A method of manufacturing a valuable material product from an industrial dust is described. The method comprises: i) providing the industrial dust which comprises at least one valuable material and a first concentration of volatile constituents to a heating device with an operation temperature of 600° C. or more, ii) processing the industrial dust by the heating device, wherein processing comprises: iia) heating the industrial dust with a rate of 20° C./min or more, iib) thermally treating the industrial dust by the heating device with a treating temperature in the range of 900° C. to 1200° C., in particular in the range of 1000° C. to 1100° C., for 30 minutes or more, and iic) controlling and/or regulating the oxidizing conditions during processing, wherein processing comprises: at least partially removing the volatile constituents from the industrial dust, and iii) providing the valuable material product. Furthermore, the processed valuable material product is described.

The present invention relates to a sustainable regeneration process for metallurgical plant dusts and sludges for producing iron-containing, heavy metal-depleted secondary raw materials and recovering lead and zinc, by providing a first starting material which comprises at least one iron, zinc, lead and further heavy metal components containing metallurgical plant dust and/or sludge, and a second starting material containing at least one chlorine component, mixing the starting materials and drying the mixture, pyrolyzing the mixture for expelling zinc, lead and further heavy metal components, capturing the gas phase of the pyrolysis in sulfuric acid, and providing the residue which remains as an iron-containing secondary raw material depleted in zinc, lead and further heavy metal components.

Some variations provide a composition for reducing a metal ore, the composition comprising a carbon-metal ore particulate, wherein the carbon-metal ore particulate comprises at least about 0.1 wt % to at most about 50 wt % fixed carbon on a moisture-free and ash-free basis, and wherein the carbon is at least 50% renewable carbon as determined from a measurement of the .sup.14C/.sup.12C isotopic ratio. Some variations provide a process for reducing a metal ore, comprising: providing a biomass feedstock; pyrolyzing the feedstock to generate a biogenic reagent comprising carbon and a pyrolysis off-gas comprising hydrogen or carbon monoxide; obtaining a metal ore comprising a metal oxide; combining the carbon with the metal ore, to generate a carbon-metal ore particulate; optionally pelletizing the carbon-metal ore particulate; and utilizing the pyrolysis off-gas to chemically reduce the metal oxide to elemental metal, such as iron. The disclosed technologies are environmentally superior to conventional processes based on coal.

A method of forming a compact includes removing material from a workpiece, transferring metallic dust released during the material removal into a conduit, operating a plurality of slide gates to selectively control movement of the dust from the conduit to either one of a primary collector and a back-up collector, drawing the dust through the conduit to a compactor, and compacting the dust in the compactor.

In some variations, the disclosure provides a renewable biocarbon composition comprising from 50 wt% to 99 wt% total carbon, wherein the biocarbon composition is characterized by a base-acid ratio selected from 0.1 to 10, an iron-calcium ratio selected from 0.05 to 5, iron-plus-calcium parameter selected from 5 to 50 wt%, a slagging factor selected from 0.001 to 1, and/or a fouling factor or modified fouling factor selected from 0.1 to 10. Some variations provide a process comprising: providing a biomass feedstock; pyrolyzing the biomass feedstock to generate an intermediate biocarbon stream; washing or treating the intermediate biocarbon stream with an acid, a base, a salt, a metal, H.sub.2, H.sub.2O, CO, CO.sub.2, or a combination thereof, and/or introducing an additive in the process, to adjust a base-acid ratio or other compositional parameter; and recovering a biocarbon composition comprising from 50 wt% to 99 wt% total carbon and optimized for a compositional parameter.

This invention refers to a technically and economically viable process for recovery of relevant metallic and non-metallic contents from mining residues, particularly the bauxite residue, using it in its integral form. Such a process route uses energy from microwaves, assisted leaching and logic sequencing of steps that allow a technically and economically viable removal of components from the bauxite residue, particularly the residue from the Bayer process. The invention also refers to a microwave reactor that is appropriate for performing the above-mentioned process, as well as to a method for heating a mining product.

Some variations provide a carbon-negative carbon product that is characterized by a carbon intensity less than 0 kg CO.sub.2e per metric ton of the carbon-negative carbon product, wherein the carbon-negative carbon product contains at least about 50 wt % carbon. In some embodiments, the carbon intensity is less than −500 kg CO.sub.2e per metric ton of the carbon-negative carbon product. Other variations provide a carbon-negative metal product (e.g., a steel product) that is characterized by a carbon intensity less than 0 kg CO.sub.2e per metric ton of the carbon-negative metal product, wherein the metal product contains from 50 wt % to 100 wt % of one or more metals and optionally one or more alloying elements. In some embodiments, the carbon-negative metal product is characterized by a carbon intensity less than −200 kg CO.sub.2e per metric ton of the carbon-negative metal product. The carbon-negative metal product can contain a wide variety of metals.

A two stage dross treatment capable of being performed in a single reaction vessel is disclosed. Dross, especially white dross, can be contacted with salt flux in a rotary furnace to recover metal from the dross. This first stage can recover metal during the conversion of white dross and salt flux to salt cake. In a second stage, the furnace can be raised to a sufficiently high temperature to evaporate the salt content of the salt cake, allowing the evaporated salt to exit the furnace and be separately condensed and collected. The result of the second stage is collected salt and salt-free oxides. After removing the salt-free oxides, residual heat in the furnace and collected salt can be used for a subsequent dross treatment.

Some variations provide a carbon-negative carbon product that is characterized by a carbon intensity less than 0 kg CO.sub.2e per metric ton of the carbon-negative carbon product, wherein the carbon-negative carbon product contains at least about 50 wt % carbon. In some embodiments, the carbon intensity is less than −500 kg CO.sub.2e per metric ton of the carbon-negative carbon product. Other variations provide a carbon-negative metal product (e.g., a steel product) that is characterized by a carbon intensity less than 0 kg CO.sub.2e per metric ton of the carbon-negative metal product, wherein the metal product contains from 50 wt % to 100 wt % of one or more metals and optionally one or more alloying elements. In some embodiments, the carbon-negative metal product is characterized by a carbon intensity less than −200 kg CO.sub.2e per metric ton of the carbon-negative metal product. The carbon-negative metal product can contain a wide variety of metals.

Some variations provide a composition for reducing a metal ore, the composition comprising a carbon-metal ore particulate, wherein the carbon-metal ore particulate comprises at least about 0.1 wt % to at most about 50 wt % fixed carbon on a moisture-free and ash-free basis, and wherein the carbon is at least 50% renewable carbon as determined from a measurement of the .sup.14C/.sup.12C isotopic ratio. Some variations provide a process for reducing a metal ore, comprising: providing a biomass feedstock; pyrolyzing the feedstock to generate a biogenic reagent comprising carbon and a pyrolysis off-gas comprising hydrogen or carbon monoxide; obtaining a metal ore comprising a metal oxide; combining the carbon with the metal ore, to generate a carbon-metal ore particulate; optionally pelletizing the carbon-metal ore particulate; and utilizing the pyrolysis off-gas to chemically reduce the metal oxide to elemental metal, such as iron. The disclosed technologies are environmentally superior to conventional processes based on coal.