# US 8,540,798 B2 · Systems and methods for recycling steelmaking converter sludge > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,540,798 B2 - Document ID: US8540798B2 - Status: Granted - Kind: B2 - Application number: 12/984,409 - Filed: 2011-01-04 - Published: 2012-07-05 - Granted: 2013-09-24 - Earliest claimed: 2011-01-04 - Applicants: Guilherme Santana Lopes Gomes; Victor Loureiro Dos Santos - Inventors: Guilherme Santana Lopes Gomes; Victor Loureiro Dos Santos - Web page: https://patentgrep.com/patent/US8540798B2 ## CPC - C21B 3/04: Recovery of by-products, e.g. slag - C21C 5/38: Removal of waste gases or dust - C21C 5/40: Offtakes or separating apparatus for converter waste gases or dust - C22B 1/14: Agglomerating; Briquetting; Binding; Granulating - C22B 1/20: in sintering machines with movable grates - C22B 1/2406: {pelletizing} - C22B 1/243: inorganic - C22B 1/244: organic - C22B 7/005: {Separation by a physical processing technique only, e.g. by mechanical breaking} - C22B 7/02: Working-up flue dust - Y02P 10/20: Recycling - Y02P 10/25: Process efficiency - C21B: MANUFACTURE OF IRON OR STEEL (preliminary treatment of ferrous ores or scrap C22B1/00) - C21C: PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS - C22B: PRODUCTION AND REFINING OF METALS (electrolytic C25); PRETREATMENT OF RAW MATERIALS - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract Systems and methods for processing sludge from a fume scrubbing system that scrubs fumes from a steelmaking converter in a manner that separates/isolates a significant portion of the metallic iron particles in the sludge and prepares these particles for convenient handling. In an exemplary system, the system includes separating equipment that isolates metallic iron particles in the sludge and forming equipment that forms the isolated particles into briquettes that have relatively high mechanical resistance that allow the briquettes to maintain their integrity during handling and storage. The high-metallic-iron-content briquettes can be recycled in the steelmaking process, for example, as charging material for a basic oxygen converter or an electric arc furnace. Water used in the system can be recycled and reused within the system, thereby making the system environmentally friendly. ## Claims ### Claim 1 A system for processing sludge from a fume scrubbing system that scrubs fumes from a steelmaking converter, wherein the sludge includes metallic iron microspheres and non-metallic-iron material, the system comprising: separating equipment designed and configured to process the sludge so as to isolate substantially only metallic iron microspheres from the non-metallic-iron material, said separating equipment including an ultrasonic cleaner designed and configured to remove surficial fines bound to the metallic iron microspheres using at least two differing acoustic-cavitation excitation frequencies so as to create surface-cleaned metallic microspheres; and forming equipment designed and configured to receive the surface-cleaned metallic iron microspheres isolated by said separating equipment and form therewith cohesive bodies consisting essentially of the metallic iron microspheres isolated by said separating equipment. ### Claim 2 (depends on 1) A system according to claim 1, wherein said ultrasonic cleaner includes an acoustic cavitation device designed and configured to process a slurry made from the sludge in a continuous flow. ### Claim 3 (depends on 2) A system according to claim 2 wherein said acoustic cavitation device includes an acoustic cavitation duct defining an elongate fluid passageway having a flow axis, said acoustic cavitation device further comprising a plurality of ultrasonic transducers in acoustic communication with said elongate fluid passageway and spaced apart along said acoustic cavitation duct, wherein each of at least two of said plurality of ultrasonic transducers operate at said at least two differing acoustic-cavitation excitation frequencies. ### Claim 4 (depends on 1) A system according to claim 1, wherein said separating equipment further comprises a sludge conditioner designed and configured to make a slurry from the sludge for use in the ultrasonic cleaner. ### Claim 5 (depends on 1) A system according to claim 1, wherein the non-metallic-iron material includes non-metallic-iron particles and said separating equipment further comprises a separator downstream of said ultrasonic cleaner designed and configured to separate the metallic iron microspheres from the non-metallic-iron particles. ### Claim 6 (depends on 5) A system according to claim 5, wherein said separator comprises at least one gravity-separation spiral. ### Claim 7 (depends on 5) A system according to claim 5, wherein said forming equipment includes a pressure former designed and configured to form the metallic iron microspheres into loosely bound bodies. ### Claim 8 (depends on 7) A system according to claim 7, wherein said pressure former is a high-pressure briquette former that applies at least 30 metric tons to each briquette formed thereby. ### Claim 9 (depends on 7) A system according to claim 7, wherein said forming equipment further includes a heat-treatment device for converting the loosely bound bodies into the cohesive bodies. ### Claim 10 (depends on 1) A system according to claim 1, wherein said forming equipment includes a pressure former designed and configured to form the metallic iron microspheres into loosely bound bodies. ### Claim 11 (depends on 10) A system according to claim 10, wherein said pressure former is a high-pressure briquette former that applies at least 30 metric tons to each briquette formed thereby. ### Claim 12 (depends on 10) A system according to claim 10, wherein said forming equipment further includes a heat-treatment device for converting the loosely bound bodies into the cohesive bodies. ### Claim 13 A method for making metallic iron charge material for a steel converter or an electric arc furnace, the method comprising: receiving steel converter fume sludge; subjecting metallic iron microspheres present in the steel converter fume sludge to multi-frequency micro-acoustic cavitations designed to surface-clean the metallic iron microspheres; isolating the metallic iron microspheres; and forming a cohesive body consisting essentially only of the metallic iron microspheres isolated from the steel converter fume sludge. ### Claim 14 (depends on 13) A method according to claim 13, wherein said forming the cohesive body includes pressure forming the metallic iron microspheres into a loosely bound body. ### Claim 15 (depends on 14) A method according to claim 14, wherein said forming the cohesive body further includes heat treating the loosely bound body to create the cohesive body. ### Claim 16 (depends on 15) A method according to claim 15, wherein said heat treating the loosely bound body includes heating the loosely bound body to a point below which the metallic iron microspheres fuse with one another. ### Claim 17 A method of making steel, comprising: receiving basic oxygen converter fume sludge; surface-cleaning metallic iron microspheres present in the basic oxygen converter fume sludge using multi-frequency acoustic cavitations; isolating the metallic iron microspheres; collecting the isolated metallic iron microspheres; and adding the collected iron microspheres as charge material to a basic oxygen converter or an electric-arc furnace. ### Claim 18 (depends on 17) A method according to claim 17, wherein said collecting the isolated metallic iron microspheres includes forming a cohesive body consisting essentially only of the metallic iron microspheres isolated from the basic oxygen converter fume sludge, and said adding the collected metallic iron microspheres as charge material includes adding the cohesive body to the basic oxygen converter or the electric-arc furnace. ### Claim 19 (depends on 18) A method according to claim 18, wherein said forming the cohesive body includes pressure forming the metallic iron microspheres into a loosely bound body. ### Claim 20 (depends on 19) A method according to claim 19 wherein said forming the cohesive body further includes heat treating the loosely bound body to create the cohesive body. ### Claim 21 (depends on 20) A method according to claim 20, wherein said heat treating the loosely bound body includes heating the loosely bound body to a point below which the metallic microspheres fuse with one another.