The refinement of the natural mineral Natural expanded silicate is carried out in the direct environment of the mining areas and eliminates costly raw material transportation.

The Natural expanded silicate is cleaned in an ecological water treatment plant and after drying through energy conserving means ground and sieved for processing into different high-purity granules.

The entire refinement process consumes comparatively low amounts of energy and is considered the most environmentally friendly process - an advantage which supports the excellent energy balance of ROTEC^® Natural expanded silicate.

In contrast, other lightweight aggregates are expanded via complex and highly energy intensive thermal processes.