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
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, in particular in oxide form, 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 the mineral melt part of between 90 and 110, wherein the incorporation of the reducing agent is carried out in a non-oxidising furnace atmosphere,
- defined cooling, wherein the melt solidifies in 15 minutes at the latest,
- mechanical separation of at least part of the elemental iron from the solidified melt, and
- subsequent direct supply of the solidified melt with a reduced iron content and an alite content of at least 40 wt. % with a content of crystalline phases of at least 60 wt. % for use as hydraulic mineral binder.
Method according to clam 1,
- characterised in that
- liquid elemental iron is separated after the reduction and before solidification of the melt.
Dependencies are inferred from the claim text.