4.3. Principal Process Engineer-Recycling

Energy Vault; Burlington (VT); On-site; USD 100,000 - 130,000; Full time

Job summary

A leading clean mining and metals production startup seeks a Principal Process Engineer – Recycling to lead the design of zero-waste systems. This role focuses on architecting closed-loop processes and contributes to sustainable metallurgy, driven by innovation. Great opportunity for those passionate about sustainable technologies.

Benefits

100% Medical, dental, and vision coverage

Ownership in a fast-growing venture-backed company

Parental leave and flexibility for families

Flexible vacation policy

Regular team events and celebrations

Learning and development opportunities

Fun, hard-working, and kind team

Results-focused culture

Qualifications

• 8+ years of experience in process development or chemical engineering.
• Expertise in hydrometallurgical techniques, especially solvent extraction.
• Demonstrated leadership in technical innovation.

Responsibilities

• Lead design and scaling of recycling systems.
• Optimize closed-loop circuits for solvents and reagents.
• Conduct system-level material and energy balances.

Skills

Process Development

Chemical Recovery

Recycling Expertise

Systems Thinking

Leadership

Education

B.S. in Chemical Engineering

M.S. in Chemical Engineering

Ph.D. in Chemical Engineering

Tools

Aspen Plus

HSC Chemistry

MATLAB

Job description

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:

Who We Are Looking For:

Phoenix Tailings is seeking a visionary and hands-on Principal Process Engineer – Recycling to lead the charge in designing and implementing our zero-waste, zero-emissions recycling systems. This role is central to achieving our mission of full circularity in critical metal production. You’ll architect closed-loop recovery processes that reclaim solvents, reagents, and materials across multiple refining technologies—from solvent extraction to metallization. Your work will define how modern, sustainable metallurgy operates, and you’ll play a key role in establishing Phoenix Tailings as a global leader in clean metals innovation.

Key Responsibilities

• Lead the design, development, and scaling of internal recycling systems across our entire process.
• Build and optimize closed-loop circuits that recover solvents, extractants, and reagents with high efficiency and minimal loss.
• Architect integrated recycling solutions for systems including solvent extraction and rare earth metallization.
• Conduct system-level material and energy balances to model recycling pathways and their impact on plant-wide operations.
• Evaluate and select advanced separation, purification, and recovery technologies tailored for Phoenix’s unique chemistries.
• Design and execute pilot and bench-scale experiments to validate recovery strategies before full-scale implementation.
• Work cross-functionally with R&D, engineering, and operations teams to embed recycling into every process layer.
• Establish KPIs and monitoring systems to track recycling efficiency and environmental impact over time.
• Set technical direction and mentor junior engineers in sustainable process and systems design.

Qualifications:

• B.S., M.S., or Ph.D. in Chemical Engineering, Materials Science, or related field.
• 8+ years of experience in process development or chemical engineering, with deep expertise in recycling, purification, or chemical recovery systems.
• Proven success in scaling and implementing closed-loop processes within a high-throughput or industrial setting.
• Strong foundation in hydrometallurgical techniques, especially solvent extraction, ion exchange, and electrochemical systems.
• Expertise in process modeling and simulation (e.g., Aspen Plus, HSC Chemistry, MATLAB).
• Exceptional systems thinking and the ability to translate sustainability goals into engineered solutions.
• Demonstrated leadership in technical innovation and ability to drive multidisciplinary projects from concept through execution.
• Passion for building a future rooted in clean, sustainable technologies.

We offer a competitive compensation package that is based on expertise. We also offer the following benefits:

• Healthcare, we care about you and your family:100% Medical, dental, and vision coverage
• Stock:Ownership in a fast-growing venture-backed company.
• Family Focus:Parental leave and flexibility for families.
• Time Off:Flexible vacation policy to encourage people to get out and see the world.
• Team Fun:Regularly scheduled events, and celebrations.
• Learning:Learning and development Opportunities to grow your skills and career.
• Great team:Working with fun, hard-working, kind people committed to making a difference!
• Flexible culture:We are results-focused. We don’t work at the office every day.

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).