The following diploma thesis deals with a gravel plant in Liechtenstein. In this plant sellable products refined through washing processes are produced. In the course of time also demolition and construction waste had been accepted, but were not further utilised. In summer 2007 the company started dealing with secondary materials and carried out experiments on this field. Granulate material consisting of secondary materials was produced and processed into gravelly sand. This product was used in concrete production and out of this experimental concrete a plate was poured. The further use of the basic granulate material was discussed with a concrete producer but more tests have to be run. In addition the purification plant for waste water was extended. A tank was installed which enabled on the one hand to store more process water and on the other hand to alter the static head of the pump tube which decreased energy costs. The whole reconstruction has been finished in September 2007. Stone platters wastes were also processed. A big problem represents the tailing pond which contains fine fractions in a high grade causing a rapid filling of the pond and therefore a more complicated processing of the material. The recycling industry becomes more important and it is vital to create innovative mineral processing methods to produce secondary materials of a high-grade quality. This topic shall be discussed by this diploma thesis.