3.1. Principal Chemical Process Engineer-Separation
Phoenix Tailings
Other Engineering
Burlington, MA, USA
USD 150k-180k / year + Equity
Posted on Apr 30, 2026
Key Responsibilities:
- Lead the development and optimization of solvent extraction circuits for rare earth element separation from both primary and secondary sources
- Design and execute bench- and pilot-scale experiments to evaluate separation efficiency, reagent performance, and system dynamics
- Translate laboratory-scale successes into scalable, industrial processes with a focus on safety, sustainability, and cost-effectiveness
- Own and evolve process flow diagrams (PFDs), mass balances, and P&IDs for solvent extraction systems
- Drive selection and specification of extractants, diluents, and equipment (e.g., mixer-settlers, columns, or centrifugal contactors)
- Analyze separation performance data to identify improvement opportunities and implement process changes
- Collaborate closely with metallurgy, chemical engineering, and operations teams to support plant commissioning and troubleshooting
- Author technical reports, scale-up plans, and design documentation to support commercialization of Phoenix Tailings’ extraction technologies
- Stay at the forefront of solvent extraction technologies and rare earth processing trends to inform and elevate process strategy
Qualifications:
- Ph.D. or M.S. in Chemical Engineering, Metallurgical Engineering, or related discipline with 8+ years of relevant experience
- Proven expertise in rare earth element/critical metals separation via solvent extraction, including reagent chemistry, process configuration, and optimization
- Hands-on experience with lab-scale and pilot-scale solvent extraction systems, including safety and operational best practices
- Deep understanding of phase equilibria, thermodynamics, and kinetics relevant to solvent extraction
- Demonstrated success in scaling up chemical separation processes from bench to pilot to commercial scale
- Proficiency with process modeling tools (e.g., Aspen, METSIM, or similar)
- Excellent problem-solving skills with a passion for experimental validation and continuous improvement
- Strong written and verbal communication skills, especially in cross-disciplinary environments
We offer a competitive compensation package that is based on expertise. We also offer the following benefits:
- Healthcare: 100% Medical, dental, and vision coverage for employee
- Stock Options: Ownership in a fast-growing venture-backed company.
- Time Off: Unlimited PTO.
- Learning: Learning and development opportunities to grow your skills and career.
This pay range reflects best estimate for the total cash compensation which includes salary + discretionary bonus for this role. Total package may vary based on experience and qualifications.
Pay Range: $150,000- $180,000 total cash compensation plus equity