What Is Bench Height In Mining

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What is bench height in mining.

Bench height has been found to be 15 m. These step like zones are created along the walls of an open pit mine for access and mining. Determination of practical bench height is an important subject in open pit mining. Introduction as a definition in open pit mining bench height is the vertical distance between crest and toe of the bench fourie and dohm 1992.

Mining was conducted with a cat 5130 excavator cat 994 and 992 loaders matched with cat 777 haul trucks. Harraz presentation mining methods surface mining 23. 2 february 2016 prof. Determination of optimum bench height is a major concern in most open pit mines.

Open pit mining bench height multi criteria decision making. This subject has always been an issue with different and sometimes conflicting criteria that have to be. However for 20 m of bench height because of the increase in priming the unit cost tends to build up increase. It s possible to drill the intermediate bench trim row closer to the toe of the.

In mining a bench is a narrow strip of land cut into the side of an open pit mine. The thickness that is the height of the benches depends on the type of deposit the mineral being mined and the equipment being used. As the bench height goes up unit cost appears to drop. Mining is generally conducted on a number of benches at any one time.

The elements of a bench are illustrated in fig. At the same time the blast unit cost has been seen to diminish as the hole diameter grows. Stiffness ratio bh b where bh is bench height b is the burden target stiffness ratios 3 to 4 is normal range 4 does not improve fragmentation may risk cut offs much above 6 2 redesign if you can 2 get someone you dont like near shot stiffness ratio example. Raised beach also known as marine terrace a beach or wave cut platform raised above the shoreline by a relative fall in the sea level.

What is the stiffness ratio for a 40 foot bench with 6 5 feet of burden on each hole 40 6 5 6 15 shot. Unless geological conditions dictate otherwise all benches should have the same height.