What Is Bench Height In Mining

Mining is generally conducted on a number of benches at any one time.

What is bench height in mining.

Harraz presentation mining methods surface mining 23. Open pit mining bench height multi criteria decision making. 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. The thickness that is the height of the benches depends on the type of deposit the mineral being mined and the equipment being used.

The elements of a bench are illustrated in fig. 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. As the bench height goes up unit cost appears to drop. It s possible to drill the intermediate bench trim row closer to the toe of the.

Determination of optimum bench height is a major concern in most open pit mines. However for 20 m of bench height because of the increase in priming the unit cost tends to build up increase. 1 5 bench height the bench height is the vertical distance between each horizontal level of the pit. 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.

At the same time the blast unit cost has been seen to diminish as the hole diameter grows. 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. 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.

This subject has always been an issue with different and sometimes conflicting criteria that have to be. Bench height has been found to be 15 m. 2 february 2016 prof. 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.

Unless geological conditions dictate otherwise all benches should have the same height. In mining a bench is a narrow strip of land cut into the side of an open pit mine.