3.1. Principal Chemical Process Engineer-Separation
Phoenix Tailings
Other Engineering
Burlington, MA, USA
USD 150k-180k / year + Equity
Posted on Nov 1, 2025
About Phoenix Tailings
Phoenix Tailings is a rapidly growing clean mining and metals production startup dedicated to sustainable and economic critical metals production. Our mission is to be the world's first fully clean mining and metals production company, producing the resources needed for the next generation of our economy.
Why Phoenix Tailings
At Phoenix, we believe that nothing great is ever accomplished alone or without the passion of people who push and motivate one another. If you are someone who shares our relentless pursuit of a better future, passion for innovation, and are excited about working with some of the top innovators in the world, then this is the place for you.
Our Values
● You are only crazy if you are wrong, it’s ok to be wrong
● Lead with Compassion
● Be Resourceful
● Listen
● Hustle
Who We Are Looking For
Phoenix Tailings is looking for a Principal Chemical Process Engineer who brings deep technical expertise in solvent extraction, especially as applied to the separation of rare earth elements. This role is pivotal in advancing our mission to build the foundational infrastructure for a clean, domestic supply of critical materials. You will lead the design, development, optimization and scale-up of solvent extraction processes, directly shaping our technology and creating a greener, more resilient critical metals supply chain.
This pay range reflects the expected compensation for this role and may vary based on experience and qualifications.
Salary Range: $150,000/year- $180,000/year
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
At Phoenix Tailings, we have an open culture that values learning, and we are looking to grow the team with enthusiastic individuals who share our vision of sustainable mining.
Phoenix Tailings, Inc. is an Equal Opportunity Employer, and we value diversity at all levels. All qualified candidates will receive consideration for employment without regard to race, color, religion, sex (including gender identity, sexual orientation, and pregnancy), national origin, age, disability or genetic information, or any other applicable protected characteristics, and these characteristics will not be a factor for consideration of any work-related decisions (including but not limited to hiring, firing, compensation, and discipline).
