The Vermeer team of Mark Cooper, Jeff Flahive and Jim Hutchins will be inducted in the Surface Production category at the gala dinner in the Brown Palace Hotel, Denver on February 16 (www.im-halloffame.com). Vermeer introduced its first Terrain Leveler® surface excavation machine (SEM) to the mining industry in 2002. The innovative Vermeer® T1255III Terrain Leveler SEM offers superior production in a variety of applications, including surface mining. Depending on the model, a Terrain Leveler SEM can cut areas up to 4.6 m wide and up to 813 mm deep in a single pass.
A patented, industry-exclusive tilting cutter drum with two-direction leveling on the Terrain Leveler SEM aids production by keeping the drum level or to follow an ore body in 3D — allowing the unit to take on jobs that were not possible before — regardless of ground conditions. It also offers the ability to use GPS/laser guidance to control grade.
Featuring heavy-duty CAT engines ranging from 261 kW to 447.4 kW, these units have ample power to grind through some of the toughest material at a mine. Greater rock penetration is achieved with a top-down cutting system, TECTM Plus technology, and a host of other features that contribute to the effectiveness of the Terrain Leveler SEM. Top-down cutting allows the cutter teeth to achieve greater rock penetration. When the machine travels forward, the teeth on top of the drum are positioned over the top of the rock surface. As contact is made, the teeth instantly cut the rock.
The Terrain Leveler technology is designed to eliminate the need for primary crushers, large loaders, large mining haul trucks and associated permits, in addition to rippers and vertical drills and explosives. As well as mining material, these machines can perform site preparation and excavation, stabilise contaminated soil and break up concrete roads.
At a copper mine in the DRC, for example, the mining sequence begins by identifying ore and waste. A 100 mm wide cut is made across the strike of the ore zones with a Vermeer rock saw. The trench cuttings are sampled in 2.5 m intervals between rock units. Samples are sent to the laboratory where total and acid soluble grades and gangue acid consumption are determined. The assays from the lab are used to develop an ore control model from which the ore zones can be designed. Surveyors stake the outlines of the ore zones in the field after the surface miner has fragmented the rock.
The mine has five Vermeer T1255 Terrain Leveler SEMs that cut the ore zones first. The Terrain Leveler SEMs are used to fragment ore and some waste. Careful planning is essential at the interface of the 5 m waste bench mining and the 0.625m ore cuts to minimise issues with access and interference from blasting in the waste.
The mine has found that surface miners can be at least four times as selective in rock fragmentation compared with drilling and blasting. They avoid the mixing and displacement issues inherent in blasting and eliminate the need for a crusher. Based upon operational experience to-date the current expectation is that the surface miners will produce, on average, 650 t/h with an overall availability of 70% and utilisation is 70% for a combined overall asset efficiency of 70% x 70% = 49%.