UG LOAD AND HAUL
In a presentation from the International Conference on Renewable Energies and Power Quality in 2014 from the Department of Mining, Metallurgical and Materials Engineering at Université Laval and Atlas Copco, the authors state:“ The most important advantage of these trucks is their high overload capacity and very good gradeability. On a 14 % ramp the speed for the electric truck running up is almost double when compared to a similar diesel unit. Due to this, their production rate is on average 20 % higher and a smaller truck fleet is needed to meet certain production targets. Electric trucks also have a favourable ratio between useful load and empty vehicle weight( 1.06 and 1.1 for EMT- 35 and EMT-50 respectively), similar to dieselpowered trucks. It is estimated that for the same ramp haulage system and production rate, electric trucks will use only 24 % of the energy per tonne hauled as compared to a diesel fleet. This means that application of electric trucks can generate economies stemming not only from a lower ventilation cost, but also from substantially smaller energy cost.”
Vale’ s Coleman mine near Sudbury has 18 years of experience with electric trucks. It now operates a fleet of five 50 t vehicles running on the longest trolley line ever built( cumulative length of 6,200 m).“ Trolley-powered trucks constitute a solution that has not yet received adequate recognition it merits. The example of the Coleman mine in Canada, where Kiruna trucks have been successfully used for the last 18 years and whose performance is fully satisfactory to mine management proves that full commitment of both the mine and the OEM makes this concept a winning solution. Electric trolley-powered trucks definitely merit more consideration in the cases of future and existing mines with truck haulage over long ramps. Again, this solution is not a universal one, but it has the potential to be beneficial in some particular applications. Any potential application should be thoroughly studied and analysed to maximise chances for a success.”
Finally the Haggloäder continuous loaders have been used in tunnelling mainly to date but Atlas Copco believes strongly in the usage of this type of equipment in mining.“ We are working with several mining companies to explore this opportunity and to explain the benefits of a continuous system. The launch of the LOT( Loading Optimisation Tool) has rendered a lot of interest and opened up the eyes for the use of Häggloader instead of traditional loaders. Currently we have sold Haggloäders into mining in Canada and Indonesia and also performed successful trials in South Africa’ s platinum mines to replace traditional pneumatic rail bound equipment. Here it proved to increase rates( cubic metres per hour) by 40 %.”
Caterpillar refocuses for the future
The big change at Caterpillar in terms of underground load and haul machines has of course been the moving of production from Burnie, Tasmania( with some production in the past near Sao Paulo, Brazil) to the Port of Rayong, Thailand, with some machines now being made in Houston, Pennsylvania, and Burnie remaining as a major engineering centre. The range still covers LHDs from the R1300G( 6.8 t payload), R1600H( 10.2 t), R1700G( 14 t), R2900G( 17.2 t) and R3000H, the newest and largest LHD with 20 t payload. The truck range includes the AD30( 30 t), AD45B( 45 t) and AD60( 60 t). Compared to competitors, Caterpillar as it does with its surface equipment emphasises that these are largely 100 % Caterpillar products including engines and major components, backed up by the company’ s unique dealer structure and parts supply network.
Robert Droogleever Fortuyn, General Manager, Caterpillar Underground Mining told IM:“ By restructuring and implementing Caterpillar’ s new facilities, we have been able to focus on quality control through use of the Caterpillar Production System( CPS). Caterpillar manufacturing processes are unmatched. Restructuring at a lowvolume part of the cycle is much easier than at other times.” See this month’ s High Profile article for more comments on the market from Robert Droogleever Fortuyn
In terms of automation, Freeport and Codelco remain the key strategic partners for ongoing Command for Underground development and implementation. A good case study is Freeport’ s Grasberg operation in Indonesia – Drooglever comments:“ We have operators on the surface working the underground loaders. The next stage is auto-digging with loaders and then, after that, truly autonomous loaders with no operator input … the loaders are our current target, then truck automation will follow. Previously our focus was on remote – in this case line-of-sight – working; now we are conducting fully remote with the operators distanced from the actual operation but connected by cameras and sensors. Next we will move towards installing sensor nodes and the diggers will drive themselves without any operator involvement. We’ re actually pretty close to that now.”
The still fairly new R3000H LHD already has a number of references( see table), including with different automation levels. Global contractor Byrnecut as an example is using an RH3000H equipped with Command for Underground at Sandfire’ s DeGrussa mine in Western Australia. The machine and the system have been working productively for about two years. Two RH2900G LHDs are also achieving success with Command for Underground at Sandfire.
Why
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REASON # 8: Fast sample loading
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JUNE 2016 | International Mining 29