Bulk material stockpiles for prehomogenising individual raw material components or mixtures, are generally stacked by belt stackers and tripper carriages.

The belt stacker is mainly installed in open-air storage facilities and builds up the stockpile using the CHEVRON or CONESHELL methods. The tripper carriage can be used if the stockpile is in a hall or is spanned by a framework structure. It usually builds up the stockpile using the CONESHELL method.

Bridge scrapers reclaiming the stockpile end face achieve the highest blending effects. Portal or side scrapers reclaiming the stockpile side face are successfully used if lower demands are placed on the degree of blending.

Polysius stacker and scraper systems are of modular design. They ensure that the materials needed in the cement factory are supplied at a constant flow rate.