Basic ideas on Celitement

Raw materials: starting mixture low in calcium

Starting materials are similar to the manufacturing of conventional cementitious binders: a calcium component (CaO from limestone) and a silicon component (different kinds of silicates)

The molar ratio of calcium to silicon comprises the range of 0,5 to 2.

Hydrothermal synthesis in autoclaves

In an autoclav raw materials and water are transformed into calcium silicate hydrates - temperature is between 150 and 300°C with the respective saturation vapour pressure.

Drying leads to non hydraulic phases that need further processing.

Activation and conditioning

The hydrothermal product is mixed with a second silicate component. Reactive milling activates the phases and controls product properties.

This leeds to Celitements, i.e. hydraulically active calcium hydrosilicates.

Additives can be used to control the hydration with water and the quality of the final product.

Celitement: Mixing with water and hardening

Finally, a binding material is obtained that can be handle like Ordinary Portland Cement (OPC).

The molar ratio of calcium to silicon is smaller than 2, in some cases it can be considerably lower. In this way, the amount of calcium carbonate and the corresponding carbon dioxide emission is reduced.

OPC and puzzolans can be added as well.