Method for processing steel slag and hydraulic mineral binder
AssigneeLoesche GmbH
InventorsHolger Wulfert, Horst Michael Ludwig
Life of this patent
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Abstract
The invention relates to a method for processing steel slag to produce a hydraulic mineral binder with a high hardening potential and to recover iron. There is provision for this purpose to provide a feed product comprising steel slag with MnO. This feed product is further processed as a melt by introducing reducing agents into the melt. A lime saturation factor of between 90 and 110 is hereby to be achieved in the mineral melt portion. Subsequently the melt is cooled in a defined manner and elemental iron is mechanically separated from the solidified melt. The solidified melt is then supplied for use as hydraulic mineral binder.
Claims14
A method for processing steel slag to produce a hydraulic mineral binder with high hardening potential and to recover iron, comprising the steps:
- providing a feed product comprising steel slag with iron compounds, and MnO, whereby the MnO may be contained in the steel slag, processing the feed product as melt in a furnace,
- incorporating reducing agents into the melt to reduce the iron compounds in order to achieve a lime saturation factor in a mineral part of the melt between 90 and 110, wherein the reduction is carried out in a non-oxidizing furnace atmosphere,
- cooling the melt such that the melt solidifies in less than 15 minutes, and
- mechanically separating at least part of the elemental iron from the solidified melt,
- wherein the solidified melt following the mechanical separation has a reduced iron content and an alite content of at least 40 wt. % with a content of crystalline phases of at least 60 wt. %, and wherein the solidified melt with the reduced iron content is for use as a hydraulic mineral binder.
Dependencies are inferred from the claim text.