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.

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. We are moving from pilot to commercial scale, and we are hiring a Process Engineer to own the two highest-leverage unit operations in our refinery.

The Role: Process Engineer — Reactor and Separations

You will own the engineering scale-up of our primary high-temperature reactor and the downstream separations train that recovers gallium, germanium, and silicon as separate product streams. The reactor runs hot and in corrosive gas service; the separations train is where the product slate is actually made. Both have to scale from our current multi-kilogram pilot to a 100 ton-per-day facility in Montana over the next two and a half years.

This is not a desk role. You will be in the pilot bay running campaigns, in the design tools sizing equipment, on calls with vendors specifying alloys and internals, and on site for commissioning.

What You Will Own

• Reactor scale-up. Take our current single-zone pilot reactor to a multi-zone commercial system. Own residence time, gas-solid contacting, freeboard, refractory and alloy selection, and heat integration. Specify and procure the long-lead reactor itself.

• Separations train. Design and commission the downstream train that splits a mixed product vapor into discrete gallium, germanium, and silicon streams. Own the thermal profile, vessel internals, materials of construction, sequencing logic, and the close-cut separations that determine final product purity.

• Gas management. Own the hot corrosive gas stream end to end: reactor offtake, transport lines between unit operations, pressure balance, vent and scrub systems, and the recycle loop that closes the reagent balance at commercial scale.

• Mass and energy balances, P&IDs, and equipment specs across the full refinery. Support AACE Class 3 cost estimation as we move into the commercial design phase.

• Bench and pilot experiments to close the engineering uncertainties that block scale-up — separation efficiency at each stage, fouling and plugging, alloy and refractory compatibility at temperature, dust carryover.

• Safety systems for reactive-gas service, in line with OSHA PSM, NFPA, EPA RMP, and Chlorine Institute pamphlets — interlocks, ventilation, scrubbing, leak detection, emergency response.

• Standard operating procedures and commissioning protocols for the commercial facility, translated directly from pilot campaign learnings.

Who You Are

• 5+ years of process engineering experience in pyrometallurgy, extractive metallurgy, or reactive-gas chemical processing

• Hands-on work on unconventional feedstocks (coal ash, slag, tailings, ores, or similar).

• Direct experience designing, scaling, or operating high-temperature reactors and condensation or distillation trains in corrosive gas service (e.g., titanium industry).

• Demonstrated track record taking a process from bench through pilot toward commercial scale: reactor sizing, materials selection for halogen environments (nickel alloys, refractory linings, quartz/borosilicate), equipment specification, and vendor management.

• Working knowledge of the reactive-gas safety code stack: OSHA PSM, NFPA 55, EPA RMP, Chlorine Institute.

• Strong process modeling: mass/energy balances, gas-solid kinetics, condensation and distillation thermodynamics. Aspen Plus, HSC, FactSage, or equivalent.

• Hands-on with analytical methods (ICP-OES/MS, XRD, SEM) for tracking recovery, purity, and impurity partitioning across the process.

• Direct communicator. You write clearly, push back when something is wrong, and do not hide behind hedges or buzzwords.

• Excited to be on-site at our pilot and at the commercial facility, in person with the team.

• Familiarity with coal ash, slag, or tailings valorization, or with SCM/ASTM C618, is a plus.

What We Offer

• Ownership of two of the most consequential unit operations in the domestic critical minerals supply chain.

• A fast-paced, mission-driven team where your design decisions get built and run, not filed.

• Competitive cash and meaningful equity.

• A path to a senior technical leadership 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.