180T/H Crushing and Screening Plant

The crushing process has a design throughput of 180-200 t/h and is schematically illustrated in the Crushing Circuit Process Flow Diagram (PFD), pls see our drawing:

ROM material from the two mines, is hauled by mining trucks to the ROM stockpile, near the ROM bin. A front-end loader (FEL) is used for ore blending at a ratio of 1:1 and feeds the ROM bin. As material has much higher silver grade than that from the Vein Zone, controlled blending is required to provide uniform precious metals loadings for the operation of the CCD and refinery. Blending also ensures consistency of ore comminution characteristics ahead of the SAG mill. The ROM bin is provided with a static grizzly, sloped to bring oversize material back to the loading side for removal by the FEL. Grizzly oversize may be broken on the ROM pad area or sent to the overburden dump.

Material from the ROM bin reports to the vibrating grizzly feeder. The grizzly feeder oversize is fed to the throat of the jaw crusher. The undersize bypasses the crusher, is fed on to the crusher discharge conveyor and joins the crusher product. The vibrating grizzly feeder has a variable speed drive to provide controlled feed to the crusher. Crushed material is conveyed by two conveyors in sequence, to the coarse ore bin, which has a live capacity of 2,000 t. In light of the strong winds and high abrasiveness of the material, an in-line coarse ore bin was selected to provide surge capacity ahead of the milling circuit, rather than a conventional open stockpile or a direct feed arrangement, either with or without an open emergency stockpile. The coarse ore bin is installed above the ground and material is discharged from the bin by two variable speed belt feeders, each capable of feeding at the design SAG mill capacity. The belt feeders report to the SAG mill feed conveyor. A controlled amount of dry quicklime is added onto the SAG mill feed conveyor in preparation for the downstream leaching stage.