Open pit mining is the process of extracting ore, rocks or any valuable material from the ground by digging. Some people call open pit mines quarries. Most open pits are designed in a step-like structure, with each step (sometimes called ledge or bench) dug deeper into the earth to reach the area to be mined. The steps include access roads, and as more material is removed, new steps can be built. The goal is to remove the valuable material, but that involves first removing large quantities of rock at the lowest possible price.
Crushing plant: jaw crusher for primary crushing, impact crusher and hammer crusher for secondary crushing, gyratory crusher and cone crusher for tertiary crushing.
Grinding mill: ball mill, high pressure mill, ultrafine mill, vertical roller mill, trapezium mill, raymond mill etc.
Auxilary machine: vibrating screen, belt conveyor, sand washing machine, drying plant etc.
Separation equipment: magnetic separator, gravity concentration plant, flotation machine, spiral classifier etc.
Surface quarrying is a considerably more common method of producing limestone and is typically much more economical than underground mining methods. Many surface operations are simply hillside cuts or open pit type quarries. Controlled blasting at the quarry face is used to break the rocks into pieces. If necessary, this material is further reduced in size by rock crushers to a desirable size. The rock is then separated and cleaned. Limestone quarry operation consists of removing blocks or pieces of stone from an identified and unearthed geologic deposit. There are many different types of limestone quarry plant involved in the operation process.