The history of Rammelsbach Quarry in Rhineland-Palatinate stretches back to the 1860s when extraction began there. In the 1930s, Rammelsbach was regarded as the biggest quarry in Europe. Since 2001, the quarry has been owned by the Basalt-Actien-Gesellschaft (BAG), one of the biggest aggregate producers in Europe. The company offers its customers a full range of products: high-grade chippings, railway ballast, aggregates for asphalt and concrete as well as other aggregates needed in the construction industry. In Rammelsbach, microdiorite, i.e. cuselite, which is named after the nearby town of Kusel, is quarried. The hard rock with a specific density of 2.68 t/m³ is especially suitable for producing high-quality railway ballast. That’s why around 50 % of the total production is supplied to the railway company Deutsche Bahn AG and used all over Germany. The 150-year-old Rammelsbach Quarry still holds reserves for at least 20 years.
“Operational reliability is our highest priority. With the new Nordberg® GP330™ gyratory crusher, we ensure continuous, trouble-free crushing in our secondary crushing stage and crush around 4000 t high-grade aggregates daily,” says Kurt Schön, Production Manager at BAG-Rammelsbach Quarry, talking about the GP330 gyratory crusher – the first of its type in operation in Germany. “Thanks to the IC50C process control, all functions of the crusher can be easily adjusted – a huge improvement on its predecessor from the 1980s. To ensure interruption-free continuous operation in future, too, we have concluded an EPP contract with Metso for five years. The Equipment Protection Plan includes regular inspections as well as the most important service functions and replacement parts,” adds Kurt Schön.
It’s not the quantity that counts in Rammelsbach, but consistently high quality. “Everything is meticulously documented in our operation. From every 1000th tonne loaded railway ballast, a sample is taken. Every stone produced has to meet our high quality standards with regard to size, particle shape and purity, which is why we have six different testing steps in our production,” the production manager stresses. Besides ballast, in Rammelsbach they produce everything needed to cover the regional demand: various high-grade chipping sizes for asphalt, concrete and other aggregate mixes.
The blasted microdiorite is transported on a heavy-duty truck to the primary gyratory crusher. After this, the material is separated into three particle sizes: 0 – 32 mm is removed, 32 – 70 mm and 70 – 240 mm are intermediately stored in silos and fed in a suitable mix on feeders and a feed belt to the Metso GP330 gyratory crusher. With a constant throughput rate of 340 t/h, the crusher produces well-shaped particles in the size range 0 – 80 mm for further processing. The microdiorite is abrasive, for this reason the crushing tools have to be replaced after 1900 operating hours – thanks to the high throughput rate and capacity utilization, the specific wear costs are low. Costs are also saved with the new Metso bypass oil filter, which substantially lengthens the service lifetime of the hydraulic oil.