A new Technology for Steep Incline High Capacity Open Pit Conveying
A new conveyor design is set to help reduce conventional heavy-duty truck traffic and the resulting high operating costs in open pit mines. This article presents the design and the initial findings of the feasibility study on the Chevron-Megapipe conveyor for a 350 m-deep open pit mine and a mass flow of 5000 t/h.
In the test rig, a Megapipe belt piece 10 m in length in the original diameter with and without chevron is placed into a supporting frame, filled with bulk material conveyed, and closed to form a pipe belt. A crane then lifts the supporting frame on one side until the material starts sliding. Vibrations are imposed to the material bed via pneumatic shakers in order to emulate the dynamic stimuli that idler stations produce on a running belt. Since the test rig pipe belt is not scaled down in diameter, a scaling down of the material sample conveyed can also be avoided. Thus, tests with real material samples from open pit mines can be conducted in the Megapipe test rig.
Tests on the Chevron-Megapipe Belt Sample
The goal of the tests was to clarify whether the chevron ribbing influences the transverse stiffness and roll-in behavior of the Megapipe. To this end, an existing sample with a 50-mm-high and 32-mm-wide (H50 x B32) chevron cleats was used to evaluate the form forces and pipe shape on the hexagonal test rig (Fig. 15 in the Contitech technical center. The sample’s form forces (Fn,1…Fn,6) measured after 23h were then compared with the form forces of an identical unribbed Megapipe sample.
Fig. 15 (left) shows impeccable roll-in behavior and safe closing of the overlapping area in the Chevron-Megapipe. If we use the spider diagram (Fig. 15, right) to compare the form forces (Fn,1…Fn,6) of an identical Megapipe with and without chevron cleat ribbing as measured in the hexagonal test rig, it becomes clear that the chevron cleat ribbing does not have a major influence on the transverse stiffness.
In the present article, the innovative technology of the Chevron-Megapipe as well as the initial findings from theoretical examinations of the conveyance behavior of steep-angle conveyor belting have been described in discharging and nominal load mode.
Some of the findings of the DEM-FEM simulations for a troughed belt and a Megapipe with and without a chevron cleat-ribbed carrying side cover were verified. To further safeguard the theoretical findings from DEM-FEM simulations, a Megapipe test rig is being built as the research project progresses. The roll-in behavior as well as the transverse stiffness of a Chevron-Megapipe were examined on the hexagonal test rig.
Initial project-related calculations comparing capital expenditure and operating costs of the new system with conventional transport technology (CAPEX/OPEX analyses) in ore extraction countries were executed. The findings clearly show that the use of the Chevron-Megapipe technology in combination with a pre-crushing stage compared to conventional heavy-duty transport or even normal troughed belt conveyors at angles of incline between 30° and 45° is profitable n
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 Stanisic Z., Dos Santos J.A. In&Pit Crushing and High Angle Conveying at Copper Mine Majdanpek – BSH
 Stacey T.R., Y. Xianbin, R. Armstrong, and G.J. Keyter: New slope stability considerations for deep open pit mines, The Journal of The South African Institute of Mining and Metallurgy, JULY/AUGUST 2003
 ContiTech brochure “Conveyor Belts – System Design Calculations”