# US 11,898,798 B1 · High-efficiency photonic furnaces for metal production > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,898,798 B1 - Document ID: US11898798B1 - Status: Granted - Kind: B1 - Application number: 18/176,997 - Filed: 2023-03-01 - Published: 2024-03-07 - Granted: 2024-02-13 - Earliest claimed: 2022-09-01 - Assignees: Limelight Steel Inc. - Applicants: Limelight Steel Inc. - Inventors: Olivia Faye Dippo; Andrew Zigang Zhao - Web page: https://patentgrep.com/patent/US11898798B1 ## CPC - F27B 3/20: Arrangements of heating devices - B23K 26/0648: {comprising lenses} - C21B 13/0006: {obtaining iron or steel in a molten state} - C21B 13/0073: {Selection or treatment of the reducing gases} - F27B 3/08: heated electrically, with or without any other source of heat - F27B 3/14: Arrangements of linings - F27D 99/0006: {Electric heating elements or system} - F27B: FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM - C21B: MANUFACTURE OF IRON OR STEEL (preliminary treatment of ferrous ores or scrap C22B1/00) - F27D: DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE ## Abstract Described herein are photonic furnaces and methods of using the same to produce metal products from a precursor material. ## Claims ### Claim 1 A photonic furnace for producing a metal product from a precursor material, the photonic furnace comprising: a reaction chamber; a precursor material inlet providing access to the reaction chamber; a product outlet adapted to facilitate retrieval of the metal product from the photonic furnace; a preheating chamber connected between the precursor material inlet and the reaction chamber; one or more light sources comprising a diode array, the light sources producing a light beam having an emission wavelength shorter than about 600 nm, the light beam of the one or more light sources being focused by one or more lenses to a beam impact area disposed within the reaction chamber or the preheating chamber, such that the focused beam of the one or more light sources provides a substantially uniform power density at the beam impact area, sufficient power density to raise a temperature of the beam impact area to at least a reaction temperature of the precursor material within less than about 5 seconds, the beam impact area being configured to facilitate conversion of the precursor material to the metal product. ### Claim 2 (depends on 1) The photonic furnace of claim 1, wherein the reaction temperature is a melting temperature of at least one component of the precursor material, or wherein the reaction temperature is a temperature required to cause a reducing agent in the reaction chamber to reduce a metal oxide in the reaction chamber. ### Claim 3 (depends on 2) The photonic furnace of claim 2, wherein the reducing agent is selected from the group consisting of hydrogen, ammonia, carbon, carbon monoxide, and combinations of two or more thereof. ### Claim 4 (depends on 3) The photonic furnace of claim 3, wherein the reducing agent and the metal oxide are heated separately. ### Claim 5 (depends on 1) The photonic furnace of claim 1, wherein the wavelength is about 400 nm to about 475 nm. ### Claim 6 (depends on 1) The photonic furnace of claim 1, wherein the reaction chamber comprises steel lined with a refractory ceramic coating, the refractory ceramic coating selected from the group consisting of aluminum oxide, zirconium oxide, silicon carbide, graphite, silicon oxide, and combinations thereof. ### Claim 7 (depends on 1) The photonic furnace of claim 1, wherein the furnace is configured to remove impurities from the precursor material during production of the metal product. ### Claim 8 (depends on 1) The photonic furnace of claim 1, wherein the precursor material is combined with at least one alloying element during production of the metal product. ### Claim 9 (depends on 2) The photonic furnace of claim 2, wherein the metal product is steel, a non-steel alloy comprising iron, or metallic iron and the precursor material is iron ore. ### Claim 10 (depends on 9) The photonic furnace of claim 9, wherein the reaction temperature is at least about 1600° C. ### Claim 11 (depends on 10) The photonic furnace of claim 10, wherein an amount of energy consumed by the furnace during production of the metal product is about 5-12 GJ/tonne of metal product. ### Claim 12 (depends on 10) The photonic furnace of claim 10, wherein an amount of electricity consumed by the furnace during production of the metal product is about 1-6 MWhr/tonne of metal product. ### Claim 13 (depends on 10) The photonic furnace of claim 10, wherein operation of the photonic furnace to produce steel consumes at least 30% less energy than operation of a blast furnace and/or a basic oxygen furnace to produce an equivalent amount of steel. ### Claim 14 (depends on 10) The photonic furnace of claim 10, wherein the total carbon dioxide emissions caused by production of the metal product by the furnace is at least 40% less than an equivalent metal product produced by a blast furnace. ### Claim 15 (depends on 1) The photonic furnace of claim 1, wherein the furnace is designed to be operated in a flow through manner and is capable of continuous metal product production. ### Claim 16 (depends on 1) The photonic furnace claim 1, wherein the one or more light sources comprises a laser or an electroluminescent light emitting diode. ### Claim 17 (depends on 16) The photonic furnace of claim 16, wherein the laser comprises a laser diode. ### Claim 18 (depends on 1) The photonic furnace of claim 1, comprising at least two light sources producing a light beam, wherein an emission wavelength of each light beam is shorter than about 600 nm and the beam impact areas of the light beams of the at least two light sources overlap in space by at least 20%. ### Claim 19 (depends on 18) The photonic furnace of claim 18, further comprising lenses, wherein the lenses are configured to focus or shape a profile of the beam impact area of the one or more light sources. ### Claim 20 (depends on 1) The photonic furnace of claim 1, wherein the furnace provides a substantially uniform power density at the beam impact area of the one or more light sources and a total power output to reactor volume ratio of about 5 kW/m3 to about 1600 kW/m3.