Cement Development Engineer Jobs in Kent, WA (NOW HIRING)

Mafix transforms the world's most abundant rocks and minerals into the next generation of fertilizers. Our products help farmers maintain and improve crop yields while permanently removing CO₂ from the atmosphere through enhanced rock weathering, delivering a dual return that conventional agricultural products cannot.

We produce our mineral fertilizer using spare capacity in cement rotary kilns, making it cost-competitive without building new infrastructure. Applied to soil, it releases plant-available silicon and other nutrients that strengthen crops against climate stress, drought, and pests, while sequestering carbon as the mineral dissolves.

With core chemistry published in Nature, our pre‑seed funding secured, and key partnerships in place, we are scaling fast: moving from pilot production to a 1,000‑tonne commercial run in 2027. We are looking for team members excited to unlock the power of abundant rocks towards a climate positive and food abundant future!

We are looking for an experienced, enthusiastic Scientist who is passionate about creating products that deliver agronomic and environmental returns. This R&D Scientist will work closely with the Head of Technology to advance Mafix’s first‑generation product and set the course for the company’s technology development. They will independently design and execute experimental campaigns utilizing techniques from chemistry, materials science, and agronomy as part of the technology development team.

This role will report to the Head of Technology and be full‑time onsite in Seattle, WA.

• Design, execute, and analyze laboratory experiments involving wet chemistry techniques and solid‑state chemistry.
• Design new experimental protocols based on literature procedures, including identifying and setting up the necessary equipment.
• Build out R&D capabilities including equipment commissioning, lab facility setup and others alongside the Head of Technology and other team members.
• Analyze and present results and implications from R&D experiments.
• Be a collaborative member of a growing R&D team.

• PhD (or equivalent Masters + Experience, or BS + Experience) in Chemistry, Geochemistry, Materials Science, or related scientific or engineering field.
• Experience designing and executing experiments in a laboratory setting
• Experience with analytical techniques such as XRF, XRD, ICP, SEM, PSA
• Experience executing literature searches and designing new experiments based on literature protocols
• Experience with hydrometallurgy and/or pyrometallurgy preferred
• Self‑motivated and able to work independently with strong attention to detail.

• Onsite in Seattle, WA
• Competitive salary
• Equity options

• Competitive benefits (including 401k, healthcare coverage)