Patent ID: 7879132

Claim:
A method of reduction treatment of steelmaking waste, characterized by: mixing by agitation steelmaking waste in water sufficient to solubilize alkali salts, a pH adjuster, and a carbon-bearing material, then concentrating the mixture to produce a slurry, wherein the pH of water forming said slurry is adjusted to within the range from 7 to 11.5 to reduce dissolution of zinc and/or lead compounds, wherein said pH adjuster is at least one of a substance containing OH-groups and fly ash discharged from a refuse melting furnace or incinerator furnace, pressing said slurry to dehydrate said slurry, thereby providing a dehydrated material enriched in zinc, extruding said dehydrated material to shape it into shaped articles, charging said shaped articles into a moving hearth type reduction furnace for reduction and recovering a secondary dust enriched in zinc oxide.