Loesche Gmbh

Joerg Langel

Holger Wulfert

Carsten Gerold

Frank Dardemann

The invention relates to a preparation method for stainless steel slags and modified steelworks slags for recovery of metal. In order to create a dry preparation method which guarantees a low wear and energy efficient comminution and de-agglomeration of stainless steel slags and modified steelworks slags as well as a selective separation of a metal fraction and a silicate fraction and which can be variable in relation to the different slag compositions and different requirements upon the quality of the metal fraction and the at least one silicate fraction, a roller mill is used at least for the comminution. The slags are supplied with a feed grain size of up to approximately 150 mm. The use of an air swept roller mill is advantageous, in which the comminution and de-agglomeration, if necessary drying, and at the same time a separation into an extensively mineral-free metal fraction and a virtually metal-free silicate fraction are brought together. When using an overflow roller mill the separation of the metal fraction and the silicate fraction takes place in an external classifier.

Preparation method for stainless steel slags and steelworks slags for recovery of metal

A roller mill, particularly an air swept roller mill of the LOESCHE type. The roller mill is preferably provided for the comminution of cement clinker or granulated blast furnace slag and comprises on a grinding track of a rotating grinding pan stationary, rotating grinding rollers and between the grinding rollers stationary, rotatable preparation rollers which compress and remove air from the grinding bed. In order to increase the efficiency of the grinding process and at the same time to reduce the energy requirement the position of the preparation rollers is changed in such a way that the grinding material fed spirally to the grinding rollers is completely rolled over and compressed by the previously arranged preparation rollers. The preparation rollers are, seen in a top view of the grinding pan, positioned radially in the direction of the grinding pan center and roll with their running surfaces on a smaller running ring than the associated grinding rollers.

Roller mill

The invention relates to a roller mill having a grinding pan which is rotatable about a mill axis, on the grinding track of which grinding pan stationarily disposed grinding rollers roll and thereby define with their circumferential surfaces on the grinding track a running circle with an inner diameter and an outer diameter, and having a grinding material distributor for grinding material to be reduced, which is arranged as an elevation in the centre of the grinding pan coaxially with respect to the mill axis and rotates with the grinding pan. In order to achieve an improved inflow of the grinding material to the grinding rollers and an increased throughput performance of the roller mill a distributing plate is provided as the grinding material distributor, which is arranged at a defined distance from the grinding rollers and is thereby designed and dimensioned in such a way that there is a defined ratio between the inner diameter of the rolling circle and the diameter of the distributing plate at the level of the grinding track.

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Koeln-Porz, Germany

Joerg Langel