> Case Introduction

Hard rock refers that under saturated humidity the uniaxial compressive strength of rock sample is more than 29.4×103kPa(diameter of the sample is 7～10CM, height is the same as diameter ) (magmatic rock such as granite, diorite, basalt; sedimentary rock such as calcareous ferruginous cemented conglomerate, sandstone, limestone, argillaceous limestone, dolomite; metamorphic rock such as gneiss, quartzite, marble, slate ), and has a high abrasiveness to abrasion resistant parts, therefore the hard rock production line should be designed properly, which not only consider the investment cost of crushing project, but also consider the operation cost.

Rock material is conveyed by vibrating feeder to jaw crusher for primary crushing, the crushed rock is conveyed by belt conveyor to cone crusher for further crushing; secondary crushed rock is conveyed by belt conveyor to vibrating screen for screening, rock with qualified particle size is conveyed by belt conveyor to final product; and rock with unqualified particle size is conveyed by belt conveyor to secondary or tertiary cone crusher for crushing again, to form multiple closed circulation.