Granodiorite – efficient extraction in the countryside
EUROVIA Gestein GmbH is a subsidiary of VINCI, a French group of companies represented in around 100 countries. The company operates five quarries and about a dozen sand and gravel pits in Germany. The quarry in Oberottendorf (Fig. 1) has been in operation since 1938. At this site, 32 employees produce ballast, mineral blends and chippings. Around 1 mill. t granodiorite are extracted annually. All the crushing stages for processing the chippings are equipped with Sandvik crushers: 1 x JM1511, 1 x S4000, 3 x H3000. In the production of various mineral blends, crushers and screens from Sandvik are used: 1 x JM1211 as a primary crusher, 1 x S4000 as a secondary crusher, as well as various screens which process according to the specifications of highly varying mineral mixes for freeway, railway and watercourse construction.
The operations manager, Richard Bauhuber, was recently faced with the decision of replacing the Pantera 1100 with a new drill with the aim of increasing the annual drilling capacity to around 35 000 metres of drill holes in regular shifts. Prelimiary discussions were started on-site about the new model of the rig, the DP1100i (Fig. 2), the letter “i” standing for “intelligent”. From the start, Bauhuber was impressed by the improvements and technic novelties. GPS and laser technology in combination with Sandvik GT60 drill bits (Fig. 3) and steels were an important aspects in making the decision for the DP1100i. After negotiations at the company headquarters of EUROVIA Gestein GmbH in Bottrop, the decision was quickly finalized.
EUROVIA’s operations manager and drill operative were excited to receive the delivery of the new rig and instructions how to use it. Due to the good experience with the preceding model, the expectations were very high. The new technology of the GPS compass systems was designed to make the work in the cramped quarry easier and more accurate allowing a constant blasting direction to be maintained. Lager-based depth measuring should enhance the depth measurements and help the operator to keep a constant drilling depth. Compared with the ST58 tools previously used, the combination of GT60 drill steels and GT60 Retrac dril bits enable shorter drilling times, more accurate drilling and longer tool life. Sandvik‘s drill tip reconditioning service is a further benefit appreciated by the Oberottendorf team. Worn bits are collected at the quarry, and re-delivered by Sandvik after regrinding (Fig. 4). The tools costs are additionally lowered by the multiple use of the drill bits.
Mr. Bauhuber already has positive words about the experience thanks to a short start-up and positive feedback from the operator: “The GPS system and the laser levelling are easier to operate than we had feared and work better than expected.”
