Metallurgical Engineer at PHNX Materials in San Leandro, CA

Metallurgical Engineer

Note: We can only hire U.S. nationals due to obligations around our funding.

About PHNX Materials:

China controls 98% of the world's gallium, 92% of germanium, and 93% of silicon. In 2024, China weaponized export restrictions on gallium and germanium, putting the vulnerability on full display. Each of these metals is a byproduct of heavy industry that no longer exists in the United States. We cannot reshore the supply chain because the underlying industries are gone.

PHNX is the Department of Energy's and Department of War's answer to closing that gap. We are a "solids refinery" turning industrial waste, primarily coal ash and zinc slag, into three product streams: critical metals for semiconductors and defense, cement replacement material for construction, and fertilizer for agriculture.

Our platform delivers a triple win: securing domestic critical mineral supply chains, helping power producers retire coal ash liabilities, and giving concrete producers a cheaper, lower-carbon alternative to cement. We support coal communities and remediate groundwater. PHNX was founded by Stanford, Tesla, and national lab alumni, backed by Trust Ventures, Overture, and KdT, and sponsored by the U.S. Department of War and the U.S. Department of Energy.

The role

PHNX Materials is seeking a Metallurgical Engineer to develop and scale metal extraction processes in a hands-on pilot plant environment. You will work closely with our R&D and process engineering teams to design flowsheets, run experimental campaigns, and solve real-world metallurgical problems across hydrometallurgical and pyrometallurgical unit operations.

This is an engineering role with real ownership: you will help take processes from bench results to pilot operation and contribute to scale-up recommendations. The role reports to the CTO and works closely with R&D, EH&S, vendors, and national lab partners.

Responsibilities

• Pilot Plant Operations: Plan and execute bench- and pilot-scale campaigns, evaluate equipment performance, and guide operating strategies for hydrometallurgical and pyrometallurgical circuits.

• Process Design: Develop and evaluate flowsheets for metal extraction and separation, including equipment selection, operating conditions, and materials of construction for high-temperature and corrosive service.

• Process Optimization: Design experiments to improve recovery, selectivity, product purity, and reagent efficiency for critical metals from industrial byproduct feedstocks.

• Data Analysis: Analyze experimental and operating data, develop mass and energy balances, and translate findings into process improvements and scale-up recommendations.

• Metallurgical Characterization: Interpret analytical results from techniques such as ICP, XRD, and XRF to understand feedstock variability, metal distribution, and process performance.

• Equipment and Vendors: Support equipment specifications, RFQs, and vendor evaluation, and assist with installation and commissioning of pilot equipment.

• Troubleshooting: Investigate process bottlenecks and inconsistent performance, identify root causes, and implement practical engineering solutions.

• Safety First: Incorporate safe operating practices into process design and experimental planning, contribute to hazard assessments, and develop and follow Standard Operating Procedures (SOPs).

• Reporting: Contribute engineering content to technical reports and milestone updates for government-funded programs

Required qualifications

• Education: B.S. or M.S. in Metallurgical Engineering, Chemical Engineering, Materials Science, Mineral Processing, Geochemistry, or a related field.

• Technical Knowledge: Strong understanding of hydrometallurgical principles, including leaching, solvent extraction, and precipitation, along with mineral processing fundamentals. Pyrometallurgical experience a plus.

• Hands-On Engineering: Ability to translate engineering concepts into practical experimental setups and operating improvements in a pilot plant or industrial environment.

• Data Driven: Proficiency in Excel for engineering analysis and mass balance calculations; experience with design of experiments (DoE) or process modeling software (e.g., Aspen, FactSage, HSC Chemistry) is a plus.

• Ownership and Communication: Ability to independently plan work, communicate technical findings, and collaborate across disciplines in a fast-moving startup where priorities evolve.

Preferred qualifications

• Pyrometallurgy: Exposure to high-temperature processing such as roasting, calcination, or volatilization and product recovery, through coursework, research, or industry.

• Critical Minerals: Experience developing or scaling processes for critical minerals, industrial byproducts, or unconventional feedstocks.

• Analytical Techniques: Experience using ICP, XRF, XRD, or SEM data to inform process development.

• Scale-Up: Experience with equipment sizing, vendor interaction, techno-economic analysis, or pilot plant commissioning.

• Safety: Familiarity with hazard assessments, SOPs, and safe handling of hot, corrosive, or toxic materials.

• Background: Previous industry, research, or internship experience in mining, metals recovery, chemical processing, or semiconductor manufacturing.

Location

This is a full-time, on-site role at our lab in San Leandro, CA. Bench and pilot work require regular presence in the lab.

What We Offer

• A fast-paced, mission-driven team where your work directly feeds decisions that flow to the commercial plant design.

• Competitive cash and meaningful equity.

• A path to a senior technical role as we scale from pilot to commercial production.

PHNX Materials is an Equal Opportunity/Affirmative Action employer. All qualified applicants will receive consideration for employment without regard to sex, gender identity, sexual orientation, race, color, religion, disability, protected Veteran status, age, or any other characteristic protected by applicable law.