公开(公告)号：EP1340822B1

公开(公告)日：2008-01-16

申请号：EP01982753.4

申请日：2001-11-09

申请人： Nippon Steel Corporation

发明人： IBARAKI, Tetuharu ,  ODA, Hiroshi ,  TAKAHASHI, Masaharu

IPC分类号： C21B13/10 ,  C21B11/08 ,  F27D17/00 ,  C22B1/16 ,  C21B13/08

CPC分类号： C21B13/105 ,  C21B13/0073 ,  C21B13/10 ,  C21B2100/44 ,  C21B2100/66 ,  C22B5/10 ,  F27B9/16 ,  F27D17/004 ,  Y02P10/136 ,  Y02P10/216

摘要： A method of operating a rotary hearth type reducing furnace, characterized in that a combustion gas generated in the furnace is held in a state, wherein the temperature of the gas is 800 DEG C or higher, the concentration of carbon monoxide is 2000 ppm by volume or less and turbulent flow is satisfactorily developed, for a period of a predetermined time or more, in at least one of the inside of an exhaust gas exit duct and the vicinity of the exhaust gas exit duct, and then is cooled rapidly; and rotary hearth type reducing furnace facilities required for the practice of the method of operation. The operating method allows the suppression of generation of dioxins in a combustion exhaust gas and also the efficient recovery of heat from the combustion exhaust gas having an elevated temperature, in a process of firing and reducing pellets or the like formed from a ore powder such as a chromium ore or iron ore powder, or a dust, a sludge or the like containing an oxidized metal such as iron oxide generated in the metal industry in a rotary hearth type reducing furnace, and also allows the total mole number of zinc and lead, the total mole number of alkali metals, and the total mole number of halogen elements contained in a dust in the combustion exhaust gas to be controlled so that the three numbers satisfy a specific relationship.

公开(公告)号：EP1340822A1

公开(公告)日：2003-09-03

申请号：EP01982753.4

申请日：2001-11-09

申请人： NIPPON STEEL CORPORATION

发明人： IBARAKI, Tetuharu ,  ODA, Hiroshi ,  TAKAHASHI, Masaharu

IPC分类号： C21B13/10 ,  C21B11/08 ,  F27D17/00 ,  C22B1/16

CPC分类号： C21B13/105 ,  C21B13/0073 ,  C21B13/10 ,  C21B2100/44 ,  C21B2100/66 ,  C22B5/10 ,  F27B9/16 ,  F27D17/004 ,  Y02P10/136 ,  Y02P10/216

摘要： The present invention provides a method of operation and a facility for the same suppressing the generation of dioxins in the combustion exhaust gas and efficiently reclaiming heat from high temperature combustion exhaust gas when firing and reducing fines of chromium ore, iron ore, or other ore or pellets formed from dust, sludge, etc. containing iron oxide or other metal oxides generated in the metal industry in a reducing rotary hearth furnace. This treats the combustion gas generated in the reducing rotary hearth furnace to make the temperature of the gas 800°C or higher for at least a certain time, to make the concentration of the carbon monoxide not more than 200 ppm in terms of volume ratio, and to achieve a sufficiently well developed turbulent state at least at one of the inside of the exhaust gas outlet duct and the vicinity of the exhaust gas outlet duct for at least a certain time, then rapidly cooling the gas. Further, it controls the total number of moles of zinc and lead, the total number of moles of alkali metals, and the total number of moles of halogen elements contained in the combustion exhaust gas to a predetermined ratio.

公开(公告)号：EP1426451B1

公开(公告)日：2012-05-09

申请号：EP02765426.8

申请日：2002-09-05

申请人： Nippon Steel Corporation

发明人： IBARAKI, Tetsuharu ,  IMURA, Shouji ,  ODA, Hiroshi ,  TAKAHASHI, Masaharu ,  ABE, Yoichi ,  TAKAHASHI, Shigeki ,  SUZUKI, Satoshi

IPC分类号： C21B13/00 ,  C21B13/02 ,  C21B13/10

CPC分类号： C21B13/105 ,  C21B13/0046 ,  C21B13/023

摘要： A method for producing a reduced iron compact having a high crushing strength, hardly powdering, and having a high reducibility by using a baking reducing furnace of solid reducing type such as a rotary hearth reducing furnace, a reduced iron compact produced by the method, and a method for smelting-reducing the reduced iron compact in a blast furnace. In the method for producing the reduced iron compact, the compact is so produced that the atomic molar ratios of the carbon in a raw powder of a mixture of an iron oxide-containing powder and a carbon-containing powder and the oxygen chemically bonded to iron, manganese, nickel, zinc, and lead or the content of the ferric oxide in the raw powder is in a specific range and that the porosity is in a specific range, and the compact is placed on the hearth of a reducing furnace which the hearth rotates the compact, heated by the heat of the burning gas in the upper part of the furnace, and baked and reduced above a predetermined temperature.