MOLTEN IRON DEPHOSPHORIZATION METHOD

    公开(公告)号:US20220259686A1

    公开(公告)日:2022-08-18

    申请号:US17626083

    申请日:2020-07-02

    IPC分类号: C21C1/02

    摘要: A dephosphorization method using a top and bottom blown converter. This method uses a converter charged with molten iron and slag, to blow an oxygen-containing gas from a top-blowing lance, supply the gas from an inlet of a blowing hole, and supply a control gas from an opening toward an axial center. This method has: a slag top-surface position measurement step, with the top surface of the molten iron measured in advance, measuring an arbitrary position in a top surface of the slag; a slag top-surface difference calculation of slag thickness difference between the measured top-surface positions of the molten iron and the slag; and a jetting condition adjustment step of, using the obtained slag thickness, adjusting a jetting condition of the gas jetted from the top-blowing lance into an appropriate range. The top-blown jetting condition is adjusted by comparing the slag thickness and the depth of a surface depression.

    METHOD FOR PREDICTING SLOPPING IN CONVERTER, METHOD FOR OPERATING CONVERTER, AND SYSTEM FOR PREDICTING SLOPPING IN CONVERTER

    公开(公告)号:US20220177987A1

    公开(公告)日:2022-06-09

    申请号:US17600827

    申请日:2020-03-24

    IPC分类号: C21C5/46 C21C5/30 G01N21/71

    摘要: A method and system for predicting slopping in a converter occurring during decarburization refining in the converter in which molten steel is produced from a molten pig iron by blowing oxidizing gas to the molten pig iron in the converter from a top blowing lance, or optionally further blowing oxidizing gas or inert gas from a bottom blowing tuyere to perform the decarburization refining of the molten pig iron. The method includes measuring an emission spectrum of a throat combustion flame blowing out from a throat of the converter, calculating emission intensity of the measured emission spectrum at a wavelength in a range of 580 to 620 nm, and predicting the occurrence of the slopping based on a time-series change of the calculated emission intensity.

    METHOD FOR OPERATING CONVERTER
    3.
    发明申请

    公开(公告)号:US20200157645A1

    公开(公告)日:2020-05-21

    申请号:US16611674

    申请日:2018-05-07

    IPC分类号: C21C5/32 C21C5/46

    摘要: When the decarburization refining of molten iron is performed by top-blowing oxygen gas from the top blowing lance, the oscillation of molten iron, a bubble burst, and spitting due to the bubble burst are suppressed. A refining method for a converter includes decarburizing molten iron in the converter with a top blowing lance having Laval nozzles disposed at the lower end thereof by blowing oxygen gas on the surface of the molten iron in the converter through the Laval nozzles, in which one or both of an oxygen feeding rate from the top blowing lance and lance height LH are adjusted in such a manner that an oxygen accumulation index S(F) is 40 or less.

    CONVERTER STEELMAKING METHOD
    4.
    发明公开

    公开(公告)号:US20240068061A1

    公开(公告)日:2024-02-29

    申请号:US18270606

    申请日:2021-12-17

    摘要: A converter steelmaking method has molten pig iron subjected to dephosphorization process for dephosphorized molten iron, dephosphorized molten iron is subjected to decarburization process for molten steel. For dephosphorization process, a first cold iron source in amount meeting Formula (1) is charged into first converter-type vessel, then undephosphorized molten pig iron is charged and subjected to dephosphorization process. Dephosphorized molten iron is discharged and held in molten metal receiving vessel. After second cold iron source is charged into first converter-type vessel in which dephosphorization process has been performed, the dephosphorized molten iron held in molten metal receiving vessel is charged and subjected to decarburization process. % Ws0≤0.1186T−134 (% Ws0≥0) . . . (1), where % Ws0: a ratio (%) of first cold iron source to sum of first cold iron source and charge amount of undephosphorized molten pig iron, and T: a temperature (° C.) of undephosphorized molten pig iron.

