Coal Age Magazine - For more than 100 years, Coal Age has been the magazine that readers can trust for guidance and insight on this important industry.
Issue link: https://coal.epubxp.com/i/1032065
product news September 2018 www.coalage.com 41 Mine operators for some time now have been increasingly turning to an alterna- tive to conventional rip-and-stack or drill- and-blast coal mining: the use of surface miners. Diverse studies and tests now show that surface miners offer consider- able advantages in terms of both econom- ic efficiency and the final product. Wirtgen said the main advantages of surface mining technology include selec- tive mining; avoidance of blasting; cutting, crushing and loading in a single operation; maximum exploitation of deposits; and reduced transport costs. Working in collaboration with RWTH Aachen University, Wirtgen conducted a study at a coal mine in Queensland, Austra- lia. A 4200 SM surface miner was integrated into an ongoing operation for the selective mining of coal and interburden. Previous- ly defined targets were checked regularly to determine if they were being met. The project score card illustrates the advantages of using a surface miner in this mine. The production rates of the surface miner were compared with that of the previously used rip-and-stack method over a period of four months based on various performance in- dicators. The conventional mining system comprises two supersize dozers for ripping and stacking the material and a super-large wheel loader for loading it to dump trucks with 130- to 190-metric-ton (mt) payloads. Compared to the three mining ma- chines the mine previously used, the use of a surface miner significantly reduced noise emissions. Mining with the 4200 SM likewise had a similar, positive impact on dust emissions. In contrast to the dozers and wheel loader — all of which generate considerable quantities of dust — the dust produced by a surface miner is contained in the cutting-drum housing. A dust sup- pression system with an integrated water spray system also helps to additionally re- duce and bind the dust. An analysis of the two mining methods further demonstrated that fuel consump- tion is about 79% lower with surface miners than when using the conventional method. The lower number machines in use addi- tionally has a positive effect on risk man- agement, because fewer machines mean a reduced risk of accident at the mine. The surface miner's anti-vibration cab- in offers better ergonomics and optimized working conditions for the machine opera- tor. The vibrations generated in the 4200 SM were rated as "low" according to Australia's AS 2670-2001 standard, while the ratings for the conventional systems were higher. The mining technique also offers lower processing costs thanks to reduced fines. Coal seams to vary in thickness and can be separated by interburden layers. Precisely separating the various materials is of tre- mendous importance if coal is to be mined as cost-efficiently as possible, because it significantly reduces processing costs. An- other major cost driver in this regard is the percentage of fines, because they are much more costly to process than coarse material. For the study, a total of 100 samples (30- mt each) were analyzed during operation of Surface Miners Offer Savings in Several Areas product news