HAZEMAG & EPR GmbH supplied the first semi-mobile impact roll crusher plant in Austria. It was purchased by “Zementwerk Leube GmbH”, one of the leading companies of the Austrian building materials industry. Besides the compact and simple semi-mobile design (which is rather unusual for a 600 – 800 t/h limestone crushing plant) the integration of a feeder grate as a primary screen was the decisive reason for the purchase of the impact roll crusher. Even with high through put and the large feed size of up to 1.2 m the end pro-duct had to have a final crush size of 0 –250 mm with a minimal amount of fines production in the final product.
The plant utilizes a 15 m² feed hopper and is fed using front end loaders (Fig. 1). Thanks to the unique technology of the horizontal flow neither a bench edge, nor a loading ramp is required for the feeding in comparison to conventional primary crushing plants. Therefore, the unit may be relocated easily and quickly. It is simple to use a front end loader to reposition the plant in less than 30 minutes without any problems or any special pad to set the unit on. The material is conveyed from the feed hopper via a solid chain conveyor (KF 1200) to the crushing chamber. The roller screen (RR 1,1 x 14 x 25), which is integrated in the chain conveyor, guarantees a primary screening of up to 120 mm (Fig. 2). The feed greater then 120 mm is crushed in the impact roll crusher to a conveyor-sized dimension with a grain composition of k98 = 250 mm. In doing so, the end product will only contain up to 17 % max. grain size range of 0-16 mm.
The roll of the crusher is fitted with 7 adjustable impact elements 3 on one side and four on the same plane on the other side. These impact elements crush the material directly on the chain conveyor as it fed into and through the crushing chamber (Fig. 3). The crushed limestone is then fed to the discharge belt of the crushing plant which transports the material via a downstream mobile conveyor plant to the secondary crushing plant.
In comparison to most other mobile plants of this performance class, this plant is exclusively environment-friendly, utilizing 100% electric line power. The compact design means there is no powered tracks required, which means there is no requirement for a diesel generator to operate the necessary hydraulics to operate the powered tracks. Within only 10 days the plant was assembled in the quarry and the first test runs with and without material could be carried out. After the necessary fine adjustments the customer’s target values with regard to throughput rate and fine grain were achieved.