Hard-rock operations
Processing natural stone with mobile crushers and stationary plants
Natural stone processing uses a multi-stage crushing and screening process for producing defined grain sizes from large lumps of rock. Such classified final grain fractions are used as aggregates for concrete, asphalt base, binder and surface course layers in road construction, as well as in building construction.
Stationary plant, AL-Khobar, Saudi-Arabia
MOBICAT MC 120 Z processing natural stone
Rock extraction
The rock is quarried by means of drilling and blasting. There are then two possible options for processing the bulk material after it has been reduced to feeding size of the crushing plant.
Transport by excavator or heavy-duty truck
When processed in mobile crushing plants, excavators or wheel loaders are used for feeding the rock into the crusher that is usually set up right at the quarry face. The crushed material is then either sent to the next processing stage via belt conveyors, or is transported from the quarry by trucks. The second option involves transporting the bulk material from the quarry face by heavy-duty trucks. The rock is loaded into the heavy-duty trucks by excavators or wheel loaders, and is then transported to the stationary processing plant.
Cubic particles withstand pressure
The higher the compressive strength of rock, the higher is also its quality, which plays an important role in particular in road construction. The compressive strength of a material divides it into hard, medium-hard or soft rock, which also determines the crushing techniques used for processing to obtain the desired grain sizes. The material’s quality is influenced significantly, however, by yet another important parameter: grain shape. The more cubic-shaped the individual grains are, the better the resulting particle interlock. Final grains of pronounced cubic shape are achieved by using several crushing stages. A cubicity showing an edge ratio of better than 1:3 is typical of high-quality final aggregate.
