Mining operations frequently require a slot or box hole within stoping blocks to provide void space for subsequent blasting operations. Traditionally these have been excavated by either the inherently high risk hand held method; the moderate risk, high consequence long hole blasting method or the low risk although time consuming method of box hole raise boring.
To address the shortcomings of the traditional methods, Mancala in conjunction with Herrenknecht of Germany has developed the Vertical Miner. The is a self propelled, electrically powered (Jumbo Box connection) machine designed to quickly and safely bore vertical to -60 degree, 1.1m diameter blind up-holes to 35m in length. Based upon proven pipe jacking technology, the MVM has 950kN of thrust and 48kNm of torque enabling it to bore through most rock formations.
At its recent commissioning at Newcrest's Cadia mine, the MVM has bored over 650m achieving the boring cycle of rig up, bore and rig down in 30 hours for an 18m hole. With productivity a KPI within the MVM's design, the machine uses standard mine services, does not need a concrete pad and is self contained. Tram to site (3kph), bore a hole and tram away. Operator safety is inherent in the MVM with the operator stationed remotely from the machine, drill pipe stationary (head alone rotates) and spoil is directed internally within the thrust pipes to a collection bin.
With an operational capability of 30m, the MVM can be used to excavate mine infrastructure, including escape rises and ventiliation shafts. Further applications for the MVM beyond box hole boring include narrow vein mining of high value ore.