What Is Bench Height In Mining

Determination of practical bench height is an important subject in open pit mining.

What is bench height in mining.

Harraz presentation mining methods surface mining 23. As the bench height goes up unit cost appears to drop. 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.

1 5 bench height the bench height is the vertical distance between each horizontal level of the pit. Mining was conducted with a cat 5130 excavator cat 994 and 992 loaders matched with cat 777 haul trucks. 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.

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. However for 20 m of bench height because of the increase in priming the unit cost tends to build up increase. For large mines it is on the order of 12 to 15 metres about 40 to 50 feet. 2 february 2016 prof.

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. Open pit mining bench height multi criteria decision making. The elements of a bench are illustrated in fig. 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.

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

Unless geological conditions dictate otherwise all benches should have the same height. The thickness that is the height of the benches depends on the type of deposit the mineral being mined and the equipment being used.