What Is Bench Height In Mining

Determination of optimum bench height is a major concern in most open pit mines.

What is bench height in mining. This subject has always been an issue with different and sometimes conflicting criteria that have to be. These step like zones are created along the walls of an open pit mine for access and mining. It s possible to drill the intermediate bench trim row closer to the toe of the. At the same time the blast unit cost has been seen to diminish as the hole diameter grows.

Mining is generally conducted on a number of benches at any one time. In mining a bench is a narrow strip of land cut into the side of an open pit mine. 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. Determination of practical bench height is an important subject in open pit mining.

Mining was conducted with a cat 5130 excavator cat 994 and 992 loaders matched with cat 777 haul trucks. 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. Opencast working method of opencast working bench bench height bench width and bench slope angle provision regarding bench height bench width and bench slope angle bord and pillar method video. However for 20 m of bench height because of the increase in priming the unit cost tends to build up increase.

Unless geological conditions dictate otherwise all benches should have the same height. 1 5 bench height the bench height is the vertical distance between each horizontal level of the pit. Harraz presentation mining methods surface mining 23. Diagram it can be seen that the single bench height was 15m with a drill offset on the intermediate bench of between 5 6m from the toe of the upper bench.

Bench height has been found to be 15 m. The elements of a bench are illustrated in fig. 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. For large mines it is on the order of 12 to 15 metres about 40 to 50 feet.

The thickness that is the height of the benches depends on the type of deposit the mineral being mined and the equipment being used. 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.