Über die Stelle
Ready to help produce circular concrete materials in our lab?
At everox, we are scaling from successful pilot projects into industrial operations. Our first commercial plant processes waste concrete into recycled aggregates, ultrafines and low-carbon supplementary cementitious materials (SCMs).
As we expand, we keep investing in innovation. In our lab in Rotterdam we crush, sieve, mill and carbonate waste concrete at lab scale to produce materials for R&D, product development and customer samples. For the coming two months, our lab team needs an extra pair of hands, and that is where this role comes in.
About the job
As Temporary Laboratory Technician, you support our lab and the wider lab team for approximately two months. You operate and maintain our lab equipment: a jaw crusher, sieving equipment, two ball mills and our carbonators. With them, you produce well-documented material batches for R&D, product development and customer samples.
You work closely with our Advanced Characterization Lab (ACL), Quality Control Lab (QCL) and R&D team. You turn process data into clear, actionable insights, and you step in wherever the lab needs an extra pair of hands, from sample preparation to housekeeping and inventory.
This role suits someone who enjoys operating equipment, is comfortable working with concrete and cementitious materials, and likes being the person who makes things happen in the lab, whether that's a milling campaign, a carbonation run or a quick data summary.
It is a full-time, temporary position of approximately two months, with a possible extension depending on business needs.
What you will do
Operate the jaw crusher, sieving equipment and two ball mills to produce aggregates, sand and fines to target particle size distributions.
Run carbonation experiments and campaigns in our carbonators: set-up, monitoring (temperature, pressure, CO₂ flow and uptake) and safe shutdown.
Plan and execute material production batches for R&D, product development and customer samples, including sample intake, labelling, splitting and chain-of-custody.
Log process parameters and build basic data analyses (mass balances, PSD curves, milling time and energy, CO₂ uptake), summarised in clear reports.
Take on general lab tasks as needed, such as sample preparation and testing support for the ACL and QCL, lab housekeeping, waste handling, receiving deliveries, inventory checks and ordering supplies.
Be a flexible member of the lab team: fill gaps, support colleagues and suggest improvements to workflows.
About you
We are looking for a hands-on, flexible person who is happy to roll up their sleeves in the lab. You are comfortable with heavy equipment and with data, you switch easily between tasks and priorities, and you keep safety and good documentation front of mind. Above all, you can start soon and give us your full attention for about two months.
An MBO-4, HBO or BSc degree (or in progress) in Process Technology, Chemical Engineering, Materials Science, Civil Engineering or a related field.
At least 1 year of hands-on experience in a lab, pilot plant or processing/production environment.
Comfortable operating mechanical equipment (crushers, mills, sieves) and working with pressurised gas systems, with basic mechanical troubleshooting skills.
Sufficient Excel skills to clean, analyse and visualise process data.
Organised, safety-conscious and flexible, and comfortable switching between tasks and priorities.
Able to start on short notice and commit full-time for approximately two months.
Nice-to-haves
Experience with XRD and XRF workflows, laser diffraction (LD) dispersion or R3 tests.
Familiarity with EN 933/1097 aggregate tests or with cement and SCM materials.
Experience in a start-up or pilot-plant environment.
What we offer
Monthly gross salary between €3,000 - €3,300 excluding holiday allowance.
A temporary contract for approximately two months, 40 hours per week, with a possible extension depending on business needs.
Holiday leave accrued pro rata, based on 27 days of annual holiday leave.
Hands-on experience at the forefront of concrete recycling and low-carbon construction materials, across our ACL, QCL and R&D teams.
An impactful position in a fast-growing, mission-driven scale-up.
The chance to help build a company that's redefining how the construction industry uses and values waste materials.
Why join us?
Join a diverse team committed to sustainability and making a real impact on CO₂ reduction. Even in a short assignment, you are a full member of our team: our flat hierarchy gives you ownership of your work, broad experience across our labs and the chance to contribute to building a sustainable future.
Interested?
Ready to get hands-on with circular concrete?
We'd love to hear from you. Even if you don't meet every requirement, please apply - your unique background could be exactly what we need.