers, builds, and operates mines and refineries using its proprietary MarianaOS platform, which integrates capital project execution, refinery operations, and mine management into a single AI and machine learning stack. The company targets domestic U.S. critical mineral supply for sectors facing supply chain vulnerabilities, including copper and lithium.

Other roles at Mariana Minerals

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Job details

Location

San Francisco, CA

Company

NameMariana Minerals
IndustryArtificial Intelligence (AI)
Team Size3

Funding

Total raised

$400M

Last stage

Series A

Investors

a16z

Founders

TC

Turner Caldwell

CEO & Co-Founder

LinkedIn
JL

Juan Lozano

Co-Founder & CTO

BT

Baker Tilney

Co-Founder & CFO

LinkedIn

What happens next.

No applications, no recruiter spam. Just the intro.

01

Confirm the fit

A few questions to make sure this role is the right shape for you. Two minutes.

02

I pitch you to the company

I write the intro, send it to the founder, and handle the back-and-forth.

03

A meeting lands on your calendar

If they’re a yes, I book the chat. You show up — that’s the whole job-hunt.