Raw material preparation

A ball mill wet-grinds the quartz sand with water to a sand slurry. The sand slurry is stored in slurry tanks and pumped into the slurry weighing hopper in the mixer tower. The binders (lime, cement and anhydrite) are stored in silos. It is also possible to mill the anhydrite together with the sand in the ball mill. The aluminum powder or paste is prepared in a separate building where it is dispersed in water. 

All the components are accurately weighed, and are released into the mixer in a pre defined order. The HESS recipe and temperature control system constantly monitors this process.

HESS also has the knowledge and the experience to produce AAC with alternative raw materials, for example with fly ash.