Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • 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
  • F27D1/00—Casings; Linings; Walls; Roofs
  • F27D1/16—Making or repairing linings increasing the durability of linings or breaking away linings
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
  • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
  • C21C5/28—Manufacture of steel in the converter
  • C21C5/30—Regulating or controlling the blowing
  • C21C5/35—Blowing from above and through the bath
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
  • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
  • C21C5/28—Manufacture of steel in the converter
  • C21C5/36—Processes yielding slags of special composition
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
  • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
  • C21C5/28—Manufacture of steel in the converter
  • C21C5/42—Constructional features of converters
  • C21C5/44—Refractory linings
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
  • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
  • C21C7/0087—Treatment of slags covering the steel bath, e.g. for separating slag from the molten metal
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • 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
  • F27D1/00—Casings; Linings; Walls; Roofs
  • F27D1/0003—Linings or walls
  • F27D1/003—Linings or walls comprising porous bricks
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • 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
  • F27D3/00—Charging; Discharging; Manipulation of charge
  • F27D3/16—Introducing a fluid jet or current into the charge
  • F27D2003/161—Introducing a fluid jet or current into the charge through a porous element
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27M—INDEXING SCHEME RELATING TO ASPECTS OF THE CHARGES OR FURNACES, KILNS, OVENS OR RETORTS
  • F27M2003/00—Type of treatment of the charge
  • F27M2003/02—Preheating, e.g. in a laminating line
  • F27M2003/025—Drying

Definitions

• the present invention relates to the field of the production of metals, in particular steel. More specifically, it relates to metallurgical refining vessels, in particular steel refinery converters with top-blown oxygen blowing, the bottom of which is provided with permeable refractory elements.
• Metallurgical treatments consist in subjecting a bath of molten metal to pneumatic stirring by controlled injection of a stirring fluid, usually an inert gas such as nitrogen or argon, through permeable refractory elements mounted in the usual refractory lining which forms the bottom of the container containing the bath (FR-A-2,322,202, US No. 3,259,484).
• a stirring fluid usually an inert gas such as nitrogen or argon
• the subject of the invention is a method for improving the life of the permeable refractory elements fitted to the bottom of metallurgical refining vessels, in particular the converters of steel blown from above, said elements serving for the controlled injection of a stirring fluid into the molten metal bath contained in the container, process characterized in that during the refining of any charge, a fluid slag is formed which is kept then in the converter after casting the molten metal by tilting said container; in that the container is straightened in a vertical position so that the milk is deposited and distributed on the bottom; and in that said slag is allowed to dry and ensure its setting while maintaining in the permeable refractory elements a sufficient pressure to ensure a permanent flow of the brewing fluid not exceeding approximately 30 m 3 / h per element, counted in m 3 gas, so as to form a network of channels connecting the blowing face of said elements to the free surface of the bottom through the layer of slag deposited.
• the metallurgical refining container is a converter of steelworks to oxygen blown from above (type LD), it being understood that the invention also applies to any metallurgical container capable of tipping over. around a horizontal axis and in which the refining operation is accompanied by the formation of a slag.
• the deposition technique according to the invention is inspired by the practice of maintaining the funds of steelworks converters, known under the Anglo-Saxon name pictured "slagging-in” and reported, for example, in the European patent application. published n ° 0007657. It can be carried out systematically after each charge, or at least after each charge which has led to exposure, even partial, of the permeable refractory elements.
• the proposed method is very simple and poses no uncontrolled difficulty. It supposes only the precaution of forming, during, or more simply at the end of refining of a charge, a slag capable, by its fluidity, of flowing along the wall of the converter, then spreading over the bottom and stick to it while hardening. In practice, this boils down to a person skilled in the art to a visual verification of the slag's ability to meet these three requirements, which, moreover, is intended to be designated by the expression "we form a fluid slag" used in the above formulation of the object of the invention.
• thinning agents such as fluorspar, or other usual flux, which lowers its melting temperature.
• thickeners will be added to the slag, for example dolomite or any other refractory oxide or mixture of refractory oxides which is commonly used in steel works.
• the slag forms a refractory layer which subtracts the permeable elements from direct contact with the molten metal bath. Furthermore, the presence of these permeable elements at the bottom does not imply any other requirement during the hardening of the slag than that which consists in maintaining through them a low flow rate of brewing fluid, flow which can be qualified "safety" and which, moreover, does not penalize productivity in any way, since it takes place during the necessary hardening of the slag.
• a possible indicator of the "level" of permeability can be constituted by the pressure / flow rate ratio of fluid in the supply line of the latter to the permeable refractory element. This ratio can be determined from a reference value taken when the element is in the new state by vacuum blowing, or during the refining of the first charge to the converter.
• stirring fluid which can, for one part, circulate laterally in zones of less pressure drop which possibly form at the interface of the layer of slag deposited and of the pre-existing refractory bottom.
• the technique according to the invention can be implemented at any time, between any two loads of the same campaign or even at the end of the first load, on a converter in the state new.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Analytical Chemistry (AREA)
• Carbon Steel Or Casting Steel Manufacturing (AREA)
• Treatment Of Steel In Its Molten State (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (2)

Family

ID=9273360

Family Applications (1)

Country Status (13)

Cited By (1)

Families Citing this family (7)

Family Cites Families (15)

• 1982
  • 1982-04-22 FR FR8207118A patent/FR2525633A1/fr active Granted
• 1983
  • 1983-04-11 LU LU84742A patent/LU84742A1/fr unknown
  • 1983-04-18 DE DE8383400766T patent/DE3376225D1/de not_active Expired
  • 1983-04-18 AT AT83400766T patent/ATE33401T1/de not_active IP Right Cessation
  • 1983-04-18 EP EP83400766A patent/EP0093040B1/fr not_active Expired
  • 1983-04-19 BR BR8302006A patent/BR8302006A/pt not_active IP Right Cessation
  • 1983-04-19 ZA ZA832760A patent/ZA832760B/xx unknown
  • 1983-04-20 US US06/486,844 patent/US4690386A/en not_active Expired - Fee Related
  • 1983-04-21 CA CA000426382A patent/CA1205637A/fr not_active Expired
  • 1983-04-21 BE BE6/47817A patent/BE896539A/fr not_active IP Right Cessation
  • 1983-04-22 KR KR1019830001714A patent/KR910002863B1/ko not_active IP Right Cessation
  • 1983-04-22 JP JP58071332A patent/JPS5941412A/ja active Pending
  • 1983-04-22 IT IT20765/83A patent/IT1194212B/it active
• 1987
  • 1987-04-15 US US07/038,542 patent/US4735398A/en not_active Expired - Fee Related

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