Conveyor Loading of Skips

摘要

The basic methods to remove material from underground mines are to:rn?convey continuously,rn?batch in trucks,orrn?batch in a shaft hoisting system.rnA critical aspect in shaft hoisting is accurately batch loading thernconveyance or skip.During the 20th century,the almost universallyrnaccepted method of loading was via a measuring flask.A measuredrnquantity of material was filled into the flask as the conveyance travelledrnthrough the shaft and then,when the conveyance arrive at the loadingrnposition,it was ‘dumped 'into the skip for hoisting.rnProblems associated with flask loading are:rn?high wear in the flask and in the back of the skip;rn?the danger and difficulty of accessing and maintaining the flask;rn?non-standard off-shaft excavations for the loading system;andrn?high dynamic rope loads imposed during loading.rnDirect,high speed loading of the skip with a pre-measured quantity ofrnmaterial on a belt conveyor offers significant advantages over flaskrnloading.These include:rn?standard horizontal excavations for the loading station;rn?maintenance carried out away from the shaft in relative safety;rn?elimination of the flasks and the associated high maintenance wearrnliners;rn?the ability to control and vary the trajectory of the ore into the skip tornminimise skip liner wear;andrn?reduction of dynamic head rope loads by controlling the loading rate.rnTwo skip loading conveyor systems have been developed in Australia:rn1.BHP Billiton 's Cannington Hoisting System,installed in 1996,isrnbelieve to be the first conveyor loading system designed for twornskips.Two parallel conveyors were installed with a two-way gaterncontrolling feed onto each belt.Cannington was ideally suited tornconveyor loading as the very high ore density and relatively lowrnproduction rate required a relatively small volumetric storagerncapacity on the weighed belt.rn2.Newcrest Mining 's Telfer Hoisting System,which is to berncommissioned in 2005,consists of a single slewing conveyor loadingrneach skip with 32 tonnes of ore.The development of this systemrneliminates the two-way transfer,improves the accessibility andrnminimises the excavation required.rnWhile every hoisting system must be considered on its merits,rnconveyor loading offers significant advantages to the Mining Industry inrnthe 21st century.