# R&D Metallurgist - Company: [Marianaminerals]() - Location: San Francisco HQ - Team: Process Development - Employment type: Full Time - Salary: $110K – $140K - Posted: September 10, 2026 ## Job description # **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!** ## Apply [Apply on Marianaminerals]() Canonical job page: