Job Description

Job Title :

Internship offer

R&D Engineer Intern

Calcined Clay

Business Unit and Location

Holcim Innovation Center, Saint-Quentin-Fallavier

Department

Cement

WHO IS HOLCIM?

Holcim is the leading partner for sustainable construction with net sales of CHF 15.7 billion in 2025, creating value across the built environment from infrastructure and industry to buildings. Headquartered in Zug, Switzerland, Holcim has more than 50 000 employees in 45 countries – across Europe, Latin America and Asia, Middle East & Africa – and has been recognized as a Global Top Employer by the Top Employers Institute. Holcim offers high-value end-to-end Building Materials and Building Solutions, from foundation and flooring to walling and roofing – powered by premium brands including ECOPact, ECOPlanet, ECOCycle, and Ytong.

WHO ARE HOLCIM PEOPLE?

Holcim people are passionate about finding better ways to build. They embrace innovation and improvement with a pioneering spirit. They work as trusted partners, creating better solutions and experiences for their customers, communities, and colleagues.

YOUR HOLCIM EXPERIENCE

At Holcim, there are endless opportunities for you to play your part. Whether you’re in a technical, managerial, or frontline role, you can shape a career that works for you. With us you’ll have the chance to embrace the passion we share for our planet. You’ll be encouraged to seek out diverse perspectives, share your ideas and build the skills and connections you need to perform at your best. Because it’s only when we work together in a culture where everyone thrives that we can build the world we all want to live in. To find out more, visit www.holcim.com/careers.

THE OPPORTUNITY – CONTEXT OF THE MISSIONS

The development of tomorrow's sustainable cement and reinforced concrete requires a decrease of the clinker content to minimize CO2 net emissions of the final product. Different Supplementary Cementitious Materials (SCM) with zero to negative carbon emissions (carbon sink) are developed at HIC. The optimization of these innovative low CO2 cements is based on linking phases assemblage after reaction to mechanical and physical properties. Because of the large range of sourcing and composition of SCM, unified measurement strategy and predictive tools are needed.

MISSIONS:

As part of your missions, you will drive the integration of a python tool for quantifying phase assemblage from experimental methods (XRD, XRF, TGA C/H). Specifically, you will focus on the following key objectives:

• Data Management & Database Architecture: Design and structure the database schemas (JSON) to store experimental raw data (XRD, XRF, TGA) alongside mineral metadata (stoichiometry, molar masses, densities).
• Multi-Tool Data Fusion & Mathematical Solver: Implement the core mass-balance linear algebra and global optimization algorithms in Python to simultaneously solve, from XRD, XRF, and TGA datasets, for phase assemblage, total amorphous fraction and amorphous composition (e.g., C-S-H gel, calcined clay).
• Method Benchmarking & Validation: Compare the elemental mass-balance output against current internal estimations based on ultra-nanocrystalline models and internal standards.
• Software Engineering & Package Development: Refactor existing scripts into a modular, production-ready Python package within an IDE environment, enforcing Git version control and unit testing.
• Experimental Benchmarking & Prototyping: Execute the validation protocol against existing dataset to establish error margins.
• UI & Dashboarding: Create an interactive dashboard to showcase tool outputs and phase development graphs to non-specialist R&D teams.

ABOUT YOU

REQUIRED SKILLS

• Hard skills:
• Analytical Techniques: Solid theoretical foundation in X-ray Diffraction (XRD / Rietveld refinement), TGA (thermogravimetry), and XRF (elemental chemistry),
• Mathematics: Comfortable with linear algebra, possibly multi-objective optimization, and error minimization,
• Programming: Strong interest in Python. Knowledge of python libraries (NumPy, Pandas, SciPy, Matplotlib, LMFIT), version control (GIT) system and IDE workflows (such as PyCharm) would be a plus.
• Soft skills:
• Team Spirit,
• Self-motivated and self-reliant,
• Problem-Solving and scientific rigor.
• Languages: Effective Communication in English (French is a plus)

EDUCATION LEVEL / TRAINING

• Currently pursuing a Master’s degree (Bac +4/5) in Materials Science, Solid-State Inorganic Chemistry, Physic, Chemical Engineering, Geosciences or Chemistry

FURTHER INFORMATION

Duration: 6 months

Start date: 01/03/2026

Holcim Innovation Center:

95 rue du Montmurier, 38291 St-Quentin-Fallavier (France), approximately 30 km East of Lyon (accessible by public transport).