    METHOD FOR MANUFACTURING MANGANESE RAW MATERIAL AND METHOD FOR MANUFACTURING MANGANESE-CONTAINING MOLTEN STEEL

    公开(公告)号:US20210054479A1

    公开(公告)日:2021-02-25

    申请号:US16977378

    申请日:2019-02-22

    IPC分类号: C22B9/14 C22B47/00 C21C7/00

    摘要: A manufacturing method includes a first pulverization step of compressively pulverizing a manganese oxide-containing material containing at least manganese, calcium, silicon, iron, and phosphorus, which is used as a raw material, to form a composite in which a compound phase of nCaO.P2O5 is combined with at least one phase of a spinel phase and a calcium ferrite phase, which are ferromagnetic materials, and produce a first pulverized manganese oxide-containing material containing the composite; a first magnetic separation step of separating the first pulverized manganese oxide-containing material produced in the pulverization step into a magnetic substance and a non-magnetic substance under a magnetic force; and a step of recovering the non-magnetic substance separated in the first magnetic separation step as a manganese raw material.

    METHOD FOR REFINING MOLTEN STEEL IN VACUUM DEGASSING EQUIPMENT

    公开(公告)号:US20190048431A1

    公开(公告)日:2019-02-14

    申请号:US16079712

    申请日:2017-02-15

    IPC分类号: C21C7/10 C21C7/064 C21C7/072

    摘要: A molten steel refining method includes throwing a powder to molten steel while heating the powder with a flame formed by combustion of a hydrocarbon gas at the leading end of a top blowing lance. The lance height of the top blowing lance (the distance between the static bath surface of the molten steel and the leading end of the lance) is controlled to 1.0 to 7.0 m, and the dynamic pressure P of a jet flow ejected from the top blowing lance calculated from equation (1) below is controlled to 20.0 kPa or more and 100.0 kPa or less. P=ρg× U2/2 . . . (1) wherein P is the dynamic pressure (kPa) of the jet flow at an exit of the top blowing lance, ρg the density (kg/Nm3) of the jet flow, and U the velocity (m/sec) of the jet flow at the exit of the top blowing lance.

    MOLTEN IRON REFINING METHOD
    7.
    发明公开

    公开(公告)号:US20240076754A1

    公开(公告)日:2024-03-07

    申请号:US18270617

    申请日:2021-12-21

    IPC分类号: C21C5/35 C21C7/064 C21C7/068

    CPC分类号: C21C5/35 C21C7/064 C21C7/068

    摘要: A molten iron refining method having, an auxiliary material, and an oxidizing gas supplied through a top-blowing lance, to a cold iron source and molten pig iron that are contained/fed in a converter-type vessel, and molten iron is subjected to a refining process. A pre-charged cold iron source is charged into the converter-type vessel at an amount not larger than 0.15 times. A furnace-top-added cold iron source that's part or all of the cold iron source and added from a furnace top is fed during the refining process. A burner at a leading end of the top-blowing lance that spray holes through which a fuel and a combustion-supporting gas are ejected. During the refining process, a powdery auxiliary material processed into powder that's part of the auxiliary material is blown in, to pass through a flame formed by the burner.

    LANCE NOZZLE
    10.
    发明申请

    公开(公告)号:US20220154299A1

    公开(公告)日:2022-05-19

    申请号:US17601481

    申请日:2020-04-02

    IPC分类号: C21C5/46

    摘要: A top-blowing lance nozzle is configured to freely switch an adequate expansion condition so as to control an oxygen-blowing amount and a jetting velocity independently of each other without requiring a plurality of lance nozzles or a mechanically movable part. A lance nozzle is configured to blow refining oxygen to molten iron charged in a reaction vessel while a gas is blown from a top-blowing lance to the molten iron. One or more blowing holes for blowing a working gas are on an inner wall side surface of the nozzle, at a site where the lance nozzle has a minimum cross-sectional area in a nozzle axis direction or at a neighboring site of the site.