NEW LIMESTONE QUARRY WITH NEW TECHNOLOGY

A new limestone quarry was opened up at Marker Zementwerk in Harburg i n 1996. The quarry has a mobile, crawler-mounted continuous stream cru sher, and the crashed limestone is transported on a curved belt convey or over a distance of 1.2 km to the old quarry in the immediate vicini ty of the works. Because it is used for feeding lime kilns the finishe d product should have the highest possible proportion in the edge leng th range from 50 to 200 mm with little fine-grained material, so it wa s decided to use a continuous stream crasher Incidentally, this type o f crusher also proved to be the best option with respect to capital co sts. The continuous stream crusher is fed by the upper strand of a cha in conveyor located underneath the rotor which is supplied via a feed hopper by a wheeled front-end rotor with a bucket capacity of 8.4 m(3) . The mobile crashing plant provides a throughput of 1 000 t/h and is actually controlled by the driver of the front-end loader. This one-ma n operation has proved successful with travel distances of the front-e nd loader of up to 100 m. After eliminating numerous faults in the mob ile crushing plant the equipment in the new quarry has now reached a l evel of availability which fully matches the expectations.