Rock crushers are used in the aggregate, mining, and mineral industries. Cost-effective production, including size reduction and size classification, is the primary challenge in these industries. Size reduction is achieved using crushers, while classification is achieved by screens.
Aggregates are used in homes and office buildings as well as in transportation infrastructure. Due to their low inherent value of about €5-15 per tonne, they are usually manufactured less than 40 km from where they are being used. Aggregates can be composed of gravel, crushed rock material, or both. Aggregate rock materials are processed by both crushers and screens, while sand and gravel sometimes are only screened. In Sweden in year 2008, 78 million tonnes of aggregates were produced from crushed rock materials, corresponding to 79% of all manufactured aggregate products. The remaining 21% of aggregates were mainly produced from sand and gravel deposits. However, extraction from natural sand and gravel deposits is steadily decreasing, which motivates finding more cost-efficient processing methodologies for crushed rock aggregates. In Europe, about three billion tonnes of aggregates were produced at about 28000 production sites in year 2007.
Aggregate rock crushing plants are used as a pre-processing stage before milling and other fine particle treatments in the mineral and mining industries. In year 2008, 51 million tonnes of ore and bedrock from iron ore mines and non ferrous mines and 9 million tonnes of limestone were extracted in Sweden. These tonnages were pre-processed by crushing plants.