Alternative ye’elimite (CSA) cement clinkers from industrial byproducts

Thesis event information

Date and time of the thesis defence

Place of the thesis defence

TA 105

Topic of the dissertation

Alternative ye’elimite (CSA) cement clinkers from industrial byproducts

Doctoral candidate

M.Sc. Visa Isteri

Faculty and unit

University of Oulu Graduate School, Faculty of Technology, Process metallurgy

Subject of study

Process metallurgy / Fibre and particle engineering


Doctor Alexander Pisch, SIMAP, Grenoble, France


Professor Timo Fabritius, University of Oulu, Process metallurgy

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Alternative ye’elimite (CSA) cement clinkers from industrial byproducts

The cement industry is responsible for 5-8% of global anthropogenic CO2 emissions. The aim of my thesis was to utilize Finnish industrial waste materials to produce alternative CSA (calcium sulfoaluminate) cement clinkers. The industrial waste materials utilized were mainly slags from metallurgical industry that contains the necessary ingredients for cement production such as alumina, lime, silica, and iron.
Approximately two thirds of the CO2 emissions of cement production arise from the calcination of limestone (CaCO3). The basic idea of the CSA cements developed in my research was to replace the main minerals in traditional cement with minerals that have lower calcium content. This reduces the amount of limestone (CaCO3) required for cement production, resulting in lower CO2 emissions from limestone calcination. The minerals in CSA cement require a lower formation temperature, which reduces the production temperature of CSA cement by about 200 ˚C when compared to traditional cement. Additionally, the production of CSA cement allows for the versatile use of waste materials containing sulfates, iron, and aluminum oxides.
Based on preliminary laboratory research results, the production of CSA cement was tested in a pilot-scale production in January 2020 (Weimar, Germany), which successfully produced 400 kg of cement with properties similar to those in laboratory tests. In the produced cement, up to 85% of the raw materials were replaced with industrial waste materials. Due to the combined effect of raw material substitution and lower production temperature, CO2 emissions were significantly lower than those in traditional cement production. The mechanical and chemical properties of the produced cement have been studied for applications such as winter concreting, mine backfilling, and stabilizing sulfate and heavy metal contents in hazardous waste and mine tailings.
Last updated: 9.5.2023