Defining the Excavated Layer’s Height for Coal Extraction by Backhoes

DOI

10.2991/coal-18.2018.28How to use a DOI?

Keywords

open pit mining, hydraulic backhoes, excavated layer, coal losses, backhoe productivity

Abstract

Currently, large machine building companies produce hydraulic excavators serially with a wide range of operating parameters (bucket capacity, digging radius, digging depth and height). Hydraulic excavators have found wide application in quarries all over the world (USA, France, England, Japan, Australia, Russian Federation etc.). A sufficiently wide range of backhoe capabilities for the formation of various forms of surface workings and bench slopes allows them to work without leaving various prisms of coal losses in the coal seam’s bottom, at the optimum height of the excavated layer. The most efficient way is to work off the bench by hydraulic backhoe by downward digging and bottom loading. The depth of digging (the height of the face) is approximately equal to the height of the body of a dump truck. The minimum value of the excavation cycle is achieved when the dump truck is positioned at an angle of 35-60° to the axis of the excavator. To reduce the time for installing a dump truck for loading, an end-to-end truck approach scheme is recommended, but the duration of the excavation cycle is increased as a result of increasing the angle of the excavator during loading. The research shows that: (1) at the excavated layer’s height of 5.0 m, additional coal losses due to non-scooping is not formed only for seam’s angle of 50 or more, except when using hydraulic backhoes with large operating parameters; (2) for excavated layer’s height of 4.0 m, the minimal coal losses will be achieved for dip angle of at least 40 degrees, and for long-boom excavators – not less than 30°; (3) the excavated layer’s height of 3.0 m makes it possible to virtually eliminate coal losses, except for excavators with a short boom.

Copyright

© 2018, the Authors. Published by Atlantis Press.

Open Access

This is an open access article distributed under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).

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TY  - CONF
AU  - Oleg Litvin
AU  - Maxim Tyulenev
AU  - Sergey Zhironkin
AU  - Sergey Markov
PY  - 2018/10
DA  - 2018/10
TI  - Defining the Excavated Layer’s Height for Coal Extraction by Backhoes
BT  - Proceedings of the 9th China-Russia Symposium "Coal in the 21st Century: Mining, Intelligent Equipment and Environment Protection" (COAL 2018)
PB  - Atlantis Press
SP  - 154
EP  - 158
SN  - 2352-5401
UR  - https://doi.org/10.2991/coal-18.2018.28
DO  - 10.2991/coal-18.2018.28
ID  - Litvin2018/10
ER  -