A process for producing substantially dry slag granules comprises adding a controlled amount of water to a molten stream of slag, and granulating the slag to produce solidified slag comprising substantially dry slag granules and slag wool. An apparatus for producing substantially dry slag granules comprises: (a) an inclined surface having an upper and lower ends for receiving and discharging the stream of slag; (b) a dispersion device at the lower end of the inclined surface for dispersion of the molten slag; (c) one or more water addition devices for adding a controlled amount of water to the molten slag; and (d) a collection area adjacent to the dispersion device for deposition of solidified slag produced by the dispersion. The quantity of slag wool produced by the process and apparatus is less than that which would be produced without the addition of water.

A process for producing substantially dry slag granules comprises adding a controlled amount of water to a molten stream of slag, and granulating the slag to produce solidified slag comprising substantially dry slag granules and slag wool. An apparatus for producing substantially dry slag granules comprises: (a) an inclined surface having an upper and lower ends for receiving and discharging the stream of slag; (b) a dispersion device at the lower end of the inclined surface for dispersion of the molten slag; (c) one or more water addition devices for adding a controlled amount of water to the molten slag; and (d) a collection area adjacent to the dispersion device for deposition of solidified slag produced by the dispersion. The quantity of slag wool produced by the process and apparatus is less than that which would be produced without the addition of water.

Improved casting powders and improved casting slags enable production of steels having high aluminum contents of greater than or equal to 1% by weight and, in some cases, high manganese content of greater than or equal to 15% by weight. In some examples, such steels may also or alternatively include greater than or equal to 0.2% by weight titanium. The casting slag may result from a casting powder that comprises CaO and Al.sub.2O.sub.3 components essentially in the form of prefused calcium aluminate. Methods for casting steel, including methods for continuously casting steel, are also disclosed based on the use of the disclosed casting powders or casting slags.

Improved casting powders and improved casting slags enable production of steels having high aluminum contents of greater than or equal to 1% by weight and, in some cases, high manganese content of greater than or equal to 15% by weight. In some examples, such steels may also or alternatively include greater than or equal to 0.2% by weight titanium. The casting slag may result from a casting powder that comprises CaO and Al.sub.2O.sub.3 components essentially in the form of prefused calcium aluminate. Methods for casting steel, including methods for continuously casting steel, are also disclosed based on the use of the disclosed casting powders or casting slags.

A process for preparing solid slag granules from a molten slag composition comprises: (a) providing the molten slag composition; (b) converting the molten slag composition into the solid slag granules in a dispersion apparatus; and (c) sorting the solid slag granules by shape in a separator to produce a plurality of fractions having different sphericities. Granular slag products comprise one or more fractions of solid slag granules produced by the process, and include proppants, roofing granules, catalyst supports, which may be porous or non-porous, and coated or uncoated.

A process for preparing solid slag granules from a molten slag composition comprises: (a) providing the molten slag composition; (b) converting the molten slag composition into the solid slag granules in a dispersion apparatus; and (c) sorting the solid slag granules by shape in a separator to produce a plurality of fractions having different sphericities. Granular slag products comprise one or more fractions of solid slag granules produced by the process, and include proppants, roofing granules, catalyst supports, which may be porous or non-porous, and coated or uncoated.

A method for producing hydrogen and/or other gases from steel plant wastes and waste heat is disclosed. The method comprises the steps of providing molten waste from steel plant like molten slag in a reactor. The molten slag is contacted with water and/or steam in the presence of a reducing agent to form a stream of hydrogen and/or other gases. The hydrogen and/or other gases can then be extracted from the stream of gases from the reactor.

A method for producing hydrogen and/or other gases from steel plant wastes and waste heat is disclosed. The method comprises the steps of providing molten waste from steel plant like molten slag in a reactor. The molten slag is contacted with water and/or steam in the presence of a reducing agent to form a stream of hydrogen and/or other gases. The hydrogen and/or other gases can then be extracted from the stream of gases from the reactor.

An apparatus for steel slag carbon fixation includes an apparatus body. A spray thrower and a gas outlet arranged at a top of a structure of the apparatus body, a material inlet, a material outlet and a gas inlet are formed on the apparatus body. A transfer unit having a plurality of transfer mechanisms is arranged inside the apparatus body. The apparatus feeds industrial waste gas containing carbon dioxide into steel slag while maintaining environmental humidity in a range from 80% to 100% to implement steel slag carbon fixation. Water content of the steel slag is maintained by controlling the environment humidity. Time of contact between water and the steel slag is reduced, element calcium in the steel slag is prevented from being dissolved out, a water film is not formed on a surface of the steel slag, thereby facilitating deep reaction of carbon dioxide and free calcium oxide.

An apparatus for steel slag carbon fixation includes an apparatus body. A spray thrower and a gas outlet arranged at a top of a structure of the apparatus body, a material inlet, a material outlet and a gas inlet are formed on the apparatus body. A transfer unit having a plurality of transfer mechanisms is arranged inside the apparatus body. The apparatus feeds industrial waste gas containing carbon dioxide into steel slag while maintaining environmental humidity in a range from 80% to 100% to implement steel slag carbon fixation. Water content of the steel slag is maintained by controlling the environment humidity. Time of contact between water and the steel slag is reduced, element calcium in the steel slag is prevented from being dissolved out, a water film is not formed on a surface of the steel slag, thereby facilitating deep reaction of carbon dioxide and free calcium oxide.