Abstract: The beneficiation of an electric arc furnace (EAF) dust waste stream comprising zinc compounds by collecting and combining dust from two or more EAF batches with coal fines to form briquettes, adding the briquettes to a final EAF batch with the charge, and collecting the dust from the final EAF batch, so that the zinc in the beneficiated dust is of a greater proportion than in a typical batch of EAF dust. Alternatively, the EAF dust can be split into two dust streams, one of which is returned to the EAF, while the other is treated in a hydrometallurgical process. Either waste stream preliminary can be treated by adding carbon and an ammonium chloride solution, separating any undissolved components from the solution, displacing undesired metal ions from the solution using zinc metal, treating the solution to remove therefrom zinc compounds, and further treating the zinc compounds and the undissolved components resulting in zinc products and an optional iron-carbon feedback.

Abstract: A method for producing a more concentrated iron product from an industrial waste materials stream comprising iron and non-iron constituents such as EAF and basic oxygen furnace dust generally comprising the steps of compacting or briquetting the waste materials stream, roasting the waste materials stream at temperatures above about 980.degree. C. to convert the iron compounds to direct reduced iron, crushing the roasted waste materials stream, separating the iron compounds contained in the waste materials stream by magnetic separation or flotation, and providing the iron compounds back to the EAF or basic oxygen furnace.

Abstract: An improved method for the recovery of metal and/or chemical values from an industrial waste stream containing zinc, cadmium, lead and/or iron compounds by heating the waste stream in a reducing atmosphere, treating the resultant fumes in an ammonium chloride solution, separating any undissolved components from the solution, adjusting the pH of the solution, if necessary, to less than about 6.3, displacing undesired metal ions from the solution using zinc metal, treating the solution to remove therefrom zinc compounds, adjusting the pH of the solution to about 6.5 to about 7.0, and further treating the zinc compounds and the undissolved components, as necessary, resulting in the zinc products and the optional iron-carbon feedstock.

Abstract: A method for producing direct reduced iron or/and pig iron from an industrial waste materials stream such as EAF and blast furnace dust generally comprising the steps of separating the materials contained in the waste materials stream by magnetic separation or flotation, briquetting the iron-containing materials separated during the separation process with carbon, and providing the briquettes to a reduction furnace or/and to a small scale blast furnace or cupola furnace to produce direct reduced iron or/and pig iron, respectively. The exhaust streams from the process are further treated to recover chemical values and to allow the recycle of the exhaust streams to the main process.

Abstract: A method for the production of Group IA salts during a process for the recycling of industrial waste streams containing Group IA compounds and iron and/or zinc compounds, by heating the waste stream in a reducing atmosphere, treating the exhaust fumes from the heating step with an ammonium chloride leaching solution resulting in a Group IA salt containing precipitate, and recovering the Group IA salts from the precipitate.

Abstract: A method for the production of zinc ammonium chloride complex salts for use as galvanizing fluxes by heating waste materials captured from industrial processes containing zinc in a reducing atmosphere, leaching the resultant captured waste materials in an ammonium chloride solution resulting in a first product solution and a first undissolved materials, adding zinc metal to the first product solution resulting in a second product solution and a second undissolved materials, and adding additional ammonium chloride and/or hydrochloric acid to the second product solution resulting in the production of zinc ammonium chloride complex salts for use as galvanizing fluxes.

Abstract: A method for the recovery of high purity zinc oxide products, and optionally iron-carbon feedstocks, from industrial waste streams containing zinc oxide and/or iron. The waste streams preliminarily can be treated by adding carbon and an ammonium chloride solution, separating any undissolved components from the solution, displacing undesired metal ions from the solution using zinc metal, treating the solution to remove therefrom zinc compounds, and further treating the zinc compounds and the undissolved components, as necessary, resulting in the zinc products and the optional iron-carbon feedbacks. Once the zinc oxide has been recovered, the purification process is used to further purify the zinc oxide to obtain zinc oxide which is at least 99.8% pure and which hsa predeterminable purity and particle characteristics.

Abstract: A method for the recovery of iron products, specifically direct reduced iron and iron oxide suitable for use as the feedstock for steel mills, from industrial waste streams containing iron, by treating the waste streams with an ammonium chloride leaching solution, separating the undissolved precipitates comprising iron compounds from the leachant solution, and further treating the undissolved precipitants by elevated temperature roasting, resulting in the iron feedstocks.

Abstract: A method for the removal of calcium byproducts created during the production of an iron-based feedstock suitable for use as the feedstock for steel mills, from industrial waste streams containing iron, by treating the waste stream with an ammonium chloride leaching solution, treating the leachant with a soluble ammonium salt in which the negative ion will form an insoluble compound with calcium, and separating the undissolved precipitates comprising iron compounds and calcium compounds from the leachant solution. The undissolved precipitants may be treated further by elevated temperature roasting, resulting in the iron-based feedstocks.

Abstract: A method for the production of an iron-based feedstock suitable for use as the feedstock for steel mills, from industrial waste streams containing iron, by combining an iron poor material such as exhaust fumes from metals production processes with the waste streams, treating the combined waste stream with an ammonium chloride leaching solution, separating the undissolved precipitates comprising iron compounds from the leachant solution, and further treating the undissolved precipitants by elevated temperature roasting, resulting in the iron-based feedstocks.

Abstract: A method for the production of an enriched iron product, specifically direct reduced iron and iron oxide suitable for use as the feedstock for steel mills, from industrial waste streams containing iron, by combining an iron oxide rich material such as mill scale and/or used batteries with the waste streams, treating the combined waste stream with an ammonium chloride leaching solution, separating the undissolved precipitates comprising iron compounds from the leachant solution, and further treating the undissolved precipitants by elevated temperature roasting, resulting in the iron feedstocks.

Abstract: A method for the recovery of zinc products, including zinc oxide and elemental zinc, and optionally iron-carbon feedstocks, from industrial waste streams containing zinc and iron, by treating the waste streams with carbon and an ammonium chloride solution, separating any undissolved components from the solution, displacing undesired metal ions from the solution using zinc metal, treating the solution to remove therefrom zinc compounds, and further treating the zinc compounds and the undissolved components, as necessary, resulting in the zinc products and the optional iron-carbon feedbacks.

Abstract: A method for the recovery of zinc oxide from industrial waste materials of various components, including zinc, lead, iron and cadmium, comprising the steps of treating the waste material with an ammonium chloride solution maintained at an elevated temperature, separating the undissolved components from the solution, treating the solution with zinc metal to displace undesired metal ions from the solution, cooling the solution to precipitate therefrom zinc compounds, washing the precipitated zinc compounds to remove unwanted compounds such as diamino zinc dichloride, and drying the remaining zinc compound which is essentially hydrated zinc oxide, resulting in essentially pure zinc oxide.