A method for manufacturing cement clinker raw materials includes at least one stainless steel slag material that is calcined and burned to produce the cement clinker. The method further includes solidifying the liquid steel slag so that it comprises a sufficiently small amount of fines. These fines and/or the fines produced when crushing the coarser fraction of the steel slag to recover stainless steel are used as powdery stainless steel slag material for manufacturing cement clinker. These fines contain considerably less chromium than the sand and the coarser aggregate fractions produced from the solidified stainless steel slag. By replacing the conventional lime sources partially by the stainless steel slag material, carbon dioxide emissions and the energy requirements of the cement kiln can be reduced. The powdery stainless steel slag material also does not need to be finely ground and melts immediately in the rotary kiln.

A method for manufacturing cement clinker raw materials includes at least one stainless steel slag material that is calcined and burned to produce the cement clinker. The method further includes solidifying the liquid steel slag so that it comprises a sufficiently small amount of fines. These fines and/or the fines produced when crushing the coarser fraction of the steel slag to recover stainless steel are used as powdery stainless steel slag material for manufacturing cement clinker. These fines contain considerably less chromium than the sand and the coarser aggregate fractions produced from the solidified stainless steel slag. By replacing the conventional lime sources partially by the stainless steel slag material, carbon dioxide emissions and the energy requirements of the cement kiln can be reduced. The powdery stainless steel slag material also does not need to be finely ground and melts immediately in the rotary kiln.

A method and apparatus for processing a material are provided, the material being the upper layer from a metal melting process, the material containing one or more salts, the material containing one or more metals, the salts and/or metals being recycled as a result of the method/apparatus. The method includes feeding the material to a leaching step; obtaining a leachate from the leaching step; feeding the leachate to a drying step or spray drying step; obtaining a solid from the drying step or spray drying step. Off gases from the leaching step are used to provide heat to the drying step. The drying step provides a product well suited to being turned into pellets for reuse.

A method and apparatus for processing a material are provided, the material being the upper layer from a metal melting process, the material containing one or more salts, the material containing one or more metals, the salts and/or metals being recycled as a result of the method/apparatus. The method includes feeding the material to a leaching step; obtaining a leachate from the leaching step; feeding the leachate to a drying step or spray drying step; obtaining a solid from the drying step or spray drying step. Off gases from the leaching step are used to provide heat to the drying step. The drying step provides a product well suited to being turned into pellets for reuse.

A method of manufacturing inorganic binder by reduction furnace slag includes a raw material preparation step, a stirring step, a maintaining step and a drying step. The raw material preparation step is to provide a powder mixture containing 30 wt % to 55 wt % of reduction furnace slag, and 45 wt % to 70 wt % of glass powder. The stirring step is to place the powder mixture in a mixing tank, and add an alkali activator to the mixing tank to stir and react to form mixed slurry. The alkali equivalent (AE) of the mixed slurry is 2% to 7%, and the water-binder ratio is 0.25 to 0.4. The maintaining step is to place the mixed slurry in a high-temperature and high pressure maintaining environment for a maintaining time to get a binder. The drying step is to dry the binder.